Merge branch 'master' of https://github.com/eugenp/tutorials

algorithms-miscellaneous-2/README.md

@@ -15,3 +15,5 @@
 - [Calculate Percentage in Java](https://www.baeldung.com/java-calculate-percentage)
 - [Converting Between Byte Arrays and Hexadecimal Strings in Java](https://www.baeldung.com/java-byte-arrays-hex-strings)
 - [Convert Latitude and Longitude to a 2D Point in Java](https://www.baeldung.com/java-convert-latitude-longitude)
+- [Reversing a Binary Tree in Java](https://www.baeldung.com/java-reversing-a-binary-tree)
+- [Find If Two Numbers Are Relatively Prime in Java](https://www.baeldung.com/java-two-relatively-prime-numbers)

algorithms-miscellaneous-3/README.md

@@ -4,4 +4,3 @@
 - [Implementing Simple State Machines with Java Enums](https://www.baeldung.com/java-enum-simple-state-machine)
 - [Converting Between Roman and Arabic Numerals in Java](http://www.baeldung.com/java-convert-roman-arabic)
 - [Practical Java Examples of the Big O Notation](http://www.baeldung.com/java-algorithm-complexity)
-- [An Introduction to the Theory of Big-O Notation](http://www.baeldung.com/big-o-notation)

core-groovy-2/README.md

@@ -3,5 +3,5 @@
 ## Relevant articles:
 
 - [String Matching in Groovy](http://www.baeldung.com/)
-- [Groovy def Keyword]
-
+- [Groovy def Keyword](https://www.baeldung.com/groovy-def-keyword)
+- [Pattern Matching in Strings in Groovy](https://www.baeldung.com/groovy-pattern-matching)

core-groovy-2/src/main/resources/articleEmail.template

@@ -0,0 +1,5 @@
+Dear <% out << (user) %>,
+Please read the requested article below.
+<% out << (articleText) %>
+From,
+<% out << (signature) %>

core-groovy-2/src/main/resources/email.template

@@ -0,0 +1,3 @@
+Dear $user,
+Thanks for subscribing our services.
+${signature}

core-groovy-2/src/test/groovy/com/baeldung/templateengine/TemplateEnginesUnitTest.groovy

@@ -0,0 +1,96 @@
+package com.baeldung.templateengine
+
+import groovy.text.SimpleTemplateEngine
+import groovy.text.StreamingTemplateEngine
+import groovy.text.GStringTemplateEngine
+import groovy.text.XmlTemplateEngine
+import groovy.text.XmlTemplateEngine
+import groovy.text.markup.MarkupTemplateEngine
+import groovy.text.markup.TemplateConfiguration
+
+class TemplateEnginesUnitTest extends GroovyTestCase {
+    
+    def bindMap = [user: "Norman", signature: "Baeldung"]
+    
+    void testSimpleTemplateEngine() {
+        def smsTemplate = 'Dear <% print user %>, Thanks for reading our Article. ${signature}'
+        def smsText = new SimpleTemplateEngine().createTemplate(smsTemplate).make(bindMap)
+
+        assert smsText.toString() == "Dear Norman, Thanks for reading our Article. Baeldung"
+    }
+    
+    void testStreamingTemplateEngine() {
+        def articleEmailTemplate = new File('src/main/resources/articleEmail.template')
+        bindMap.articleText = """1. Overview
+This is a tutorial article on Template Engines""" //can be a string larger than 64k
+        
+        def articleEmailText = new StreamingTemplateEngine().createTemplate(articleEmailTemplate).make(bindMap)
+        
+        assert articleEmailText.toString() == """Dear Norman,
+Please read the requested article below.
+1. Overview
+This is a tutorial article on Template Engines
+From,
+Baeldung"""
+        
+    }
+    
+    void testGStringTemplateEngine() {
+        def emailTemplate = new File('src/main/resources/email.template')
+        def emailText = new GStringTemplateEngine().createTemplate(emailTemplate).make(bindMap)
+        
+        assert emailText.toString() == "Dear Norman,\nThanks for subscribing our services.\nBaeldung"
+    }
+    
+    void testXmlTemplateEngine() {
+        def emailXmlTemplate = '''<xs xmlns:gsp='groovy-server-pages'>
+                                      <gsp:scriptlet>def emailContent = "Thanks for subscribing our services."</gsp:scriptlet>
+                                      <email>
+                                          <greet>Dear ${user}</greet>
+                                          <content><gsp:expression>emailContent</gsp:expression></content>
+                                          <signature>${signature}</signature>
+                                      </email>
+                                  </xs>'''
+        def emailXml = new XmlTemplateEngine().createTemplate(emailXmlTemplate).make(bindMap)
+        println emailXml.toString()
+    }
+    
+    void testMarkupTemplateEngineHtml() {
+        def emailHtmlTemplate = """html {
+                                       head {
+                                           title('Service Subscription Email')
+                                       }
+                                       body {
+                                           p('Dear Norman')
+                                           p('Thanks for subscribing our services.')
+                                           p('Baeldung')
+                                       }
+                                   }"""
+        
+        
+        def emailHtml = new MarkupTemplateEngine().createTemplate(emailHtmlTemplate).make()
+        println emailHtml.toString()
+        
+    }
+    
+    void testMarkupTemplateEngineXml() {
+        def emailXmlTemplate = """xmlDeclaration()  
+                                      xs{
+                                          email {
+                                              greet('Dear Norman')
+                                              content('Thanks for subscribing our services.')
+                                              signature('Baeldung')
+                                          }  
+                                      }
+                               """
+        TemplateConfiguration config = new TemplateConfiguration()
+        config.autoIndent = true
+        config.autoEscape = true
+        config.autoNewLine = true
+
+        def emailXml = new MarkupTemplateEngine(config).createTemplate(emailXmlTemplate).make()
+        
+        println emailXml.toString()
+    }
+    
+}

core-groovy-collections/README.md

@@ -2,5 +2,5 @@
 
 ## Relevant articles:
 
-- [Maps in Groovy](http://www.baeldung.com/)
+- [Maps in Groovy](https://www.baeldung.com/groovy-maps)
 

core-java-arrays/README.MD

@@ -0,0 +1,3 @@
+## Relevant Articles
+
+- [Extending an Array’s Length](https://www.baeldung.com/java-array-add-element-at-the-end)

core-java-arrays/src/main/java/com/baeldung/array/conversions/StreamArrayConversion.java

@@ -0,0 +1,52 @@
+package com.baeldung.array.conversions;
+
+import java.util.Arrays;
+import java.util.function.IntFunction;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
+
+public class StreamArrayConversion {
+
+    public static String[] stringStreamToStringArrayUsingFunctionalInterface(Stream<String> stringStream) {
+        IntFunction<String[]> intFunction = new IntFunction<String[]>() {
+            @Override
+            public String[] apply(int value) {
+                return new String[value];
+            }
+        };
+
+        return stringStream.toArray(intFunction);
+    }
+
+    public static String[] stringStreamToStringArrayUsingMethodReference(Stream<String> stringStream) {
+        return stringStream.toArray(String[]::new);
+    }
+
+    public static String[] stringStreamToStringArrayUsingLambda(Stream<String> stringStream) {
+        return stringStream.toArray(value -> new String[value]);
+    }
+
+    public static Integer[] integerStreamToIntegerArray(Stream<Integer> integerStream) {
+        return integerStream.toArray(Integer[]::new);
+    }
+
+    public static int[] intStreamToPrimitiveIntArray(Stream<Integer> integerStream) {
+        return integerStream.mapToInt(i -> i).toArray();
+    }
+
+    public static Stream<String> stringArrayToStreamUsingArraysStream(String[] stringArray) {
+        return Arrays.stream(stringArray);
+    }
+
+    public static Stream<String> stringArrayToStreamUsingStreamOf(String[] stringArray) {
+        return Stream.of(stringArray);
+    }
+
+    public static IntStream primitiveIntArrayToStreamUsingArraysStream(int[] intArray) {
+        return Arrays.stream(intArray);
+    }
+
+    public static Stream<int[]> primitiveIntArrayToStreamUsingStreamOf(int[] intArray) {
+        return Stream.of(intArray);
+    }
+}

core-java-arrays/src/test/java/com/baeldung/array/conversions/StreamArrayConversionUnitTest.java

@@ -0,0 +1,70 @@
+package com.baeldung.array.conversions;
+
+import static com.baeldung.array.conversions.StreamArrayConversion.intStreamToPrimitiveIntArray;
+import static com.baeldung.array.conversions.StreamArrayConversion.integerStreamToIntegerArray;
+import static com.baeldung.array.conversions.StreamArrayConversion.stringStreamToStringArrayUsingFunctionalInterface;
+import static com.baeldung.array.conversions.StreamArrayConversion.stringStreamToStringArrayUsingLambda;
+import static com.baeldung.array.conversions.StreamArrayConversion.stringStreamToStringArrayUsingMethodReference;
+import static com.baeldung.array.conversions.StreamArrayConversion.stringArrayToStreamUsingArraysStream;
+import static com.baeldung.array.conversions.StreamArrayConversion.stringArrayToStreamUsingStreamOf;
+import static com.baeldung.array.conversions.StreamArrayConversion.primitiveIntArrayToStreamUsingArraysStream;
+import static com.baeldung.array.conversions.StreamArrayConversion.primitiveIntArrayToStreamUsingStreamOf;
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import com.google.common.collect.Iterators;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
+import org.junit.Test;
+
+public class StreamArrayConversionUnitTest {
+
+    private String[] stringArray = new String[]{"baeldung", "convert", "to", "string", "array"};
+    private Integer[] integerArray = new Integer[]{1, 2, 3, 4, 5, 6, 7};
+    private int[] intPrimitiveArray = new int[]{1, 2, 3, 4, 5, 6, 7};
+
+    @Test
+    public void givenStringStream_thenConvertToStringArrayUsingFunctionalInterface() {
+        Stream<String> stringStream = Stream.of("baeldung", "convert", "to", "string", "array");
+        assertArrayEquals(stringArray, stringStreamToStringArrayUsingFunctionalInterface(stringStream));
+    }
+
+    @Test
+    public void givenStringStream_thenConvertToStringArrayUsingMethodReference() {
+        Stream<String> stringStream = Stream.of("baeldung", "convert", "to", "string", "array");
+        assertArrayEquals(stringArray, stringStreamToStringArrayUsingMethodReference(stringStream));
+    }
+
+    @Test
+    public void givenStringStream_thenConvertToStringArrayUsingLambda() {
+        Stream<String> stringStream = Stream.of("baeldung", "convert", "to", "string", "array");
+        assertArrayEquals(stringArray, stringStreamToStringArrayUsingLambda(stringStream));
+    }
+
+    @Test
+    public void givenIntegerStream_thenConvertToIntegerArray() {
+        Stream<Integer> integerStream = Stream.of(1, 2, 3, 4, 5, 6, 7);
+        assertArrayEquals(integerArray, integerStreamToIntegerArray(integerStream));
+    }
+
+    @Test
+    public void givenIntStream_thenConvertToIntegerArray() {
+        Stream<Integer> integerStream = IntStream.rangeClosed(1, 7).boxed();
+        assertArrayEquals(intPrimitiveArray, intStreamToPrimitiveIntArray(integerStream));
+    }
+
+    @Test
+    public void givenStringArray_whenConvertedTwoWays_thenConvertedStreamsAreEqual() {
+        assertTrue(Iterators
+            .elementsEqual(stringArrayToStreamUsingArraysStream(stringArray).iterator(),
+                stringArrayToStreamUsingStreamOf(stringArray).iterator()));
+    }
+
+    @Test
+    public void givenPrimitiveArray_whenConvertedTwoWays_thenConvertedStreamsAreNotEqual() {
+        assertFalse(Iterators.elementsEqual(
+            primitiveIntArrayToStreamUsingArraysStream(intPrimitiveArray).iterator(),
+            primitiveIntArrayToStreamUsingStreamOf(intPrimitiveArray).iterator()));
+    }
+}

core-java-lambdas/README.md

@@ -0,0 +1,2 @@
+### Relevant Articles:
+- [Java 9 java.lang.Module API](https://www.baeldung.com/java-lambda-effectively-final-local-variables)

core-java-modules/core-java-11/README.md

@@ -7,3 +7,4 @@
 - [Exploring the New HTTP Client in Java 9 and 11](https://www.baeldung.com/java-9-http-client)
 - [An Introduction to Epsilon GC: A No-Op Experimental Garbage Collector](https://www.baeldung.com/jvm-epsilon-gc-garbage-collector)
 - [Guide to jlink](https://www.baeldung.com/jlink)
+- [Transforming an Empty String into an Empty Optional](https://www.baeldung.com/java-empty-string-to-empty-optional)

core-java-modules/core-java-8-2/README.md

@@ -3,4 +3,5 @@
 ## Core Java 8 Cookbooks and Examples (part 2)
 
 ### Relevant Articles: 
-- [Anonymous Classes in Java](http://www.baeldung.com/)
+- [Anonymous Classes in Java](https://www.baeldung.com/java-anonymous-classes)
+- [Run JAR Application With Command Line Arguments](https://www.baeldung.com/java-run-jar-with-arguments)

core-java-modules/core-java-8/src/test/java/com/baeldung/java8/optional/OptionalChainingUnitTest.java

@@ -101,7 +101,7 @@ public class OptionalChainingUnitTest {
     }
 
     private Optional<String> createOptional(String input) {
-        if (input == null || input == "" || input == "empty") {
+        if (input == null || "".equals(input) || "empty".equals(input)) {
             return Optional.empty();
         }
 

core-java-modules/core-java-9/README.md

@@ -20,6 +20,14 @@
 - [Multi-Release Jar Files](https://www.baeldung.com/java-multi-release-jar)
 - [Ahead of Time Compilation (AoT)](https://www.baeldung.com/ahead-of-time-compilation)
 - [Java 9 Process API Improvements](https://www.baeldung.com/java-9-process-api)
-- [Guide to java.lang.Process API](https://www.baeldung.com/java-process-api)
-
-
+- [Java 9 java.util.Objects Additions](https://www.baeldung.com/java-9-objects-new)
+- [Java 9 Reactive Streams](https://www.baeldung.com/java-9-reactive-streams)
+- [Java 9 Optional API Additions](https://www.baeldung.com/java-9-optional)
+- [Java 9 CompletableFuture API Improvements](https://www.baeldung.com/java-9-completablefuture)
+- [Introduction to Java 9 StackWalking API](https://www.baeldung.com/java-9-stackwalking-api)
+- [Java 9 Convenience Factory Methods for Collections](https://www.baeldung.com/java-9-collections-factory-methods)
+- [Java 9 Stream API Improvements](https://www.baeldung.com/java-9-stream-api)
+- [A Guide to Java 9 Modularity](https://www.baeldung.com/java-9-modularity)
+- [Java 9 Platform Module API](https://www.baeldung.com/java-9-module-api)
+- [Java 9 Platform Logging API](https://www.baeldung.com/java-9-logging-api)
+- [Filtering a Stream of Optionals in Java](https://www.baeldung.com/java-filter-stream-of-optional)

core-java-modules/core-java-collections-set/README.md

@@ -8,4 +8,5 @@
 - [A Guide to HashSet in Java](http://www.baeldung.com/java-hashset)
 - [A Guide to TreeSet in Java](http://www.baeldung.com/java-tree-set)
 - [Initializing HashSet at the Time of Construction](http://www.baeldung.com/java-initialize-hashset)
-- [Guide to EnumSet](https://www.baeldung.com/java-enumset)
+- [Guide to EnumSet](https://www.baeldung.com/java-enumset)
+- [Set Operations in Java](https://www.baeldung.com/java-set-operations)

core-java-modules/core-java-exceptions/pom.xml

@@ -0,0 +1,26 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>com.baeldung.exception.numberformat</groupId>
+    <artifactId>core-java-exceptions</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>core-java-exceptions</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-java</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../../parent-java</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.12</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+</project>

core-java-modules/core-java-exceptions/src/test/java/com/baeldung/exception/numberformat/NumberFormatExceptionUnitTest.java

