Merge branch 'eugenp:master' into master

core-java-modules/core-java-14/pom.xml

@@ -14,6 +14,15 @@
         <version>1.0.0-SNAPSHOT</version>
     </parent>
 
+    <dependencies>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>1.18.24</version>
+            <scope>provided</scope>
+        </dependency>
+    </dependencies>
+
     <build>
         <plugins>
             <plugin>

core-java-modules/core-java-14/src/main/java/com/baeldung/java14/recordvslombok/ColorData.java

@@ -0,0 +1,18 @@
+package com.baeldung.java14.recordvslombok;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+
+@Data
+@AllArgsConstructor
+public class ColorData {
+
+    private int red;
+    private int green;
+    private int blue;
+
+    public String getHexString() {
+        return String.format("#%02X%02X%02X", red, green, blue);
+    }
+
+}

core-java-modules/core-java-14/src/main/java/com/baeldung/java14/recordvslombok/ColorRecord.java

@@ -0,0 +1,8 @@
+package com.baeldung.java14.recordvslombok;
+
+public record ColorRecord(int red, int green, int blue) {
+
+    public String getHexString() {
+        return String.format("#%02X%02X%02X", red, green, blue);
+    }
+}

core-java-modules/core-java-14/src/main/java/com/baeldung/java14/recordvslombok/ColorValueObject.java

@@ -0,0 +1,17 @@
+package com.baeldung.java14.recordvslombok;
+
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.Value;
+
+@Value
+@Getter(AccessLevel.NONE)
+public class ColorValueObject {
+    int red;
+    int green;
+    int blue;
+
+    public String getHexString() {
+        return String.format("#%02X%02X%02X", red, green, blue);
+    }
+}

core-java-modules/core-java-14/src/main/java/com/baeldung/java14/recordvslombok/MonochromeColor.java

@@ -0,0 +1,12 @@
+package com.baeldung.java14.recordvslombok;
+
+import lombok.Value;
+
+@Value
+public class MonochromeColor extends ColorData {
+
+    public MonochromeColor(int grayScale) {
+        super(grayScale, grayScale, grayScale);
+    }
+
+}

core-java-modules/core-java-14/src/main/java/com/baeldung/java14/recordvslombok/StudentBuilder.java

@@ -0,0 +1,17 @@
+package com.baeldung.java14.recordvslombok;
+
+import lombok.Builder;
+import lombok.Getter;
+
+@Getter
+@Builder
+public class StudentBuilder {
+    private String firstName;
+    private String lastName;
+    private Long studentId;
+    private String email;
+    private String phoneNumber;
+    private String address;
+    private String country;
+    private int age;
+}

core-java-modules/core-java-14/src/main/java/com/baeldung/java14/recordvslombok/StudentRecord.java

@@ -0,0 +1,4 @@
+package com.baeldung.java14.recordvslombok;
+
+public record StudentRecord(String firstName, String lastName, Long studentId, String email, String phoneNumber, String address, String country, int age) {
+}

core-java-modules/core-java-14/src/test/java/com/baeldung/java14/recordvslombok/RecordVsLombokUntTest.java

@@ -0,0 +1,43 @@
+package com.baeldung.java14.recordvslombok;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.Test;
+
+public class RecordVsLombokUntTest {
+
+    @Test
+    public void givenAColorRecord_hexStringIsCorrect() {
+        var red = new ColorRecord(255, 0, 0);
+
+        assertThat(red.getHexString()).isEqualTo("#FF0000");
+    }
+
+    @Test
+    public void givenAColorValueObject_hexStringIsCorrect() {
+        var red = new ColorValueObject(255, 0, 0);
+
+        assertThat(red.getHexString()).isEqualTo("#FF0000");
+    }
+
+    @Test
+    public void givenRecordWithManyAttributes_firstNameShouldBeJohn() {
+        StudentRecord john = new StudentRecord("John", "Doe", null, "john@doe.com", null, null, "England", 20);
+
+        assertThat(john.firstName()).isEqualTo("John");
+    }
+
+    @Test
+    public void givenBuilderWithManyAttributes_firstNameShouldBeJohn() {
+        StudentBuilder john = StudentBuilder.builder()
+            .firstName("John")
+            .lastName("Doe")
+            .email("john@doe.com")
+            .country("England")
+            .age(20)
+            .build();
+
+        assertThat(john.getFirstName()).isEqualTo("John");
+    }
+
+}

core-java-modules/core-java-15/README.md

@@ -5,4 +5,3 @@ This module contains articles about Java 15.
 ### Relevant articles
 
 - [Hidden Classes in Java 15](https://www.baeldung.com/java-hidden-classes)
-- [Sealed Classes and Interfaces in Java 15](https://www.baeldung.com/java-sealed-classes-interfaces)

core-java-modules/core-java-17/README.md

@@ -5,3 +5,4 @@
 - [Introduction to HexFormat in Java 17](https://www.baeldung.com/java-hexformat)
 - [New Features in Java 17](https://www.baeldung.com/java-17-new-features)
 - [Random Number Generators in Java 17](https://www.baeldung.com/java-17-random-number-generators)
+- [Sealed Classes and Interfaces in Java 17](https://www.baeldung.com/java-sealed-classes-interfaces)

core-java-modules/core-java-17/src/test/java/com/baeldung/sealed/classes/VehicleUnitTest.java

