Merge branch 'eugenp:master' into master

apache-poi-2/pom.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <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">
+    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>apache-poi-2</artifactId>
     <version>0.0.1-SNAPSHOT</version>
@@ -26,4 +26,3 @@
     </properties>
 
 </project>
-

apache-spark/README.md

@@ -9,3 +9,4 @@ This module contains articles about Apache Spark
 - [Machine Learning with Spark MLlib](https://www.baeldung.com/spark-mlib-machine-learning)
 - [Introduction to Spark Graph Processing with GraphFrames](https://www.baeldung.com/spark-graph-graphframes)
 - [Apache Spark: Differences between Dataframes, Datasets and RDDs](https://www.baeldung.com/java-spark-dataframe-dataset-rdd)
+- [Spark DataFrame](https://www.baeldung.com/spark-dataframes)

apache-spark/src/test/java/com/baeldung/differences/rdd/ActionsUnitTest.java

@@ -12,17 +12,25 @@ import org.junit.AfterClass;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import scala.Tuple2;
 
 public class ActionsUnitTest {
+
+    public static final Logger LOG = LoggerFactory.getLogger(ActionsUnitTest.class);
+
     private static JavaRDD<String> tourists;
     private static JavaSparkContext sc;
     public static final String COMMA_DELIMITER = ",(?=([^\"]*\"[^\"]*\")*[^\"]*$)";
 
     @BeforeClass
     public static void init() {
-        SparkConf conf = new SparkConf().setAppName("reduce")
-            .setMaster("local[*]");
+        SparkConf conf = new SparkConf()
+          .setAppName("reduce")
+          .setMaster("local[*]")
+          .set("spark.driver.allowMultipleContexts", "true");
+
         sc = new JavaSparkContext(conf);
         tourists = sc.textFile("data/Tourist.csv").filter(line -> !line.startsWith("Region"));
     }
@@ -40,7 +48,7 @@ public class ActionsUnitTest {
         })
             .distinct();
         Long numberOfCountries = countries.count();
-        System.out.println("Count: " + numberOfCountries);
+        LOG.debug("Count: {}", numberOfCountries);
 
         assertEquals(Long.valueOf(220), numberOfCountries);
     }
@@ -53,9 +61,11 @@ public class ActionsUnitTest {
             String[] columns = line.split(COMMA_DELIMITER);
             return new Tuple2<>(columns[1], Double.valueOf(columns[6]));
         });
-        List<Tuple2<String, Double>> totalByCountry = expenditurePairRdd.reduceByKey((x, y) -> x + y)
-            .collect();
-        System.out.println("Total per Country: " + totalByCountry);
+        List<Tuple2<String, Double>> totalByCountry = expenditurePairRdd
+          .reduceByKey(Double::sum)
+          .collect();
+
+        LOG.debug("Total per Country: {}", totalByCountry);
 
         for(Tuple2<String, Double> tuple : totalByCountry) {
             if (tuple._1.equals("Mexico")) {

apache-spark/src/test/java/com/baeldung/differences/rdd/DataFrameUnitTest.java

@@ -39,7 +39,9 @@ public class DataFrameUnitTest {
     @Test
     public void whenSelectSpecificColumns_thenColumnsFiltered() {
         Dataset<Row> selectedData = data.select(col("country"), col("year"), col("value"));
-        selectedData.show();
+
+        // uncomment to see table
+        // selectedData.show();
 
         List<String> resultList = Arrays.asList(selectedData.columns());
         assertTrue(resultList.contains("country"));
@@ -52,7 +54,9 @@ public class DataFrameUnitTest {
     @Test
     public void whenFilteringByCountry_thenCountryRecordsSelected() {
         Dataset<Row> filteredData = data.filter(col("country").equalTo("Mexico"));
-        filteredData.show();
+
+        // uncomment to see table
+        // filteredData.show();
 
         filteredData.foreach(record -> {
             assertEquals("Mexico", record.get(1));
@@ -64,10 +68,12 @@ public class DataFrameUnitTest {
     public void whenGroupCountByCountry_thenContryTotalRecords() {
         Dataset<Row> recordsPerCountry = data.groupBy(col("country"))
             .count();
-        recordsPerCountry.show();
+
+        // uncomment to see table
+        // recordsPerCountry.show();
 
         Dataset<Row> filteredData = recordsPerCountry.filter(col("country").equalTo("Sweden"));
-        assertEquals(new Long(12), filteredData.first()
+        assertEquals(12L, filteredData.first()
             .get(1));
     }
 

apache-spark/src/test/java/com/baeldung/differences/rdd/DatasetUnitTest.java

@@ -3,6 +3,7 @@ package com.baeldung.differences.rdd;
 import static org.apache.spark.sql.functions.col;
 import static org.apache.spark.sql.functions.sum;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
 import org.apache.spark.api.java.function.FilterFunction;
 import org.apache.spark.sql.DataFrameReader;
@@ -45,7 +46,9 @@ public class DatasetUnitTest {
         Dataset<TouristData> selectedData = typedDataset
             .filter((FilterFunction<TouristData>) record -> record.getCountry()
             .equals("Norway"));
-        selectedData.show();
+
+        // uncomment to see output
+        // selectedData.show();
 
         selectedData.foreach(record -> {
             assertEquals("Norway", record.getCountry());
@@ -56,28 +59,41 @@ public class DatasetUnitTest {
     public void whenGroupCountByCountry_thenContryTotalRecords() {
         Dataset<Row> countriesCount = typedDataset.groupBy(typedDataset.col("country"))
             .count();
-        countriesCount.show();
 
-        assertEquals(Long.valueOf(220), Long.valueOf(countriesCount.count()));
+        // uncomment to see output
+        // countriesCount.show();
+
+        assertEquals(220, countriesCount.count());
     }
 
     @Test
     public void whenFilteredByPropertyRange_thenRetreiveValidRecords() {
         // Filter records with existing data for years between 2010 and 2017
-        typedDataset.filter((FilterFunction<TouristData>) record -> record.getYear() != null 
-            && (Long.valueOf(record.getYear()) > 2010 && Long.valueOf(record.getYear()) < 2017))
-            .show();
+        Dataset<TouristData> filteredData = typedDataset.filter(
+          (FilterFunction<TouristData>) record -> record.getYear() != null
+            && (Long.parseLong(record.getYear()) > 2010 && Long.parseLong(record.getYear()) < 2017));
+
+        // uncomment to see output
+        // filteredData.show();
+
+        assertEquals(394, filteredData.count());
+        filteredData.foreach(record -> {
+            assertTrue(Integer.parseInt(record.getYear()) > 2010 && Integer.parseInt(record.getYear()) < 2017);
+        });
     }
 
     @Test
     public void whenSumValue_thenRetreiveTotalValue() {
         // Total tourist expenditure by country
-        typedDataset.filter((FilterFunction<TouristData>) record -> record.getValue() != null 
-            && record.getSeries()
-            .contains("expenditure"))
-            .groupBy("country")
-            .agg(sum("value"))
-            .show();
+        Dataset<Row> filteredData = typedDataset.filter((FilterFunction<TouristData>) record -> record.getValue() != null
+            && record.getSeries().contains("expenditure"))
+          .groupBy("country")
+          .agg(sum("value"));
+
+        // uncomment to see output
+        // filteredData.show();
+
+        assertEquals(212, filteredData.count());
     }
 
 }

apache-spark/src/test/java/com/baeldung/differences/rdd/TransformationsUnitTest.java

@@ -23,8 +23,11 @@ public class TransformationsUnitTest {
 
     @BeforeClass
     public static void init() {
-        SparkConf conf = new SparkConf().setAppName("uppercaseCountries")
-            .setMaster("local[*]");
+        SparkConf conf = new SparkConf()
+          .setAppName("uppercaseCountries")
+          .setMaster("local[*]")
+          .set("spark.driver.allowMultipleContexts", "true");
+
         sc = new JavaSparkContext(conf);
         tourists = sc.textFile("data/Tourist.csv")
             .filter(line -> !line.startsWith("Region")); //filter header row

aws-modules/aws-miscellaneous/pom.xml

@@ -78,6 +78,25 @@
                     </execution>
                 </executions>
             </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-dependency-plugin</artifactId>
+                <version>${maven-plugins-version}</version>
+                <executions>
+                    <execution>
+                        <id>copy</id>
+                        <phase>compile</phase>
+                        <goals>
+                            <goal>copy-dependencies</goal>
+                        </goals>
+                        <configuration>
+                            <includeScope></includeScope>
+                            <includeTypes>so,dll,dylib</includeTypes>
+                            <outputDirectory>native-libs</outputDirectory>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
         </plugins>
     </build>
 
@@ -99,6 +118,7 @@
         <commons-codec-version>1.10.L001</commons-codec-version>
         <jets3t-version>0.9.4.0006L</jets3t-version>
         <maven-shade-plugin.version>3.0.0</maven-shade-plugin.version>
+        <maven-plugins-version>3.1.1</maven-plugins-version>
     </properties>
 
 </project>

aws-modules/aws-s3/pom.xml

@@ -20,7 +20,6 @@
             <artifactId>aws-java-sdk</artifactId>
             <version>${aws-java-sdk.version}</version>
         </dependency>
-        
         <dependency>
             <groupId>commons-io</groupId>
             <artifactId>commons-io</artifactId>

core-java-modules/core-java-11-2/README.md

@@ -12,3 +12,4 @@ This module contains articles about Java 11 core features
 - [Java HTTPS Client Certificate Authentication](https://www.baeldung.com/java-https-client-certificate-authentication)
 - [Call Methods at Runtime Using Java Reflection](https://www.baeldung.com/java-method-reflection)
 - [Java HttpClient Basic Authentication](https://www.baeldung.com/java-httpclient-basic-auth)
+- [Java HttpClient With SSL](https://www.baeldung.com/java-httpclient-ssl)

core-java-modules/core-java-11-2/src/test/java/com/baeldung/httpclient/ssl/HttpClientSSLBypassUnitTest.java

@@ -0,0 +1,32 @@
+package com.baeldung.httpclient.ssl;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.util.Properties;
+
+public class HttpClientSSLBypassUnitTest {
+
+    @Test
+    public void whenHttpsRequest_thenCorrect() throws IOException, InterruptedException {
+        final Properties props = System.getProperties();
+        props.setProperty("jdk.internal.httpclient.disableHostnameVerification", Boolean.TRUE.toString());
+
+        HttpClient httpClient = HttpClient.newBuilder()
+          .build();
+
+        HttpRequest request = HttpRequest.newBuilder()
+          .uri(URI.create("https://www.testingmcafeesites.com/"))
+          .build();
+
+        HttpResponse<String> response = httpClient.send(request, HttpResponse.BodyHandlers.ofString());
+        props.setProperty("jdk.internal.httpclient.disableHostnameVerification", Boolean.FALSE.toString());
+
+        Assertions.assertEquals(200, response.statusCode());
+    }
+}

core-java-modules/core-java-11-2/src/test/java/com/baeldung/httpclient/ssl/HttpClientSSLUnitTest.java

@@ -0,0 +1,41 @@
+package com.baeldung.httpclient.ssl;
+
+import org.junit.Test;
+
+import javax.net.ssl.SSLHandshakeException;
+import java.io.IOException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+
+import static org.junit.Assert.assertEquals;
+
+public class HttpClientSSLUnitTest {
+
+    @Test
+    public void whenValidHttpsRequest_thenCorrect() throws URISyntaxException, IOException, InterruptedException {
+        HttpClient httpClient = HttpClient.newHttpClient();
+        HttpRequest request = HttpRequest.newBuilder()
+          .uri(new URI("https://www.google.com/"))
+          .build();
+
+        HttpResponse<String> response = httpClient.send(request, HttpResponse.BodyHandlers.ofString());
+
+        assertEquals(200, response.statusCode());
+    }
+
+    @Test(expected = SSLHandshakeException.class)
+    public void whenInvalidHttpsRequest_thenInCorrect() throws IOException, InterruptedException {
+        HttpClient httpClient = HttpClient.newHttpClient();
+        HttpRequest request = HttpRequest.newBuilder()
+          .uri(URI.create("https://expired.badssl.com/"))
+          .build();
+
+        HttpResponse<String> response = httpClient.send(request, HttpResponse.BodyHandlers.ofString());
+
+        assertEquals(200, response.statusCode());
+    }
+
+}

core-java-modules/core-java-9/src/main/java/com/baeldung/java9/delimiters/DelimiterDemo.java

@@ -0,0 +1,36 @@
+package com.baeldung.java9.delimiters;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Scanner;
+import java.util.regex.Pattern;
+
+public class DelimiterDemo {
+
+    public static List<String> scannerWithDelimiter(String input, String delimiter) {
+        try (Scanner scan = new Scanner(input)) {
+            scan.useDelimiter(delimiter);
+            List<String> result = new ArrayList<String>();
+            scan.forEachRemaining(result::add);
+            return result;
+        }
+    }
+
+    public static List<String> scannerWithDelimiterUsingPattern(String input, Pattern delimiter) {
+        try (Scanner scan = new Scanner(input)) {
+            scan.useDelimiter(delimiter);
+            List<String> result = new ArrayList<String>();
+            scan.forEachRemaining(result::add);
+            return result;
+        }
+    }
+
+    public static List<String> baseScanner(String input) {
+        try (Scanner scan = new Scanner(input)) {
+            List<String> result = new ArrayList<String>();
+            scan.forEachRemaining(result::add);
+            return result;
+        }
+    }
+
+}

core-java-modules/core-java-9/src/test/java/com/baeldung/java9/delimiters/DelimiterDemoUnitTest.java