@@ -0,0 +1,154 @@
+package com.baeldung.exception.numberformat;
+
+import static org.junit.Assert.assertEquals;
+
+import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.text.NumberFormat;
+import java.text.ParseException;
+import java.util.Locale;
+import java.util.logging.Logger;
+
+import org.junit.Test;
+
+/**
+ * A set of examples tested to show cases where NumberFormatException is thrown and not thrown.
+ */
+public class NumberFormatExceptionUnitTest {
+
+    Logger LOG = Logger.getLogger(NumberFormatExceptionUnitTest.class.getName());
+
+    /* ---INTEGER FAIL CASES--- */
+    @Test(expected = NumberFormatException.class)
+    public void givenByteConstructor_whenAlphabetAsInput_thenFail() {
+        Byte byteInt = new Byte("one");
+    }
+
+    @Test(expected = NumberFormatException.class)
+    public void givenShortConstructor_whenSpaceInInput_thenFail() {
+        Short shortInt = new Short("2 ");
+    }
+
+    @Test(expected = NumberFormatException.class)
+    public void givenParseIntMethod_whenSpaceInInput_thenFail() {
+        Integer aIntPrim = Integer.parseInt("6000 ");
+    }
+
+    @Test(expected = NumberFormatException.class)
+    public void givenParseIntMethod_whenUnderscoreInInput_thenFail() {
+        int bIntPrim = Integer.parseInt("6_000");
+    }
+
+    @Test(expected = NumberFormatException.class)
+    public void givenIntegerValueOfMethod_whenCommaInInput_thenFail() {
+        Integer cIntPrim = Integer.valueOf("6,000");
+    }
+
+    @Test(expected = NumberFormatException.class)
+    public void givenBigIntegerConstructor_whenDecimalInInput_thenFail() {
+        BigInteger bigInteger = new BigInteger("4.0");
+    }
+
+    @Test(expected = NumberFormatException.class)
+    public void givenDecodeMethod_whenAlphabetInInput_thenFail() {
+        Long decodeInteger = Long.decode("64403L");
+    }
+
+    /* ---INTEGER PASS CASES--- */
+    @Test
+    public void givenInvalidNumberInputs_whenOptimized_thenPass() {
+        Byte byteInt = new Byte("1");
+        assertEquals(1, byteInt.intValue());
+
+        Short shortInt = new Short("2 ".trim());
+        assertEquals(2, shortInt.intValue());
+
+        Integer aIntObj = Integer.valueOf("6");
+        assertEquals(6, aIntObj.intValue());
+
+        BigInteger bigInteger = new BigInteger("4");
+        assertEquals(4, bigInteger.intValue());
+
+        int aIntPrim = Integer.parseInt("6000 ".trim());
+        assertEquals(6000, aIntPrim);
+
+        int bIntPrim = Integer.parseInt("6_000".replaceAll("_", ""));
+        assertEquals(6000, bIntPrim);
+
+        int cIntPrim = Integer.parseInt("-6000");
+        assertEquals(-6000, cIntPrim);
+
+        Long decodeInteger = Long.decode("644032334");
+        assertEquals(644032334L, decodeInteger.longValue());
+    }
+
+    /* ---DOUBLE FAIL CASES--- */
+    @Test(expected = NumberFormatException.class)
+    public void givenFloatConstructor_whenAlphabetInInput_thenFail() {
+        Float floatDecimalObj = new Float("one.1");
+    }
+
+    @Test(expected = NumberFormatException.class)
+    public void givenDoubleConstructor_whenAlphabetInInput_thenFail() {
+        Double doubleDecimalObj = new Double("two.2");
+    }
+
+    @Test(expected = NumberFormatException.class)
+    public void givenBigDecimalConstructor_whenSpecialCharsInInput_thenFail() {
+        BigDecimal bigDecimalObj = new BigDecimal("3_0.3");
+    }
+
+    @Test(expected = NumberFormatException.class)
+    public void givenParseDoubleMethod_whenCommaInInput_thenFail() {
+        double aDoublePrim = Double.parseDouble("4000,1");
+    }
+
+    /* ---DOUBLE PASS CASES--- */
+    @Test
+    public void givenDoubleConstructor_whenDecimalInInput_thenPass() {
+        Double doubleDecimalObj = new Double("2.2");
+        assertEquals(2.2, doubleDecimalObj.doubleValue(), 0);
+    }
+
+    @Test
+    public void givenDoubleValueOfMethod_whenMinusInInput_thenPass() {
+        Double aDoubleObj = Double.valueOf("-6000");
+        assertEquals(-6000, aDoubleObj.doubleValue(), 0);
+    }
+
+    @Test
+    public void givenUsDecimalNumber_whenParsedWithNumberFormat_thenPass() throws ParseException {
+        Number parsedNumber = parseNumberWithLocale("4000.1", Locale.US);
+        assertEquals(4000.1, parsedNumber);
+        assertEquals(4000.1, parsedNumber.doubleValue(), 0);
+        assertEquals(4000, parsedNumber.intValue());
+    }
+
+    /**
+     * In most European countries (for example, France), comma is used as decimal in place of period.
+     * @throws ParseException if the input string contains special characters other than comma or decimal. 
+     * In this test case, anything after decimal (period) is dropped when a European locale is set.
+     */
+    @Test
+    public void givenEuDecimalNumberHasComma_whenParsedWithNumberFormat_thenPass() throws ParseException {
+        Number parsedNumber = parseNumberWithLocale("4000,1", Locale.FRANCE);
+        LOG.info("Number parsed is: " + parsedNumber);
+        assertEquals(4000.1, parsedNumber);
+        assertEquals(4000.1, parsedNumber.doubleValue(), 0);
+        assertEquals(4000, parsedNumber.intValue());
+    }
+
+    /**
+     * Converts a string into a number retaining all decimals, and symbols valid in a locale.
+     * @param number the input string for a number.
+     * @param locale the locale to consider while parsing a number.
+     * @return the generic number object which can represent multiple number types.
+     * @throws ParseException when input contains invalid characters.
+     */
+    private Number parseNumberWithLocale(String number, Locale locale) throws ParseException {
+        locale = locale == null ? Locale.getDefault() : locale;
+        NumberFormat numberFormat = NumberFormat.getInstance(locale);
+        return numberFormat.parse(number);
+    }
+
+}

core-java-modules/core-java-io/README.md

@@ -40,3 +40,4 @@
 - [How to Write to a CSV File in Java](https://www.baeldung.com/java-csv)
 - [List Files in a Directory in Java](https://www.baeldung.com/java-list-directory-files)
 - [Java InputStream to Byte Array and ByteBuffer](https://www.baeldung.com/convert-input-stream-to-array-of-bytes)
+- [Introduction to the Java NIO Selector](https://www.baeldung.com/java-nio-selector)

core-java-modules/core-java-lang-oop-2/README.md

@@ -4,3 +4,5 @@
 
 ### Relevant Articles: 
 - [Generic Constructors in Java](https://www.baeldung.com/java-generic-constructors)
+- [Cannot Reference “X” Before Supertype Constructor Has Been Called](https://www.baeldung.com/java-cannot-reference-x-before-supertype-constructor-error)
+- [Anonymous Classes in Java](https://www.baeldung.com/java-anonymous-classes)

core-java-modules/core-java-reflection/README.MD

@@ -0,0 +1,3 @@
+## Relevant Articles
+
+- [Void Type in Java](https://www.baeldung.com/java-void-type)

core-java-modules/core-java/README.md

@@ -51,3 +51,4 @@
 - [Java Bitwise Operators](https://www.baeldung.com/java-bitwise-operators)
 - [Guide to Creating and Running a Jar File in Java](https://www.baeldung.com/java-create-jar)
 - [Making a JSON POST Request With HttpURLConnection](https://www.baeldung.com/httpurlconnection-post)
+- [Convert Hex to ASCII in Java](https://www.baeldung.com/java-convert-hex-to-ascii)

core-java-modules/core-java/pom.xml

@@ -454,7 +454,7 @@
         <gson.version>2.8.2</gson.version>
 
         <!-- util -->
-        <commons-lang3.version>3.5</commons-lang3.version>
+        <commons-lang3.version>3.9</commons-lang3.version>
         <commons-io.version>2.5</commons-io.version>
         <commons-math3.version>3.6.1</commons-math3.version>
         <decimal4j.version>1.0.3</decimal4j.version>

core-java-modules/core-java/src/main/java/com/baeldung/exceptions/RootCauseFinder.java

@@ -30,7 +30,7 @@ public class RootCauseFinder {
         private AgeCalculator() {
         }
 
-        public static int calculateAge(String birthDate) throws CalculationException {
+        public static int calculateAge(String birthDate) {
             if (birthDate == null || birthDate.isEmpty()) {
                 throw new IllegalArgumentException();
             }
@@ -44,7 +44,7 @@ public class RootCauseFinder {
             }
         }
 
-        private static LocalDate parseDate(String birthDateAsString) throws DateParseException {
+        private static LocalDate parseDate(String birthDateAsString) {
 
             LocalDate birthDate;
             try {
@@ -62,14 +62,14 @@ public class RootCauseFinder {
 
     }
 
-    static class CalculationException extends Exception {
+    static class CalculationException extends RuntimeException {
 
         CalculationException(DateParseException ex) {
             super(ex);
         }
     }
 
-    static class DateParseException extends Exception {
+    static class DateParseException extends RuntimeException {
 
         DateParseException(String input) {
             super(input);

core-java-modules/pom.xml

@@ -15,6 +15,7 @@
 
     <modules>
         <module>pre-jpms</module>
+        <module>core-java-exceptions</module>
     </modules>
     
 </project>

core-java-modules/pre-jpms/README.MD

@@ -0,0 +1,3 @@
+## Relevant Articles
+
+- [Java 9 Migration Issues and Resolutions](https://www.baeldung.com/java-9-migration-issue)