@@ -21,7 +21,7 @@ public class VehicleUnitTest {
     public void givenCar_whenUsingReflectionAPI_thenSuperClassIsSealed() {
         Assertions.assertThat(car.getClass().isSealed()).isEqualTo(false);
         Assertions.assertThat(car.getClass().getSuperclass().isSealed()).isEqualTo(true);
-        Assertions.assertThat(car.getClass().getSuperclass().permittedSubclasses())
+        Assertions.assertThat(car.getClass().getSuperclass().getPermittedSubclasses())
                 .contains(ClassDesc.of(car.getClass().getCanonicalName()));
     }
 
@@ -29,7 +29,7 @@ public class VehicleUnitTest {
     public void givenTruck_whenUsingReflectionAPI_thenSuperClassIsSealed() {
         Assertions.assertThat(truck.getClass().isSealed()).isEqualTo(false);
         Assertions.assertThat(truck.getClass().getSuperclass().isSealed()).isEqualTo(true);
-        Assertions.assertThat(truck.getClass().getSuperclass().permittedSubclasses())
+        Assertions.assertThat(truck.getClass().getSuperclass().getPermittedSubclasses())
                 .contains(ClassDesc.of(truck.getClass().getCanonicalName()));
     }
 

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

@@ -4,3 +4,4 @@
 
 ### Relevant Articles: 
 - [Java 8 Predicate Chain](https://www.baeldung.com/java-predicate-chain)
+- [Use Cases for Static Methods in Java](https://www.baeldung.com/java-static-methods-use-cases)

core-java-modules/core-java-io-conversions-2/README.md

@@ -9,4 +9,5 @@ This module contains articles about core Java input/output(IO) conversions.
 - [Converting a BufferedReader to a JSONObject](https://www.baeldung.com/java-bufferedreader-to-jsonobject)
 - [Reading a CSV File into an Array](https://www.baeldung.com/java-csv-file-array)
 - [How to Write to a CSV File in Java](https://www.baeldung.com/java-csv)
+- [How to Convert InputStream to Base64 String](https://www.baeldung.com/java-inputstream-to-base64-string)
 - More articles: [[<-- prev]](/core-java-modules/core-java-io-conversions)

core-java-modules/core-java-jar/src/main/java/com/baeldung/jar/MySampleGUIAppn.java

@@ -0,0 +1,31 @@
+package com.baeldung.jar;
+
+import java.awt.event.*;
+import java.awt.*;
+
+import javax.swing.*;
+
+public class MySampleGUIAppn extends JFrame {
+    public  MySampleGUIAppn() {
+        if (!GraphicsEnvironment.isHeadless()) {
+            setSize(300,300);
+            setTitle("MySampleGUIAppn");
+            Button b = new Button("Click Me!");
+            b.setBounds(30,100,80,30);
+            add(b);
+            setVisible(true);
+            addWindowListener(new WindowAdapter() {
+                public void windowClosing(WindowEvent e) {
+                    dispose();
+                    System.exit(0);
+                }
+            });
+        }
+        else {
+            System.exit(0);
+        }
+    }
+    public static void main(String[] args) {
+        MySampleGUIAppn app=new  MySampleGUIAppn();
+    }
+}

core-java-modules/core-java-jar/src/test/java/com/baeldung/jar/MySampleGUIAppnUnitTest.java

@@ -0,0 +1,15 @@
+package com.baeldung.jar;
+
+import java.io.IOException;
+
+import org.junit.jupiter.api.Test;
+
+class MySampleGUIAppnUnitTest {
+    @Test
+    void testMain() throws IOException {
+        System.setProperty("java.awt.headless", "true");
+        String [] args = null;
+        System.exit(0);
+        MySampleGUIAppn.main(args);
+    }
+}

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

@@ -6,3 +6,4 @@ This module contains articles about types in Java
 
 - [Convert an Array of Primitives to an Array of Objects](https://www.baeldung.com/java-primitive-array-to-object-array)
 - [Check if an Enum Value Exists in Java](https://www.baeldung.com/java-search-enum-values)
+- [Generate a Random Value From an Enum](https://www.baeldung.com/java-enum-random-value)

core-java-modules/core-java-numbers-4/README.md

@@ -7,7 +7,6 @@
 - [Automorphic Numbers in Java](https://www.baeldung.com/java-automorphic-numbers)
 - [Convert Byte Size Into a Human-Readable Format in Java](https://www.baeldung.com/java-human-readable-byte-size)
 - [Convert boolean to int in Java](https://www.baeldung.com/java-boolean-to-int)
-- [Generate a Random Value From an Enum](https://www.baeldung.com/java-enum-random-value)
 - [Reverse a Number in Java](https://www.baeldung.com/java-reverse-number)
 - [Check if BigDecimal Value Is Zero](https://www.baeldung.com/java-bigdecimal-zero)
 - More articles: [[<-- prev]](../core-java-numbers-3) [[next -->]](../core-java-numbers-5)

core-java-modules/core-java-streams-4/README.md

@@ -1,3 +1,4 @@
 ## Relevant Articles:
 