@@ -0,0 +1,67 @@
+package com.baeldung.java9.delimiters;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.function.BiFunction;
+import java.util.regex.Pattern;
+
+import org.junit.jupiter.api.Test;
+
+class DelimiterDemoUnitTest {
+
+    @Test
+    void givenSimpleCharacterDelimiter_whenScannerWithDelimiter_ThenInputIsCorrectlyParsed() {
+        checkOutput(DelimiterDemo::scannerWithDelimiter, "Welcome to Baeldung", "\\s", Arrays.asList("Welcome", "to", "Baeldung"));
+    }
+
+    @Test
+    void givenStringDelimiter_whenScannerWithDelimiter_ThenInputIsCorrectlyParsed() {
+        checkOutput(DelimiterDemo::scannerWithDelimiter, "HelloBaeldungHelloWorld", "Hello", Arrays.asList("Baeldung", "World"));
+    }
+
+    @Test
+    void givenVariousPossibleDelimiters_whenScannerWithDelimiter_ThenInputIsCorrectlyParsed() {
+        checkOutput(DelimiterDemo::scannerWithDelimiter, "Welcome to Baeldung.\nThank you for reading.\nThe team", "\n|\\s", Arrays.asList("Welcome", "to", "Baeldung.", "Thank", "you", "for", "reading.", "The", "team"));
+    }
+
+    @Test
+    void givenWildcardRegexDelimiter_whenScannerWithDelimiter_ThenInputIsCorrectlyParsed() {
+        checkOutput(DelimiterDemo::scannerWithDelimiter, "1aaaaaaa2aa3aaa4", "a+", Arrays.asList("1", "2", "3", "4"));
+    }
+
+    @Test
+    void givenSimpleCharacterDelimiter_whenScannerWithDelimiterUsingPattern_ThenInputIsCorrectlyParsed() {
+        checkOutput(DelimiterDemo::scannerWithDelimiterUsingPattern, "Welcome to Baeldung", Pattern.compile("\\s"), Arrays.asList("Welcome", "to", "Baeldung"));
+    }
+
+    @Test
+    void givenStringDelimiter_whenScannerWithDelimiterUsingPattern_ThenInputIsCorrectlyParsed() {
+        checkOutput(DelimiterDemo::scannerWithDelimiterUsingPattern, "HelloBaeldungHelloWorld", Pattern.compile("Hello"), Arrays.asList("Baeldung", "World"));
+    }
+
+    @Test
+    void givenVariousPossibleDelimiters_whenScannerWithDelimiterUsingPattern_ThenInputIsCorrectlyParsed() {
+        checkOutput(DelimiterDemo::scannerWithDelimiterUsingPattern, "Welcome to Baeldung.\nThank you for reading.\nThe team", Pattern.compile("\n|\\s"), Arrays.asList("Welcome", "to", "Baeldung.", "Thank", "you", "for", "reading.", "The", "team"));
+    }
+
+    @Test
+    void givenWildcardRegexDelimiters_whenScannerWithDelimiterUsingPattern_ThenInputIsCorrectlyParsed() {
+        checkOutput(DelimiterDemo::scannerWithDelimiterUsingPattern, "1aaaaaaa2aa3aaa4", Pattern.compile("a*"), Arrays.asList("1", "2", "3", "4"));
+    }
+
+    void checkOutput(BiFunction<String, String, List<String>> function, String input, String delimiter, List<String> expectedOutput) {
+        assertEquals(expectedOutput, function.apply(input, delimiter));
+    }
+
+    void checkOutput(BiFunction<String, Pattern, List<String>> function, String input, Pattern delimiter, List<String> expectedOutput) {
+        assertEquals(expectedOutput, function.apply(input, delimiter));
+    }
+
+    @Test
+    void whenBaseScanner_ThenWhitespacesAreUsedAsDelimiters() {
+        assertEquals(List.of("Welcome", "at", "Baeldung"), DelimiterDemo.baseScanner("Welcome at Baeldung"));
+    }
+
+}

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

@@ -12,3 +12,4 @@
 - [Sorting in Java](https://www.baeldung.com/java-sorting)
 - [Getting the Size of an Iterable in Java](https://www.baeldung.com/java-iterable-size)
 - [Java Null-Safe Streams from Collections](https://www.baeldung.com/java-null-safe-streams-from-collections)
+- [Differences Between Iterator and Iterable and How to Use Them?](https://www.baeldung.com/java-iterator-vs-iterable)

core-java-modules/core-java-collections-2/src/main/java/com/baeldung/collections/iterable/CustomIterableClient.java

@@ -0,0 +1,17 @@
+package com.baeldung.collections.iterable;
+
+class CustomIterableClient {
+
+    public static void main(String[] args) {
+
+        ShoppingCart<Product> shoppingCart = new ShoppingCart<>();
+        shoppingCart.add(new Product("Tuna", 42));
+        shoppingCart.add(new Product("Eggplant", 65));
+        shoppingCart.add(new Product("Salad", 45));
+        shoppingCart.add(new Product("Banana", 29));
+
+        for (Product product : shoppingCart) {
+            System.out.println(product.getName());
+        }
+    }
+}

core-java-modules/core-java-collections-2/src/main/java/com/baeldung/collections/iterable/IterableExample.java

@@ -0,0 +1,32 @@
+package com.baeldung.collections.iterable;
+
+import java.util.Iterator;
+import java.util.List;
+
+public class IterableExample {
+
+    public void iterateUsingIterator(List<Integer> numbers) {
+        Iterator<Integer> iterator = numbers.iterator();
+        while (iterator.hasNext()) {
+            System.out.println(iterator.next());
+        }
+    }
+
+    public void iterateUsingEnhancedForLoop(List<Integer> numbers) {
+        for (Integer number : numbers) {
+            System.out.println(number);
+        }
+    }
+
+    public void iterateUsingForEachLoop(List<Integer> numbers) {
+        numbers.forEach(System.out::println);
+    }
+
+    public void removeElementsUsingIterator(List<Integer> numbers) {
+        Iterator<Integer> iterator = numbers.iterator();
+        while (iterator.hasNext()) {
+            iterator.next();
+            iterator.remove();
+        }
+    }
+}

core-java-modules/core-java-collections-2/src/main/java/com/baeldung/collections/iterable/Product.java

@@ -0,0 +1,28 @@
+package com.baeldung.collections.iterable;
+
+class Product {
+
+    private String name;
+    private double price;
+
+    public Product(String code, double price) {
+        this.name = code;
+        this.price = price;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public double getPrice() {
+        return price;
+    }
+
+    public void setPrice(double price) {
+        this.price = price;
+    }
+}

core-java-modules/core-java-collections-2/src/main/java/com/baeldung/collections/iterable/ShoppingCart.java

@@ -0,0 +1,72 @@
+package com.baeldung.collections.iterable;
+
+import java.util.Arrays;
+import java.util.ConcurrentModificationException;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
+public class ShoppingCart<E> implements Iterable<E> {
+
+    private E[] elementData;
+    private int size;
+
+    public ShoppingCart() {
+        this.elementData = (E[]) new Object[]{};
+    }
+
+    public void add(E element) {
+        ensureCapacity(size + 1);
+        elementData[size++] = element;
+    }
+
+    private void ensureCapacity(int minCapacity) {
+        int oldCapacity = elementData.length;
+        int newCapacity = oldCapacity + (oldCapacity >> 1);
+        if (newCapacity - minCapacity < 0) {
+            newCapacity = minCapacity;
+        }
+        elementData = Arrays.copyOf(elementData, newCapacity);
+    }
+
+    @Override
+    public Iterator<E> iterator() {
+        return new ShoppingCartIterator();
+    }
+
+    public class ShoppingCartIterator implements Iterator<E> {
+        int cursor;
+        int lastReturned = -1;
+
+        public boolean hasNext() {
+            return cursor != size;
+        }
+
+        public E next() {
+            return getNextElement();
+        }
+
+        private E getNextElement() {
+            int current = cursor;
+            exist(current);
+
+            E[] elements = ShoppingCart.this.elementData;
+            validate(elements, current);
+
+            cursor = current + 1;
+            lastReturned = current;
+            return elements[lastReturned];
+        }
+
+        private void exist(int current) {
+            if (current >= size) {
+                throw new NoSuchElementException();
+            }
+        }
+
+        private void validate(E[] elements, int current) {
+            if (current >= elements.length) {
+                throw new ConcurrentModificationException();
+            }
+        }
+    }
+}

core-java-modules/core-java-collections-2/src/main/java/com/baeldung/collections/iterator/CustomIteratorClient.java

@@ -0,0 +1,14 @@
+package com.baeldung.collections.iterator;
+
+import java.util.Iterator;
+
+class CustomIteratorClient {
+
+    public static void main(String[] args) {
+        Iterator<Integer> iterator = Numbers.iterator();
+
+        while (iterator.hasNext()) {
+            System.out.println(iterator.next());
+        }
+    }
+}

core-java-modules/core-java-collections-2/src/main/java/com/baeldung/collections/iterator/Numbers.java

@@ -0,0 +1,60 @@
+package com.baeldung.collections.iterator;
+
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+import java.util.NoSuchElementException;
+
+class Numbers {
+
+    private static final List<Integer> NUMBER_LIST = Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
+
+    private Numbers() {
+    }
+
+    public static Iterator<Integer> iterator() {
+        return new PrimeIterator();
+    }
+
+    private static class PrimeIterator implements Iterator<Integer> {
+
+        private int cursor;
+
+        @Override
+        public Integer next() {
+            exist(cursor);
+            return NUMBER_LIST.get(cursor++);
+        }
+
+        private void exist(int current) {
+            if (current >= NUMBER_LIST.size()) {
+                throw new NoSuchElementException();
+            }
+        }
+
+        @Override
+        public boolean hasNext() {
+            if (cursor > NUMBER_LIST.size()) {
+                return false;
+            }
+
+            for (int i = cursor; i < NUMBER_LIST.size(); i++) {
+                if (isPrime(NUMBER_LIST.get(i))) {
+                    cursor = i;
+                    return true;
+                }
+            }
+
+            return false;
+        }
+
+        private boolean isPrime(int number) {
+            for (int i = 2; i <= number / 2; ++i) {
+                if (number % i == 0) {
+                    return false;
+                }
+            }
+            return true;
+        }
+    }
+}

core-java-modules/core-java-collections-2/src/test/java/com/baeldung/collections/iterable/IterableUnitTest.java

@@ -0,0 +1,54 @@
+package com.baeldung.collections.iterable;
+
+import com.baeldung.collections.iterable.IterableExample;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class IterableUnitTest {
+
+    private static List<Integer> getNumbers() {
+        List<Integer> numbers = new ArrayList<>();
+        numbers.add(10);
+        numbers.add(20);
+        numbers.add(30);
+        numbers.add(40);
+        return numbers;
+    }
+
+    @Test
+    void givenNumbers_whenUsingIterator_thenCorrectSize() {
+        List<Integer> numbers = getNumbers();
+        IterableExample iterableExample = new IterableExample();
+        iterableExample.iterateUsingIterator(numbers);
+        assertEquals(4, numbers.size());
+    }
+
+    @Test
+    void givenNumbers_whenRemoveElements_thenEmptyList() {
+        List<Integer> numbers = getNumbers();
+        IterableExample iterableExample = new IterableExample();
+        iterableExample.removeElementsUsingIterator(numbers);
+        assertEquals(0, numbers.size());
+    }
+
+    @Test
+    void givenNumbers_whenIterateUsingEnhancedForLoop_thenCorrectSize() {
+        List<Integer> numbers = getNumbers();
+        IterableExample iterableExample = new IterableExample();
+        iterableExample.iterateUsingEnhancedForLoop(numbers);
+        assertEquals(4, numbers.size());
+    }
+
+    @Test
+    void givenNumbers_whenIterateUsingForEachLoop_thenCorrectSize() {
+        List<Integer> numbers = getNumbers();
+        IterableExample iterableExample = new IterableExample();
+        iterableExample.iterateUsingForEachLoop(numbers);
+        assertEquals(4, numbers.size());
+    }
+}

core-java-modules/core-java-collections-4/pom.xml

@@ -14,4 +14,16 @@
         <version>0.0.1-SNAPSHOT</version>
     </parent>
 
+    <dependencies>
+        <dependency>
+            <groupId>commons-lang</groupId>
+            <artifactId>commons-lang</artifactId>
+            <version>${commons-lang.version}</version>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <commons-lang.version>2.2</commons-lang.version>
+    </properties>
+
 </project>

core-java-modules/core-java-collections-4/src/main/java/com/baeldung/collections/sorting/Employee.java

@@ -0,0 +1,72 @@
+package com.baeldung.collections.sorting;
+
+import java.util.Date;
+
+public class Employee implements Comparable<Employee>{
+
+  private String name;
+  private int age;
+  private double salary;
+  private Date joiningDate;
+
+  public Employee(String name, int age, double salary, Date joiningDate) {
+    this.name = name;
+    this.age = age;
+    this.salary = salary;
+    this.joiningDate = joiningDate;
+  }
+
+  public String getName() {
+    return name;
+  }
+
+  public void setName(String name) {
+    this.name = name;
+  }
+
+  public int getAge() {
+    return age;
+  }
+
+  public void setAge(int age) {
+    this.age = age;
+  }
+
+  public double getSalary() {
+    return salary;
+  }
+
+  public void setSalary(double salary) {
+    this.salary = salary;
+  }
+
+  public Date getJoiningDate() {
+    return joiningDate;
+  }
+
+  public void setJoiningDate(Date joiningDate) {
+    this.joiningDate = joiningDate;
+  }
+
+  @Override
+  public boolean equals(Object obj) {
+    return ((Employee) obj).getName()
+      .equals(getName());
+  }
+
+  @Override
+  public String toString() {
+    return new StringBuffer().append("(")
+      .append(getName()).append(",")
+      .append(getAge())
+      .append(",")
+      .append(getSalary()).append(",").append(getJoiningDate())
+      .append(")")
+      .toString();
+  }
+
+  @Override
+  public int compareTo(Employee employee) {
+    return getJoiningDate().compareTo(employee.getJoiningDate());
+  }
+}

core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/sorting/EmployeeSortingByDateUnitTest.java