core-java/pom.xml

@@ -1,492 +0,0 @@
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-    <modelVersion>4.0.0</modelVersion>
-    <artifactId>core-java</artifactId>
-    <version>0.1.0-SNAPSHOT</version>
-    <name>core-java</name>
-    <packaging>jar</packaging>
-
-    <parent>
-        <groupId>com.baeldung</groupId>
-        <artifactId>parent-java</artifactId>
-        <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../parent-java</relativePath>
-    </parent>
-
-
-    <dependencies>
-        <dependency>
-            <groupId>commons-io</groupId>
-            <artifactId>commons-io</artifactId>
-            <version>${commons-io.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.apache.commons</groupId>
-            <artifactId>commons-lang3</artifactId>
-            <version>${commons-lang3.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.unix4j</groupId>
-            <artifactId>unix4j-command</artifactId>
-            <version>${unix4j.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>com.googlecode.grep4j</groupId>
-            <artifactId>grep4j</artifactId>
-            <version>${grep4j.version}</version>
-        </dependency>
-        <!-- web -->
-        <!-- marshalling -->
-        <dependency>
-            <groupId>com.fasterxml.jackson.core</groupId>
-            <artifactId>jackson-databind</artifactId>
-            <version>${jackson.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>com.google.code.gson</groupId>
-            <artifactId>gson</artifactId>
-            <version>${gson.version}</version>
-        </dependency>
-        <!-- logging -->
-        <dependency>
-            <groupId>log4j</groupId>
-            <artifactId>log4j</artifactId>
-            <version>${log4j.version}</version>
-        </dependency>
-        <dependency> <!-- needed to bridge to slf4j for projects that use the log4j APIs directly -->
-            <groupId>org.slf4j</groupId>
-            <artifactId>log4j-over-slf4j</artifactId>
-            <version>${org.slf4j.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.projectlombok</groupId>
-            <artifactId>lombok</artifactId>
-            <version>${lombok.version}</version>
-            <scope>provided</scope>
-        </dependency>
-        <!-- test scoped -->
-        <dependency>
-            <groupId>org.assertj</groupId>
-            <artifactId>assertj-core</artifactId>
-            <version>${assertj-core.version}</version>
-            <scope>test</scope>
-        </dependency>
-        <dependency>
-            <groupId>org.javamoney</groupId>
-            <artifactId>moneta</artifactId>
-            <version>${javamoney.moneta.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.owasp.esapi</groupId>
-            <artifactId>esapi</artifactId>
-            <version>${esapi.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>com.sun.messaging.mq</groupId>
-            <artifactId>fscontext</artifactId>
-            <version>${fscontext.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>com.codepoetics</groupId>
-            <artifactId>protonpack</artifactId>
-            <version>${protonpack.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>one.util</groupId>
-            <artifactId>streamex</artifactId>
-            <version>${streamex.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>io.vavr</groupId>
-            <artifactId>vavr</artifactId>
-            <version>${vavr.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.openjdk.jmh</groupId>
-            <artifactId>jmh-core</artifactId>
-            <version>${jmh-core.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.openjdk.jmh</groupId>
-            <artifactId>jmh-generator-annprocess</artifactId>
-            <version>${jmh-generator-annprocess.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>com.h2database</groupId>
-            <artifactId>h2</artifactId>
-            <version>${h2database.version}</version>
-        </dependency>
-        <!-- instrumentation -->
-        <dependency>
-            <groupId>org.javassist</groupId>
-            <artifactId>javassist</artifactId>
-            <version>${javaassist.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>com.sun</groupId>
-            <artifactId>tools</artifactId>
-            <version>${sun.tools.version}</version>
-            <scope>system</scope>
-            <systemPath>${java.home}/../lib/tools.jar</systemPath>
-        </dependency>
-    </dependencies>
-
-    <build>
-        <finalName>core-java</finalName>
-        <resources>
-            <resource>
-                <directory>src/main/resources</directory>
-                <filtering>true</filtering>
-            </resource>
-        </resources>
-
-        <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-dependency-plugin</artifactId>
-                <executions>
-                    <execution>
-                        <id>copy-dependencies</id>
-                        <phase>prepare-package</phase>
-                        <goals>
-                            <goal>copy-dependencies</goal>
-                        </goals>
-                        <configuration>
-                            <outputDirectory>${project.build.directory}/libs</outputDirectory>
-                        </configuration>
-                    </execution>
-                </executions>
-            </plugin>
-
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-jar-plugin</artifactId>
-                <version>${maven-jar-plugin.version}</version>
-                <configuration>
-                    <archive>
-                        <manifest>
-                            <addClasspath>true</addClasspath>
-                            <classpathPrefix>libs/</classpathPrefix>
-                            <mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
-                        </manifest>
-                    </archive>
-                </configuration>
-            </plugin>
-
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-assembly-plugin</artifactId>
-                <executions>
-                    <execution>
-                        <phase>package</phase>
-                        <goals>
-                            <goal>single</goal>
-                        </goals>
-                        <configuration>
-                            <archiveBaseDirectory>${project.basedir}</archiveBaseDirectory>
-                            <archive>
-                                <manifest>
-                                    <mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
-                                </manifest>
-                            </archive>
-                            <descriptorRefs>
-                                <descriptorRef>jar-with-dependencies</descriptorRef>
-                            </descriptorRefs>
-                        </configuration>
-                    </execution>
-                </executions>
-            </plugin>
-
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-shade-plugin</artifactId>
-                <version>${maven-shade-plugin.version}</version>
-                <executions>
-                    <execution>
-                        <goals>
-                            <goal>shade</goal>
-                        </goals>
-                        <configuration>
-                            <shadedArtifactAttached>true</shadedArtifactAttached>
-                            <transformers>
-                                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
-                                    <mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
-                                </transformer>
-                            </transformers>
-                        </configuration>
-                    </execution>
-                </executions>
-            </plugin>
-
-            <plugin>
-                <groupId>com.jolira</groupId>
-                <artifactId>onejar-maven-plugin</artifactId>
-                <version>${onejar-maven-plugin.version}</version>
-                <executions>
-                    <execution>
-                        <configuration>
-                            <mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
-                            <attachToBuild>true</attachToBuild>
-                            <filename>${project.build.finalName}-onejar.${project.packaging}</filename>
-                        </configuration>
-                        <goals>
-                            <goal>one-jar</goal>
-                        </goals>
-                    </execution>
-                </executions>
-            </plugin>
-
-            <plugin>
-                <groupId>org.springframework.boot</groupId>
-                <artifactId>spring-boot-maven-plugin</artifactId>
-                <version>${spring-boot-maven-plugin.version}</version>
-                <executions>
-                    <execution>
-                        <goals>
-                            <goal>repackage</goal>
-                        </goals>
-                        <configuration>
-                            <classifier>spring-boot</classifier>
-                            <mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
-                        </configuration>
-                    </execution>
-                </executions>
-            </plugin>
-
-            <plugin>
-                <groupId>org.codehaus.mojo</groupId>
-                <artifactId>exec-maven-plugin</artifactId>
-                <version>${exec-maven-plugin.version}</version>
-                <configuration>
-                    <executable>java</executable>
-                    <mainClass>com.baeldung.outofmemoryerror.OutOfMemoryGCLimitExceed</mainClass>
-                    <arguments>
-                        <argument>-Xmx300m</argument>
-                        <argument>-XX:+UseParallelGC</argument>
-                        <argument>-classpath</argument>
-                        <classpath />
-                        <argument>com.baeldung.outofmemoryerror.OutOfMemoryGCLimitExceed</argument>
-                    </arguments>
-                </configuration>
-            </plugin>
-            
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-javadoc-plugin</artifactId>
-                <version>${maven-javadoc-plugin.version}</version>
-                <configuration>
-                    <source>1.8</source>
-                    <target>1.8</target>
-                </configuration>
-            </plugin>
-        </plugins>
-    </build>
-
-    <profiles>
-        <profile>
-            <id>integration</id>
-            <build>
-                <plugins>
-                    <plugin>
-                        <groupId>org.apache.maven.plugins</groupId>
-                        <artifactId>maven-surefire-plugin</artifactId>
-                        <executions>
-                            <execution>
-                                <phase>integration-test</phase>
-                                <goals>
-                                    <goal>test</goal>
-                                </goals>
-                                <configuration>
-                                    <excludes>
-                                        <exclude>**/*ManualTest.java</exclude>
-                                    </excludes>
-                                    <includes>
-                                        <include>**/*IntegrationTest.java</include>
-                                        <include>**/*IntTest.java</include>
-                                    </includes>
-                                </configuration>
-                            </execution>
-                        </executions>
-                        <configuration>
-                            <systemPropertyVariables>
-                                <test.mime>json</test.mime>
-                            </systemPropertyVariables>
-                        </configuration>
-                    </plugin>
-                    <plugin>
-                        <groupId>org.codehaus.mojo</groupId>
-                        <artifactId>exec-maven-plugin</artifactId>
-                        <version>${exec-maven-plugin.version}</version>
-                        <executions>
-                            <execution>
-                                <id>run-benchmarks</id>
-                                <!-- <phase>integration-test</phase> -->
-                                <phase>none</phase>
-                                <goals>
-                                    <goal>exec</goal>
-                                </goals>
-                                <configuration>
-                                    <classpathScope>test</classpathScope>
-                                    <executable>java</executable>
-                                    <arguments>
-                                        <argument>-classpath</argument>
-                                        <classpath />
-                                        <argument>org.openjdk.jmh.Main</argument>
-                                        <argument>.*</argument>
-                                    </arguments>
-                                </configuration>
-                            </execution>
-                        </executions>
-                    </plugin>
-                </plugins>
-            </build>
-        </profile>
-
-        <!-- java instrumentation profiles to build jars -->
-        <profile>
-            <id>buildAgentLoader</id>
-            <build>
-                <plugins>
-                    <plugin>
-                        <groupId>org.apache.maven.plugins</groupId>
-                        <artifactId>maven-jar-plugin</artifactId>
-                        <executions>
-                            <execution>
-                                <phase>package</phase>
-                                <goals>
-                                    <goal>jar</goal>
-                                </goals>
-                                <configuration>
-                                    <classifier>agentLoader</classifier>
-                                    <classesDirectory>target/classes</classesDirectory>
-                                    <archive>
-                                        <manifest>
-                                            <addClasspath>true</addClasspath>
-                                        </manifest>
-                                        <manifestFile>${project.build.outputDirectory}/META-INF/MANIFEST.MF</manifestFile>
-                                    </archive>
-
-                                    <includes>
-                                        <include>com/baeldung/instrumentation/application/AgentLoader.class</include>
-                                        <include>com/baeldung/instrumentation/application/Launcher.class</include>
-                                    </includes>
-                                </configuration>
-                            </execution>
-                        </executions>
-                    </plugin>
-                </plugins>
-            </build>
-        </profile>
-        <profile>
-            <id>buildApplication</id>
-            <build>
-                <plugins>
-                    <plugin>
-                        <groupId>org.apache.maven.plugins</groupId>
-                        <artifactId>maven-jar-plugin</artifactId>
-                        <executions>
-                            <execution>
-                                <phase>package</phase>
-                                <goals>
-                                    <goal>jar</goal>
-                                </goals>
-                                <configuration>
-                                    <classifier>application</classifier>
-                                    <classesDirectory>target/classes</classesDirectory>
-                                    <archive>
-                                        <manifest>
-                                            <addClasspath>true</addClasspath>
-                                        </manifest>
-                                        <manifestFile>${project.build.outputDirectory}/META-INF/MANIFEST.MF</manifestFile>
-                                    </archive>
-
-                                    <includes>
-                                        <include>com/baeldung/instrumentation/application/MyAtm.class</include>
-                                        <include>com/baeldung/instrumentation/application/MyAtmApplication.class</include>
-                                        <include>com/baeldung/instrumentation/application/Launcher.class</include>
-                                    </includes>
-                                </configuration>
-                            </execution>
-                        </executions>
-                    </plugin>
-                </plugins>
-            </build>
-        </profile>
-        <profile>
-            <id>buildAgent</id>
-            <build>
-                <plugins>
-                    <plugin>
-                        <groupId>org.apache.maven.plugins</groupId>
-                        <artifactId>maven-jar-plugin</artifactId>
-                        <executions>
-                            <execution>
-                                <phase>package</phase>
-                                <goals>
-                                    <goal>jar</goal>
-                                </goals>
-                                <configuration>
-                                    <classifier>agent</classifier>
-                                    <classesDirectory>target/classes</classesDirectory>
-                                    <archive>
-                                        <manifest>
-                                            <addClasspath>true</addClasspath>
-                                        </manifest>
-                                        <manifestFile>${project.build.outputDirectory}/META-INF/MANIFEST.MF</manifestFile>
-                                    </archive>
-
-                                    <includes>
-                                        <include>com/baeldung/instrumentation/agent/AtmTransformer.class</include>
-                                        <include>com/baeldung/instrumentation/agent/MyInstrumentationAgent.class</include>
-                                    </includes>
-                                </configuration>
-                            </execution>
-                        </executions>
-                    </plugin>
-                </plugins>
-            </build>
-        </profile>
-    </profiles>
-
-    <properties>
-        
-        <!-- marshalling -->
-        <gson.version>2.8.2</gson.version>
-
-        <!-- util -->
-        <commons-lang3.version>3.9</commons-lang3.version>
-        <commons-io.version>2.5</commons-io.version>
-        <commons-math3.version>3.6.1</commons-math3.version>
-        <decimal4j.version>1.0.3</decimal4j.version>
-        <unix4j.version>0.4</unix4j.version>
-        <grep4j.version>1.8.7</grep4j.version>
-        <fscontext.version>4.6-b01</fscontext.version>
-        <protonpack.version>1.13</protonpack.version>
-        <streamex.version>0.6.5</streamex.version>
-        <vavr.version>0.9.0</vavr.version>
-
-        <!-- testing -->
-        <assertj-core.version>3.10.0</assertj-core.version>
-
-        <!-- maven plugins -->
-        <maven-surefire-plugin.version>2.21.0</maven-surefire-plugin.version>
-        
-        <javamoney.moneta.version>1.1</javamoney.moneta.version>
-        <h2database.version>1.4.197</h2database.version>
-        <esapi.version>2.1.0.1</esapi.version>
-        <jmh-core.version>1.19</jmh-core.version>
-       
-        <jmh-generator-annprocess.version>1.19</jmh-generator-annprocess.version>
-        <maven-javadoc-plugin.version>3.0.0-M1</maven-javadoc-plugin.version>
-        <maven-jar-plugin.version>3.0.2</maven-jar-plugin.version>
-        <onejar-maven-plugin.version>1.4.4</onejar-maven-plugin.version>
-        <maven-shade-plugin.version>3.1.1</maven-shade-plugin.version>
-        <spring-boot-maven-plugin.version>2.0.3.RELEASE</spring-boot-maven-plugin.version>
-        <exec-maven-plugin.version>1.6.0</exec-maven-plugin.version>
-        <icu4j.version>61.1</icu4j.version>
-        <!-- instrumentation -->
-        <javaassist.version>3.21.0-GA</javaassist.version>
-        
-        <sun.tools.version>1.8.0</sun.tools.version>
-    </properties>
-</project>

core-kotlin-2/README.md

@@ -6,4 +6,5 @@
 - [Kotlin Scope Functions](https://www.baeldung.com/kotlin-scope-functions)
 - [Kotlin Annotations](https://www.baeldung.com/kotlin-annotations)
 - [Split a List into Parts in Kotlin](https://www.baeldung.com/kotlin-split-list-into-parts)
-- [String Comparison in Kotlin](https://www.baeldung.com/kotlin-string-comparison)
+- [String Comparison in Kotlin](https://www.baeldung.com/kotlin-string-comparison)
+- [Guide to JVM Platform Annotations in Kotlin](https://www.baeldung.com/kotlin-jvm-annotations)

guava-collections-set/README.md

@@ -0,0 +1,4 @@
+
+### Relevant Articles: 
+
+- [Guide to Guava Multiset](https://www.baeldung.com/guava-multiset)

jackson-2/README.md

@@ -7,4 +7,6 @@ The "REST With Spring" Classes: http://bit.ly/restwithspring
 
 ### Relevant Articles: 
 - [Mapping Multiple JSON Fields to a Single Java Field](https://www.baeldung.com/json-multiple-fields-single-java-field)
+- [How to Process YAML with Jackson](https://www.baeldung.com/jackson-yaml)
 - [Working with Tree Model Nodes in Jackson](https://www.baeldung.com/jackson-json-node-tree-model)
+

java-collections-maps-2/README.md

@@ -1,2 +1,3 @@
 ## Relevant Articles:
 - [Map of Primitives in Java](https://www.baeldung.com/java-map-primitives)
+- [Copying a HashMap in Java](https://www.baeldung.com/java-copy-hashmap)

java-dates-2/README.md

@@ -1,2 +1,3 @@
 ## Relevant Articles:
 - [Converting Between LocalDate and XMLGregorianCalendar](https://www.baeldung.com/java-localdate-to-xmlgregoriancalendar)
+- [Convert Time to Milliseconds in Java](https://www.baeldung.com/java-time-milliseconds)

java-strings-2/README.MD

@@ -0,0 +1,4 @@
+## Relevant Articles
+
+- [Java Localization – Formatting Messages](https://www.baeldung.com/java-localization-messages-formatting)
+- [Check If a String Contains a Substring](https://www.baeldung.com/java-string-contains-substring)

jee-7/src/main/java/com/baeldung/singleton/Car.java

@@ -0,0 +1,28 @@
+package com.baeldung.singleton;
+
+public class Car {
+    
+    private String type;
+    private String model;
+    private boolean serviced = false;
+    
+    public Car(String type, String model) {
+        super();
+        this.type = type;
+        this.model = model;
+    }
+
+    public boolean isServiced () {
+        return serviced;
+    }
+    
+    public void setServiced(Boolean serviced) {
+        this.serviced = serviced;
+    }
+
+    @Override
+    public String toString() {
+        return "Car [type=" + type + ", model=" + model + "]";
+    }
+    
+}

jee-7/src/main/java/com/baeldung/singleton/CarServiceBean.java

@@ -0,0 +1,23 @@
+package com.baeldung.singleton;
+
+import java.util.UUID;
+
+import javax.enterprise.context.Dependent;
+
+import org.springframework.web.context.annotation.RequestScope;
+
+@RequestScope
+public class CarServiceBean {
+
+    private UUID id = UUID.randomUUID();
+
+    public UUID getId() {
+        return this.id;
+    }
+
+    @Override
+    public String toString() {
+        return "CarService [id=" + id + "]";
+    }
+
+}

jee-7/src/main/java/com/baeldung/singleton/CarServiceEjbSingleton.java

@@ -0,0 +1,46 @@
+package com.baeldung.singleton;
+
+import java.util.UUID;
+
+import javax.ejb.Singleton;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@Singleton
+public class CarServiceEjbSingleton {
+
+    private static Logger LOG = LoggerFactory.getLogger(CarServiceEjbSingleton.class);
+
+    private UUID id = UUID.randomUUID();
+
+    private static int serviceQueue;
+
+    public UUID getId() {
+        return this.id;
+    }
+
+    @Override
+    public String toString() {
+        return "CarServiceEjbSingleton [id=" + id + "]";
+    }
+
+    public int service(Car car) {
+        serviceQueue++;
+        LOG.info("Car {} is being serviced @ CarServiceEjbSingleton - serviceQueue: {}", car, serviceQueue);
+        simulateService(car);
+        serviceQueue--;
+        LOG.info("Car service for {} is completed - serviceQueue: {}", car, serviceQueue);
+        return serviceQueue;
+    }
+    
+    private void simulateService(Car car) {
+        try {
+            Thread.sleep(100);
+            car.setServiced(true);
+        } catch (InterruptedException e) {
+            LOG.error("CarServiceEjbSingleton::InterruptedException: {}", e);
+        }
+    }
+
+}

jee-7/src/main/java/com/baeldung/singleton/CarServiceSingleton.java

@@ -0,0 +1,47 @@
+package com.baeldung.singleton;
+
+import java.util.UUID;
+
+import javax.inject.Singleton;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@Singleton
+public class CarServiceSingleton {
+
+    private static Logger LOG = LoggerFactory.getLogger(CarServiceSingleton.class);
+
+    private UUID id = UUID.randomUUID();
+
+    private static int serviceQueue;
+
+    public UUID getId() {
+        return this.id;
+    }
+
+    @Override
+    public String toString() {
+        return "CarServiceSingleton [id=" + id + "]";
+    }
+
+    public int service(Car car) {
+        serviceQueue++;
+        LOG.info("Car {} is being serviced @ CarServiceSingleton - serviceQueue: {}", car, serviceQueue);
+        simulateService(car);
+        serviceQueue--;
+        LOG.info("Car service for {} is completed - serviceQueue: {}", car, serviceQueue);
+        return serviceQueue;
+
+    }
+
+    private void simulateService(Car car) {
+        try {
+            Thread.sleep(100);
+            car.setServiced(true);
+        } catch (InterruptedException e) {
+            LOG.error("CarServiceSingleton::InterruptedException: {}", e);
+        }
+    }
+
+}

jee-7/src/test/java/com/baeldung/singleton/CarServiceIntegrationTest.java

@@ -0,0 +1,142 @@
+package com.baeldung.singleton;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+
+import javax.ejb.EJB;
+import javax.inject.Inject;
+
+import org.jboss.arquillian.container.test.api.Deployment;
+import org.jboss.arquillian.junit.Arquillian;
+import org.jboss.shrinkwrap.api.ShrinkWrap;
+import org.jboss.shrinkwrap.api.asset.EmptyAsset;
+import org.jboss.shrinkwrap.api.spec.JavaArchive;
+import org.junit.Before;
+import org.junit.FixMethodOrder;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.MethodSorters;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@RunWith(Arquillian.class)
+@FixMethodOrder(MethodSorters.NAME_ASCENDING)
+public class CarServiceIntegrationTest {
+
+    public static final Logger LOG = LoggerFactory.getLogger(CarServiceIntegrationTest.class);
+
+    @Deployment
+    public static JavaArchive createDeployment() {
+        return ShrinkWrap.create(JavaArchive.class)
+            .addClasses(CarServiceBean.class, CarServiceSingleton.class, CarServiceEjbSingleton.class, Car.class)
+            .addAsResource("META-INF/persistence.xml")
+            .addAsManifestResource(EmptyAsset.INSTANCE, "beans.xml");
+    }
+
+    @Inject
+    private CarServiceBean carServiceBean;
+
+    @Inject
+    private CarServiceSingleton carServiceSingleton;
+
+    @EJB
+    private CarServiceEjbSingleton carServiceEjbSingleton;
+
+    private static Map<String, UUID> idMap = new HashMap<>();
+
+    @Before
+    public void setUp() {
+        // populate idMap only on first run
+        if (idMap.isEmpty()) {
+            LOG.info("setUp::carServiceBean: {}", carServiceBean.getId());
+            idMap.put("carServiceBeanId", carServiceBean.getId());
+
+            LOG.info("setUp::carServiceSingleton: {}", carServiceSingleton.getId());
+            idMap.put("carServiceSingletonId", carServiceSingleton.getId());
+
+            LOG.info("setUp::carServiceEjbSingleton: {}", carServiceEjbSingleton.getId());
+            idMap.put("carServiceEjbSingletonId", carServiceEjbSingleton.getId());
+        }
+    }
+
+    @Test
+    public void givenRun1_whenGetId_thenSingletonIdEqual() {
+        int testRun = 1;
+
+        assertNotNull(carServiceBean);
+        assertNotNull(carServiceSingleton);
+        assertNotNull(carServiceEjbSingleton);
+
+        UUID carServiceBeanId = carServiceBean.getId();
+        assertEquals(idMap.get("carServiceBeanId"), carServiceBeanId);
+        LOG.info("Test run {}::carServiceBeanId: {}", testRun, carServiceBeanId);
+
+        UUID carServiceSingletonId = carServiceSingleton.getId();
+        assertEquals(idMap.get("carServiceSingletonId"), carServiceSingletonId);
+        LOG.info("Test run {}::carServiceSingletonId: {}", testRun, carServiceSingletonId);
+
+        UUID carServiceEjbSingletonId = carServiceEjbSingleton.getId();
+        assertEquals(idMap.get("carServiceEjbSingletonId"), carServiceEjbSingletonId);
+        LOG.info("Test run {}::carServiceEjbSingletonId: {}", testRun, carServiceEjbSingletonId);
+    }
+
+    @Test
+    public void givenRun2_whenGetId_thenSingletonIdEqual() {
+        int testRun = 2;
+
+        assertNotNull(carServiceBean);
+        assertNotNull(carServiceSingleton);
+        assertNotNull(carServiceEjbSingleton);
+
+        UUID carServiceBeanId = carServiceBean.getId();
+        assertNotEquals(idMap.get("carServiceBeanId"), carServiceBeanId);
+        LOG.info("Test run {}::carServiceBeanId: {}", testRun, carServiceBeanId);
+
+        UUID carServiceSingletonId = carServiceSingleton.getId();
+        assertEquals(idMap.get("carServiceSingletonId"), carServiceSingletonId);
+        LOG.info("Test run {}::carServiceSingletonId: {}", testRun, carServiceSingletonId);
+
+        UUID carServiceEjbSingletonId = carServiceEjbSingleton.getId();
+        assertEquals(idMap.get("carServiceEjbSingletonId"), carServiceEjbSingletonId);
+        LOG.info("Test run {}::carServiceEjbSingletonId: {}", testRun, carServiceEjbSingletonId);
+    }
+
+    @Test
+    public void givenRun3_whenSingleton_thenNoLocking() {
+        for (int i = 0; i < 10; i++) {
+            new Thread(new Runnable() {
+                @Override
+                public void run() {
+                    String model = Double.toString(Math.round(Math.random() * 100));
+                    Car car = new Car("Speedster", model);
+                    int serviceQueue = carServiceSingleton.service(car);
+                    assertTrue(serviceQueue < 10);                     
+                }
+            }).start();
+        }
+        return;
+    }
+    
+    @Test
+    public void givenRun4_whenEjb_thenLocking() {
+        for (int i = 0; i < 10; i++) {
+            new Thread(new Runnable() {
+                @Override
+                public void run() {
+                    String model = Double.toString(Math.round(Math.random() * 100));
+                    Car car = new Car("Speedster", model);
+                    int serviceQueue = carServiceEjbSingleton.service(car);
+                    assertEquals(0, serviceQueue);
+                }
+            }).start();
+        }
+        return;
+    }
+
+}