 - [Count Occurrences Using Java groupingBy Collector](https://www.baeldung.com/java-groupingby-count)
+- [How to Split a Stream into Multiple Streams](https://www.baeldung.com/java-split-stream)

core-java-modules/core-java-string-operations-4/src/main/java/com/baeldung/truncate/TruncateString.java

@@ -0,0 +1,105 @@
+package com.baeldung.truncate;
+
+import java.util.Optional;
+import java.util.regex.MatchResult;
+import java.util.regex.Pattern;
+
+import org.apache.commons.lang3.StringUtils;
+
+import com.google.common.base.Splitter;
+
+public class TruncateString {
+
+    private static final String EMPTY = "";
+
+    public static String usingSubstringMethod(String text, int length) {
+        if (length < 0) {
+            throw new IllegalArgumentException("length cannot be negative");
+        }
+
+        if (text == null) {
+            return EMPTY;
+        }
+
+        if (text.length() <= length) {
+            return text;
+        } else {
+            return text.substring(0, length);
+        }
+    }
+
+    public static String usingSplitMethod(String text, int length) {
+        if (length < 0) {
+            throw new IllegalArgumentException("length cannot be negative");
+        }
+
+        if (text == null) {
+            return EMPTY;
+        }
+
+        String[] results = text.split("(?<=\\G.{" + length + "})");
+
+        return results[0];
+    }
+
+    public static String usingPattern(String text, int length) {
+        if (length < 0) {
+            throw new IllegalArgumentException("length cannot be negative");
+        }
+
+        if (text == null) {
+            return EMPTY;
+        }
+
+        Optional<String> result = Pattern.compile(".{1," + length + "}")
+            .matcher(text)
+            .results()
+            .map(MatchResult::group)
+            .findFirst();
+
+        return result.isPresent() ? result.get() : EMPTY;
+
+    }
+
+    public static String usingCodePointsMethod(String text, int length) {
+        if (length < 0) {
+            throw new IllegalArgumentException("length cannot be negative");
+        }
+
+        if (text == null) {
+            return EMPTY;
+        }
+
+        return text.codePoints()
+            .limit(length)
+            .collect(StringBuilder::new, StringBuilder::appendCodePoint, StringBuilder::append)
+            .toString();
+    }
+
+    public static String usingLeftMethod(String text, int length) {
+
+        return StringUtils.left(text, length);
+    }
+
+    public static String usingTruncateMethod(String text, int length) {
+
+        return StringUtils.truncate(text, length);
+    }
+
+    public static String usingSplitter(String text, int length) {
+        if (length < 0) {
+            throw new IllegalArgumentException("length cannot be negative");
+        }
+
+        if (text == null) {
+            return EMPTY;
+        }
+
+        Iterable<String> parts = Splitter.fixedLength(length)
+            .split(text);
+
+        return parts.iterator()
+            .next();
+    }
+
+}

core-java-modules/core-java-string-operations-4/src/test/java/com/baeldung/truncate/TruncateStringUnitTest.java

@@ -0,0 +1,53 @@
+package com.baeldung.truncate;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class TruncateStringUnitTest {
+
+    private static final String TEXT = "Welcome to baeldung.com";
+
+    @Test
+    public void givenStringAndLength_whenUsingSubstringMethod_thenTruncate() {
+
+        assertEquals(TruncateString.usingSubstringMethod(TEXT, 10), "Welcome to");
+    }
+
+    @Test
+    public void givenStringAndLength_whenUsingSplitMethod_thenTruncate() {
+
+        assertEquals(TruncateString.usingSplitMethod(TEXT, 13), "Welcome to ba");
+    }
+
+    @Test
+    public void givenStringAndLength_whenUsingPattern_thenTruncate() {
+
+        assertEquals(TruncateString.usingPattern(TEXT, 19), "Welcome to baeldung");
+    }
+
+    @Test
+    public void givenStringAndLength_whenUsingCodePointsMethod_thenTruncate() {
+
+        assertEquals(TruncateString.usingCodePointsMethod(TEXT, 6), "Welcom");
+    }
+
+    @Test
+    public void givenStringAndLength_whenUsingLeftMethod_thenTruncate() {
+
+        assertEquals(TruncateString.usingLeftMethod(TEXT, 15), "Welcome to bael");
+    }
+
+    @Test
+    public void givenStringAndLength_whenUsingTruncateMethod_thenTruncate() {
+
+        assertEquals(TruncateString.usingTruncateMethod(TEXT, 20), "Welcome to baeldung.");
+    }
+
+    @Test
+    public void givenStringAndLength_whenUsingSplitter_thenTruncate() {
+
+        assertEquals(TruncateString.usingSplitter(TEXT, 3), "Wel");
+    }
+
+}

docker-modules/docker-environment-variables/README.md

@@ -0,0 +1,3 @@
+
+## Relevant Articles:
+- [How to Pass Environment Variable Value into Dockerfile](https://www.baeldung.com/ops/dockerfile-env-variable)

docker-modules/docker-java-jar/Dockerfile

@@ -0,0 +1,4 @@
+FROM openjdk:11
+MAINTAINER baeldung.com
+COPY target/docker-java-jar-0.0.1-SNAPSHOT.jar app.jar
+ENTRYPOINT ["java","-jar","/app.jar"]