@@ -0,0 +1,146 @@
+package com.baeldung.collections.sorting;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.Date;
+import java.util.List;
+import org.apache.commons.lang.time.DateUtils;
+import org.junit.Before;
+import org.junit.Test;
+
+public class EmployeeSortingByDateUnitTest {
+
+  private List<Employee> employees = new ArrayList<>();
+  private List<Employee> employeesSortedByDateAsc = new ArrayList<>();
+  private List<Employee> employeesSortedByDateDesc = new ArrayList<>();
+
+  @Before
+  public void initVariables() {
+
+    Collections.addAll(employees,
+      new Employee("Earl", 43, 10000, DateUtils.addMonths(new Date(), -2)),
+      new Employee("Frank", 33, 7000, DateUtils.addDays(new Date(), -20)),
+      new Employee("Steve", 26, 6000, DateUtils.addDays(new Date(), -10)),
+      new Employee("Jessica", 23, 4000, DateUtils.addMonths(new Date(), -6)),
+      new Employee("Pearl", 33, 6000, DateUtils.addYears(new Date(), -1)),
+      new Employee("John", 23, 5000, new Date())
+    );
+
+    Collections.addAll(employeesSortedByDateDesc,
+      new Employee("John", 23, 5000, new Date()),
+      new Employee("Steve", 26, 6000, DateUtils.addDays(new Date(), -10)),
+      new Employee("Frank", 33, 7000, DateUtils.addDays(new Date(), -20)),
+      new Employee("Earl", 43, 10000, DateUtils.addMonths(new Date(), -2)),
+      new Employee("Jessica", 23, 4000, DateUtils.addMonths(new Date(), -6)),
+      new Employee("Pearl", 33, 6000, DateUtils.addYears(new Date(), -1))
+    );
+
+    Collections.addAll(employeesSortedByDateAsc,
+      new Employee("Pearl", 33, 6000, DateUtils.addYears(new Date(), -1)),
+      new Employee("Jessica", 23, 4000, DateUtils.addMonths(new Date(), -6)),
+      new Employee("Earl", 43, 10000, DateUtils.addMonths(new Date(), -2)),
+      new Employee("Frank", 33, 7000, DateUtils.addDays(new Date(), -20)),
+      new Employee("Steve", 26, 6000, DateUtils.addDays(new Date(), -10)),
+      new Employee("John", 23, 5000, new Date())
+    );
+  }
+
+  @Test
+  public void givenEmpList_SortEmpList_thenSortedListinNaturalOrder() {
+    Collections.sort(employees);
+
+    assertEquals(employees, employeesSortedByDateAsc);
+  }
+
+  @Test
+  public void givenEmpList_SortEmpList_thenCheckSortedList() {
+
+    Collections.sort(employees, new Comparator<Employee>() {
+      public int compare(Employee o1, Employee o2) {
+        return o1.getJoiningDate().compareTo(o2.getJoiningDate());
+      }
+    });
+
+    assertEquals(employees, employeesSortedByDateAsc);
+  }
+
+  @Test
+  public void givenEmpList_SortEmpList_thenCheckSortedListV1() {
+
+    Collections.sort(employees, new Comparator<Employee>() {
+      public int compare(Employee emp1, Employee emp2) {
+        if (emp1.getJoiningDate() == null || emp2.getJoiningDate() == null)
+          return 0;
+        return emp1.getJoiningDate().compareTo(emp2.getJoiningDate());
+      }
+    });
+
+    assertEquals(employees, employeesSortedByDateAsc);
+  }
+
+  @Test
+  public void givenEmpList_SortEmpList_thenSortedListinAscOrder() {
+    Collections.sort(employees, Collections.reverseOrder());
+
+    assertEquals(employees, employeesSortedByDateDesc);
+  }
+
+  @Test
+  public void givenEmpList_SortEmpList_thenCheckSortedListAsc() {
+
+    Collections.sort(employees, new Comparator<Employee>() {
+      public int compare(Employee emp1, Employee emp2) {
+        return emp2.getJoiningDate().compareTo(emp1.getJoiningDate());
+      }
+    });
+
+    assertEquals(employees, employeesSortedByDateDesc);
+  }
+
+  @Test
+  public void givenEmpList_SortEmpList_thenCheckSortedListAscV1() {
+
+    Collections.sort(employees, new Comparator<Employee>() {
+      public int compare(Employee emp1, Employee emp2) {
+        if (emp1.getJoiningDate() == null || emp2.getJoiningDate() == null)
+          return 0;
+        return emp2.getJoiningDate().compareTo(emp1.getJoiningDate());
+      }
+    });
+
+    assertEquals(employees, employeesSortedByDateDesc);
+  }
+
+  @Test
+  public void givenEmpList_SortEmpList_thenCheckSortedListDescLambda() {
+
+    Collections.sort(employees,
+      (emp1, emp2) -> emp2.getJoiningDate().compareTo(emp1.getJoiningDate()));
+
+    assertEquals(employees, employeesSortedByDateDesc);
+  }
+
+  @Test
+  public void givenEmpList_SortEmpList_thenCheckSortedListDescLambdaV1() {
+
+    Collections.sort(employees, (emp1, emp2) -> {
+      if (emp1.getJoiningDate() == null || emp2.getJoiningDate() == null)
+        return 0;
+      return emp2.getJoiningDate().compareTo(emp1.getJoiningDate());
+    });
+
+    assertEquals(employees, employeesSortedByDateDesc);
+  }
+
+  @Test
+  public void givenEmpList_SortEmpList_thenCheckSortedListAscLambda() {
+    Collections.sort(employees,
+      Comparator.comparing(Employee::getJoiningDate));
+    assertEquals(employees, employeesSortedByDateAsc);
+  }
+
+}

core-java-modules/core-java-collections-list-4/README.md

@@ -0,0 +1,7 @@
+## Core Java Collections List (Part 4)
+
+This module contains articles about the Java List collection
+
+### Relevant Articles: 
+- [Working With a List of Lists in Java](https://www.baeldung.com/java-list-of-lists)
+- [[<-- Prev]](/core-java-modules/core-java-collections-list-3)

core-java-modules/core-java-collections-list-4/pom.xml

@@ -0,0 +1,56 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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-collections-list-4</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>core-java-collections-list-4</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <artifactId>core-java-modules</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-collections4</artifactId>
+            <version>${commons-collections4.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>net.sf.trove4j</groupId>
+            <artifactId>trove4j</artifactId>
+            <version>${trove4j.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>it.unimi.dsi</groupId>
+            <artifactId>fastutil</artifactId>
+            <version>${fastutil.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>colt</groupId>
+            <artifactId>colt</artifactId>
+            <version>${colt.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.version}</version>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <trove4j.version>3.0.2</trove4j.version>
+        <fastutil.version>8.1.0</fastutil.version>
+        <colt.version>1.2.0</colt.version>
+    </properties>
+
+</project>

core-java-modules/core-java-concurrency-advanced-4/README.md

@@ -6,3 +6,4 @@
 - [Volatile Variables and Thread Safety](https://www.baeldung.com/java-volatile-variables-thread-safety)
 - [Producer-Consumer Problem With Example in Java](https://www.baeldung.com/java-producer-consumer-problem)
 - [Acquire a Lock by a Key in Java](https://www.baeldung.com/java-acquire-lock-by-key)
+- [Differences Between set() and lazySet() in Java Atomic Variables](https://www.baeldung.com/java-atomic-set-vs-lazyset)

core-java-modules/core-java-exceptions-3/pom.xml

@@ -32,8 +32,8 @@
                 <version>3.8.1</version>
                 <configuration>
                     <compilerArgs>
-<!--                         Comment the arg below to print complete stack trace information -->
-<!--                        <arg>-g:none</arg>-->
+                        <!-- Comment the arg below to print complete stack trace information -->
+                        <!-- <arg>-g:none</arg> -->
                     </compilerArgs>
                 </configuration>
             </plugin>

core-java-modules/core-java-exceptions-4/pom.xml

@@ -32,8 +32,8 @@
                 <version>3.8.1</version>
                 <configuration>
                     <compilerArgs>
-<!--                         Comment the arg below to print complete stack trace information -->
-<!--                        <arg>-g:none</arg>-->
+                        <!-- Comment the arg below to print complete stack trace information -->
+                        <!-- <arg>-g:none</arg> -->
                     </compilerArgs>
                 </configuration>
             </plugin>

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

@@ -0,0 +1,6 @@
+## Java HttpClient
+
+This module contains articles about Java HttpClient
+
+### Relevant articles
+- TODO

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

@@ -0,0 +1,58 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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-httpclient</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>core-java-httpclient</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+        <relativePath>../../pom.xml</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.mock-server</groupId>
+            <artifactId>mockserver-netty</artifactId>
+            <version>${mockserver.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.mock-server</groupId>
+            <artifactId>mockserver-client-java</artifactId>
+            <version>${mockserver.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>${maven-compiler-plugin.version}</version>
+                <configuration>
+                    <source>${maven.compiler.source.version}</source>
+                    <target>${maven.compiler.target.version}</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <maven.compiler.source.version>11</maven.compiler.source.version>
+        <maven.compiler.target.version>11</maven.compiler.target.version>
+        <assertj.version>3.22.0</assertj.version>
+        <mockserver.version>5.11.2</mockserver.version>
+    </properties>
+
+</project>

core-java-modules/core-java-httpclient/src/main/java/com/baeldung/httpclient/HttpClientPost.java

@@ -0,0 +1,162 @@
+package com.baeldung.httpclient;
+
+import java.io.IOException;
+import java.net.Authenticator;
+import java.net.PasswordAuthentication;
+import java.net.URI;
+import java.net.URLEncoder;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Path;
+import java.util.Base64;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.CompletableFuture;
+import java.util.stream.Collectors;
+
+public class HttpClientPost {
+
+    public static HttpResponse<String> sendSynchronousPost(String serviceUrl) throws IOException, InterruptedException {
+        HttpClient client = HttpClient.newHttpClient();
+
+        HttpRequest request = HttpRequest.newBuilder()
+          .uri(URI.create(serviceUrl))
+          .POST(HttpRequest.BodyPublishers.noBody())
+          .build();
+
+        HttpResponse<String> response = client
+          .send(request, HttpResponse.BodyHandlers.ofString());
+
+        return response;
+    }
+
+    public static CompletableFuture<HttpResponse<String>> sendAsynchronousPost(String serviceUrl) {
+        HttpClient client = HttpClient.newHttpClient();
+
+        HttpRequest request = HttpRequest.newBuilder()
+          .uri(URI.create(serviceUrl))
+          .POST(HttpRequest.BodyPublishers.noBody())
+          .build();
+
+        CompletableFuture<HttpResponse<String>> futureResponse = client
+          .sendAsync(request, HttpResponse.BodyHandlers.ofString());
+
+        return futureResponse;
+    }
+
+    public static List<CompletableFuture<HttpResponse<String>>> sendConcurrentPost(List<String> serviceUrls) {
+        HttpClient client = HttpClient.newHttpClient();
+
+        List<CompletableFuture<HttpResponse<String>>> completableFutures = serviceUrls.stream()
+          .map(URI::create)
+          .map(HttpRequest::newBuilder)
+          .map(builder -> builder.POST(HttpRequest.BodyPublishers.noBody()))
+          .map(HttpRequest.Builder::build)
+          .map(request -> client.sendAsync(request, HttpResponse.BodyHandlers.ofString()))
+          .collect(Collectors.toList());
+
+        return completableFutures;
+    }
+
+    public static HttpResponse<String> sendPostWithAuthHeader(String serviceUrl) throws IOException, InterruptedException {
+        HttpClient client = HttpClient.newHttpClient();
+
+        HttpRequest request = HttpRequest.newBuilder()
+          .uri(URI.create(serviceUrl))
+          .POST(HttpRequest.BodyPublishers.noBody())
+          .header("Authorization", "Basic " + Base64.getEncoder()
+            .encodeToString(("baeldung:123456").getBytes()))
+          .build();
+
+        HttpResponse<String> response = client
+          .send(request, HttpResponse.BodyHandlers.ofString());
+
+        return response;
+    }
+
+    public static HttpResponse<String> sendPostWithAuthClient(String serviceUrl) throws IOException, InterruptedException {
+        HttpClient client = HttpClient.newBuilder()
+          .authenticator(new Authenticator() {
+              @Override
+              protected PasswordAuthentication getPasswordAuthentication() {
+                  return new PasswordAuthentication(
+                    "baeldung",
+                    "123456".toCharArray());
+              }
+          })
+          .build();
+
+        HttpRequest request = HttpRequest.newBuilder()
+          .uri(URI.create(serviceUrl))
+          .POST(HttpRequest.BodyPublishers.noBody())
+          .build();
+
+        HttpResponse<String> response = client
+          .send(request, HttpResponse.BodyHandlers.ofString());
+
+        return response;
+    }
+
+    public static HttpResponse<String> sendPostWithJsonBody(String serviceUrl) throws IOException, InterruptedException {
+        HttpClient client = HttpClient.newHttpClient();
+
+        HttpRequest request = HttpRequest.newBuilder()
+          .uri(URI.create(serviceUrl))
+          .POST(HttpRequest.BodyPublishers.ofString("{\"action\":\"hello\"}"))
+          .build();
+
+        HttpResponse<String> response = client
+          .send(request, HttpResponse.BodyHandlers.ofString());
+
+        return response;
+    }
+
+    public static HttpResponse<String> sendPostWithFormData(String serviceUrl) throws IOException, InterruptedException {
+        HttpClient client = HttpClient.newHttpClient();
+
+        Map<String, String> formData = new HashMap<>();
+        formData.put("username", "baeldung");
+        formData.put("message", "hello");
+
+        HttpRequest request = HttpRequest.newBuilder()
+          .uri(URI.create(serviceUrl))
+          .POST(HttpRequest.BodyPublishers.ofString(getFormDataAsString(formData)))
+          .build();
+
+        HttpResponse<String> response = client
+          .send(request, HttpResponse.BodyHandlers.ofString());
+
+        return response;
+    }
+
+    public static HttpResponse<String> sendPostWithFileData(String serviceUrl, Path file) throws IOException, InterruptedException {
+        HttpClient client = HttpClient.newHttpClient();
+
+        HttpRequest request = HttpRequest.newBuilder()
+          .uri(URI.create(serviceUrl))
+          .POST(HttpRequest.BodyPublishers.ofFile(file))
+          .build();
+
+        HttpResponse<String> response = client
+          .send(request, HttpResponse.BodyHandlers.ofString());
+
+        return response;
+    }
+
+    private static String getFormDataAsString(Map<String, String> formData) {
+        StringBuilder formBodyBuilder = new StringBuilder();
+        for (Map.Entry<String, String> singleEntry : formData.entrySet()) {
+            if (formBodyBuilder.length() > 0) {
+                formBodyBuilder.append("&");
+            }
+            formBodyBuilder.append(URLEncoder.encode(singleEntry.getKey(), StandardCharsets.UTF_8));
+            formBodyBuilder.append("=");
+            formBodyBuilder.append(URLEncoder.encode(singleEntry.getValue(), StandardCharsets.UTF_8));
+        }
+        return formBodyBuilder.toString();
+    }
+
+}

core-java-modules/core-java-httpclient/src/test/java/com/baeldung/httpclient/HttpClientPostUnitTest.java