jhipster-5/README.md

@@ -0,0 +1,3 @@
+## Relevant articles:
+
+- [Creating New APIs and Views in JHipster](https://www.baeldung.com/jhipster-new-apis-and-views)

kotlin-libraries/build.gradle

@@ -7,6 +7,7 @@ version '1.0-SNAPSHOT'
 buildscript {
     ext.kotlin_version = '1.2.41'
     ext.ktor_version = '0.9.2'
+    ext.khttp_version = '0.1.0'
 
     repositories {
         mavenCentral()
@@ -47,11 +48,16 @@ dependencies {
     compile "io.ktor:ktor-server-netty:$ktor_version"
     compile "ch.qos.logback:logback-classic:1.2.1"
     compile "io.ktor:ktor-gson:$ktor_version"
+    compile "khttp:khttp:$khttp_version"
     testCompile group: 'junit', name: 'junit', version: '4.12'
+    testCompile group: 'org.jetbrains.spek', name: 'spek-api', version: '1.1.5'
+    testCompile group: 'org.jetbrains.spek', name: 'spek-subject-extension', version: '1.1.5'
+    testCompile group: 'org.jetbrains.spek', name: 'spek-junit-platform-engine', version: '1.1.5'
     implementation 'com.beust:klaxon:3.0.1'
+    implementation 'io.reactivex.rxjava2:rxkotlin:2.3.0'
 
 }
 task runServer(type: JavaExec) {
     main = 'APIServer'
    classpath = sourceSets.main.runtimeClasspath
-}
+}

kotlin-libraries/pom.xml

@@ -166,6 +166,12 @@
             <version>2.6</version>
             <scope>compile</scope>
         </dependency>
+
+        <dependency>
+            <groupId>io.reactivex.rxjava2</groupId>
+            <artifactId>rxkotlin</artifactId>
+            <version>2.3.0</version>
+        </dependency>
     </dependencies>
 
     <properties>

kotlin-libraries/src/test/kotlin/com/baeldung/kotlin/rxkotlin/RxKotlinTest.kt

@@ -0,0 +1,157 @@
+package com.baeldung.kotlin.rxkotlin
+
+import io.reactivex.Maybe
+import io.reactivex.Observable
+import io.reactivex.functions.BiFunction
+import io.reactivex.rxkotlin.*
+import io.reactivex.subjects.PublishSubject
+import org.junit.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFalse
+
+class RxKotlinTest {
+
+    @Test
+    fun whenBooleanArrayToObserver_thenBooleanObserver() {
+        val observable = listOf(true, false, false).toObservable()
+        observable.test().assertValues(true, false, false)
+    }
+
+    @Test
+    fun whenBooleanArrayToFlowable_thenBooleanFlowable() {
+        val flowable = listOf(true, false, false).toFlowable()
+        flowable.buffer(2).test().assertValues(listOf(true, false), listOf(false))
+    }
+
+    @Test
+    fun whenIntArrayToObserver_thenIntObserver() {
+        val observable = listOf(1, 1, 2, 3).toObservable()
+        observable.test().assertValues(1, 1, 2, 3)
+    }
+
+    @Test
+    fun whenIntArrayToFlowable_thenIntFlowable() {
+        val flowable = listOf(1, 1, 2, 3).toFlowable()
+        flowable.buffer(2).test().assertValues(listOf(1, 1), listOf(2, 3))
+    }
+
+    @Test
+    fun whenObservablePairToMap_thenSingleNoDuplicates() {
+        val list = listOf(Pair("a", 1), Pair("b", 2), Pair("c", 3), Pair("a", 4))
+        val observable = list.toObservable()
+        val map = observable.toMap()
+        assertEquals(mapOf(Pair("a", 4), Pair("b", 2), Pair("c", 3)), map.blockingGet())
+    }
+
+    @Test
+    fun whenObservablePairToMap_thenSingleWithDuplicates() {
+        val list = listOf(Pair("a", 1), Pair("b", 2), Pair("c", 3), Pair("a", 4))
+        val observable = list.toObservable()
+        val map = observable.toMultimap()
+        assertEquals(
+                mapOf(Pair("a", listOf(1, 4)), Pair("b", listOf(2)), Pair("c", listOf(3))),
+                map.blockingGet())
+    }
+
+    @Test
+    fun whenMergeAll_thenStream() {
+        val subject = PublishSubject.create<Observable<String>>()
+        val observable = subject.mergeAll()
+        val testObserver = observable.test()
+        subject.onNext(Observable.just("first", "second"))
+        testObserver.assertValues("first", "second")
+        subject.onNext(Observable.just("third", "fourth"))
+        subject.onNext(Observable.just("fifth"))
+        testObserver.assertValues("first", "second", "third", "fourth", "fifth")
+    }
+
+    @Test
+    fun whenConcatAll_thenStream() {
+        val subject = PublishSubject.create<Observable<String>>()
+        val observable = subject.concatAll()
+        val testObserver = observable.test()
+        subject.onNext(Observable.just("first", "second"))
+        testObserver.assertValues("first", "second")
+        subject.onNext(Observable.just("third", "fourth"))
+        subject.onNext(Observable.just("fifth"))
+        testObserver.assertValues("first", "second", "third", "fourth", "fifth")
+    }
+
+    @Test
+    fun whenSwitchLatest_thenStream() {
+        val subject = PublishSubject.create<Observable<String>>()
+        val observable = subject.switchLatest()
+        val testObserver = observable.test()
+        subject.onNext(Observable.just("first", "second"))
+        testObserver.assertValues("first", "second")
+        subject.onNext(Observable.just("third", "fourth"))
+        subject.onNext(Observable.just("fifth"))
+        testObserver.assertValues("first", "second", "third", "fourth", "fifth")
+    }
+
+    @Test
+    fun whenMergeAllMaybes_thenObservable() {
+        val subject = PublishSubject.create<Maybe<Int>>()
+        val observable = subject.mergeAllMaybes()
+        val testObserver = observable.test()
+        subject.onNext(Maybe.just(1))
+        subject.onNext(Maybe.just(2))
+        subject.onNext(Maybe.empty())
+        testObserver.assertValues(1, 2)
+        subject.onNext(Maybe.error(Exception("")))
+        subject.onNext(Maybe.just(3))
+        testObserver.assertValues(1, 2).assertError(Exception::class.java)
+    }
+
+    @Test
+    fun whenMerge_thenStream() {
+        val observables = mutableListOf(Observable.just("first", "second"))
+        val observable = observables.merge()
+        observables.add(Observable.just("third", "fourth"))
+        observables.add(Observable.error(Exception("e")))
+        observables.add(Observable.just("fifth"))
+
+        observable.test().assertValues("first", "second", "third", "fourth").assertError(Exception::class.java)
+    }
+
+    @Test
+    fun whenMergeDelayError_thenStream() {
+        val observables = mutableListOf<Observable<String>>(Observable.error(Exception("e1")))
+        val observable = observables.mergeDelayError()
+        observables.add(Observable.just("1", "2"))
+        observables.add(Observable.error(Exception("e2")))
+        observables.add(Observable.just("3"))
+
+        observable.test().assertValues("1", "2", "3").assertError(Exception::class.java)
+    }
+
+    @Test
+    fun whenCast_thenUniformType() {
+        val observable = Observable.just<Number>(1, 1, 2, 3)
+        observable.cast<Int>().test().assertValues(1, 1, 2, 3)
+    }
+
+    @Test
+    fun whenOfType_thenFilter() {
+        val observable = Observable.just(1, "and", 2, "and")
+        observable.ofType<Int>().test().assertValues(1, 2)
+    }
+
+    @Test
+    fun whenFunction_thenCompletable() {
+        var value = 0
+        val completable = { value = 3 }.toCompletable()
+        assertFalse(completable.test().isCancelled)
+        assertEquals(3, value)
+    }
+
+    @Test
+    fun whenHelper_thenMoreIdiomaticKotlin() {
+        val zipWith = Observable.just(1).zipWith(Observable.just(2)) { a, b -> a + b }
+        zipWith.subscribeBy(onNext = { println(it) })
+        val zip = Observables.zip(Observable.just(1), Observable.just(2)) { a, b -> a + b }
+        zip.subscribeBy(onNext = { println(it) })
+        val zipOrig = Observable.zip(Observable.just(1), Observable.just(2), BiFunction<Int, Int, Int> { a, b -> a + b })
+        zipOrig.subscribeBy(onNext = { println(it) })
+    }
+}

libraries-2/README.md

@@ -1,3 +1,7 @@
-## Relevant Articles
 
+### Relevant Articles: 
+
+- [A Guide to jBPM with Java](https://www.baeldung.com/jbpm-java)
 - [Guide to Classgraph Library](https://www.baeldung.com/classgraph)
+- [Create a Java Command Line Program with Picocli](https://www.baeldung.com/java-picocli-create-command-line-program)
+

logging-modules/logback/README.md

@@ -1,3 +1,4 @@
 ### Relevant Articles:
 
 - [Get Log Output in JSON](https://www.baeldung.com/java-log-json-output)
+- [SLF4J Warning: Class Path Contains Multiple SLF4J Bindings](https://www.baeldung.com/slf4j-classpath-multiple-bindings)

persistence-modules/README.md

@@ -5,7 +5,6 @@
 ### Relevant Articles:
 
 - [Introduction to Hibernate Search](http://www.baeldung.com/hibernate-search)
-- [Bootstrapping Hibernate 5 with Spring](http://www.baeldung.com/hibernate-5-spring)
 - [Introduction to Lettuce – the Java Redis Client](http://www.baeldung.com/java-redis-lettuce)
 - [A Guide to Jdbi](http://www.baeldung.com/jdbi)
 - [Pessimistic Locking in JPA](http://www.baeldung.com/jpa-pessimistic-locking)
@@ -13,3 +12,6 @@
 - [Spring Data with Reactive Cassandra](https://www.baeldung.com/spring-data-cassandra-reactive)
 - [Spring Data JPA – Derived Delete Methods](https://www.baeldung.com/spring-data-jpa-deleteby)
 - [Difference Between save() and saveAndFlush() in Spring Data JPA](https://www.baeldung.com/spring-data-jpa-save-saveandflush)
+- [Spring Boot with Hibernate](https://www.baeldung.com/spring-boot-hibernate)
+- [Persisting Maps with Hibernate](https://www.baeldung.com/hibernate-persisting-maps)
+- [Difference Between @Size, @Length, and @Column(length=value)](https://www.baeldung.com/jpa-size-length-column-differences)

persistence-modules/core-java-persistence/README.md

@@ -8,3 +8,4 @@
 - [Introduction to the JDBC RowSet Interface in Java](http://www.baeldung.com/java-jdbc-rowset)
 - [A Simple Guide to Connection Pooling in Java](https://www.baeldung.com/java-connection-pooling)
 - [Guide to the JDBC ResultSet Interface](https://www.baeldung.com/jdbc-resultset)
+- [Types of SQL Joins](https://www.baeldung.com/sql-joins)

persistence-modules/hibernate-mapping/README.md

@@ -0,0 +1,4 @@
+
+### Relevant Articles: 
+
+- [Persisting Maps with Hibernate](https://www.baeldung.com/hibernate-persisting-maps)

persistence-modules/java-jpa/README.md

@@ -2,8 +2,9 @@
 
 - [A Guide to SqlResultSetMapping](http://www.baeldung.com/jpa-sql-resultset-mapping)
 - [A Guide to Stored Procedures with JPA](http://www.baeldung.com/jpa-stored-procedures)
-- [Fixing the JPA error “java.lang.String cannot be cast to [Ljava.lang.String;”]](https://www.baeldung.com/jpa-error-java-lang-string-cannot-be-cast) 
+- [Fixing the JPA error “java.lang.String cannot be cast to Ljava.lang.String;”](https://www.baeldung.com/jpa-error-java-lang-string-cannot-be-cast)
 - [JPA Entity Graph](https://www.baeldung.com/jpa-entity-graph)
 - [JPA 2.2 Support for Java 8 Date/Time Types](https://www.baeldung.com/jpa-java-time)
 - [Converting Between LocalDate and SQL Date](https://www.baeldung.com/java-convert-localdate-sql-date)
 - [Combining JPA And/Or Criteria Predicates](https://www.baeldung.com/jpa-and-or-criteria-predicates)
+- [Types of JPA Queries](https://www.baeldung.com/jpa-queries)

persistence-modules/java-jpa/src/main/java/com/baeldung/jpa/basicannotation/Course.java

@@ -0,0 +1,33 @@
+package com.baeldung.jpa.basicannotation;
+
+import javax.persistence.Basic;
+import javax.persistence.Entity;
+import javax.persistence.FetchType;
+import javax.persistence.Id;
+
+@Entity
+public class Course {
+
+    @Id
+    private int id;
+
+    @Basic(optional = false, fetch = FetchType.LAZY)
+    private String name;
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+}
+

persistence-modules/java-jpa/src/main/java/com/baeldung/jpa/enums/Article.java

@@ -0,0 +1,91 @@
+package com.baeldung.jpa.enums;
+
+import javax.persistence.*;
+
+@Entity
+public class Article {
+
+    @Id
+    private int id;
+
+    private String title;
+
+    @Enumerated(EnumType.ORDINAL)
+    private Status status;
+
+    @Enumerated(EnumType.STRING)
+    private Type type;
+
+    @Basic
+    private int priorityValue;
+
+    @Transient
+    private Priority priority;
+
+    private Category category;
+
+    public Article() {
+    }
+
+    @PostLoad
+    void fillTransient() {
+        if (priorityValue > 0) {
+            this.priority = Priority.of(priorityValue);
+        }
+    }
+
+    @PrePersist
+    void fillPersistent() {
+        if (priority != null) {
+            this.priorityValue = priority.getPriority();
+        }
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public Status getStatus() {
+        return status;
+    }
+
+    public void setStatus(Status status) {
+        this.status = status;
+    }
+
+    public Type getType() {
+        return type;
+    }
+
+    public void setType(Type type) {
+        this.type = type;
+    }
+
+    public Priority getPriority() {
+        return priority;
+    }
+
+    public void setPriority(Priority priority) {
+        this.priority = priority;
+    }
+
+    public Category getCategory() {
+        return category;
+    }
+
+    public void setCategory(Category category) {
+        this.category = category;
+    }
+}

persistence-modules/java-jpa/src/main/java/com/baeldung/jpa/enums/Category.java

@@ -0,0 +1,17 @@
+package com.baeldung.jpa.enums;
+
+import java.util.stream.Stream;
+
+public enum Category {
+    SPORT("S"), MUSIC("M"), TECHNOLOGY("T");
+
+    private String code;
+
+    Category(String code) {
+        this.code = code;
+    }
+
+    public String getCode() {
+        return code;
+    }
+}

persistence-modules/java-jpa/src/main/java/com/baeldung/jpa/enums/CategoryConverter.java