docker-modules/docker-java-jar/pom.xml

@@ -0,0 +1,37 @@
+<?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">
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-boot-2</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../../parent-boot-2</relativePath>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>docker-java-jar</artifactId>
+
+    <properties>
+        <maven.compiler.source>11</maven.compiler.source>
+        <maven.compiler.target>11</maven.compiler.target>
+    </properties>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-jar-plugin</artifactId>
+                <version>${maven-jar-plugin.version}</version>
+                <configuration>
+                    <archive>
+                        <manifest>
+                            <mainClass>com.baeldung.HelloWorld</mainClass>
+                        </manifest>
+                    </archive>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

docker-modules/docker-java-jar/src/main/java/com/baeldung/HelloWorld.java

@@ -0,0 +1,8 @@
+package com.baeldung;
+
+public class HelloWorld {
+
+    public static void main(String[] args){
+        System.out.println("Welcome to our application");
+    }
+}

docker-modules/pom.xml

@@ -23,6 +23,7 @@
         <module>docker-images</module>
         <module>docker-spring-boot</module>
         <module>docker-spring-boot-postgres</module>
+        <module>docker-java-jar</module>
     </modules>
 
     <properties>

libraries-data-io/src/main/java/com/baeldung/libraries/opencsv/Application.java

@@ -1,5 +1,6 @@
 package com.baeldung.libraries.opencsv;
 
+import com.baeldung.libraries.opencsv.beans.CsvBean;
 import com.baeldung.libraries.opencsv.beans.NamedColumnBean;
 import com.baeldung.libraries.opencsv.beans.SimplePositionBean;
 import com.baeldung.libraries.opencsv.examples.sync.BeanExamples;
@@ -7,102 +8,60 @@ import com.baeldung.libraries.opencsv.examples.sync.CsvReaderExamples;
 import com.baeldung.libraries.opencsv.examples.sync.CsvWriterExamples;
 import com.baeldung.libraries.opencsv.helpers.Helpers;
 
-import java.io.Reader;
-import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.List;
 
 public class Application {
 
-        /*
-         *  Bean Examples.
-         */
-
-    public static String simpleSyncPositionBeanExample() {
-        Path path = null;
-        try {
-            path = Helpers.twoColumnCsvPath();
-        } catch (Exception ex) {
-            Helpers.err(ex);
-        }
-        return BeanExamples.beanBuilderExample(path, SimplePositionBean.class).toString();
+    // CSV Reader Examples
+    public static List<String[]> readLineByLineSyncExample() throws Exception {
+        Path path = Helpers.twoColumnCsvPath();
+        return CsvReaderExamples.readLineByLine(path);
     }
 
-    public static String namedSyncColumnBeanExample() {
-        Path path = null;
-        try {
-            path = Helpers.namedColumnCsvPath();
-        } catch (Exception ex) {
-            Helpers.err(ex);
-        }
-        return BeanExamples.beanBuilderExample(path, NamedColumnBean.class).toString();
+    public static List<String[]> readAllLinesSyncExample() throws Exception {
+        Path path = Helpers.twoColumnCsvPath();
+        return CsvReaderExamples.readAllLines(path);
     }
 
-    public static String writeSyncCsvFromBeanExample() {
-        Path path = null;
-        try {
-            path = Helpers.fileOutBeanPath();
-        } catch (Exception ex) {
-            Helpers.err(ex);
+    // CSV Writer Examples
+    public static String writeLineByLineSyncExample() throws Exception {
+        Path path = Helpers.fileOutOnePath();
+        return CsvWriterExamples.writeLineByLine(Helpers.fourColumnCsvString(), path);
     }
+
+    public static String writeAllLinesSyncExample() throws Exception {
+        Path path = Helpers.fileOutAllPath();
+        return CsvWriterExamples.writeAllLines(Helpers.fourColumnCsvString(), path);
+    }
+
+    // Bean Examples
+    public static List<CsvBean> simpleSyncPositionBeanExample() throws Exception {
+        Path path = Helpers.twoColumnCsvPath();
+        return BeanExamples.beanBuilderExample(path, SimplePositionBean.class);
+    }
+
+    public static List<CsvBean> namedSyncColumnBeanExample() throws Exception {
+        Path path = Helpers.namedColumnCsvPath();
+        return BeanExamples.beanBuilderExample(path, NamedColumnBean.class);
+    }
+
+    public static String writeSyncCsvFromBeanExample() throws Exception {
+        Path path = Helpers.fileOutBeanPath();
         return BeanExamples.writeCsvFromBean(path);
     }
 