@@ -0,0 +1,99 @@
+package com.baeldung.httpclient;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.io.IOException;
+import java.net.http.HttpResponse;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Arrays;
+import java.util.List;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
+import java.util.stream.Collectors;
+
+import static org.assertj.core.api.Assertions.*;
+
+class HttpClientPostUnitTest extends PostRequestMockServer {
+
+    @Test
+    void givenSyncPostRequest_whenServerIsAvailable_thenOkStatusIsReceived() throws IOException, InterruptedException {
+        HttpResponse<String> response = HttpClientPost.sendSynchronousPost(serviceUrl);
+        assertThat(response.statusCode()).isEqualTo(200);
+        assertThat(response.body()).isEqualTo("{\"message\":\"ok\"}");
+    }
+
+    @Test
+    void givenAsyncPostRequest_whenServerIsAvailable_thenOkStatusIsReceived() throws ExecutionException, InterruptedException {
+        CompletableFuture<HttpResponse<String>> futureResponse = HttpClientPost.sendAsynchronousPost(serviceUrl);
+        HttpResponse<String> response = futureResponse.get();
+
+        assertThat(response.statusCode()).isEqualTo(200);
+        assertThat(response.body()).isEqualTo("{\"message\":\"ok\"}");
+    }
+
+    @Test
+    void givenConcurrentPostRequests_whenServerIsAvailable_thenOkStatusIsReceived() throws ExecutionException, InterruptedException {
+        List<CompletableFuture<HttpResponse<String>>> completableFutures = HttpClientPost
+          .sendConcurrentPost(List.of(serviceUrl, serviceUrl));
+
+        CompletableFuture<List<HttpResponse<String>>> combinedFutures = CompletableFuture
+          .allOf(completableFutures.toArray(new CompletableFuture[0]))
+          .thenApply(future ->
+            completableFutures.stream()
+              .map(CompletableFuture::join)
+              .collect(Collectors.toList()));
+
+        List<HttpResponse<String>> responses = combinedFutures.get();
+        responses.forEach((response) -> {
+            assertThat(response.statusCode()).isEqualTo(200);
+            assertThat(response.body()).isEqualTo("{\"message\":\"ok\"}");
+        });
+    }
+
+    @Test
+    void givenPostRequestWithAuthClient_whenServerIsAvailable_thenOkStatusIsReceived() throws IOException, InterruptedException {
+        HttpResponse<String> response = HttpClientPost.sendPostWithAuthClient(serviceUrl);
+
+        assertThat(response.statusCode()).isEqualTo(200);
+        assertThat(response.body()).isEqualTo("{\"message\":\"ok\"}");
+    }
+
+    @Test
+    void givenPostRequestWithAuthHeader_whenServerIsAvailable_thenOkStatusIsReceived() throws IOException, InterruptedException {
+        HttpResponse<String> response = HttpClientPost.sendPostWithAuthHeader(serviceUrl);
+
+        assertThat(response.statusCode()).isEqualTo(200);
+        assertThat(response.body()).isEqualTo("{\"message\":\"ok\"}");
+    }
+
+    @Test
+    void givenPostRequestWithJsonBody_whenServerIsAvailable_thenOkStatusIsReceived() throws IOException, InterruptedException {
+        HttpResponse<String> response = HttpClientPost.sendPostWithJsonBody(serviceUrl);
+
+        assertThat(response.statusCode()).isEqualTo(200);
+        assertThat(response.body()).isEqualTo("{\"message\":\"ok\"}");
+    }
+
+    @Test
+    void givenPostRequestWithFormData_whenServerIsAvailable_thenOkStatusIsReceived() throws IOException, InterruptedException {
+        HttpResponse<String> response = HttpClientPost.sendPostWithFormData(serviceUrl);
+
+        assertThat(response.statusCode()).isEqualTo(200);
+        assertThat(response.body()).isEqualTo("{\"message\":\"ok\"}");
+    }
+
+    @Test
+    void givenPostRequestWithFileData_whenServerIsAvailable_thenOkStatusIsReceived(@TempDir Path tempDir) throws IOException, InterruptedException {
+        Path file = tempDir.resolve("temp.txt");
+        List<String> lines = Arrays.asList("1", "2", "3");
+        Files.write(file, lines);
+
+        HttpResponse<String> response = HttpClientPost.sendPostWithFileData(serviceUrl, file);
+
+        assertThat(response.statusCode()).isEqualTo(200);
+        assertThat(response.body()).isEqualTo("{\"message\":\"ok\"}");
+    }
+
+}

core-java-modules/core-java-httpclient/src/test/java/com/baeldung/httpclient/PostRequestMockServer.java

@@ -0,0 +1,61 @@
+package com.baeldung.httpclient;
+
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.mockserver.client.MockServerClient;
+import org.mockserver.integration.ClientAndServer;
+import org.mockserver.model.HttpStatusCode;
+
+import java.io.IOException;
+import java.net.ServerSocket;
+import java.net.URISyntaxException;
+
+import static org.mockserver.integration.ClientAndServer.startClientAndServer;
+import static org.mockserver.model.HttpRequest.request;
+import static org.mockserver.model.HttpResponse.response;
+
+public abstract class PostRequestMockServer {
+
+    public static ClientAndServer mockServer;
+    public static String serviceUrl;
+
+    private static int serverPort;
+
+    public static final String SERVER_ADDRESS = "127.0.0.1";
+    public static final String PATH = "/test1";
+    public static final String METHOD = "POST";
+
+    @BeforeAll
+    static void startServer() throws IOException, URISyntaxException {
+        serverPort = getFreePort();
+        serviceUrl = "http://" + SERVER_ADDRESS + ":" + serverPort + PATH;
+        mockServer = startClientAndServer(serverPort);
+        mockBasicPostRequest();
+    }
+
+    @AfterAll
+    static void stopServer() {
+        mockServer.stop();
+    }
+
+    private static void mockBasicPostRequest() {
+        new MockServerClient(SERVER_ADDRESS, serverPort)
+          .when(
+            request()
+              .withPath(PATH)
+              .withMethod(METHOD)
+          )
+          .respond(
+            response()
+              .withStatusCode(HttpStatusCode.OK_200.code())
+              .withBody("{\"message\":\"ok\"}")
+          );
+    }
+
+    private static int getFreePort () throws IOException {
+        try (ServerSocket serverSocket = new ServerSocket(0)) {
+            return serverSocket.getLocalPort();
+        }
+    }
+
+}

core-java-modules/core-java-lang-4/src/main/java/com/baeldung/employee/EmployeeVO.java

@@ -28,9 +28,15 @@ public class EmployeeVO {
 
     @Override
     public boolean equals(Object obj) {
-        return Objects.equals(firstName, this.firstName)
-            && Objects.equals(lastName, this.lastName)
-            && Objects.equals(startDate, this.startDate);
+        
+        if (this == obj) return true;
+        if (obj == null || getClass() != obj.getClass()) return false;
+
+        EmployeeVO emp = (EmployeeVO) obj;
+        
+        return Objects.equals(firstName, emp.firstName)
+            && Objects.equals(lastName, emp.lastName)
+            && Objects.equals(startDate, emp.startDate);
     }
 
     @Override

core-java-modules/core-java-lang-5/README.md

@@ -2,4 +2,6 @@
 
 This module contains articles about core features in the Java language
 
-## TODO ##
+### Relevant Articles:
+
+- [Difference Between == and equals() in Java](https://www.baeldung.com/java-equals-method-operator-difference)

core-java-modules/core-java-lang-math-3/README.md

@@ -5,4 +5,5 @@
 ### Relevant articles:
 
 - [Evaluating a Math Expression in Java](https://www.baeldung.com/java-evaluate-math-expression-string)
+- [Swap Two Variables in Java](https://www.baeldung.com/java-swap-two-variables)
 - More articles: [[<-- Prev]](/core-java-modules/core-java-lang-math-2)

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

@@ -35,7 +35,6 @@
                 <filtering>true</filtering>
             </resource>
         </resources>
-
         <plugins>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>

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

@@ -67,7 +67,7 @@
         <dependency>
             <groupId>com.google.gdata</groupId>
             <artifactId>core</artifactId>
-            <version>1.47.1</version>
+            <version>${gdata.version}</version>
         </dependency>
     </dependencies>
 
@@ -193,6 +193,7 @@
         <source.version>1.8</source.version>
         <target.version>1.8</target.version>
         <spring.core.version>4.3.20.RELEASE</spring.core.version>
+        <gdata.version>1.47.1</gdata.version>
     </properties>
 
 </project>

core-java-modules/java-collections-conversions-2/pom.xml

@@ -28,7 +28,7 @@
         <dependency>
             <groupId>io.vavr</groupId>
             <artifactId>vavr</artifactId>
-            <version>0.10.3</version>
+            <version>${vavr.version}</version>
         </dependency>
     </dependencies>
 
@@ -42,4 +42,8 @@
         </resources>
     </build>
 
+    <properties>
+        <vavr.version>0.10.3</vavr.version>
+    </properties>
+
 </project>

core-java-modules/java-collections-maps-3/pom.xml

@@ -19,7 +19,7 @@
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-api</artifactId>
-            <version>5.8.1</version>
+            <version>${junit-jupiter.version}</version>
         </dependency>
         <dependency>
             <groupId>org.springframework</groupId>

core-java-modules/pom.xml

@@ -35,6 +35,7 @@
         <module>core-java-collections-list</module>
         <module>core-java-collections-list-2</module>
         <module>core-java-collections-list-3</module>
+        <module>core-java-collections-list-4</module>
         <module>core-java-collections-maps</module>
         <module>core-java-collections-maps-2</module>
         <module>core-java-collections-maps-3</module>

docker/docker-caching/multi-module-caching/core/pom.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <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">
+    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</artifactId>
 
@@ -22,4 +22,5 @@
         <maven.compiler.source>8</maven.compiler.source>
         <maven.compiler.target>8</maven.compiler.target>
     </properties>
+
 </project>

docker/docker-caching/multi-module-caching/pom.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.baeldung</groupId>
     <artifactId>multi-module-caching</artifactId>
@@ -8,22 +9,24 @@
     <description>Multi-module Maven caching example</description>
     <packaging>pom</packaging>
 
+    <modules>
+        <module>runner</module>
+        <module>core</module>
+    </modules>
+
     <dependencyManagement>
         <dependencies>
             <dependency>
                 <groupId>com.google.guava</groupId>
                 <artifactId>guava</artifactId>
-                <version>31.0.1-jre</version>
+                <version>${guava.version}</version>
             </dependency>
         </dependencies>
     </dependencyManagement>
 
     <properties>
         <java.version>1.8</java.version>
+        <guava.version>31.0.1-jre</guava.version>
     </properties>
 
-    <modules>
-        <module>runner</module>
-        <module>core</module>
-    </modules>
 </project>

docker/docker-caching/multi-module-caching/runner/pom.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <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">
+    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>runner</artifactId>
 
@@ -53,4 +53,5 @@
         <maven.compiler.source>8</maven.compiler.source>
         <maven.compiler.target>8</maven.compiler.target>
     </properties>
+
 </project>

docker/docker-caching/single-module-caching/pom.xml

@@ -1,9 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <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">
+    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</groupId>
     <artifactId>single-module-caching</artifactId>
     <version>1.0-SNAPSHOT</version>
@@ -12,7 +11,7 @@
         <dependency>
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>
-            <version>31.0.1-jre</version>
+            <version>${guava.version}</version>
         </dependency>
     </dependencies>
 
@@ -49,5 +48,7 @@
     <properties>
         <maven.compiler.source>8</maven.compiler.source>
         <maven.compiler.target>8</maven.compiler.target>
+        <guava.version>31.0.1-jre</guava.version>
     </properties>
+
 </project>

docker/docker-internal-dto/pom.xml

@@ -3,13 +3,13 @@
     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>docker-internal-dto</artifactId>
+    <name>docker-internal-dto</name>
+
     <parent>
         <groupId>com.baeldung.docker</groupId>
         <artifactId>docker</artifactId>
         <version>0.0.1</version>
     </parent>
 
-    <artifactId>docker-internal-dto</artifactId>
-    <name>docker-internal-dto</name>
-
 </project>

docker/docker-push-to-private-repo/README.md

@@ -1 +1,3 @@
 ### Relevant Articles:
+
+- [Pushing a Docker Image to a Private Repository](https://www.baeldung.com/ops/docker-push-image-to-private-repository)

docker/docker-sample-app/pom.xml

@@ -1,21 +1,18 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
+    <artifactId>docker-sample-app</artifactId>
+    <name>docker-sample-app</name>
+    <description>Demo project for Spring Boot and Docker</description>
+
     <parent>
         <groupId>com.baeldung.docker</groupId>
         <artifactId>docker</artifactId>
         <version>0.0.1</version>
     </parent>
 
-    <artifactId>docker-sample-app</artifactId>
-    <name>docker-sample-app</name>
-    <description>Demo project for Spring Boot and Docker</description>
-
-    <properties>
-        <java.version>11</java.version>
-    </properties>
-
     <dependencies>
         <dependency>
             <groupId>org.springframework.boot</groupId>
@@ -42,4 +39,8 @@
         </plugins>
     </build>
 
+    <properties>
+        <java.version>11</java.version>
+    </properties>
+
 </project>

docker/docker-spring-boot-postgres/pom.xml

@@ -1,12 +1,13 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
-	<modelVersion>4.0.0</modelVersion>
-	<groupId>com.baeldung.docker</groupId>
-	<artifactId>docker-spring-boot-postgres</artifactId>
-	<version>0.0.1-SNAPSHOT</version>
-	<name>docker-spring-boot-postgres</name>
-	<description>Demo project showing Spring Boot, PostgreSQL, and Docker</description>
+<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>com.baeldung.docker</groupId>
+    <artifactId>docker-spring-boot-postgres</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>docker-spring-boot-postgres</name>
+    <description>Demo project showing Spring Boot, PostgreSQL, and Docker</description>
 
     <parent>
         <groupId>com.baeldung</groupId>
@@ -15,32 +16,31 @@
         <relativePath>../../parent-boot-2</relativePath>
     </parent>
 
-	<dependencies>
-		<dependency>
-			<groupId>org.springframework.boot</groupId>
-			<artifactId>spring-boot-starter-data-jpa</artifactId>
-		</dependency>
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-jpa</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.postgresql</groupId>
+            <artifactId>postgresql</artifactId>
+            <scope>runtime</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
 
-		<dependency>
-			<groupId>org.postgresql</groupId>
-			<artifactId>postgresql</artifactId>
-			<scope>runtime</scope>
-		</dependency>
-		<dependency>
-			<groupId>org.springframework.boot</groupId>
-			<artifactId>spring-boot-starter-test</artifactId>
-			<scope>test</scope>
-		</dependency>
-	</dependencies>
-
-	<build>
-		<plugins>
-			<plugin>
-				<groupId>org.springframework.boot</groupId>
-				<artifactId>spring-boot-maven-plugin</artifactId>
-			</plugin>
-		</plugins>
-	</build>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
 