@@ -0,0 +1,28 @@
+package com.baeldung.jpa.enums;
+
+import javax.persistence.AttributeConverter;
+import javax.persistence.Converter;
+import java.util.stream.Stream;
+
+@Converter(autoApply = true)
+public class CategoryConverter implements AttributeConverter<Category, String> {
+    @Override
+    public String convertToDatabaseColumn(Category category) {
+        if (category == null) {
+            return null;
+        }
+        return category.getCode();
+    }
+
+    @Override
+    public Category convertToEntityAttribute(final String code) {
+        if (code == null) {
+            return null;
+        }
+
+        return Stream.of(Category.values())
+                .filter(c -> c.getCode().equals(code))
+                .findFirst()
+                .orElseThrow(IllegalArgumentException::new);
+    }
+}

persistence-modules/java-jpa/src/main/java/com/baeldung/jpa/enums/Priority.java

@@ -0,0 +1,24 @@
+package com.baeldung.jpa.enums;
+
+import java.util.stream.Stream;
+
+public enum Priority {
+    LOW(100), MEDIUM(200), HIGH(300);
+
+    private int priority;
+
+    private Priority(int priority) {
+        this.priority = priority;
+    }
+
+    public int getPriority() {
+        return priority;
+    }
+
+    public static Priority of(int priority) {
+        return Stream.of(Priority.values())
+                .filter(p -> p.getPriority() == priority)
+                .findFirst()
+                .orElseThrow(IllegalArgumentException::new);
+    }
+}

persistence-modules/java-jpa/src/main/java/com/baeldung/jpa/enums/Status.java

@@ -0,0 +1,5 @@
+package com.baeldung.jpa.enums;
+
+public enum Status {
+    OPEN, REVIEW, APPROVED, REJECTED;
+}

persistence-modules/java-jpa/src/main/java/com/baeldung/jpa/enums/Type.java

@@ -0,0 +1,5 @@
+package com.baeldung.jpa.enums;
+
+enum Type {
+    INTERNAL, EXTERNAL;
+}

persistence-modules/java-jpa/src/main/resources/META-INF/persistence.xml

@@ -26,6 +26,8 @@
     <persistence-unit name="jpa-h2">
         <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
         <class>com.baeldung.jpa.stringcast.Message</class>
+        <class>com.baeldung.jpa.enums.Article</class>
+        <class>com.baeldung.jpa.enums.CategoryConverter</class>
         <exclude-unlisted-classes>true</exclude-unlisted-classes>
         <properties>
             <property name="javax.persistence.jdbc.driver" value="org.h2.Driver"/>
@@ -146,4 +148,4 @@
         </properties>
     </persistence-unit>
 
-</persistence>
+</persistence>

persistence-modules/java-jpa/src/test/java/com/baeldung/jpa/basicannotation/BasicAnnotationIntegrationTest.java

@@ -0,0 +1,56 @@
+package com.baeldung.jpa.basicannotation;
+
+import org.hibernate.PropertyValueException;
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.Persistence;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.AfterClass;
+import org.junit.Test;
+
+import java.io.IOException;
+
+public class BasicAnnotationIntegrationTest {
+
+    private static EntityManager entityManager;
+    private static EntityManagerFactory entityManagerFactory;
+
+    @BeforeClass
+    public void setup() {
+        entityManagerFactory = Persistence.createEntityManagerFactory("java-jpa-scheduled-day");
+        entityManager = entityManagerFactory.createEntityManager();
+    }
+
+    @Test
+    public void givenACourse_whenCourseNamePresent_shouldPersist() {
+        Course course = new Course();
+        course.setName("Computers");
+
+        entityManager.persist(course);
+        entityManager.flush();
+        entityManager.clear();
+
+    }
+
+    @Test(expected = PropertyValueException.class)
+    public void givenACourse_whenCourseNameAbsent_shouldFail() {
+        Course course = new Course();
+
+        entityManager.persist(course);
+        entityManager.flush();
+        entityManager.clear();
+    }
+
+    @AfterClass
+    public void destroy() {
+
+        if (entityManager != null) {
+            entityManager.close();
+        }
+        if (entityManagerFactory != null) {
+            entityManagerFactory.close();
+        }
+    }
+}

persistence-modules/java-jpa/src/test/java/com/baeldung/jpa/enums/ArticleUnitTest.java

@@ -0,0 +1,118 @@
+package com.baeldung.jpa.enums;
+
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.EntityTransaction;
+import javax.persistence.Persistence;
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class ArticleUnitTest {
+
+    private static EntityManager em;
+    private static EntityManagerFactory emFactory;
+
+    @BeforeClass
+    public static void setup() {
+        Map properties = new HashMap();
+        properties.put("hibernate.show_sql", "true");
+        properties.put("hibernate.format_sql", "true");
+        emFactory = Persistence.createEntityManagerFactory("jpa-h2", properties);
+        em = emFactory.createEntityManager();
+    }
+
+    @Test
+    public void shouldPersistStatusEnumOrdinalValue() {
+        // given
+        Article article = new Article();
+        article.setId(1);
+        article.setTitle("ordinal title");
+        article.setStatus(Status.OPEN);
+
+        // when
+        EntityTransaction tx = em.getTransaction();
+        tx.begin();
+        em.persist(article);
+        tx.commit();
+
+        // then
+        Article persistedArticle = em.find(Article.class, 1);
+
+        assertEquals(1, persistedArticle.getId());
+        assertEquals("ordinal title", persistedArticle.getTitle());
+        assertEquals(Status.OPEN, persistedArticle.getStatus());
+    }
+
+    @Test
+    public void shouldPersistTypeEnumStringValue() {
+        // given
+        Article article = new Article();
+        article.setId(2);
+        article.setTitle("string title");
+        article.setType(Type.EXTERNAL);
+
+        // when
+        EntityTransaction tx = em.getTransaction();
+        tx.begin();
+        em.persist(article);
+        tx.commit();
+
+        // then
+        Article persistedArticle = em.find(Article.class, 2);
+
+        assertEquals(2, persistedArticle.getId());
+        assertEquals("string title", persistedArticle.getTitle());
+        assertEquals(Type.EXTERNAL, persistedArticle.getType());
+    }
+
+    @Test
+    public void shouldPersistPriorityIntValue() {
+        // given
+        Article article = new Article();
+        article.setId(3);
+        article.setTitle("callback title");
+        article.setPriority(Priority.HIGH);
+
+        // when
+        EntityTransaction tx = em.getTransaction();
+        tx.begin();
+        em.persist(article);
+        tx.commit();
+
+        // then
+        Article persistedArticle = em.find(Article.class, 3);
+
+        assertEquals(3, persistedArticle.getId());
+        assertEquals("callback title", persistedArticle.getTitle());
+        assertEquals(Priority.HIGH, persistedArticle.getPriority());
+
+    }
+
+    @Test
+    public void shouldPersistCategoryEnumConvertedValue() {
+        // given
+        Article article = new Article();
+        article.setId(4);
+        article.setTitle("converted title");
+        article.setCategory(Category.MUSIC);
+
+        // when
+        EntityTransaction tx = em.getTransaction();
+        tx.begin();
+        em.persist(article);
+        tx.commit();
+
+        // then
+        Article persistedArticle = em.find(Article.class, 4);
+
+        assertEquals(4, persistedArticle.getId());
+        assertEquals("converted title", persistedArticle.getTitle());
+        assertEquals(Category.MUSIC, persistedArticle.getCategory());
+    }
+
+}

persistence-modules/java-mongodb/README.md

@@ -2,3 +2,4 @@
 
 - [A Guide to MongoDB with Java](http://www.baeldung.com/java-mongodb)
 - [A Simple Tagging Implementation with MongoDB](http://www.baeldung.com/mongodb-tagging)
+- [MongoDB BSON Guide](https://www.baeldung.com/mongodb-bson)

persistence-modules/pom.xml

@@ -55,5 +55,6 @@
         <module>spring-hibernate-5</module>
         <module>spring-hibernate4</module>
         <module>spring-jpa</module>
+        <module>spring-persistence-simple</module>
     </modules>
 </project>

persistence-modules/spring-data-jpa-2/README.md

@@ -1,6 +1,14 @@
-=========
-
-## Spring Data JPA Example Project
-
-### Relevant Articles: 
-- [Spring Data JPA – Derived Delete Methods](https://www.baeldung.com/spring-data-jpa-deleteby)
+=========
+
+## Spring Data JPA Example Project
+
+### Relevant Articles: 
+- [Spring Data JPA – Derived Delete Methods](https://www.baeldung.com/spring-data-jpa-deleteby)
+- [JPA Join Types](https://www.baeldung.com/jpa-join-types)
+- [Case Insensitive Queries with Spring Data Repository](https://www.baeldung.com/spring-data-case-insensitive-queries)
+- [The Exists Query in Spring Data](https://www.baeldung.com/spring-data-exists-query)
+- [Spring Data JPA Repository Populators](https://www.baeldung.com/spring-data-jpa-repository-populators)
+- [Spring Data JPA and Null Parameters](https://www.baeldung.com/spring-data-jpa-null-parameters)
+- [Spring Data JPA Projections](https://www.baeldung.com/spring-data-jpa-projections)
+- [JPA @Embedded And @Embeddable](https://www.baeldung.com/jpa-embedded-embeddable)
+- [Spring Data JPA Delete and Relationships](https://www.baeldung.com/spring-data-jpa-delete)

persistence-modules/spring-data-jpa-2/src/main/java/com/baeldung/derivedquery/entity/User.java

@@ -0,0 +1,70 @@
+package com.baeldung.derivedquery.entity;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.Table;
+import java.time.ZonedDateTime;
+
+@Table(name = "users")
+@Entity
+public class User {
+
+    @Id
+    @GeneratedValue
+    private Integer id;
+    private String name;
+    private Integer age;
+    private ZonedDateTime birthDate;
+    private Boolean active;
+
+    public User() {
+    }
+
+    public User(String name, Integer age, ZonedDateTime birthDate, Boolean active) {
+        this.name = name;
+        this.age = age;
+        this.birthDate = birthDate;
+        this.active = active;
+    }
+
+    public Integer getId() {
+        return id;
+    }
+
+    public void setId(Integer id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public Integer getAge() {
+        return age;
+    }
+
+    public void setAge(Integer age) {
+        this.age = age;
+    }
+
+    public ZonedDateTime getBirthDate() {
+        return birthDate;
+    }
+
+    public void setBirthDate(ZonedDateTime birthDate) {
+        this.birthDate = birthDate;
+    }
+
+    public Boolean getActive() {
+        return active;
+    }
+
+    public void setActive(Boolean active) {
+        this.active = active;
+    }
+}

persistence-modules/spring-data-jpa-2/src/main/java/com/baeldung/derivedquery/repository/UserRepository.java

@@ -0,0 +1,60 @@
+package com.baeldung.derivedquery.repository;
+
+import com.baeldung.derivedquery.entity.User;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import java.time.ZonedDateTime;
+import java.util.Collection;
+import java.util.List;
+
+public interface UserRepository extends JpaRepository<User, Integer> {
+
+    List<User> findByName(String name);
+
+    List<User> findByNameIs(String name);
+
+    List<User> findByNameEquals(String name);
+
+    List<User> findByNameIsNull();
+
+    List<User> findByNameNot(String name);
+
+    List<User> findByNameIsNot(String name);
+
+    List<User> findByNameStartingWith(String name);
+
+    List<User> findByNameEndingWith(String name);
+
+    List<User> findByNameContaining(String name);
+
+    List<User> findByNameLike(String name);
+
+    List<User> findByAgeLessThan(Integer age);
+
+    List<User> findByAgeLessThanEqual(Integer age);
+
+    List<User> findByAgeGreaterThan(Integer age);
+
+    List<User> findByAgeGreaterThanEqual(Integer age);
+
+    List<User> findByAgeBetween(Integer startAge, Integer endAge);
+
+    List<User> findByBirthDateAfter(ZonedDateTime birthDate);
+
+    List<User> findByBirthDateBefore(ZonedDateTime birthDate);
+
+    List<User> findByActiveTrue();
+
+    List<User> findByActiveFalse();
+
+    List<User> findByAgeIn(Collection<Integer> ages);
+
+    List<User> findByNameOrBirthDate(String name, ZonedDateTime birthDate);
+
+    List<User> findByNameOrBirthDateAndActive(String name, ZonedDateTime birthDate, Boolean active);
+
+    List<User> findByNameOrderByName(String name);
+
+    List<User> findByNameOrderByNameDesc(String name);
+
+}

persistence-modules/spring-data-jpa-2/src/test/java/com/baeldung/derivedquery/repository/UserRepositoryTest.java

@@ -0,0 +1,172 @@
+package com.baeldung.derivedquery.repository;
+
+import com.baeldung.Application;
+import com.baeldung.derivedquery.entity.User;
+import com.baeldung.derivedquery.repository.UserRepository;
+import java.time.ZonedDateTime;
+import java.util.Arrays;
+import java.util.List;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.junit.Assert.assertEquals;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(classes = Application.class)
+public class UserRepositoryTest {
+
+    private static final String USER_NAME_ADAM = "Adam";
+    private static final String USER_NAME_EVE = "Eve";
+    private static final ZonedDateTime BIRTHDATE = ZonedDateTime.now();
+
+    @Autowired
+    private UserRepository userRepository;
+
+    @Before
+    public void setUp() {
+
+        User user1 = new User(USER_NAME_ADAM, 25, BIRTHDATE, true);
+        User user2 = new User(USER_NAME_ADAM, 20, BIRTHDATE, false);
+        User user3 = new User(USER_NAME_EVE, 20, BIRTHDATE, true);
+        User user4 = new User(null, 30, BIRTHDATE, false);
+
+        userRepository.saveAll(Arrays.asList(user1, user2, user3, user4));
+    }
+
+    @After
+    public void tearDown() {
+
+        userRepository.deleteAll();
+    }
+
+    @Test
+    public void whenFindByName_thenReturnsCorrectResult() {
+
+        assertEquals(2, userRepository.findByName(USER_NAME_ADAM).size());
+    }
+
+    @Test
+    public void whenFindByNameIsNull_thenReturnsCorrectResult() {
+
+        assertEquals(1, userRepository.findByNameIsNull().size());
+    }
+
+    @Test
+    public void whenFindByNameNot_thenReturnsCorrectResult() {
+
+        assertEquals(USER_NAME_EVE, userRepository.findByNameNot(USER_NAME_ADAM).get(0).getName());
+    }
+
+    @Test
+    public void whenFindByNameStartingWith_thenReturnsCorrectResult() {
+
+        assertEquals(2, userRepository.findByNameStartingWith("A").size());
+    }
+
+    @Test
+    public void whenFindByNameEndingWith_thenReturnsCorrectResult() {
+
+        assertEquals(1, userRepository.findByNameEndingWith("e").size());
+    }
+
+    @Test
+    public void whenByNameContaining_thenReturnsCorrectResult() {
+
+        assertEquals(1, userRepository.findByNameContaining("v").size());
+    }
+
+
+    @Test
+    public void whenByNameLike_thenReturnsCorrectResult() {
+
+        assertEquals(2, userRepository.findByNameEndingWith("%d%m").size());
+    }
+
+    @Test
+    public void whenByAgeLessThan_thenReturnsCorrectResult() {
+
+        assertEquals(2, userRepository.findByAgeLessThan(25).size());
+    }
+
+
+    @Test
+    public void whenByAgeLessThanEqual_thenReturnsCorrectResult() {
+
+        assertEquals(3, userRepository.findByAgeLessThanEqual(25).size());
+    }
+
+    @Test
+    public void whenByAgeGreaterThan_thenReturnsCorrectResult() {
+
+        assertEquals(1, userRepository.findByAgeGreaterThan(25).size());
+    }
+
+    @Test
+    public void whenByAgeGreaterThanEqual_thenReturnsCorrectResult() {
+
+        assertEquals(2, userRepository.findByAgeGreaterThanEqual(25).size());
+    }
+
+    @Test
+    public void whenByAgeBetween_thenReturnsCorrectResult() {
+
+        assertEquals(4, userRepository.findByAgeBetween(20, 30).size());
+    }
+
+    @Test
+    public void whenByBirthDateAfter_thenReturnsCorrectResult() {
+
+        final ZonedDateTime yesterday = BIRTHDATE.minusDays(1);
+        assertEquals(4, userRepository.findByBirthDateAfter(yesterday).size());
+    }
+
+    @Test
+    public void whenByBirthDateBefore_thenReturnsCorrectResult() {
+
+        final ZonedDateTime yesterday = BIRTHDATE.minusDays(1);
+        assertEquals(0, userRepository.findByBirthDateBefore(yesterday).size());
+    }
+
+    @Test
+    public void whenByActiveTrue_thenReturnsCorrectResult() {
+
+        assertEquals(2, userRepository.findByActiveTrue().size());
+    }
+
+    @Test
+    public void whenByActiveFalse_thenReturnsCorrectResult() {
+
+        assertEquals(2, userRepository.findByActiveFalse().size());
+    }
+
+
+    @Test
+    public void whenByAgeIn_thenReturnsCorrectResult() {
+
+        final List<Integer> ages = Arrays.asList(20, 25);
+        assertEquals(3, userRepository.findByAgeIn(ages).size());
+    }
+
+    @Test
+    public void whenByNameOrBirthDate() {
+
+        assertEquals(4, userRepository.findByNameOrBirthDate(USER_NAME_ADAM, BIRTHDATE).size());
+    }
+
+    @Test
+    public void whenByNameOrBirthDateAndActive() {
+
+        assertEquals(3, userRepository.findByNameOrBirthDateAndActive(USER_NAME_ADAM, BIRTHDATE, false).size());
+    }
+
+    @Test
+    public void whenByNameOrderByName() {
+
+        assertEquals(2, userRepository.findByNameOrderByName(USER_NAME_ADAM).size());
+    }
+}