-        /*
-         *  CSV Reader Examples.
-         */
-
-    public static String oneByOneSyncExample() {
-        Reader reader = null;
-        try {
-            reader = Files.newBufferedReader(Helpers.twoColumnCsvPath());
-        } catch (Exception ex) {
-            Helpers.err(ex);
-        }
-        return CsvReaderExamples.oneByOne(reader).toString();
-    }
-
-    public static String readAllSyncExample() {
-        Reader reader = null;
-        try {
-            reader = Files.newBufferedReader(Helpers.twoColumnCsvPath());
-        } catch (Exception ex) {
-            Helpers.err(ex);
-        }
-        return CsvReaderExamples.readAll(reader).toString();
-    }
-
-         /*
-         *  CSV Writer Examples.
-         */
-
-
-    public static String csvWriterSyncOneByOne() {
-        Path path = null;
-        try {
-            path = Helpers.fileOutOnePath();
-        } catch (Exception ex) {
-            Helpers.err(ex);
-        }
-        return CsvWriterExamples.csvWriterOneByOne(Helpers.fourColumnCsvString(), path);
-    }
-
-    public static String csvWriterSyncAll() {
-        Path path = null;
-        try {
-            path = Helpers.fileOutAllPath();
-        } catch (Exception ex) {
-            Helpers.err(ex);
-        }
-        return CsvWriterExamples.csvWriterAll(Helpers.fourColumnCsvString(), path);
-    }
-
     public static void main(String[] args) {
+        try {
             simpleSyncPositionBeanExample();
             namedSyncColumnBeanExample();
             writeSyncCsvFromBeanExample();
-        oneByOneSyncExample();
-        readAllSyncExample();
-        csvWriterSyncOneByOne();
-        csvWriterSyncAll();
+            readLineByLineSyncExample();
+            readAllLinesSyncExample();
+            writeLineByLineSyncExample();
+            writeAllLinesSyncExample();
+        } catch (Exception e) {
+            throw new RuntimeException("Error during csv processing", e);
+        }
     }
 }

libraries-data-io/src/main/java/com/baeldung/libraries/opencsv/beans/NamedColumnBean.java

@@ -27,5 +27,10 @@ public class NamedColumnBean extends CsvBean {
         this.age = age;
     }
 
+    @Override
+    public String toString() {
+        return name + ',' + age;
+    }
+
 
 }

libraries-data-io/src/main/java/com/baeldung/libraries/opencsv/beans/SimplePositionBean.java

@@ -26,4 +26,8 @@ public class SimplePositionBean extends CsvBean {
         this.exampleColTwo = exampleColTwo;
     }
 
+    @Override
+    public String toString() {
+        return exampleColOne + ',' + exampleColTwo;
+    }
 }

libraries-data-io/src/main/java/com/baeldung/libraries/opencsv/beans/WriteExampleBean.java

@@ -37,4 +37,9 @@ public class WriteExampleBean extends CsvBean {
     public void setColC(String colC) {
         this.colC = colC;
     }
+
+    @Override
+    public String toString() {
+        return colA + ',' + colB + "," + colC;
+    }
 }

libraries-data-io/src/main/java/com/baeldung/libraries/opencsv/examples/sync/BeanExamples.java

@@ -4,60 +4,49 @@ import com.baeldung.libraries.opencsv.beans.CsvBean;
 import com.baeldung.libraries.opencsv.beans.WriteExampleBean;
 import com.baeldung.libraries.opencsv.helpers.Helpers;
 import com.baeldung.libraries.opencsv.pojos.CsvTransfer;
-import com.opencsv.CSVWriter;
-import com.opencsv.bean.*;
+import com.opencsv.bean.CsvToBean;
+import com.opencsv.bean.CsvToBeanBuilder;
+import com.opencsv.bean.StatefulBeanToCsv;
+import com.opencsv.bean.StatefulBeanToCsvBuilder;
 
 import java.io.FileWriter;
 import java.io.Reader;
 import java.io.Writer;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
 public class BeanExamples {
 
-    public static List<CsvBean> beanBuilderExample(Path path, Class clazz) {
-        ColumnPositionMappingStrategy ms = new ColumnPositionMappingStrategy();
-        return beanBuilderExample(path, clazz, ms);
-    }
-
-    public static List<CsvBean> beanBuilderExample(Path path, Class clazz, MappingStrategy ms) {
+    public static List<CsvBean> beanBuilderExample(Path path, Class<? extends CsvBean> clazz) throws Exception {
         CsvTransfer csvTransfer = new CsvTransfer();
-        try {
-            ms.setType(clazz);
-
-            Reader reader = Files.newBufferedReader(path);
-            CsvToBean cb = new CsvToBeanBuilder(reader).withType(clazz)
-                .withMappingStrategy(ms)
+        try (Reader reader = Files.newBufferedReader(path)) {
+            CsvToBean<CsvBean> cb = new CsvToBeanBuilder<CsvBean>(reader)
+              .withType(clazz)
               .build();
 
             csvTransfer.setCsvList(cb.parse());
-            reader.close();
-
-        } catch (Exception ex) {
-            Helpers.err(ex);
         }
+
         return csvTransfer.getCsvList();
     }
 
-    public static String writeCsvFromBean(Path path) {
-        try {
-            Writer writer = new FileWriter(path.toString());
+    public static String writeCsvFromBean(Path path) throws Exception {
 
-            StatefulBeanToCsv sbc = new StatefulBeanToCsvBuilder(writer).withSeparator(CSVWriter.DEFAULT_SEPARATOR)
+        List<CsvBean> sampleData = Arrays.asList(
+            new WriteExampleBean("Test1", "sample", "data"),
+            new WriteExampleBean("Test2", "ipso", "facto")
+        );
+
+        try (Writer writer = new FileWriter(path.toString())) {
+            StatefulBeanToCsv<CsvBean> sbc = new StatefulBeanToCsvBuilder<CsvBean>(writer)
+              .withQuotechar('\'')
               .build();
 