     <properties>
         <java.version>11</java.version>

docker/docker-spring-boot/README.md

@@ -1,3 +1,4 @@
 ### Relevant Articles:
 
 - [Creating Docker Images with Spring Boot](https://www.baeldung.com/spring-boot-docker-images)
+- [Starting Spring Boot Application in Docker With Profile](https://www.baeldung.com/spring-boot-docker-start-with-profile)

docker/docker-spring-boot/mvnw

@@ -1,310 +0,0 @@
-#!/bin/sh
-# ----------------------------------------------------------------------------
-# Licensed to the Apache Software Foundation (ASF) under one
-# or more contributor license agreements.  See the NOTICE file
-# distributed with this work for additional information
-# regarding copyright ownership.  The ASF licenses this file
-# to you under the Apache License, Version 2.0 (the
-# "License"); you may not use this file except in compliance
-# with the License.  You may obtain a copy of the License at
-#
-#    https://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing,
-# software distributed under the License is distributed on an
-# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
-# KIND, either express or implied.  See the License for the
-# specific language governing permissions and limitations
-# under the License.
-# ----------------------------------------------------------------------------
-
-# ----------------------------------------------------------------------------
-# Maven Start Up Batch script
-#
-# Required ENV vars:
-# ------------------
-#   JAVA_HOME - location of a JDK home dir
-#
-# Optional ENV vars
-# -----------------
-#   M2_HOME - location of maven2's installed home dir
-#   MAVEN_OPTS - parameters passed to the Java VM when running Maven
-#     e.g. to debug Maven itself, use
-#       set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
-#   MAVEN_SKIP_RC - flag to disable loading of mavenrc files
-# ----------------------------------------------------------------------------
-
-if [ -z "$MAVEN_SKIP_RC" ] ; then
-
-  if [ -f /etc/mavenrc ] ; then
-    . /etc/mavenrc
-  fi
-
-  if [ -f "$HOME/.mavenrc" ] ; then
-    . "$HOME/.mavenrc"
-  fi
-
-fi
-
-# OS specific support.  $var _must_ be set to either true or false.
-cygwin=false;
-darwin=false;
-mingw=false
-case "`uname`" in
-  CYGWIN*) cygwin=true ;;
-  MINGW*) mingw=true;;
-  Darwin*) darwin=true
-    # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
-    # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
-    if [ -z "$JAVA_HOME" ]; then
-      if [ -x "/usr/libexec/java_home" ]; then
-        export JAVA_HOME="`/usr/libexec/java_home`"
-      else
-        export JAVA_HOME="/Library/Java/Home"
-      fi
-    fi
-    ;;
-esac
-
-if [ -z "$JAVA_HOME" ] ; then
-  if [ -r /etc/gentoo-release ] ; then
-    JAVA_HOME=`java-config --jre-home`
-  fi
-fi
-
-if [ -z "$M2_HOME" ] ; then
-  ## resolve links - $0 may be a link to maven's home
-  PRG="$0"
-
-  # need this for relative symlinks
-  while [ -h "$PRG" ] ; do
-    ls=`ls -ld "$PRG"`
-    link=`expr "$ls" : '.*-> \(.*\)$'`
-    if expr "$link" : '/.*' > /dev/null; then
-      PRG="$link"
-    else
-      PRG="`dirname "$PRG"`/$link"
-    fi
-  done
-
-  saveddir=`pwd`
-
-  M2_HOME=`dirname "$PRG"`/..
-
-  # make it fully qualified
-  M2_HOME=`cd "$M2_HOME" && pwd`
-
-  cd "$saveddir"
-  # echo Using m2 at $M2_HOME
-fi
-
-# For Cygwin, ensure paths are in UNIX format before anything is touched
-if $cygwin ; then
-  [ -n "$M2_HOME" ] &&
-    M2_HOME=`cygpath --unix "$M2_HOME"`
-  [ -n "$JAVA_HOME" ] &&
-    JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
-  [ -n "$CLASSPATH" ] &&
-    CLASSPATH=`cygpath --path --unix "$CLASSPATH"`
-fi
-
-# For Mingw, ensure paths are in UNIX format before anything is touched
-if $mingw ; then
-  [ -n "$M2_HOME" ] &&
-    M2_HOME="`(cd "$M2_HOME"; pwd)`"
-  [ -n "$JAVA_HOME" ] &&
-    JAVA_HOME="`(cd "$JAVA_HOME"; pwd)`"
-fi
-
-if [ -z "$JAVA_HOME" ]; then
-  javaExecutable="`which javac`"
-  if [ -n "$javaExecutable" ] && ! [ "`expr \"$javaExecutable\" : '\([^ ]*\)'`" = "no" ]; then
-    # readlink(1) is not available as standard on Solaris 10.
-    readLink=`which readlink`
-    if [ ! `expr "$readLink" : '\([^ ]*\)'` = "no" ]; then
-      if $darwin ; then
-        javaHome="`dirname \"$javaExecutable\"`"
-        javaExecutable="`cd \"$javaHome\" && pwd -P`/javac"
-      else
-        javaExecutable="`readlink -f \"$javaExecutable\"`"
-      fi
-      javaHome="`dirname \"$javaExecutable\"`"
-      javaHome=`expr "$javaHome" : '\(.*\)/bin'`
-      JAVA_HOME="$javaHome"
-      export JAVA_HOME
-    fi
-  fi
-fi
-
-if [ -z "$JAVACMD" ] ; then
-  if [ -n "$JAVA_HOME"  ] ; then
-    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
-      # IBM's JDK on AIX uses strange locations for the executables
-      JAVACMD="$JAVA_HOME/jre/sh/java"
-    else
-      JAVACMD="$JAVA_HOME/bin/java"
-    fi
-  else
-    JAVACMD="`which java`"
-  fi
-fi
-
-if [ ! -x "$JAVACMD" ] ; then
-  echo "Error: JAVA_HOME is not defined correctly." >&2
-  echo "  We cannot execute $JAVACMD" >&2
-  exit 1
-fi
-
-if [ -z "$JAVA_HOME" ] ; then
-  echo "Warning: JAVA_HOME environment variable is not set."
-fi
-
-CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
-
-# traverses directory structure from process work directory to filesystem root
-# first directory with .mvn subdirectory is considered project base directory
-find_maven_basedir() {
-
-  if [ -z "$1" ]
-  then
-    echo "Path not specified to find_maven_basedir"
-    return 1
-  fi
-
-  basedir="$1"
-  wdir="$1"
-  while [ "$wdir" != '/' ] ; do
-    if [ -d "$wdir"/.mvn ] ; then
-      basedir=$wdir
-      break
-    fi
-    # workaround for JBEAP-8937 (on Solaris 10/Sparc)
-    if [ -d "${wdir}" ]; then
-      wdir=`cd "$wdir/.."; pwd`
-    fi
-    # end of workaround
-  done
-  echo "${basedir}"
-}
-
-# concatenates all lines of a file
-concat_lines() {
-  if [ -f "$1" ]; then
-    echo "$(tr -s '\n' ' ' < "$1")"
-  fi
-}
-
-BASE_DIR=`find_maven_basedir "$(pwd)"`
-if [ -z "$BASE_DIR" ]; then
-  exit 1;
-fi
-
-##########################################################################################
-# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
-# This allows using the maven wrapper in projects that prohibit checking in binary data.
-##########################################################################################
-if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
-    if [ "$MVNW_VERBOSE" = true ]; then
-      echo "Found .mvn/wrapper/maven-wrapper.jar"
-    fi
-else
-    if [ "$MVNW_VERBOSE" = true ]; then
-      echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
-    fi
-    if [ -n "$MVNW_REPOURL" ]; then
-      jarUrl="$MVNW_REPOURL/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
-    else
-      jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
-    fi
-    while IFS="=" read key value; do
-      case "$key" in (wrapperUrl) jarUrl="$value"; break ;;
-      esac
-    done < "$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
-    if [ "$MVNW_VERBOSE" = true ]; then
-      echo "Downloading from: $jarUrl"
-    fi
-    wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"
-    if $cygwin; then
-      wrapperJarPath=`cygpath --path --windows "$wrapperJarPath"`
-    fi
-
-    if command -v wget > /dev/null; then
-        if [ "$MVNW_VERBOSE" = true ]; then
-          echo "Found wget ... using wget"
-        fi
-        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
-            wget "$jarUrl" -O "$wrapperJarPath"
-        else
-            wget --http-user=$MVNW_USERNAME --http-password=$MVNW_PASSWORD "$jarUrl" -O "$wrapperJarPath"
-        fi
-    elif command -v curl > /dev/null; then
-        if [ "$MVNW_VERBOSE" = true ]; then
-          echo "Found curl ... using curl"
-        fi
-        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
-            curl -o "$wrapperJarPath" "$jarUrl" -f
-        else
-            curl --user $MVNW_USERNAME:$MVNW_PASSWORD -o "$wrapperJarPath" "$jarUrl" -f
-        fi
-
-    else
-        if [ "$MVNW_VERBOSE" = true ]; then
-          echo "Falling back to using Java to download"
-        fi
-        javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
-        # For Cygwin, switch paths to Windows format before running javac
-        if $cygwin; then
-          javaClass=`cygpath --path --windows "$javaClass"`
-        fi
-        if [ -e "$javaClass" ]; then
-            if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
-                if [ "$MVNW_VERBOSE" = true ]; then
-                  echo " - Compiling MavenWrapperDownloader.java ..."
-                fi
-                # Compiling the Java class
-                ("$JAVA_HOME/bin/javac" "$javaClass")
-            fi
-            if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
-                # Running the downloader
-                if [ "$MVNW_VERBOSE" = true ]; then
-                  echo " - Running MavenWrapperDownloader.java ..."
-                fi
-                ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
-            fi
-        fi
-    fi
-fi
-##########################################################################################
-# End of extension
-##########################################################################################
-
-export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
-if [ "$MVNW_VERBOSE" = true ]; then
-  echo $MAVEN_PROJECTBASEDIR
-fi
-MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
-
-# For Cygwin, switch paths to Windows format before running java
-if $cygwin; then
-  [ -n "$M2_HOME" ] &&
-    M2_HOME=`cygpath --path --windows "$M2_HOME"`
-  [ -n "$JAVA_HOME" ] &&
-    JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"`
-  [ -n "$CLASSPATH" ] &&
-    CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
-  [ -n "$MAVEN_PROJECTBASEDIR" ] &&
-    MAVEN_PROJECTBASEDIR=`cygpath --path --windows "$MAVEN_PROJECTBASEDIR"`
-fi
-
-# Provide a "standardized" way to retrieve the CLI args that will
-# work with both Windows and non-Windows executions.
-MAVEN_CMD_LINE_ARGS="$MAVEN_CONFIG $@"
-export MAVEN_CMD_LINE_ARGS
-
-WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
-
-exec "$JAVACMD" \
-  $MAVEN_OPTS \
-  -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
-  "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
-  ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"

docker/docker-spring-boot/mvnw.cmd

@@ -1,182 +0,0 @@
-@REM ----------------------------------------------------------------------------
-@REM Licensed to the Apache Software Foundation (ASF) under one
-@REM or more contributor license agreements.  See the NOTICE file
-@REM distributed with this work for additional information
-@REM regarding copyright ownership.  The ASF licenses this file
-@REM to you under the Apache License, Version 2.0 (the
-@REM "License"); you may not use this file except in compliance
-@REM with the License.  You may obtain a copy of the License at
-@REM
-@REM    https://www.apache.org/licenses/LICENSE-2.0
-@REM
-@REM Unless required by applicable law or agreed to in writing,
-@REM software distributed under the License is distributed on an
-@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
-@REM KIND, either express or implied.  See the License for the
-@REM specific language governing permissions and limitations
-@REM under the License.
-@REM ----------------------------------------------------------------------------
-
-@REM ----------------------------------------------------------------------------
-@REM Maven Start Up Batch script
-@REM
-@REM Required ENV vars:
-@REM JAVA_HOME - location of a JDK home dir
-@REM
-@REM Optional ENV vars
-@REM M2_HOME - location of maven2's installed home dir
-@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
-@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
-@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
-@REM     e.g. to debug Maven itself, use
-@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
-@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
-@REM ----------------------------------------------------------------------------
-
-@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
-@echo off
-@REM set title of command window
-title %0
-@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
-@if "%MAVEN_BATCH_ECHO%" == "on"  echo %MAVEN_BATCH_ECHO%
-
-@REM set %HOME% to equivalent of $HOME
-if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
-
-@REM Execute a user defined script before this one
-if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
-@REM check for pre script, once with legacy .bat ending and once with .cmd ending
-if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
-if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
-:skipRcPre
-
-@setlocal
-
-set ERROR_CODE=0
-
-@REM To isolate internal variables from possible post scripts, we use another setlocal
-@setlocal
-
-@REM ==== START VALIDATION ====
-if not "%JAVA_HOME%" == "" goto OkJHome
-
-echo.
-echo Error: JAVA_HOME not found in your environment. >&2
-echo Please set the JAVA_HOME variable in your environment to match the >&2
-echo location of your Java installation. >&2
-echo.
-goto error
-
-:OkJHome
-if exist "%JAVA_HOME%\bin\java.exe" goto init
-
-echo.
-echo Error: JAVA_HOME is set to an invalid directory. >&2
-echo JAVA_HOME = "%JAVA_HOME%" >&2
-echo Please set the JAVA_HOME variable in your environment to match the >&2
-echo location of your Java installation. >&2
-echo.
-goto error
-
-@REM ==== END VALIDATION ====
-
-:init
-
-@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
-@REM Fallback to current working directory if not found.
-
-set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
-IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
-
-set EXEC_DIR=%CD%
-set WDIR=%EXEC_DIR%
-:findBaseDir
-IF EXIST "%WDIR%"\.mvn goto baseDirFound
-cd ..
-IF "%WDIR%"=="%CD%" goto baseDirNotFound
-set WDIR=%CD%
-goto findBaseDir
-
-:baseDirFound
-set MAVEN_PROJECTBASEDIR=%WDIR%
-cd "%EXEC_DIR%"
-goto endDetectBaseDir
-
-:baseDirNotFound
-set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
-cd "%EXEC_DIR%"
-
-:endDetectBaseDir
-
-IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
-
-@setlocal EnableExtensions EnableDelayedExpansion
-for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
-@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
-
-:endReadAdditionalConfig
-
-SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
-set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
-set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
-
-set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
-
-FOR /F "tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
-    IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B
-)
-
-@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
-@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
-if exist %WRAPPER_JAR% (
-    if "%MVNW_VERBOSE%" == "true" (
-        echo Found %WRAPPER_JAR%
-    )
-) else (
-    if not "%MVNW_REPOURL%" == "" (
-        SET DOWNLOAD_URL="%MVNW_REPOURL%/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
-    )
-    if "%MVNW_VERBOSE%" == "true" (
-        echo Couldn't find %WRAPPER_JAR%, downloading it ...
-        echo Downloading from: %DOWNLOAD_URL%
-    )
-
-    powershell -Command "&{"^
-		"$webclient = new-object System.Net.WebClient;"^
-		"if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
-		"$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
-		"}"^
-		"[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^
-		"}"
-    if "%MVNW_VERBOSE%" == "true" (
-        echo Finished downloading %WRAPPER_JAR%
-    )
-)
-@REM End of extension
-
-@REM Provide a "standardized" way to retrieve the CLI args that will
-@REM work with both Windows and non-Windows executions.
-set MAVEN_CMD_LINE_ARGS=%*
-
-%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
-if ERRORLEVEL 1 goto error
-goto end
-
-:error
-set ERROR_CODE=1
-
-:end
-@endlocal & set ERROR_CODE=%ERROR_CODE%
-
-if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
-@REM check for post script, once with legacy .bat ending and once with .cmd ending
-if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
-if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
-:skipRcPost
-
-@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
-if "%MAVEN_BATCH_PAUSE%" == "on" pause
-
-if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%
-
-exit /B %ERROR_CODE%

docker/docker-spring-boot/pom.xml

@@ -3,33 +3,21 @@
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
+    <artifactId>docker-spring-boot</artifactId>
+    <name>docker-spring-boot</name>
+    <description>Demo project showing Spring Boot and Docker</description>
+
     <parent>
         <groupId>com.baeldung.docker</groupId>
         <artifactId>docker</artifactId>
         <version>0.0.1</version>
     </parent>
 