persistence-modules/spring-data-jpa/README.md

@@ -6,7 +6,6 @@
 - [Spring JPA – Multiple Databases](http://www.baeldung.com/spring-data-jpa-multiple-databases)
 - [Spring Data JPA – Adding a Method in All Repositories](http://www.baeldung.com/spring-data-jpa-method-in-all-repositories)
 - [An Advanced Tagging Implementation with JPA](http://www.baeldung.com/jpa-tagging-advanced)
-- [Spring Data JPA @Query](http://www.baeldung.com/spring-data-jpa-query)
 - [Spring Data Annotations](http://www.baeldung.com/spring-data-annotations)
 - [Spring Data Java 8 Support](http://www.baeldung.com/spring-data-java-8)
 - [A Simple Tagging Implementation with JPA](http://www.baeldung.com/jpa-tagging)

persistence-modules/spring-hibernate4/README.md

@@ -4,7 +4,6 @@
 
 ### Relevant Articles: 
 - [Guide to Hibernate 4 with Spring](http://www.baeldung.com/hibernate-4-spring)
-- [The DAO with Spring and Hibernate](http://www.baeldung.com/persistence-layer-with-spring-and-hibernate)
 - [Hibernate Pagination](http://www.baeldung.com/hibernate-pagination)
 - [Sorting with Hibernate](http://www.baeldung.com/hibernate-sort)
 - [Stored Procedures with Hibernate](http://www.baeldung.com/stored-procedures-with-hibernate-tutorial)

persistence-modules/spring-jpa/README.md

@@ -4,8 +4,6 @@
 
 
 ### Relevant Articles: 
-- [A Guide to JPA with Spring](https://www.baeldung.com/the-persistence-layer-with-spring-and-jpa)
-- [Transactions with Spring and JPA](https://www.baeldung.com/transaction-configuration-with-jpa-and-spring)
 - [The DAO with JPA and Spring](http://www.baeldung.com/spring-dao-jpa)
 - [JPA Pagination](http://www.baeldung.com/jpa-pagination)
 - [Sorting with JPA](http://www.baeldung.com/jpa-sort)

persistence-modules/spring-persistence-simple/.gitignore

@@ -0,0 +1,13 @@
+*.class
+
+#folders#
+/target
+/neoDb*
+/data
+/src/main/webapp/WEB-INF/classes
+*/META-INF/*
+
+# Packaged files #
+*.jar
+*.war
+*.ear

persistence-modules/spring-persistence-simple/README.md

@@ -0,0 +1,24 @@
+=========
+
+## Spring Persistence Example Project
+
+
+### Relevant Articles: 
+- [A Guide to JPA with Spring](https://www.baeldung.com/the-persistence-layer-with-spring-and-jpa)
+- [Bootstrapping Hibernate 5 with Spring](http://www.baeldung.com/hibernate-5-spring)
+- [The DAO with Spring and Hibernate](http://www.baeldung.com/persistence-layer-with-spring-and-hibernate)
+- [DAO with Spring and Generics](https://www.baeldung.com/simplifying-the-data-access-layer-with-spring-and-java-generics)
+- [Transactions with Spring and JPA](https://www.baeldung.com/transaction-configuration-with-jpa-and-spring)
+- [Introduction to Spring Data JPA](http://www.baeldung.com/the-persistence-layer-with-spring-data-jpa)
+- [Spring Data JPA @Query](http://www.baeldung.com/spring-data-jpa-query)
+
+
+### Eclipse Config 
+After importing the project into Eclipse, you may see the following error:  
+"No persistence xml file found in project"
+
+This can be ignored: 
+- Project -> Properties -> Java Persistance -> JPA -> Error/Warnings -> Select Ignore on "No persistence xml file found in project"
+Or: 
+- Eclipse -> Preferences - Validation - disable the "Build" execution of the JPA Validator 
+

persistence-modules/spring-persistence-simple/pom.xml

@@ -0,0 +1,160 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>spring-persistence-simple</artifactId>
+    <version>0.1-SNAPSHOT</version>
+    <name>spring-persistence-simple</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+        <relativePath>../../</relativePath>
+    </parent>
+
+    <dependencies>
+        <!-- Spring -->
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-orm</artifactId>
+            <version>${org.springframework.version}</version>
+            <exclusions>
+                <exclusion>
+                    <artifactId>commons-logging</artifactId>
+                    <groupId>commons-logging</groupId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-context</artifactId>
+            <version>${org.springframework.version}</version>
+        </dependency>
+
+        <!-- persistence -->
+        <dependency>
+            <groupId>org.hibernate</groupId>
+            <artifactId>hibernate-core</artifactId>
+            <version>${hibernate.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>javax.transaction</groupId>
+            <artifactId>jta</artifactId>
+            <version>${jta.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.hibernate</groupId>
+            <artifactId>hibernate-entitymanager</artifactId>
+            <version>${hibernate.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>mysql</groupId>
+            <artifactId>mysql-connector-java</artifactId>
+            <version>${mysql-connector-java.version}</version>
+            <scope>runtime</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.data</groupId>
+            <artifactId>spring-data-jpa</artifactId>
+            <version>${spring-data-jpa.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+            <version>${h2.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.apache.tomcat</groupId>
+            <artifactId>tomcat-dbcp</artifactId>
+            <version>${tomcat-dbcp.version}</version>
+        </dependency>
+
+        <!-- utils -->
+
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>${guava.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+        </dependency>
+
+        <!-- test scoped -->
+
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons-lang3.version}</version>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-test</artifactId>
+            <version>${org.springframework.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.querydsl</groupId>
+            <artifactId>querydsl-jpa</artifactId>
+            <version>${querydsl.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.querydsl</groupId>
+            <artifactId>querydsl-apt</artifactId>
+            <version>${querydsl.version}</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>spring-persistence-simple</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+        <plugins>
+            <plugin>
+                <groupId>com.mysema.maven</groupId>
+                <artifactId>apt-maven-plugin</artifactId>
+                <version>1.1.3</version>
+                <executions>
+                    <execution>
+                        <phase>generate-sources</phase>
+                        <goals>
+                            <goal>process</goal>
+                        </goals>
+                        <configuration>
+                            <outputDirectory>target/generated-sources</outputDirectory>
+                            <processor>com.querydsl.apt.jpa.JPAAnnotationProcessor</processor>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>	
+    </build>
+
+    <properties>
+        <!-- Spring -->
+        <org.springframework.version>5.1.6.RELEASE</org.springframework.version>
+
+        <!-- persistence -->
+        <hibernate.version>5.4.2.Final</hibernate.version>
+        <mysql-connector-java.version>6.0.6</mysql-connector-java.version>
+        <spring-data-jpa.version>2.1.6.RELEASE</spring-data-jpa.version>
+        <tomcat-dbcp.version>9.0.0.M26</tomcat-dbcp.version>
+        <jta.version>1.1</jta.version>
+        <querydsl.version>4.2.1</querydsl.version>
+
+        <!-- util -->
+        <guava.version>21.0</guava.version>
+        <commons-lang3.version>3.5</commons-lang3.version>
+        <assertj.version>3.8.0</assertj.version>
+    </properties>
+
+</project>

persistence-modules/spring-persistence-simple/src/main/java/com/baeldung/hibernate/bootstrap/BarHibernateDAO.java

@@ -0,0 +1,39 @@
+package com.baeldung.hibernate.bootstrap;
+
+import com.baeldung.hibernate.bootstrap.model.TestEntity;
+import org.hibernate.Session;
+import org.hibernate.SessionFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+
+public abstract class BarHibernateDAO {
+
+    @Autowired
+    private SessionFactory sessionFactory;
+
+    public TestEntity findEntity(int id) {
+
+        return getCurrentSession().find(TestEntity.class, 1);
+    }
+
+    public void createEntity(TestEntity entity) {
+
+        getCurrentSession().save(entity);
+    }
+
+    public void createEntity(int id, String newDescription) {
+
+        TestEntity entity = findEntity(id);
+        entity.setDescription(newDescription);
+        getCurrentSession().save(entity);
+    }
+
+    public void deleteEntity(int id) {
+
+        TestEntity entity = findEntity(id);
+        getCurrentSession().delete(entity);
+    }
+
+    protected Session getCurrentSession() {
+        return sessionFactory.getCurrentSession();
+    }
+}

persistence-modules/spring-persistence-simple/src/main/java/com/baeldung/hibernate/bootstrap/HibernateConf.java

@@ -0,0 +1,61 @@
+package com.baeldung.hibernate.bootstrap;
+
+import com.google.common.base.Preconditions;
+import org.apache.tomcat.dbcp.dbcp2.BasicDataSource;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.PropertySource;
+import org.springframework.core.env.Environment;
+import org.springframework.orm.hibernate5.HibernateTransactionManager;
+import org.springframework.orm.hibernate5.LocalSessionFactoryBean;
+import org.springframework.transaction.PlatformTransactionManager;
+import org.springframework.transaction.annotation.EnableTransactionManagement;
+
+import javax.sql.DataSource;
+import java.util.Properties;
+
+@Configuration
+@EnableTransactionManagement
+@PropertySource({ "classpath:persistence-h2.properties" })
+public class HibernateConf {
+
+    @Autowired
+    private Environment env;
+
+    @Bean
+    public LocalSessionFactoryBean sessionFactory() {
+        final LocalSessionFactoryBean sessionFactory = new LocalSessionFactoryBean();
+        sessionFactory.setDataSource(dataSource());
+        sessionFactory.setPackagesToScan(new String[] { "com.baeldung.hibernate.bootstrap.model" });
+        sessionFactory.setHibernateProperties(hibernateProperties());
+
+        return sessionFactory;
+    }
+
+    @Bean
+    public DataSource dataSource() {
+        final BasicDataSource dataSource = new BasicDataSource();
+        dataSource.setDriverClassName(Preconditions.checkNotNull(env.getProperty("jdbc.driverClassName")));
+        dataSource.setUrl(Preconditions.checkNotNull(env.getProperty("jdbc.url")));
+        dataSource.setUsername(Preconditions.checkNotNull(env.getProperty("jdbc.user")));
+        dataSource.setPassword(Preconditions.checkNotNull(env.getProperty("jdbc.pass")));
+
+        return dataSource;
+    }
+
+    @Bean
+    public PlatformTransactionManager hibernateTransactionManager() {
+        final HibernateTransactionManager transactionManager = new HibernateTransactionManager();
+        transactionManager.setSessionFactory(sessionFactory().getObject());
+        return transactionManager;
+    }
+
+    private final Properties hibernateProperties() {
+        final Properties hibernateProperties = new Properties();
+        hibernateProperties.setProperty("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto"));
+        hibernateProperties.setProperty("hibernate.dialect", env.getProperty("hibernate.dialect"));
+
+        return hibernateProperties;
+    }
+}

persistence-modules/spring-persistence-simple/src/main/java/com/baeldung/hibernate/bootstrap/HibernateXMLConf.java

@@ -0,0 +1,24 @@
+package com.baeldung.hibernate.bootstrap;
+
+import com.google.common.base.Preconditions;
+import org.apache.tomcat.dbcp.dbcp2.BasicDataSource;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.ImportResource;
+import org.springframework.context.annotation.PropertySource;
+import org.springframework.core.env.Environment;
+import org.springframework.orm.hibernate5.HibernateTransactionManager;
+import org.springframework.orm.hibernate5.LocalSessionFactoryBean;
+import org.springframework.transaction.PlatformTransactionManager;
+import org.springframework.transaction.annotation.EnableTransactionManagement;
+
+import javax.sql.DataSource;
+import java.util.Properties;
+
+@Configuration
+@EnableTransactionManagement
+@ImportResource({ "classpath:hibernate5Configuration.xml" })
+public class HibernateXMLConf {
+
+}

persistence-modules/spring-persistence-simple/src/main/java/com/baeldung/hibernate/bootstrap/model/TestEntity.java

@@ -0,0 +1,29 @@
+package com.baeldung.hibernate.bootstrap.model;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+
+@Entity
+public class TestEntity {
+
+    private int id;
+
+    private String description;
+
+    @Id
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public void setDescription(String description) {
+        this.description = description;
+    }
+}

persistence-modules/spring-persistence-simple/src/main/java/com/baeldung/persistence/dao/common/AbstractDao.java

@@ -0,0 +1,14 @@
+package com.baeldung.persistence.dao.common;
+
+import java.io.Serializable;
+
+import com.google.common.base.Preconditions;
+
+public abstract class AbstractDao<T extends Serializable> implements IOperations<T> {
+
+    protected Class<T> clazz;
+
+    protected final void setClazz(final Class<T> clazzToSet) {
+        clazz = Preconditions.checkNotNull(clazzToSet);
+    }
+}

persistence-modules/spring-persistence-simple/src/main/java/com/baeldung/persistence/dao/common/AbstractHibernateDao.java

@@ -0,0 +1,60 @@
+package com.baeldung.persistence.dao.common;
+
+import java.io.Serializable;
+import java.util.List;
+
+import org.hibernate.Session;
+import org.hibernate.SessionFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+
+import com.google.common.base.Preconditions;
+
+@SuppressWarnings("unchecked")
+public abstract class AbstractHibernateDao<T extends Serializable> extends AbstractDao<T> implements IOperations<T> {
+
+    @Autowired
+    protected SessionFactory sessionFactory;
+
+    // API
+
+    @Override
+    public T findOne(final long id) {
+        return (T) getCurrentSession().get(clazz, id);
+    }
+
+    @Override
+    public List<T> findAll() {
+        return getCurrentSession().createQuery("from " + clazz.getName()).list();
+    }
+
+    @Override
+    public T create(final T entity) {
+        Preconditions.checkNotNull(entity);
+        getCurrentSession().saveOrUpdate(entity);
+        return entity;
+    }
+
+    @Override
+    public T update(final T entity) {
+        Preconditions.checkNotNull(entity);
+        return (T) getCurrentSession().merge(entity);
+    }
+
+    @Override
+    public void delete(final T entity) {
+        Preconditions.checkNotNull(entity);
+        getCurrentSession().delete(entity);
+    }
+
+    @Override
+    public void deleteById(final long entityId) {
+        final T entity = findOne(entityId);
+        Preconditions.checkState(entity != null);
+        delete(entity);
+    }
+
+    protected Session getCurrentSession() {
+        return sessionFactory.getCurrentSession();
+    }
+
+}

persistence-modules/spring-persistence-simple/src/main/java/com/baeldung/persistence/dao/common/GenericHibernateDao.java

@@ -0,0 +1,13 @@
+package com.baeldung.persistence.dao.common;
+
+import java.io.Serializable;
+
+import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.context.annotation.Scope;
+import org.springframework.stereotype.Repository;
+
+@Repository
+@Scope(BeanDefinition.SCOPE_PROTOTYPE)
+public class GenericHibernateDao<T extends Serializable> extends AbstractHibernateDao<T> implements IGenericDao<T> {
+    //
+}

persistence-modules/spring-persistence-simple/src/main/java/com/baeldung/persistence/dao/common/GenericJpaDao.java