-            List<CsvBean> list = new ArrayList<>();
-            list.add(new WriteExampleBean("Test1", "sfdsf", "fdfd"));
-            list.add(new WriteExampleBean("Test2", "ipso", "facto"));
-
-            sbc.write(list);
-            writer.close();
-
-        } catch (Exception ex) {
-            Helpers.err(ex);
+            sbc.write(sampleData);
         }
+
         return Helpers.readFile(path);
     }
 }

libraries-data-io/src/main/java/com/baeldung/libraries/opencsv/examples/sync/CsvReaderExamples.java

@@ -1,61 +1,58 @@
 package com.baeldung.libraries.opencsv.examples.sync;
 
-import com.baeldung.libraries.opencsv.helpers.Helpers;
 import com.opencsv.CSVParser;
 import com.opencsv.CSVParserBuilder;
 import com.opencsv.CSVReader;
 import com.opencsv.CSVReaderBuilder;
 
 import java.io.Reader;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.List;
 
 public class CsvReaderExamples {
 
-    public static List<String[]> readAll(Reader reader) {
+    public static List<String[]> readAllLines(Path filePath) throws Exception {
 
         CSVParser parser = new CSVParserBuilder()
           .withSeparator(',')
           .withIgnoreQuotations(true)
           .build();
 
-        CSVReader csvReader = new CSVReaderBuilder(reader)
+        try (Reader reader = Files.newBufferedReader(filePath)) {
+            CSVReaderBuilder csvReaderBuilder = new CSVReaderBuilder(reader)
               .withSkipLines(0)
-                .withCSVParser(parser)
-                .build();
+              .withCSVParser(parser);
 
-        List<String[]> list = new ArrayList<>();
-        try {
-            list = csvReader.readAll();
-            reader.close();
-            csvReader.close();
-        } catch (Exception ex) {
-            Helpers.err(ex);
+            try (CSVReader csvReader = csvReaderBuilder.build()) {
+                return csvReader.readAll();
             }
-        return list;
         }
 
-    public static List<String[]> oneByOne(Reader reader) {
+    }
+
+    public static List<String[]> readLineByLine(Path filePath) throws Exception {
         List<String[]> list = new ArrayList<>();
-        try {
+
         CSVParser parser = new CSVParserBuilder()
           .withSeparator(',')
           .withIgnoreQuotations(true)
           .build();
 
-            CSVReader csvReader = new CSVReaderBuilder(reader)
-                    .withSkipLines(0)
-                    .withCSVParser(parser)
-                    .build();
+        try (Reader reader = Files.newBufferedReader(filePath)) {
 
+            CSVReaderBuilder csvReaderBuilder = new CSVReaderBuilder(reader)
+              .withSkipLines(0)
+              .withCSVParser(parser);
+
+            try (CSVReader csvReader = csvReaderBuilder.build()) {
                 String[] line;
                 while ((line = csvReader.readNext()) != null) {
                     list.add(line);
                 }
-            reader.close();
-            csvReader.close();
-        } catch (Exception ex) {
-            Helpers.err(ex);
+            }
+
         }
         return list;
     }

libraries-data-io/src/main/java/com/baeldung/libraries/opencsv/examples/sync/CsvWriterExamples.java

@@ -9,26 +9,21 @@ import java.util.List;
 
 public class CsvWriterExamples {
 
-    public static String csvWriterOneByOne(List<String[]> stringArray, Path path) {
-        try {
-            CSVWriter writer = new CSVWriter(new FileWriter(path.toString()));
-            for (String[] array : stringArray) {
-                writer.writeNext(array);
+    public static String writeLineByLine(List<String[]> lines, Path path) throws Exception {
+
+        try (CSVWriter writer = new CSVWriter(new FileWriter(path.toString()))) {
+            for (String[] line : lines) {
+                writer.writeNext(line);
             }
-            writer.close();
-        } catch (Exception ex) {
-            Helpers.err(ex);
         }
+
         return Helpers.readFile(path);
     }
 
-    public static String csvWriterAll(List<String[]> stringArray, Path path) {
-        try {
-            CSVWriter writer = new CSVWriter(new FileWriter(path.toString()));
-            writer.writeAll(stringArray);
-            writer.close();
-        } catch (Exception ex) {
-            Helpers.err(ex);
+    public static String writeAllLines(List<String[]> lines, Path path) throws Exception {
+
+        try (CSVWriter writer = new CSVWriter(new FileWriter(path.toString()))) {
+            writer.writeAll(lines);
         }
         return Helpers.readFile(path);
     }

libraries-data-io/src/main/java/com/baeldung/libraries/opencsv/helpers/Helpers.java

@@ -1,9 +1,9 @@
 package com.baeldung.libraries.opencsv.helpers;
 
 import com.baeldung.libraries.opencsv.Constants;
+import org.apache.commons.io.IOUtils;
 