-    <artifactId>docker-spring-boot</artifactId>
-
-    <name>docker-spring-boot</name>
-    <description>Demo project showing Spring Boot and Docker</description>
-
-    <properties>
-        <java.version>11</java.version>
-    </properties>
-
     <dependencies>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
         </dependency>
-
-        <dependency>
-            <groupId>com.baeldung.docker</groupId>
-            <artifactId>docker-internal-dto</artifactId>
-            <version>0.0.1</version>
-        </dependency>
-
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>
@@ -58,4 +46,8 @@
         </plugins>
     </build>
 
+    <properties>
+        <java.version>11</java.version>
+    </properties>
+
 </project>

docker/heap-sizing/pom.xml

@@ -48,7 +48,6 @@
                 <groupId>com.google.cloud.tools</groupId>
                 <artifactId>jib-maven-plugin</artifactId>
                 <version>2.7.1</version>
-
                 <configuration>
                     <to>
                         <image>heapsizing-demo-jib</image>

docker/pom.xml

@@ -3,7 +3,6 @@
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
-
     <groupId>com.baeldung.docker</groupId>
     <artifactId>docker</artifactId>
     <version>0.0.1</version>
@@ -18,10 +17,6 @@
         <relativePath>../parent-boot-2</relativePath>
     </parent>
 
-    <properties>
-        <java.version>11</java.version>
-    </properties>
-
     <modules>
         <module>docker-internal-dto</module>
         <module>docker-spring-boot</module>
@@ -31,4 +26,8 @@
         <module>docker-push-to-private-repo</module>
     </modules>
 
+    <properties>
+        <java.version>11</java.version>
+    </properties>
+
 </project>

feign/pom.xml

@@ -1,5 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    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.feign</groupId>
     <artifactId>feign</artifactId>
@@ -69,6 +71,7 @@
             <scope>test</scope>
         </dependency>
     </dependencies>
+
     <build>
         <plugins>
             <plugin>
@@ -92,10 +95,8 @@
                     <sources>
                         <source>src/main/resources/users.xsd</source>
                     </sources>
-
                 </configuration>
             </plugin>
-
             <plugin>
                 <groupId>org.jvnet.jaxb2.maven2</groupId>
                 <artifactId>maven-jaxb2-plugin</artifactId>
@@ -111,7 +112,6 @@
                             <schemaIncludes>
                                 <include>*.xsd</include>
                             </schemaIncludes>
-
                             <generatePackage>com.baeldung.feign.soap</generatePackage>
                             <generateDirectory>target/generated-sources/jaxb</generateDirectory>
                         </configuration>
@@ -119,6 +119,6 @@
                 </executions>
             </plugin>
         </plugins>
-
     </build>
+
 </project>

graphql/graphql-error-handling/pom.xml

@@ -1,12 +1,12 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <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">
+    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>graphql-error-handling</artifactId>
     <version>1.0</version>
-    <packaging>jar</packaging>
     <name>graphql-error-handling</name>
+    <packaging>jar</packaging>
 
     <parent>
         <groupId>com.baeldung.graphql</groupId>
@@ -19,56 +19,47 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-data-jpa</artifactId>
         </dependency>
-
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
         </dependency>
-
         <dependency>
             <groupId>com.graphql-java</groupId>
             <artifactId>graphql-spring-boot-starter</artifactId>
             <version>${graphql-spring-boot-starter.version}</version>
         </dependency>
-
         <dependency>
             <groupId>com.graphql-java</groupId>
             <artifactId>graphql-java-tools</artifactId>
             <version>${graphql-java-tools.version}</version>
         </dependency>
-
         <dependency>
             <groupId>org.projectlombok</groupId>
             <artifactId>lombok</artifactId>
             <version>${lombok.version}</version>
         </dependency>
-
         <dependency>
             <groupId>com.h2database</groupId>
             <artifactId>h2</artifactId>
             <version>${h2.version}</version>
         </dependency>
-
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-test</artifactId>
             <scope>test</scope>
         </dependency>
-
         <dependency>
             <groupId>com.graphql-java</groupId>
             <artifactId>graphql-spring-boot-starter-test</artifactId>
             <scope>test</scope>
             <version>${graphql-spring-boot-starter.version}</version>
         </dependency>
-
         <dependency>
             <groupId>org.skyscreamer</groupId>
             <artifactId>jsonassert</artifactId>
             <version>${jsonassert.version}</version>
             <scope>test</scope>
         </dependency>
-
     </dependencies>
 
     <properties>

graphql/graphql-java/pom.xml

@@ -85,7 +85,6 @@
             <artifactId>httpclient</artifactId>
             <version>${httpclient.version}</version>
         </dependency>
-
         <dependency>
             <groupId>org.mock-server</groupId>
             <artifactId>mockserver-netty</artifactId>
@@ -98,13 +97,11 @@
             <version>${mockserver-client-java.version}</version>
             <scope>test</scope>
         </dependency>
-
         <dependency>
             <groupId>com.graphql-java</groupId>
             <artifactId>graphql-java-extended-scalars</artifactId>
             <version>${graphql-java-extended-scalars.version}</version>
         </dependency>
-
     </dependencies>
 
     <build>
@@ -155,12 +152,9 @@
         <ratpack-core.version>1.9.0</ratpack-core.version>
         <nodes.version>0.5.0</nodes.version>
         <httpclient.version>4.5.13</httpclient.version>
-
         <mockserver-netty.version>5.13.2</mockserver-netty.version>
         <mockserver-client-java.version>5.13.2</mockserver-client-java.version>
-
         <jetty-maven-plugin.version>10.0.7</jetty-maven-plugin.version>
-
         <graphql.java.generator.version>1.18</graphql.java.generator.version>
         <graphql-java-extended-scalars.version>2022-04-06T00-10-27-a70541e</graphql-java-extended-scalars.version>
     </properties>

graphql/graphql-java/src/test/java/com/baeldung/graphql/GraphQLMockServer.java

@@ -3,12 +3,13 @@ package com.baeldung.graphql;
 import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.BeforeAll;
 import org.mockserver.client.MockServerClient;
+import org.mockserver.configuration.Configuration;
 import org.mockserver.integration.ClientAndServer;
 import org.mockserver.model.HttpStatusCode;
+import org.slf4j.event.Level;
 
 import java.io.IOException;
 import java.net.ServerSocket;
-import java.net.URISyntaxException;
 
 import static org.mockserver.integration.ClientAndServer.startClientAndServer;
 import static org.mockserver.matchers.Times.exactly;
@@ -17,20 +18,22 @@ import static org.mockserver.model.HttpResponse.response;
 
 public class GraphQLMockServer {
 
-    public static ClientAndServer mockServer;
+    private static final String SERVER_ADDRESS = "127.0.0.1";
+    private static final String PATH = "/graphql";
+
     public static String serviceUrl;
 
+    private static ClientAndServer mockServer;
     private static int serverPort;
 
-    public static final String SERVER_ADDRESS = "127.0.0.1";
-    public static final String HTTP_GET_POST = "GET";
-    public static final String PATH = "/graphql";
-
     @BeforeAll
-    static void startServer() throws IOException, URISyntaxException {
+    static void startServer() throws IOException {
         serverPort = getFreePort();
         serviceUrl = "http://" + SERVER_ADDRESS + ":" + serverPort + PATH;
-        mockServer = startClientAndServer(serverPort);
+
+        Configuration config = Configuration.configuration().logLevel(Level.WARN);
+        mockServer = startClientAndServer(config, serverPort);
+
         mockAllBooksTitleRequest();
         mockAllBooksTitleAuthorRequest();
     }

graphql/graphql-spqr/pom.xml

@@ -28,4 +28,5 @@
     <properties>
         <graphql-spqr-spring-boot-starter-version>0.0.6</graphql-spqr-spring-boot-starter-version>
     </properties>
+
 </project>

grpc/pom.xml

@@ -40,7 +40,7 @@
         <dependency>
             <groupId>javax.annotation</groupId>
             <artifactId>javax.annotation-api</artifactId>
-            <version>1.2</version>
+            <version>${annotation-api.version}</version>
         </dependency>
     </dependencies>
 
@@ -79,6 +79,7 @@
         <protoc.version>3.17.2</protoc.version>
         <os-maven-plugin.version>1.6.2</os-maven-plugin.version>
         <protobuf-maven-plugin.version>0.6.1</protobuf-maven-plugin.version>
+        <annotation-api.version>1.2</annotation-api.version>
     </properties>
 
 </project>

jakarta-ee/pom.xml

@@ -51,25 +51,20 @@
                     <user>admin</user>
                     <!-- <passwordFile>${local.glassfish.passfile}</passwordFile> -->
                     <adminPassword>password</adminPassword>
-
                     <domain>
                         <name>${local.glassfish.domain}</name>
                         <httpPort>8080</httpPort>
                         <adminPort>4848</adminPort>
-
                     </domain>
                     <components>
                         <component>
                             <name>${project.artifactId}</name>
                             <artifact>target/${project.build.finalName}.war</artifact>
-
                         </component>
                     </components>
                     <debug>true</debug>
                     <terse>false</terse>
                     <echo>true</echo>
-
-
                 </configuration>
             </plugin>
             <plugin>

java-numbers-4/pom.xml

@@ -23,7 +23,6 @@
             <groupId>org.apache.commons</groupId>
             <artifactId>commons-lang3</artifactId>
             <version>${commons-lang3.version}</version>
-            <scope>test</scope>
         </dependency>
         <dependency>
             <groupId>com.google.guava</groupId>

java-numbers-4/src/main/java/com/baeldung/booleantoint/BooleanToInt.java

@@ -0,0 +1,42 @@
+package com.baeldung.booleantoint;
+
+import org.apache.commons.lang3.BooleanUtils;
+
+public class BooleanToInt {
+    public static int booleanPrimitiveToInt(boolean foo) {
+        int bar = 0;
+        if (foo) {
+            bar = 1;
+        }
+        return bar;
+    }
+
+    public static int booleanPrimitiveToIntTernary(boolean foo) {
+        return (foo) ? 1 : 0;
+    }
+
+    public static int booleanObjectToInt(boolean foo) {
+        return Boolean.compare(foo, false);
+    }
+
+    public static int booleanObjectToIntInverse(boolean foo) {
+        return Boolean.compare(foo, true) + 1;
+    }
+
+    public static int booleanObjectMethodToInt(Boolean foo) {
+        return foo.compareTo(false);
+    }
+
+    public static int booleanObjectMethodToIntInverse(Boolean foo) {
+        return foo.compareTo(true) + 1;
+    }
+
+    public static int booleanUtilsToInt(Boolean foo) {
+        return BooleanUtils.toInteger(foo);
+    }
+
+    public static int bitwiseBooleanToInt(Boolean foo) {
+        return (Boolean.hashCode(foo) >> 1) & 1;
+    }
+}
+

java-numbers-4/src/main/java/com/baeldung/reversenumber/ReverseNumber.java

@@ -0,0 +1,45 @@
+package com.baeldung.reversenumber;
+
+public class ReverseNumber {
+
+    public static int reverseNumberWhileLoop(int number) {
+        int reversedNumber = 0;
+        int numberToReverse = Math.abs(number);
+
+        while (numberToReverse > 0) {
+            int mod = numberToReverse % 10;
+            reversedNumber = reversedNumber * 10 + mod;
+            numberToReverse /= 10;
+        }
+
+        return number < 0 ? reversedNumber * -1 : reversedNumber;
+    }
+
+    public static int reverseNumberForLoop(int number) {
+        int reversedNumber = 0;
+        int numberToReverse = Math.abs(number);
+
+        for (; numberToReverse > 0; numberToReverse /= 10) {
+            int mod = numberToReverse % 10;
+            reversedNumber = reversedNumber * 10 + mod;
+        }
+
+        return number < 0 ? reversedNumber * -1 : reversedNumber;
+    }
+
+    public static int reverseNumberRecWrapper(int number) {
+        int output = reverseNumberRec(Math.abs(number), 0);
+        return number < 0 ? output * -1 : output;
+    }
+    private static int reverseNumberRec(int numberToReverse, int recursiveReversedNumber) {
+
+        if (numberToReverse > 0) {
+            int mod = numberToReverse % 10;
+            recursiveReversedNumber = recursiveReversedNumber * 10 + mod;
+            numberToReverse /= 10;
+            return reverseNumberRec(numberToReverse, recursiveReversedNumber);
+        }
+
+        return recursiveReversedNumber;
+    }
+}