@@ -0,0 +1,14 @@
+package com.baeldung.persistence.dao.common;
+
+import java.io.Serializable;
+
+import org.baeldung.persistence.dao.AbstractJpaDAO;
+import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.context.annotation.Scope;
+import org.springframework.stereotype.Repository;
+
+@Repository
+@Scope(BeanDefinition.SCOPE_PROTOTYPE)
+public class GenericJpaDao<T extends Serializable> extends AbstractJpaDAO<T> implements IGenericDao<T> {
+    //
+}

persistence-modules/spring-persistence-simple/src/main/java/com/baeldung/persistence/dao/common/IGenericDao.java

@@ -0,0 +1,7 @@
+package com.baeldung.persistence.dao.common;
+
+import java.io.Serializable;
+
+public interface IGenericDao<T extends Serializable> extends IOperations<T> {
+    //
+}

persistence-modules/spring-persistence-simple/src/main/java/com/baeldung/persistence/dao/common/IOperations.java

@@ -0,0 +1,20 @@
+package com.baeldung.persistence.dao.common;
+
+import java.io.Serializable;
+import java.util.List;
+
+public interface IOperations<T extends Serializable> {
+
+    T findOne(final long id);
+
+    List<T> findAll();
+
+    T create(final T entity);
+
+    T update(final T entity);
+
+    void delete(final T entity);
+
+    void deleteById(final long entityId);
+
+}

persistence-modules/spring-persistence-simple/src/main/java/com/baeldung/persistence/dao/impl/FooDao.java

@@ -0,0 +1,20 @@
+package com.baeldung.persistence.dao.impl;
+
+import org.baeldung.persistence.dao.IFooDao;
+import org.baeldung.persistence.model.Foo;
+import org.springframework.stereotype.Repository;
+
+import com.baeldung.persistence.dao.common.AbstractHibernateDao;
+
+@Repository
+public class FooDao extends AbstractHibernateDao<Foo> implements IFooDao {
+
+    public FooDao() {
+        super();
+
+        setClazz(Foo.class);
+    }
+
+    // API
+
+}

persistence-modules/spring-persistence-simple/src/main/java/org/baeldung/config/PersistenceConfig.java

@@ -0,0 +1,118 @@
+package org.baeldung.config;
+
+import java.util.Properties;
+
+import javax.sql.DataSource;
+
+import org.apache.tomcat.dbcp.dbcp2.BasicDataSource;
+import org.baeldung.persistence.dao.IFooDao;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.PropertySource;
+import org.springframework.core.env.Environment;
+import org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor;
+import org.springframework.data.jpa.repository.config.EnableJpaAuditing;
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
+import org.springframework.orm.hibernate5.HibernateTransactionManager;
+import org.springframework.orm.hibernate5.LocalSessionFactoryBean;
+import org.springframework.orm.jpa.JpaTransactionManager;
+import org.springframework.orm.jpa.JpaVendorAdapter;
+import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
+import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
+import org.springframework.transaction.PlatformTransactionManager;
+import org.springframework.transaction.annotation.EnableTransactionManagement;
+
+import com.baeldung.persistence.dao.impl.FooDao;
+import com.google.common.base.Preconditions;
+
+@Configuration
+@EnableTransactionManagement
+@EnableJpaRepositories(basePackages = { "com.baeldung.persistence" }, transactionManagerRef = "jpaTransactionManager")
+@EnableJpaAuditing
+@PropertySource({ "classpath:persistence-mysql.properties" })
+@ComponentScan({ "com.baeldung.persistence" })
+public class PersistenceConfig {
+
+    @Autowired
+    private Environment env;
+
+    public PersistenceConfig() {
+        super();
+    }
+
+    @Bean
+    public LocalSessionFactoryBean sessionFactory() {
+        final LocalSessionFactoryBean sessionFactory = new LocalSessionFactoryBean();
+        sessionFactory.setDataSource(restDataSource());
+        sessionFactory.setPackagesToScan(new String[] { "com.baeldung.persistence.model" });
+        sessionFactory.setHibernateProperties(hibernateProperties());
+
+        return sessionFactory;
+    }
+
+    @Bean
+    public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
+        final LocalContainerEntityManagerFactoryBean emf = new LocalContainerEntityManagerFactoryBean();
+        emf.setDataSource(restDataSource());
+        emf.setPackagesToScan(new String[] { "com.baeldung.persistence.model" });
+
+        final JpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
+        emf.setJpaVendorAdapter(vendorAdapter);
+        emf.setJpaProperties(hibernateProperties());
+
+        return emf;
+    }
+
+    @Bean
+    public DataSource restDataSource() {
+        final BasicDataSource dataSource = new BasicDataSource();
+        dataSource.setDriverClassName(Preconditions.checkNotNull(env.getProperty("jdbc.driverClassName")));
+        dataSource.setUrl(Preconditions.checkNotNull(env.getProperty("jdbc.url")));
+        dataSource.setUsername(Preconditions.checkNotNull(env.getProperty("jdbc.user")));
+        dataSource.setPassword(Preconditions.checkNotNull(env.getProperty("jdbc.pass")));
+
+        return dataSource;
+    }
+
+    @Bean
+    public PlatformTransactionManager hibernateTransactionManager() {
+        final HibernateTransactionManager transactionManager = new HibernateTransactionManager();
+        transactionManager.setSessionFactory(sessionFactory().getObject());
+        return transactionManager;
+    }
+
+    @Bean
+    public PlatformTransactionManager jpaTransactionManager() {
+        final JpaTransactionManager transactionManager = new JpaTransactionManager();
+        transactionManager.setEntityManagerFactory(entityManagerFactory().getObject());
+        return transactionManager;
+    }
+
+    @Bean
+    public PersistenceExceptionTranslationPostProcessor exceptionTranslation() {
+        return new PersistenceExceptionTranslationPostProcessor();
+    }
+
+    @Bean
+    public IFooDao fooHibernateDao() {
+        return new FooDao();
+    }
+
+    private final Properties hibernateProperties() {
+        final Properties hibernateProperties = new Properties();
+        hibernateProperties.setProperty("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto"));
+        hibernateProperties.setProperty("hibernate.dialect", env.getProperty("hibernate.dialect"));
+
+        hibernateProperties.setProperty("hibernate.show_sql", "true");
+        // hibernateProperties.setProperty("hibernate.format_sql", "true");
+        // hibernateProperties.setProperty("hibernate.globally_quoted_identifiers", "true");
+
+        // Envers properties
+        hibernateProperties.setProperty("org.hibernate.envers.audit_table_suffix", env.getProperty("envers.audit_table_suffix"));
+
+        return hibernateProperties;
+    }
+
+}

persistence-modules/spring-persistence-simple/src/main/java/org/baeldung/config/PersistenceJPAConfig.java

@@ -0,0 +1,87 @@
+package org.baeldung.config;
+
+import java.util.Properties;
+
+import javax.persistence.EntityManagerFactory;
+import javax.sql.DataSource;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.PropertySource;
+import org.springframework.core.env.Environment;
+import org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor;
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
+import org.springframework.jdbc.datasource.DriverManagerDataSource;
+import org.springframework.orm.jpa.JpaTransactionManager;
+import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
+import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
+import org.springframework.transaction.PlatformTransactionManager;
+import org.springframework.transaction.annotation.EnableTransactionManagement;
+
+import com.google.common.base.Preconditions;
+
+@Configuration
+@EnableTransactionManagement
+@PropertySource({ "classpath:persistence-h2.properties" })
+@ComponentScan({ "org.baeldung.persistence" })
+@EnableJpaRepositories(basePackages = "org.baeldung.persistence.dao")
+public class PersistenceJPAConfig {
+
+    @Autowired
+    private Environment env;
+
+    public PersistenceJPAConfig() {
+        super();
+    }
+
+    // beans
+
+    @Bean
+    public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
+        final LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
+        em.setDataSource(dataSource());
+        em.setPackagesToScan(new String[] { "org.baeldung.persistence.model" });
+
+        final HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
+        em.setJpaVendorAdapter(vendorAdapter);
+        em.setJpaProperties(additionalProperties());
+
+        return em;
+    }
+
+    @Bean
+    public DataSource dataSource() {
+        final DriverManagerDataSource dataSource = new DriverManagerDataSource();
+        dataSource.setDriverClassName(Preconditions.checkNotNull(env.getProperty("jdbc.driverClassName")));
+        dataSource.setUrl(Preconditions.checkNotNull(env.getProperty("jdbc.url")));
+        dataSource.setUsername(Preconditions.checkNotNull(env.getProperty("jdbc.user")));
+        dataSource.setPassword(Preconditions.checkNotNull(env.getProperty("jdbc.pass")));
+
+        return dataSource;
+    }
+
+    @Bean
+    public PlatformTransactionManager transactionManager(final EntityManagerFactory emf) {
+        final JpaTransactionManager transactionManager = new JpaTransactionManager();
+        transactionManager.setEntityManagerFactory(emf);
+        return transactionManager;
+    }
+
+    @Bean
+    public PersistenceExceptionTranslationPostProcessor exceptionTranslation() {
+        return new PersistenceExceptionTranslationPostProcessor();
+    }
+
+    final Properties additionalProperties() {
+        final Properties hibernateProperties = new Properties();
+        hibernateProperties.setProperty("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto"));
+        hibernateProperties.setProperty("hibernate.dialect", env.getProperty("hibernate.dialect"));
+        hibernateProperties.setProperty("hibernate.cache.use_second_level_cache", "false");
+        
+    
+        return hibernateProperties;
+    }
+
+}

persistence-modules/spring-persistence-simple/src/main/java/org/baeldung/persistence/dao/AbstractJpaDAO.java

@@ -0,0 +1,47 @@
+package org.baeldung.persistence.dao;
+
+import java.io.Serializable;
+import java.util.List;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+
+public abstract class AbstractJpaDAO<T extends Serializable> {
+
+    private Class<T> clazz;
+
+    @PersistenceContext
+    private EntityManager entityManager;
+
+    public final void setClazz(final Class<T> clazzToSet) {
+        this.clazz = clazzToSet;
+    }
+
+    public T findOne(final long id) {
+        return entityManager.find(clazz, id);
+    }
+
+    @SuppressWarnings("unchecked")
+    public List<T> findAll() {
+        return entityManager.createQuery("from " + clazz.getName()).getResultList();
+    }
+
+    public T create(final T entity) {
+        entityManager.persist(entity);
+        return entity;
+    }
+
+    public T update(final T entity) {
+        return entityManager.merge(entity);
+    }
+
+    public void delete(final T entity) {
+        entityManager.remove(entity);
+    }
+
+    public void deleteById(final long entityId) {
+        final T entity = findOne(entityId);
+        delete(entity);
+    }
+
+}

persistence-modules/spring-persistence-simple/src/main/java/org/baeldung/persistence/dao/FooDao.java

@@ -0,0 +1,17 @@
+package org.baeldung.persistence.dao;
+
+import org.baeldung.persistence.model.Foo;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public class FooDao extends AbstractJpaDAO<Foo> implements IFooDao {
+
+    public FooDao() {
+        super();
+
+        setClazz(Foo.class);
+    }
+
+    // API
+
+}

persistence-modules/spring-persistence-simple/src/main/java/org/baeldung/persistence/dao/IFooDao.java

@@ -0,0 +1,21 @@
+package org.baeldung.persistence.dao;
+
+import java.util.List;
+
+import org.baeldung.persistence.model.Foo;
+
+public interface IFooDao {
+
+    Foo findOne(long id);
+
+    List<Foo> findAll();
+
+    Foo create(Foo entity);
+
+    Foo update(Foo entity);
+
+    void delete(Foo entity);
+
+    void deleteById(long entityId);
+
+}

persistence-modules/spring-persistence-simple/src/main/java/org/baeldung/persistence/model/Bar.java

@@ -0,0 +1,102 @@
+package org.baeldung.persistence.model;
+
+import java.io.Serializable;
+import java.util.List;
+
+import javax.persistence.CascadeType;
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.FetchType;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.OneToMany;
+import javax.persistence.OrderBy;
+
+@Entity
+public class Bar implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    private long id;
+
+    @Column(nullable = false)
+    private String name;
+
+    @OneToMany(mappedBy = "bar", fetch = FetchType.EAGER, cascade = CascadeType.ALL)
+    @OrderBy("name ASC")
+    List<Foo> fooList;
+
+    public Bar() {
+        super();
+    }
+
+    public Bar(final String name) {
+        super();
+
+        this.name = name;
+    }
+
+    // API
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(final long id) {
+
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(final String name) {
+        this.name = name;
+    }
+
+    public List<Foo> getFooList() {
+        return fooList;
+    }
+
+    public void setFooList(final List<Foo> fooList) {
+        this.fooList = fooList;
+    }
+
+    //
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + ((name == null) ? 0 : name.hashCode());
+        return result;
+    }
+
+    @Override
+    public boolean equals(final Object obj) {
+        if (this == obj)
+            return true;
+        if (obj == null)
+            return false;
+        if (getClass() != obj.getClass())
+            return false;
+        final Bar other = (Bar) obj;
+        if (name == null) {
+            if (other.name != null)
+                return false;
+        } else if (!name.equals(other.name))
+            return false;
+        return true;
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder builder = new StringBuilder();
+        builder.append("Bar [name=").append(name).append("]");
+        return builder.toString();
+    }
+
+}

persistence-modules/spring-persistence-simple/src/main/java/org/baeldung/persistence/model/Foo.java

@@ -0,0 +1,104 @@
+package org.baeldung.persistence.model;
+
+import java.io.Serializable;
+
+import javax.persistence.Cacheable;
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.FetchType;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.ManyToOne;
+import javax.persistence.NamedNativeQueries;
+import javax.persistence.NamedNativeQuery;
+
+import org.hibernate.annotations.CacheConcurrencyStrategy;
+
+@Entity
+@Cacheable
+@org.hibernate.annotations.Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
+@NamedNativeQueries({ @NamedNativeQuery(name = "callGetAllFoos", query = "CALL GetAllFoos()", resultClass = Foo.class), @NamedNativeQuery(name = "callGetFoosByName", query = "CALL GetFoosByName(:fooName)", resultClass = Foo.class) })
+public class Foo implements Serializable {
+
+    private static final long serialVersionUID = 1L;
+
+    public Foo() {
+        super();
+    }
+
+    public Foo(final String name) {
+        super();
+
+        this.name = name;
+    }
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    @Column(name = "ID")
+    private Long id;
+    @Column(name = "NAME")
+    private String name;
+
+    @ManyToOne(targetEntity = Bar.class, fetch = FetchType.EAGER)
+    @JoinColumn(name = "BAR_ID")
+    private Bar bar;
+
+    public Bar getBar() {
+        return bar;
+    }
+
+    public void setBar(final Bar bar) {
+        this.bar = bar;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(final Long id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(final String name) {
+        this.name = name;
+    }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + ((name == null) ? 0 : name.hashCode());
+        return result;
+    }
+
+    @Override
+    public boolean equals(final Object obj) {
+        if (this == obj)
+            return true;
+        if (obj == null)
+            return false;
+        if (getClass() != obj.getClass())
+            return false;
+        final Foo other = (Foo) obj;
+        if (name == null) {
+            if (other.name != null)
+                return false;
+        } else if (!name.equals(other.name))
+            return false;
+        return true;
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder builder = new StringBuilder();
+        builder.append("Foo [name=").append(name).append("]");
+        return builder.toString();
+    }
+
+}

persistence-modules/spring-persistence-simple/src/main/java/org/baeldung/persistence/service/FooService.java

@@ -0,0 +1,36 @@
+package org.baeldung.persistence.service;
+
+import java.util.List;
+
+import org.baeldung.persistence.dao.IFooDao;
+import org.baeldung.persistence.model.Foo;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Service
+@Transactional
+public class FooService {
+
+    @Autowired
+    private IFooDao dao;
+
+    public FooService() {
+        super();
+    }
+
+    // API
+
+    public void create(final Foo entity) {
+        dao.create(entity);
+    }
+
+    public Foo findOne(final long id) {
+        return dao.findOne(id);
+    }
+
+    public List<Foo> findAll() {
+        return dao.findAll();
+    }
+
+}

persistence-modules/spring-persistence-simple/src/main/java/org/baeldung/spring/data/persistence/config/PersistenceConfig.java