-import java.io.BufferedReader;
-import java.io.FileReader;
+import java.io.IOException;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.nio.file.Path;
@@ -13,9 +13,7 @@ import java.util.List;
 
 public class Helpers {
 
-    /**
-     * Write Files
-     */
+    // Write Files
 
     public static Path fileOutAllPath() throws URISyntaxException {
         URI uri = ClassLoader.getSystemResource(Constants.CSV_All).toURI();
@@ -32,9 +30,7 @@ public class Helpers {
         return Paths.get(uri);
     }
 
-    /**
-     * Read Files
-     */
+    // Read Files
 
     public static Path twoColumnCsvPath() throws URISyntaxException {
         URI uri = ClassLoader.getSystemResource(Constants.TWO_COLUMN_CSV).toURI();
@@ -51,33 +47,12 @@ public class Helpers {
         return Paths.get(uri);
     }
 
-    /**
-     * Simple File Reader
-     */
-
-    public static String readFile(Path path) {
-        String response = "";
-        try {
-            FileReader fr = new FileReader(path.toString());
-            BufferedReader br = new BufferedReader(fr);
-            String strLine;
-            StringBuffer sb = new StringBuffer();
-            while ((strLine = br.readLine()) != null) {
-                sb.append(strLine);
-            }
-            response = sb.toString();
-            System.out.println(response);
-            fr.close();
-            br.close();
-        } catch (Exception ex) {
-            Helpers.err(ex);
-        }
-        return response;
+    public static String readFile(Path path) throws IOException {
+        return IOUtils.toString(path.toUri());
     }
 
-    /**
-     * Dummy Data for Writing.
-     */
+
+    // Dummy Data for Writing
 
     public static List<String[]> twoColumnCsvString() {
         List<String[]> list = new ArrayList<>();
@@ -94,15 +69,4 @@ public class Helpers {
         return list;
     }
 
-    /**
-     * Message Helpers
-     */
-
-    public static void print(String msg) {
-        System.out.println(msg);
-    }
-
-    public static void err(Exception ex) {
-        System.out.println(Constants.GENERIC_EXCEPTION + " " + ex);
-    }
 }

libraries-data-io/src/main/resources/csv/twoColumn.csv

@@ -1,4 +1,4 @@
-colA, ColB
+colA,colB
 A,B
 C,D
 G,G

libraries-data-io/src/test/java/com/baeldung/libraries/opencsv/OpenCsvIntegrationTest.java

@@ -1,66 +1,107 @@
 package com.baeldung.libraries.opencsv;
 
-import com.baeldung.libraries.opencsv.helpers.Helpers;
-import org.junit.After;
-import org.junit.Before;
+import com.baeldung.libraries.opencsv.beans.CsvBean;
 import org.junit.Test;
 
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
 public class OpenCsvIntegrationTest {
 
-    private Object testReadCsv(Object result) {
-        assert (result != null);
-        assert (result instanceof String);
-        assert (!((String) result).isEmpty());
-        System.out.println(result);
-        return result;
-    }
+    private static final String NEW_LINE = System.lineSeparator();
 
-    private Object testWriteCsv(Object result) {
-        assert (result instanceof String);
-        assert (!((String) result).isEmpty());
-        return result;
-    }
+    @Test
+    public void givenSampleData_whenReadUsingPosition_thenContentsRead() throws Exception {
+        List<CsvBean> values = Application.simpleSyncPositionBeanExample();
 
-    @Before
-    public void setup() {
+        assertThat(values)
+          .extracting(Object::toString)
+          .containsExactly(
+          "colA,colB",
+          "A,B",
+          "C,D",
+          "G,G",
+          "G,F"
+        );
     }
 
     @Test
-    public void positionExampleTest() {
-        testReadCsv(Application.simpleSyncPositionBeanExample());
+    public void givenSampleData_whenReadUsingNamedColumn_thenContentsRead() throws Exception {
+        List<CsvBean> values = Application.namedSyncColumnBeanExample();
+
+        assertThat(values)
+          .extracting(Object::toString)
+          .containsExactly(
+            "Joe,27",
+            "Jane,32",
+            "Bob,53"
+        );
     }
 
     @Test
-    public void namedColumnExampleTest() {
-        testReadCsv(Application.namedSyncColumnBeanExample());
+    public void givenSampleData_whenReadLineByLine_thenContentsRead() throws Exception {
+        List<String[]> lineByLineContents = Application.readLineByLineSyncExample();
+
+        assertThat(lineByLineContents)
+          .containsExactly(
+            new String[] {"colA", "colB"},
+            new String[] {"A", "B"},
+            new String[] {"C", "D"},
+            new String[] {"G", "G"},
+            new String[] {"G", "F"}
+          );
     }
 
     @Test
-    public void writeCsvUsingBeanBuilderTest() {
-        testWriteCsv(Application.writeSyncCsvFromBeanExample());
+    public void givenSampleData_whenReadAllLines_thenContentsRead() throws Exception {
+
+        List<String[]> contents = Application.readAllLinesSyncExample();
+
+        assertThat(contents)
+          .containsExactly(
+            new String[] {"colA", "colB"},
+            new String[] {"A", "B"},
+            new String[] {"C", "D"},
+            new String[] {"G", "G"},
+            new String[] {"G", "F"}
+          );
     }
 