java-numbers-4/src/test/java/com/baeldung/booleantoint/BooleanToIntUnitTest.java

@@ -0,0 +1,55 @@
+package com.baeldung.booleantoint;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class BooleanToIntUnitTest {
+    @Test
+    void givenBooleanPrimitiveValue_ThenReturnInt() {
+        assertEquals(1, BooleanToInt.booleanPrimitiveToInt(true));
+        assertEquals(0, BooleanToInt.booleanPrimitiveToInt(false));
+    }
+
+    @Test
+    void givenBooleanPrimitiveValue_ThenReturnIntTernary() {
+        assertEquals(1, BooleanToInt.booleanPrimitiveToIntTernary(true));
+        assertEquals(0, BooleanToInt.booleanPrimitiveToIntTernary(false));
+    }
+
+    @Test
+    void givenBooleanObject_ThenReturnInt() {
+        assertEquals(0, BooleanToInt.booleanObjectToInt(false));
+        assertEquals(1, BooleanToInt.booleanObjectToInt(true));
+    }
+
+    @Test
+    void givenBooleanObject_ThenReturnIntInverse() {
+        assertEquals(0, BooleanToInt.booleanObjectToIntInverse(false));
+        assertEquals(1, BooleanToInt.booleanObjectToIntInverse(true));
+    }
+
+    @Test
+    void givenBooleanObject_ThenReturnIntUsingClassMethod() {
+        assertEquals(0, BooleanToInt.booleanObjectMethodToInt(false));
+        assertEquals(1, BooleanToInt.booleanObjectMethodToInt(true));
+    }
+
+    @Test
+    void givenBooleanObject_ThenReturnIntUsingClassMethodInverse() {
+        assertEquals(0, BooleanToInt.booleanObjectMethodToIntInverse(false));
+        assertEquals(1, BooleanToInt.booleanObjectMethodToIntInverse(true));
+    }
+
+    @Test
+    void givenBoolean_ThenReturnIntUsingBooleanUtils() {
+        assertEquals(0, BooleanToInt.booleanUtilsToInt(false));
+        assertEquals(1, BooleanToInt.booleanUtilsToInt(true));
+    }
+
+    @Test
+    void givenBoolean_ThenReturnIntUsingBitwiseOperators() {
+        assertEquals(0, BooleanToInt.bitwiseBooleanToInt(false));
+        assertEquals(1, BooleanToInt.bitwiseBooleanToInt(true));
+    }
+}

java-numbers-4/src/test/java/com/baeldung/reversenumber/ReverseNumberUnitTest.java

@@ -0,0 +1,34 @@
+package com.baeldung.reversenumber;
+
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class ReverseNumberUnitTest {
+
+    private static final int ORIGINAL_NUMBER = 123456789;
+    private static final int REVERSED_NUMBER = 987654321;
+
+    @Test
+    void whenReverseNumberWhileLoop_thenOriginalEqualToReverse() {
+        Assertions.assertThat(ReverseNumber.reverseNumberWhileLoop(ORIGINAL_NUMBER)).isEqualTo(REVERSED_NUMBER);
+    }
+
+    @Test
+    void whenReverseNumberForLoop_thenOriginalEqualToReverse() {
+        Assertions.assertThat(ReverseNumber.reverseNumberForLoop(ORIGINAL_NUMBER)).isEqualTo(REVERSED_NUMBER);
+    }
+
+    @Test
+    void whenReverseNumberRec_thenOriginalEqualToReverse() {
+        Assertions.assertThat(ReverseNumber.reverseNumberRecWrapper(ORIGINAL_NUMBER)).isEqualTo(REVERSED_NUMBER);
+    }
+
+    @Test
+    void whenReverseNegativeNumber_thenNumberShouldReverse() {
+        Assertions.assertThat(ReverseNumber.reverseNumberWhileLoop(ORIGINAL_NUMBER * -1)).isEqualTo(REVERSED_NUMBER * -1);
+        Assertions.assertThat(ReverseNumber.reverseNumberForLoop(ORIGINAL_NUMBER * -1)).isEqualTo(REVERSED_NUMBER * -1);
+        Assertions.assertThat(ReverseNumber.reverseNumberRecWrapper(ORIGINAL_NUMBER * -1)).isEqualTo(REVERSED_NUMBER * -1);
+    }
+}

jib/pom.xml

@@ -43,4 +43,5 @@
     <properties>
         <jib-maven-plugin.version>2.5.0</jib-maven-plugin.version>
     </properties>
+
 </project>

json-2/pom.xml

@@ -27,7 +27,7 @@
         <dependency>
             <groupId>org.jsonschema2pojo</groupId>
             <artifactId>jsonschema2pojo-core</artifactId>
-            <version>1.1.1</version>
+            <version>${jsonschema2pojo-core.version}</version>
         </dependency>
         <dependency>
             <groupId>com.jsoniter</groupId>
@@ -62,7 +62,7 @@
         <dependency>
             <groupId>com.io-informatics.oss</groupId>
             <artifactId>jackson-jsonld</artifactId>
-            <version>0.1.1</version>
+            <version>${jackson-jsonld.version}</version>
             <exclusions>
                 <exclusion>
                     <artifactId>jackson-databind</artifactId>
@@ -85,7 +85,7 @@
         <dependency>
             <groupId>de.escalon.hypermedia</groupId>
             <artifactId>hydra-jsonld</artifactId>
-            <version>0.4.2</version>
+            <version>${hydra-jsonld.version}</version>
             <exclusions>
                 <exclusion>
                     <artifactId>jackson-databind</artifactId>
@@ -96,7 +96,7 @@
         <dependency>
             <groupId>com.github.jsonld-java</groupId>
             <artifactId>jsonld-java</artifactId>
-            <version>0.13.0</version>
+            <version>${jsonld-java.version}</version>
             <exclusions>
                 <exclusion>
                     <artifactId>jackson-core</artifactId>
@@ -154,6 +154,10 @@
         <moshi.version>1.9.2</moshi.version>
         <fastjson.version>1.2.21</fastjson.version>
         <json.version>20211205</json.version>
+        <jsonschema2pojo-core.version>1.1.1</jsonschema2pojo-core.version>
+        <jackson-jsonld.version>0.1.1</jackson-jsonld.version>
+        <hydra-jsonld.version>0.4.2</hydra-jsonld.version>
+        <jsonld-java.version>0.13.0</jsonld-java.version>
     </properties>
 
 </project>

kubernetes/k8s-intro/pom.xml

@@ -15,7 +15,7 @@
         <dependency>
             <groupId>io.kubernetes</groupId>
             <artifactId>client-java</artifactId>
-            <version>11.0.0</version>
+            <version>${client-java.version}</version>
         </dependency>
         <dependency>
             <groupId>ch.qos.logback</groupId>
@@ -39,4 +39,8 @@
         </plugins>
     </build>
 
+    <properties>
+        <client-java.version>11.0.0</client-java.version>
+    </properties>
+
 </project>

libraries-3/pom.xml

@@ -112,7 +112,7 @@
             <artifactId>structurizr-plantuml</artifactId>
             <version>${structurizr.version}</version>
         </dependency>
-         <dependency>
+        <dependency>
             <groupId>org.immutables</groupId>
             <artifactId>value</artifactId>
             <version>${immutables.version}</version>

libraries-data/pom.xml

@@ -172,9 +172,9 @@
         <kafka.version>1.0.0</kafka.version>
         <ignite.version>2.4.0</ignite.version>
         <gson.version>2.8.2</gson.version>
-        <cache.version>1.1.0</cache.version>
+        <cache.version>1.1.1</cache.version>
         <flink.version>1.5.0</flink.version>
-        <hazelcast.version>3.8.4</hazelcast.version>
+        <hazelcast.version>5.1.1</hazelcast.version>
         <org.apache.crunch.crunch-core.version>0.15.0</org.apache.crunch.crunch-core.version>
         <org.apache.hadoop.hadoop-client>2.2.0</org.apache.hadoop.hadoop-client>
         <jmapper.version>1.6.0.1</jmapper.version>

maven-modules/host-maven-repo-example/pom.xml

@@ -6,11 +6,11 @@
     <groupId>com.baeldung.maven.plugin</groupId>
     <artifactId>host-maven-repo-example</artifactId>
     <version>1.0-SNAPSHOT</version>
-    <url>https://github.com/sgrverma23/host-maven-repo-example.git</url>
+    <url>https://github.com/${repository-owner}/${repository-name}.git</url>
     <scm>
-        <url>https://github.com/sgrverma23/host-maven-repo-example.git</url>
-        <connection>scm:git:git@github.com:sgrverma23/host-maven-repo-example.git</connection>
-        <developerConnection>scm:git:git@github.com:sgrverma23/host-maven-repo-example.git</developerConnection>
+        <url>https://github.com/${repository-owner}/${repository-name}.git</url>
+        <connection>scm:git:git@github.com:${repository-owner}/${repository-name}.git</connection>
+        <developerConnection>scm:git:git@github.com:${repository-owner}/${repository-name}.git</developerConnection>
     </scm>
     <distributionManagement>
         <repository>
@@ -43,13 +43,13 @@
                     <message>Maven artifacts for ${project.version}</message>
                     <noJekyll>true</noJekyll>
                     <outputDirectory>${project.build.directory}</outputDirectory>
-                    <branch>refs/heads/main</branch>
+                    <branch>refs/heads/${branch-name}</branch>
                     <includes>
                         <include>**/*</include>
                     </includes>
                     <merge>true</merge>
-                    <repositoryName>host-maven-repo-example</repositoryName>
-                    <repositoryOwner>sgrverma23</repositoryOwner>
+                    <repositoryName>${repository-name}</repositoryName>
+                    <repositoryOwner>${repository-owner}</repositoryOwner>
                     <server>github</server>
                 </configuration>
                 <executions>
@@ -89,7 +89,7 @@
     <repositories>
         <repository>
             <id>PROJECT-REPO-URL</id>
-            <url>https://github.com/sgrverma23/host-maven-repo-example/main</url>
+            <url>https://github.com/${repository-owner}/${repository-name}/${branch-name}</url>
             <snapshots>
                 <enabled>true</enabled>
                 <updatePolicy>always</updatePolicy>
@@ -98,6 +98,10 @@
     </repositories>
 
     <properties>
+        <!--Put your own  properties-->
+        <repository-owner>Put-repo-owner</repository-owner>
+        <repository-name>Put-repository-name</repository-name>
+        <branch-name>Put-branch-name</branch-name>
         <github.global.server>github</github.global.server>
         <maven.compiler.source>8</maven.compiler.source>
         <maven.compiler.target>8</maven.compiler.target>

maven-modules/maven-parent-pom-resolution/disable-plugin-examples/empty-phase/pom.xml

@@ -21,7 +21,7 @@
                 <executions>
                     <execution>
                         <id>enforce-file-exists</id>
-                        <phase/>
+                        <phase />
                     </execution>
                 </executions>
             </plugin>

maven-modules/maven-parent-pom-resolution/disable-plugin-examples/pom.xml

@@ -14,6 +14,13 @@
         <version>1.0.0-SNAPSHOT</version>
     </parent>
 
+    <modules>
+        <module>plugin-enabled</module>
+        <module>skip-parameter</module>
+        <module>phase-none</module>
+        <module>empty-phase</module>
+    </modules>
+
     <build>
         <plugins>
             <plugin>
@@ -27,13 +34,13 @@
                             <goal>enforce</goal>
                         </goals>
                         <configuration>
-                          <rules>
-                            <requireFilesExist>
-                                <files>
-                                    <file>${project.basedir}/src/file-that-must-exist.txt</file>
-                                </files>
-                            </requireFilesExist>
-                          </rules>
+                            <rules>
+                                <requireFilesExist>
+                                    <files>
+                                        <file>${project.basedir}/src/file-that-must-exist.txt</file>
+                                    </files>
+                                </requireFilesExist>
+                            </rules>
                         </configuration>
                     </execution>
                 </executions>
@@ -41,13 +48,6 @@
         </plugins>
     </build>
 
-    <modules>
-        <module>plugin-enabled</module>
-        <module>skip-parameter</module>
-        <module>phase-none</module>
-        <module>empty-phase</module>
-    </modules>
-
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     </properties>

maven-modules/maven-simple/parent-project/core/pom.xml

@@ -23,4 +23,5 @@
     <properties>
         <spring-core.version>4.3.30.RELEASE</spring-core.version>
     </properties>
+
 </project>

maven-modules/maven-simple/parent-project/pom.xml

@@ -33,4 +33,5 @@
     <properties>
         <spring-core.version>5.3.16</spring-core.version>
     </properties>
+
 </project>

maven-modules/maven-simple/parent-project/webapp/pom.xml

@@ -5,7 +5,6 @@
     <modelVersion>4.0.0</modelVersion>
     <artifactId>webapp</artifactId>
     <name>webapp</name>
-
     <packaging>war</packaging>
 
     <parent>
@@ -30,4 +29,5 @@
     <properties>
         <maven-war-plugin.version>3.3.2</maven-war-plugin.version>
     </properties>
+
 </project>

maven-modules/pom.xml

@@ -15,8 +15,8 @@
     </parent>
 
     <modules>
-    	<module>animal-sniffer-mvn-plugin</module>
-    	<module>maven-archetype</module>
+        <module>animal-sniffer-mvn-plugin</module>
+        <module>maven-archetype</module>
         <!-- <module>compiler-plugin-java-9</module> --> <!-- We haven't upgraded to java 9. -->
         <module>maven-copy-files</module>
         <module>maven-custom-plugin</module>

muleesb/pom.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
-<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/maven-v4_0_0.xsd">
+<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/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.mycompany</groupId>
     <artifactId>muleesb</artifactId>

persistence-modules/core-java-persistence-2/example.csv

@@ -0,0 +1,4 @@
+Username,Id,First name,Last name
+doe1,7173,John,Doe
+smith3,3722,Dana,Smith
+john22,5490,John,Wang

persistence-modules/core-java-persistence-2/pom.xml

@@ -1,7 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<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">
+<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.core-java-persistence-2</groupId>
     <artifactId>core-java-persistence-2</artifactId>
@@ -41,6 +39,20 @@
             <artifactId>mssql-jdbc</artifactId>
             <version>${mssql.driver.version}</version>
         </dependency>
+
+
+        <dependency>
+            <groupId>org.jooq</groupId>
+            <artifactId>jooq</artifactId>
+            <version>3.11.11</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.json</groupId>
+            <artifactId>json</artifactId>
+            <version>20220320</version>
+        </dependency>
+
     </dependencies>
 
     <properties>

persistence-modules/core-java-persistence-2/src/main/java/com/baeldung/resultset2json/ResultSet2JSON.java