@@ -0,0 +1,85 @@
+package org.baeldung.spring.data.persistence.config;
+
+import java.util.Properties;
+
+import javax.sql.DataSource;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.PropertySource;
+import org.springframework.core.env.Environment;
+import org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor;
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
+import org.springframework.jdbc.datasource.DriverManagerDataSource;
+import org.springframework.orm.jpa.JpaTransactionManager;
+import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
+import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
+import org.springframework.transaction.PlatformTransactionManager;
+import org.springframework.transaction.annotation.EnableTransactionManagement;
+
+import com.google.common.base.Preconditions;
+
+@Configuration
+@EnableTransactionManagement
+@PropertySource({ "classpath:persistence-${envTarget:h2}.properties" })
+@ComponentScan({ "org.baeldung.spring.data.persistence" })
+// @ImportResource("classpath*:springDataPersistenceConfig.xml")
+@EnableJpaRepositories(basePackages = "org.baeldung.spring.data.persistence.dao")
+public class PersistenceConfig {
+
+    @Autowired
+    private Environment env;
+
+    public PersistenceConfig() {
+        super();
+    }
+
+    @Bean
+    public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
+        final LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
+        em.setDataSource(dataSource());
+        em.setPackagesToScan(new String[] { "org.baeldung.spring.data.persistence.model" });
+
+        final HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
+        // vendorAdapter.set
+        em.setJpaVendorAdapter(vendorAdapter);
+        em.setJpaProperties(additionalProperties());
+
+        return em;
+    }
+
+    @Bean
+    public DataSource dataSource() {
+        final DriverManagerDataSource dataSource = new DriverManagerDataSource();
+        dataSource.setDriverClassName(Preconditions.checkNotNull(env.getProperty("jdbc.driverClassName")));
+        dataSource.setUrl(Preconditions.checkNotNull(env.getProperty("jdbc.url")));
+        dataSource.setUsername(Preconditions.checkNotNull(env.getProperty("jdbc.user")));
+        dataSource.setPassword(Preconditions.checkNotNull(env.getProperty("jdbc.pass")));
+
+        return dataSource;
+    }
+
+    @Bean
+    public PlatformTransactionManager transactionManager() {
+        final JpaTransactionManager transactionManager = new JpaTransactionManager();
+        transactionManager.setEntityManagerFactory(entityManagerFactory().getObject());
+
+        return transactionManager;
+    }
+
+    @Bean
+    public PersistenceExceptionTranslationPostProcessor exceptionTranslation() {
+        return new PersistenceExceptionTranslationPostProcessor();
+    }
+
+    final Properties additionalProperties() {
+        final Properties hibernateProperties = new Properties();
+        hibernateProperties.setProperty("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto"));
+        hibernateProperties.setProperty("hibernate.dialect", env.getProperty("hibernate.dialect"));
+        // hibernateProperties.setProperty("hibernate.globally_quoted_identifiers", "true");
+        return hibernateProperties;
+    }
+
+}

persistence-modules/spring-persistence-simple/src/main/java/org/baeldung/spring/data/persistence/dao/IFooDao.java

@@ -0,0 +1,11 @@
+package org.baeldung.spring.data.persistence.dao;
+
+import org.baeldung.spring.data.persistence.model.Foo;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+public interface IFooDao extends JpaRepository<Foo, Long> {
+
+    @Query("SELECT f FROM Foo f WHERE LOWER(f.name) = LOWER(:name)")
+    Foo retrieveByName(@Param("name") String name);
+}

persistence-modules/spring-persistence-simple/src/main/java/org/baeldung/spring/data/persistence/dao/user/UserRepository.java

@@ -0,0 +1,98 @@
+package org.baeldung.spring.data.persistence.dao.user;
+
+import java.time.LocalDate;
+import java.util.Collection;
+import java.util.List;
+import java.util.stream.Stream;
+
+import org.baeldung.spring.data.persistence.model.User;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Sort;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+
+public interface UserRepository extends JpaRepository<User, Integer>, UserRepositoryCustom {
+
+    Stream<User> findAllByName(String name);
+
+    @Query("SELECT u FROM User u WHERE u.status = 1")
+    Collection<User> findAllActiveUsers();
+    
+    @Query("select u from User u where u.email like '%@gmail.com'")
+    List<User> findUsersWithGmailAddress();
+
+    @Query(value = "SELECT * FROM Users u WHERE u.status = 1", nativeQuery = true)
+    Collection<User> findAllActiveUsersNative();
+
+    @Query("SELECT u FROM User u WHERE u.status = ?1")
+    User findUserByStatus(Integer status);
+
+    @Query(value = "SELECT * FROM Users u WHERE u.status = ?1", nativeQuery = true)
+    User findUserByStatusNative(Integer status);
+
+    @Query("SELECT u FROM User u WHERE u.status = ?1 and u.name = ?2")
+    User findUserByStatusAndName(Integer status, String name);
+
+    @Query("SELECT u FROM User u WHERE u.status = :status and u.name = :name")
+    User findUserByStatusAndNameNamedParams(@Param("status") Integer status, @Param("name") String name);
+
+    @Query(value = "SELECT * FROM Users u WHERE u.status = :status AND u.name = :name", nativeQuery = true)
+    User findUserByStatusAndNameNamedParamsNative(@Param("status") Integer status, @Param("name") String name);
+
+    @Query("SELECT u FROM User u WHERE u.status = :status and u.name = :name")
+    User findUserByUserStatusAndUserName(@Param("status") Integer userStatus, @Param("name") String userName);
+
+    @Query("SELECT u FROM User u WHERE u.name like ?1%")
+    User findUserByNameLike(String name);
+
+    @Query("SELECT u FROM User u WHERE u.name like :name%")
+    User findUserByNameLikeNamedParam(@Param("name") String name);
+
+    @Query(value = "SELECT * FROM users u WHERE u.name LIKE ?1%", nativeQuery = true)
+    User findUserByNameLikeNative(String name);
+
+    @Query(value = "SELECT u FROM User u")
+    List<User> findAllUsers(Sort sort);
+
+    @Query(value = "SELECT u FROM User u ORDER BY id")
+    Page<User> findAllUsersWithPagination(Pageable pageable);
+
+    @Query(value = "SELECT * FROM Users ORDER BY id", countQuery = "SELECT count(*) FROM Users", nativeQuery = true)
+    Page<User> findAllUsersWithPaginationNative(Pageable pageable);
+
+    @Modifying
+    @Query("update User u set u.status = :status where u.name = :name")
+    int updateUserSetStatusForName(@Param("status") Integer status, @Param("name") String name);
+
+    @Modifying
+    @Query(value = "UPDATE Users u SET u.status = ? WHERE u.name = ?", nativeQuery = true)
+    int updateUserSetStatusForNameNative(Integer status, String name);
+
+    @Query(value = "INSERT INTO Users (name, age, email, status, active) VALUES (:name, :age, :email, :status, :active)", nativeQuery = true)
+    @Modifying
+    void insertUser(@Param("name") String name, @Param("age") Integer age, @Param("email") String email, @Param("status") Integer status, @Param("active") boolean active);
+    
+    @Modifying
+    @Query(value = "UPDATE Users u SET status = ? WHERE u.name = ?", nativeQuery = true)
+    int updateUserSetStatusForNameNativePostgres(Integer status, String name);
+    
+    @Query(value = "SELECT u FROM User u WHERE u.name IN :names")
+	  List<User> findUserByNameList(@Param("names") Collection<String> names);
+    
+    void deleteAllByCreationDateAfter(LocalDate date);
+
+    @Modifying(clearAutomatically = true, flushAutomatically = true)
+    @Query("update User u set u.active = false where u.lastLoginDate < :date")
+    void deactivateUsersNotLoggedInSince(@Param("date") LocalDate date);
+
+    @Modifying(clearAutomatically = true, flushAutomatically = true)
+    @Query("delete User u where u.active = false")
+    int deleteDeactivatedUsers();
+
+    @Modifying(clearAutomatically = true, flushAutomatically = true)
+    @Query(value = "alter table USERS add column deleted int(1) not null default 0", nativeQuery = true)
+    void addDeletedColumn();
+}

persistence-modules/spring-persistence-simple/src/main/java/org/baeldung/spring/data/persistence/dao/user/UserRepositoryCustom.java

@@ -0,0 +1,14 @@
+package org.baeldung.spring.data.persistence.dao.user;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Set;
+import java.util.function.Predicate;
+
+import org.baeldung.spring.data.persistence.model.User;
+
+public interface UserRepositoryCustom {
+    List<User> findUserByEmails(Set<String> emails);
+    
+    List<User> findAllUsersByPredicates(Collection<Predicate<User>> predicates);
+}

persistence-modules/spring-persistence-simple/src/main/java/org/baeldung/spring/data/persistence/dao/user/UserRepositoryCustomImpl.java

@@ -0,0 +1,57 @@
+package org.baeldung.spring.data.persistence.dao.user;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import javax.persistence.criteria.CriteriaBuilder;
+import javax.persistence.criteria.CriteriaQuery;
+import javax.persistence.criteria.Path;
+import javax.persistence.criteria.Predicate;
+import javax.persistence.criteria.Root;
+
+import org.baeldung.spring.data.persistence.model.User;
+
+public class UserRepositoryCustomImpl implements UserRepositoryCustom {
+
+    @PersistenceContext
+    private EntityManager entityManager;
+
+    @Override
+    public List<User> findUserByEmails(Set<String> emails) {
+        CriteriaBuilder cb = entityManager.getCriteriaBuilder();
+        CriteriaQuery<User> query = cb.createQuery(User.class);
+        Root<User> user = query.from(User.class);
+
+        Path<String> emailPath = user.get("email");
+
+        List<Predicate> predicates = new ArrayList<>();
+        for (String email : emails) {
+
+            predicates.add(cb.like(emailPath, email));
+
+        }
+        query.select(user)
+            .where(cb.or(predicates.toArray(new Predicate[predicates.size()])));
+
+        return entityManager.createQuery(query)
+            .getResultList();
+    }
+    
+    @Override
+    public List<User> findAllUsersByPredicates(Collection<java.util.function.Predicate<User>> predicates) {
+        List<User> allUsers = entityManager.createQuery("select u from User u", User.class).getResultList();
+        Stream<User> allUsersStream = allUsers.stream();
+        for (java.util.function.Predicate<User> predicate : predicates) {
+            allUsersStream = allUsersStream.filter(predicate);
+        }
+
+        return allUsersStream.collect(Collectors.toList());
+    }
+
+}

persistence-modules/spring-persistence-simple/src/main/java/org/baeldung/spring/data/persistence/model/Foo.java

@@ -0,0 +1,83 @@
+package org.baeldung.spring.data.persistence.model;
+
+import java.io.Serializable;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+
+@Entity
+public class Foo implements Serializable {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    private long id;
+
+    @Column(nullable = false)
+    private String name;
+
+    public Foo() {
+        super();
+    }
+
+    public Foo(final String name) {
+        super();
+
+        this.name = name;
+    }
+
+    // API
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(final long id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(final String name) {
+        this.name = name;
+    }
+
+    //
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + ((name == null) ? 0 : name.hashCode());
+        return result;
+    }
+
+    @Override
+    public boolean equals(final Object obj) {
+        if (this == obj)
+            return true;
+        if (obj == null)
+            return false;
+        if (getClass() != obj.getClass())
+            return false;
+        final Foo other = (Foo) obj;
+        if (name == null) {
+            if (other.name != null)
+                return false;
+        } else if (!name.equals(other.name))
+            return false;
+        return true;
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder builder = new StringBuilder();
+        builder.append("Foo [name=").append(name).append("]");
+        return builder.toString();
+    }
+
+}

persistence-modules/spring-persistence-simple/src/main/java/org/baeldung/spring/data/persistence/model/Possession.java

@@ -0,0 +1,86 @@
+package org.baeldung.spring.data.persistence.model;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.Table;
+
+@Entity
+@Table
+public class Possession {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private long id;
+
+    private String name;
+
+    public Possession() {
+        super();
+    }
+
+    public Possession(final String name) {
+        super();
+
+        this.name = name;
+    }
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(final int id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(final String name) {
+        this.name = name;
+    }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = (prime * result) + (int) (id ^ (id >>> 32));
+        result = (prime * result) + ((name == null) ? 0 : name.hashCode());
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj == null) {
+            return false;
+        }
+        if (getClass() != obj.getClass()) {
+            return false;
+        }
+        final Possession other = (Possession) obj;
+        if (id != other.id) {
+            return false;
+        }
+        if (name == null) {
+            if (other.name != null) {
+                return false;
+            }
+        } else if (!name.equals(other.name)) {
+            return false;
+        }
+        return true;
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder builder = new StringBuilder();
+        builder.append("Possesion [id=").append(id).append(", name=").append(name).append("]");
+        return builder.toString();
+    }
+
+}

persistence-modules/spring-persistence-simple/src/main/java/org/baeldung/spring/data/persistence/model/User.java

@@ -0,0 +1,132 @@
+package org.baeldung.spring.data.persistence.model;
+
+import javax.persistence.*;
+
+import java.time.LocalDate;
+import java.util.List;
+import java.util.Objects;
+
+@Entity
+@Table(name = "users")
+public class User {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private int id;
+    private String name;
+    private LocalDate creationDate;
+    private LocalDate lastLoginDate;
+    private boolean active;
+    private int age;
+    @Column(unique = true, nullable = false)
+    private String email;
+    private Integer status;
+    @OneToMany
+    List<Possession> possessionList;
+
+    public User() {
+        super();
+    }
+
+    public User(String name,  LocalDate creationDate,String email, Integer status) {
+        this.name = name;
+        this.creationDate = creationDate;
+        this.email = email;
+        this.status = status;
+        this.active = true;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(final int id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(final String name) {
+        this.name = name;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+
+    public void setEmail(final String email) {
+        this.email = email;
+    }
+
+    public Integer getStatus() {
+        return status;
+    }
+
+    public void setStatus(Integer status) {
+        this.status = status;
+    }
+
+    public int getAge() {
+        return age;
+    }
+
+    public void setAge(final int age) {
+        this.age = age;
+    }
+    
+    public LocalDate getCreationDate() {
+        return creationDate;
+    }
+
+    public List<Possession> getPossessionList() {
+        return possessionList;
+    }
+
+    public void setPossessionList(List<Possession> possessionList) {
+        this.possessionList = possessionList;
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder builder = new StringBuilder();
+        builder.append("User [name=").append(name).append(", id=").append(id).append("]");
+        return builder.toString();
+    }
+    
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        User user = (User) o;
+        return id == user.id &&
+          age == user.age &&
+          Objects.equals(name, user.name) &&
+          Objects.equals(creationDate, user.creationDate) &&
+          Objects.equals(email, user.email) &&
+          Objects.equals(status, user.status);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id, name, creationDate, age, email, status);
+    }
+
+    public LocalDate getLastLoginDate() {
+        return lastLoginDate;
+    }
+
+    public void setLastLoginDate(LocalDate lastLoginDate) {
+        this.lastLoginDate = lastLoginDate;
+    }
+
+    public boolean isActive() {
+        return active;
+    }
+
+    public void setActive(boolean active) {
+        this.active = active;
+    }
+
+}

persistence-modules/spring-persistence-simple/src/main/java/org/baeldung/spring/data/persistence/service/IFooService.java

@@ -0,0 +1,11 @@
+package org.baeldung.spring.data.persistence.service;
+
+import org.baeldung.spring.data.persistence.model.Foo;
+
+import com.baeldung.persistence.dao.common.IOperations;
+
+public interface IFooService extends IOperations<Foo> {
+
+    Foo retrieveByName(String name);
+
+}

persistence-modules/spring-persistence-simple/src/main/java/org/baeldung/spring/data/persistence/service/common/AbstractService.java

@@ -0,0 +1,56 @@
+package org.baeldung.spring.data.persistence.service.common;
+
+import java.io.Serializable;
+import java.util.List;
+
+import org.springframework.data.repository.PagingAndSortingRepository;
+import org.springframework.transaction.annotation.Transactional;
+
+import com.baeldung.persistence.dao.common.IOperations;
+import com.google.common.collect.Lists;
+
+@Transactional
+public abstract class AbstractService<T extends Serializable> implements IOperations<T> {
+
+    // read - one
+
+    @Override
+    @Transactional(readOnly = true)
+    public T findOne(final long id) {
+        return getDao().findById(id).orElse(null);
+    }
+
+    // read - all
+
+    @Override
+    @Transactional(readOnly = true)
+    public List<T> findAll() {
+        return Lists.newArrayList(getDao().findAll());
+    }
+
+    // write
+
+    @Override
+    public T create(final T entity) {
+        return getDao().save(entity);
+    }
+
+    @Override
+    public T update(final T entity) {
+        return getDao().save(entity);
+    }
+    
+    @Override
+    public void delete(T entity) {
+        getDao().delete(entity);
+    }
+    
+    @Override
+    public void deleteById(long entityId) {
+        T entity = findOne(entityId);
+        delete(entity);
+    }
+
+    protected abstract PagingAndSortingRepository<T, Long> getDao();
+
+}