@@ -0,0 +1,137 @@
+package com.baeldung.resultset2json;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.ResultSet;
+import java.sql.ResultSetMetaData;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+import org.jooq.Record;
+import org.jooq.RecordMapper;
+import org.jooq.impl.DSL;
+import org.json.JSONException;
+import org.json.JSONObject;
+import org.json.JSONArray;
+
+public class ResultSet2JSON {
+
+    public static void main(String... args) throws ClassNotFoundException, SQLException {
+
+        ResultSet2JSON testClass = new ResultSet2JSON();
+        testClass.convertWithoutJOOQ();
+    }
+
+    public void convertWithoutJOOQ() throws ClassNotFoundException, SQLException {
+        Class.forName("org.h2.Driver");
+        Connection dbConnection = DriverManager.getConnection("jdbc:h2:mem:rs2jdbc", "user", "password");
+
+        // Create a table
+        Statement stmt = dbConnection.createStatement();
+        stmt.execute("CREATE TABLE words AS SELECT * FROM CSVREAD('./example.csv')");
+        ResultSet resultSet = stmt.executeQuery("SELECT * FROM words");
+
+        JSONArray result1 = resultSet2JdbcWithoutJOOQ(resultSet);
+        System.out.println(result1);
+
+        resultSet.close();
+    }
+
+    public void convertUsingJOOQDefaultApproach() throws ClassNotFoundException, SQLException {
+        Class.forName("org.h2.Driver");
+        Connection dbConnection = DriverManager.getConnection("jdbc:h2:mem:rs2jdbc", "user", "password");
+        // Create a table
+        Statement stmt = dbConnection.createStatement();
+        stmt.execute("CREATE TABLE words AS SELECT * FROM CSVREAD('./example.csv')");
+        ResultSet resultSet = stmt.executeQuery("SELECT * FROM words");
+
+        JSONObject result1 = resultSet2JdbcUsingJOOQDefaultApproach(resultSet, dbConnection);
+        System.out.println(result1);
+
+        resultSet.close();
+    }
+
+    public void convertUsingCustomisedJOOQ() throws ClassNotFoundException, SQLException {
+        Class.forName("org.h2.Driver");
+        Connection dbConnection = DriverManager.getConnection("jdbc:h2:mem:rs2jdbc", "user", "password");
+        // Create a table
+        Statement stmt = dbConnection.createStatement();
+        stmt.execute("CREATE TABLE words AS SELECT * FROM CSVREAD('./example.csv')");
+        ResultSet resultSet = stmt.executeQuery("SELECT * FROM words");
+
+        JSONArray result1 = resultSet2JdbcUsingCustomisedJOOQ(resultSet, dbConnection);
+        System.out.println(result1);
+
+        resultSet.close();
+    }
+
+    public static JSONArray resultSet2JdbcWithoutJOOQ(ResultSet resultSet) throws SQLException {
+        ResultSetMetaData md = resultSet.getMetaData();
+        int numCols = md.getColumnCount();
+        List<String> colNames = IntStream.range(0, numCols)
+            .mapToObj(i -> {
+                try {
+                    return md.getColumnName(i + 1);
+                } catch (SQLException e) {
+
+                    e.printStackTrace();
+                    return "?";
+                }
+            })
+            .collect(Collectors.toList());
+
+        JSONArray result = new JSONArray();
+        while (resultSet.next()) {
+            JSONObject row = new JSONObject();
+            colNames.forEach(cn -> {
+                try {
+                    row.put(cn, resultSet.getObject(cn));
+                } catch (JSONException | SQLException e) {
+
+                    e.printStackTrace();
+                }
+            });
+            result.put(row);
+        }
+        return result;
+    }
+
+    public static JSONObject resultSet2JdbcUsingJOOQDefaultApproach(ResultSet resultSet, Connection dbConnection) throws SQLException {
+        JSONObject result = new JSONObject(DSL.using(dbConnection)
+            .fetch(resultSet)
+            .formatJSON());
+        return result;
+    }
+
+    public static JSONArray resultSet2JdbcUsingCustomisedJOOQ(ResultSet resultSet, Connection dbConnection) throws SQLException {
+        ResultSetMetaData md = resultSet.getMetaData();
+        int numCols = md.getColumnCount();
+        List<String> colNames = IntStream.range(0, numCols)
+            .mapToObj(i -> {
+                try {
+                    return md.getColumnName(i + 1);
+                } catch (SQLException e) {
+
+                    e.printStackTrace();
+                    return "?";
+                }
+            })
+            .collect(Collectors.toList());
+
+        List<JSONObject> json = DSL.using(dbConnection)
+            .fetch(resultSet)
+            .map(new RecordMapper<Record, JSONObject>() {
+
+                @Override
+                public JSONObject map(Record r) {
+                    JSONObject obj = new JSONObject();
+                    colNames.forEach(cn -> obj.put(cn, r.get(cn)));
+                    return obj;
+                }
+            });
+    return new JSONArray(json);
+    }
+}

persistence-modules/core-java-persistence-2/src/test/java/com/baeldung/resultset2json/ResultSet2JSONUnitTest.java

@@ -0,0 +1,75 @@
+package com.baeldung.resultset2json;
+
+import static com.baeldung.resultset2json.ResultSet2JSON.resultSet2JdbcWithoutJOOQ;
+import static com.baeldung.resultset2json.ResultSet2JSON.resultSet2JdbcUsingJOOQDefaultApproach;
+import static com.baeldung.resultset2json.ResultSet2JSON.resultSet2JdbcUsingCustomisedJOOQ;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Statement;
+
+import org.json.JSONArray;
+import org.json.JSONObject;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class ResultSet2JSONUnitTest {
+  JSONObject object = new JSONObject(
+    "{\"records\":[[\"doe1\",\"7173\",\"John\",\"Doe\"],[\"smith3\",\"3722\",\"Dana\",\"Smith\"],[\"john22\",\"5490\",\"John\",\"Wang\"]],\"fields\":[{\"schema\":\"PUBLIC\",\"name\":\"USERNAME\",\"type\":\"VARCHAR\",\"table\":\"WORDS\"},{\"schema\":\"PUBLIC\",\"name\":\"ID\",\"type\":\"VARCHAR\",\"table\":\"WORDS\"},{\"schema\":\"PUBLIC\",\"name\":\"First name\",\"type\":\"VARCHAR\",\"table\":\"WORDS\"},{\"schema\":\"PUBLIC\",\"name\":\"Last name\",\"type\":\"VARCHAR\",\"table\":\"WORDS\"}]}");
+
+  JSONArray array = new JSONArray(
+    "[{\"USERNAME\":\"doe1\",\"First name\":\"John\",\"ID\":\"7173\",\"Last name\":\"Doe\"},{\"USERNAME\":\"smith3\",\"First name\":\"Dana\",\"ID\":\"3722\",\"Last name\":\"Smith\"},{\"USERNAME\":\"john22\",\"First name\":\"John\",\"ID\":\"5490\",\"Last name\":\"Wang\"}]");
+
+  @Test
+  void whenResultSetConvertedWithoutJOOQ_shouldMatchJSON() throws SQLException, ClassNotFoundException {
+    Class.forName("org.h2.Driver");
+    Connection dbConnection = DriverManager.getConnection("jdbc:h2:mem:rs2jdbc1", "user", "password");
+
+    // Create a table
+    Statement stmt = dbConnection.createStatement();
+    stmt.execute("CREATE TABLE words AS SELECT * FROM CSVREAD('./example.csv')");
+    ResultSet resultSet = stmt.executeQuery("SELECT * FROM words");
+
+    JSONArray result1 = resultSet2JdbcWithoutJOOQ(resultSet);
+
+    resultSet.close();
+
+    assertTrue(array.similar(result1));
+  }
+
+  @Test
+  void whenResultSetConvertedUsingJOOQDefaultApproach_shouldMatchJSON() throws SQLException, ClassNotFoundException {
+    Class.forName("org.h2.Driver");
+    Connection dbConnection = DriverManager.getConnection("jdbc:h2:mem:rs2jdbc2", "user", "password");
+    // Create a table
+    Statement stmt = dbConnection.createStatement();
+    stmt.execute("CREATE TABLE words AS SELECT * FROM CSVREAD('./example.csv')");
+    ResultSet resultSet = stmt.executeQuery("SELECT * FROM words");
+
+    JSONObject result2 = resultSet2JdbcUsingJOOQDefaultApproach(resultSet, dbConnection);
+
+    resultSet.close();
+
+    assertTrue(object.similar(result2));
+  }
+
+  @Test
+  void whenResultSetConvertedUsingCustomisedJOOQ_shouldMatchJSON() throws SQLException, ClassNotFoundException {
+    Class.forName("org.h2.Driver");
+    Connection dbConnection = DriverManager.getConnection("jdbc:h2:mem:rs2jdbc3", "user", "password");
+    // Create a table
+    Statement stmt = dbConnection.createStatement();
+    stmt.execute("CREATE TABLE words AS SELECT * FROM CSVREAD('./example.csv')");
+    ResultSet resultSet = stmt.executeQuery("SELECT * FROM words");
+
+    JSONArray result3 = resultSet2JdbcUsingCustomisedJOOQ(resultSet, dbConnection);
+
+    resultSet.close();
+
+    assertTrue(array.similar(result3));
+  }
+
+}

persistence-modules/hibernate-annotations/pom.xml

@@ -16,7 +16,7 @@
     </parent>
 
     <dependencies>
-    	<!-- Spring -->
+        <!-- Spring -->
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-context</artifactId>
@@ -32,7 +32,7 @@
             <artifactId>hibernate-core</artifactId>
             <version>${hibernate-core.version}</version>
         </dependency>
-            <dependency>
+        <dependency>
             <groupId>org.hsqldb</groupId>
             <artifactId>hsqldb</artifactId>
             <version>${hsqldb.version}</version>

persistence-modules/hibernate-queries/README.md

@@ -11,3 +11,4 @@ This module contains articles about use of Queries in Hibernate.
 - [Hibernate Query Plan Cache](https://www.baeldung.com/hibernate-query-plan-cache)
 - [Hibernate’s addScalar() Method](https://www.baeldung.com/hibernate-addscalar)
 - [Distinct Queries in HQL](https://www.baeldung.com/java-hql-distinct)
+- [JPA and Hibernate – Criteria vs. JPQL vs. HQL Query](https://www.baeldung.com/jpql-hql-criteria-query)

persistence-modules/hibernate-queries/pom.xml

@@ -14,7 +14,7 @@
     </parent>
 
     <dependencies>
-    <!-- Spring -->
+        <!-- Spring -->
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-context</artifactId>
@@ -30,8 +30,7 @@
             <artifactId>tomcat-dbcp</artifactId>
             <version>${tomcat-dbcp.version}</version>
         </dependency>
-        
-         <!-- validation -->
+        <!-- validation -->
         <!-- utils -->
         <dependency>
             <groupId>com.google.guava</groupId>
@@ -45,7 +44,6 @@
             <version>${org.springframework.version}</version>
             <scope>test</scope>
         </dependency>
-        
         <dependency>
             <groupId>org.hibernate</groupId>
             <artifactId>hibernate-core</artifactId>
@@ -81,7 +79,6 @@
             <artifactId>jmh-generator-annprocess</artifactId>
             <version>${jmh-generator.version}</version>
         </dependency>
-        
     </dependencies>
 
     <properties>

persistence-modules/hibernate-queries/src/test/java/com/baeldung/hibernate/criteria/EmployeeCriteriaIntegrationTest.java

@@ -32,5 +32,4 @@ public class EmployeeCriteriaIntegrationTest {
         session.close();
         assertArrayEquals(expectedSortCritEmployeeList.toArray(), employeeCriteriaQueries.getAllEmployees().toArray());
     }
-
 }

persistence-modules/pom.xml

@@ -60,6 +60,7 @@
         <module>spring-boot-persistence</module>
         <module>spring-boot-persistence-h2</module>
         <module>spring-boot-persistence-mongodb</module>
+        <module>spring-boot-persistence-mongodb-2</module>
         <module>spring-data-arangodb</module>
         <module>spring-data-cassandra</module>
         <module>spring-data-cassandra-test</module>

persistence-modules/spring-boot-mysql/pom.xml

@@ -39,7 +39,7 @@
     </dependencies>
 
     <properties>
-        <mysql-connector-java.version>8.0.12</mysql-connector-java.version>
+        <mysql-connector-java.version>8.0.23</mysql-connector-java.version>
     </properties>
 
 </project>

persistence-modules/spring-boot-mysql/src/main/resources/application.yml

@@ -1,6 +1,6 @@
 spring:
   datasource:
-    url: jdbc:mysql://localhost:3306/test?useLegacyDatetimeCode=false
+    url: jdbc:mysql://localhost:3306/test?
     username: root
     password:
 
@@ -9,6 +9,6 @@ spring:
       ddl-auto: update
     properties:
       hibernate:
-        dialect: org.hibernate.dialect.MySQL5Dialect
+        dialect: org.hibernate.dialect.MySQL8Dialect
         jdbc:
           time_zone: UTC

persistence-modules/spring-boot-persistence-mongodb-2/.gitignore

@@ -0,0 +1,2 @@
+/.idea/
+/target/

persistence-modules/spring-boot-persistence-mongodb-2/README.md

@@ -0,0 +1,4 @@
+# Relevant Articles
+
+- [Logging MongoDB Queries with Spring Boot](https://www.baeldung.com/spring-boot-mongodb-logging)
+- More articles: [[<--prev]](../spring-boot-persistence-mongodb)

persistence-modules/spring-boot-persistence-mongodb-2/pom.xml

@@ -0,0 +1,35 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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-boot-persistence-mongodb-2</artifactId>
+    <name>spring-boot-persistence-mongodb-2</name>
+    <packaging>war</packaging>
+    <description>This is simple boot application for Spring boot persistence mongodb test</description>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-boot-2</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../../parent-boot-2</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-mongodb</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>de.flapdoodle.embed</groupId>
+            <artifactId>de.flapdoodle.embed.mongo</artifactId>
+            <version>${embed.mongo.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <embed.mongo.version>3.2.6</embed.mongo.version>
+    </properties>
+
+</project>

persistence-modules/spring-boot-persistence-mongodb-2/src/main/java/com/baeldung/SpringBootPersistenceApplication.java

@@ -0,0 +1,13 @@
+package com.baeldung;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SpringBootPersistenceApplication {
+
+    public static void main(String ... args) {
+        SpringApplication.run(SpringBootPersistenceApplication.class, args);
+    }
+
+}

persistence-modules/spring-boot-persistence-mongodb-2/src/main/resources/application.properties

@@ -0,0 +1 @@
+spring.application.name=spring-boot-persistence-mongodb-2