     @Test
-    public void oneByOneExampleTest() {
-        testReadCsv(Application.oneByOneSyncExample());
+    public void givenSampleData_whenWriteCsvUsingBean_thenContentsWritten() throws Exception {
+        String contents = Application.writeSyncCsvFromBeanExample();
+
+        assertThat(contents.split(NEW_LINE))
+          .containsExactly(
+          "'colA','colB','colC'",
+          "'Test1','sample','data'",
+          "'Test2','ipso','facto'"
+        );
     }
 
     @Test
-    public void readAllExampleTest() {
-        testReadCsv(Application.readAllSyncExample());
+    public void givenSampleData_whenWriteCsvLineByLine_thenContentsWritten() throws Exception {
+        String contents = Application.writeLineByLineSyncExample();
+
+        assertThat(contents.split(NEW_LINE))
+          .containsExactly(
+            "\"ColA\",\"ColB\",\"ColC\",\"ColD\"",
+            "\"A\",\"B\",\"A\",\"B\"",
+            "\"BB\",\"AB\",\"AA\",\"B\""
+          );
     }
 
     @Test
-    public void csvWriterOneByOneTest() {
-        testWriteCsv(Application.csvWriterSyncOneByOne());
+    public void givenSampleData_whenWriteCsvAllLines_thenContentsWritten() throws Exception {
+        String contents = Application.writeAllLinesSyncExample();
+
+        assertThat(contents.split(NEW_LINE))
+          .containsExactly(
+            "\"ColA\",\"ColB\",\"ColC\",\"ColD\"",
+            "\"A\",\"B\",\"A\",\"B\"",
+            "\"BB\",\"AB\",\"AA\",\"B\""
+          );
     }
 
-    @Test
-    public void csvWriterAllTest() {
-        testWriteCsv(Application.csvWriterSyncAll());
-    }
-
-    @After
-    public void close() {
-    }
 }

persistence-modules/java-mongodb-3/src/main/java/com/baeldung/mongo/find/FindWithObjectId.java

@@ -0,0 +1,80 @@
+package com.baeldung.mongo.find;
+
+import com.mongodb.MongoClient;
+import com.mongodb.client.FindIterable;
+import com.mongodb.client.MongoCollection;
+import com.mongodb.client.MongoCursor;
+import com.mongodb.client.MongoDatabase;
+import org.bson.Document;
+import org.bson.types.ObjectId;
+
+import static com.mongodb.client.model.Filters.eq;
+
+public class FindWithObjectId {
+
+    private static final String OBJECT_ID_FIELD = "_id";
+
+    private static MongoClient mongoClient;
+    private static MongoDatabase database;
+    private static MongoCollection<Document> collection;
+    private static String collectionName;
+    private static String databaseName;
+
+    public static void setUp() {
+        if (mongoClient == null) {
+            mongoClient = new MongoClient("localhost", 27017);
+
+            databaseName = "baeldung";
+            collectionName = "employee";
+
+            database = mongoClient.getDatabase(databaseName);
+            collection = database.getCollection(collectionName);
+        }
+    }
+
+    public static void retrieveAllDocumentsUsingFindWithObjectId() {
+        Document document = collection.find()
+          .first();
+        System.out.println(document);
+
+        FindIterable<Document> documents = collection.find(eq(OBJECT_ID_FIELD, document.get(OBJECT_ID_FIELD)));
+
+        MongoCursor<Document> cursor = documents.iterator();
+        while (cursor.hasNext()) {
+            System.out.println(cursor.next());
+        }
+    }
+
+    public static void retrieveFirstDocumentWithObjectId() {
+        Document document = collection.find()
+          .first();
+        System.out.println(document);
+
+        FindIterable<Document> documents = collection.find(eq(OBJECT_ID_FIELD, document.get(OBJECT_ID_FIELD)));
+        Document queriedDocument = documents.first();
+
+        System.out.println(queriedDocument);
+    }
+
+    public static void retrieveDocumentWithRandomObjectId() {
+        FindIterable<Document> documents = collection.find(eq(OBJECT_ID_FIELD, new ObjectId()));
+        Document queriedDocument = documents.first();
+
+        if (queriedDocument != null) {
+            System.out.println(queriedDocument);
+        } else {
+            System.out.println("No documents found");
+        }
+    }
+
+    public static void main(String args[]) {
+
+        setUp();
+
+        retrieveAllDocumentsUsingFindWithObjectId();
+
+        retrieveFirstDocumentWithObjectId();
+
+        retrieveDocumentWithRandomObjectId();
+    }
+}

persistence-modules/java-mongodb-3/src/test/java/com/baeldung/mongo/find/FindWithObjectIdLiveTest.java

@@ -0,0 +1,87 @@
+package com.baeldung.mongo.find;
+
+import com.mongodb.MongoClient;
+import com.mongodb.client.FindIterable;
+import com.mongodb.client.MongoCollection;
+import com.mongodb.client.MongoCursor;
+import com.mongodb.client.MongoDatabase;
+import org.bson.Document;
+import org.bson.types.ObjectId;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+
+import static com.mongodb.client.model.Filters.eq;
+import static org.junit.Assert.*;
+
+public class FindWithObjectIdLiveTest {
+
+    private static final String OBJECT_ID_FIELD = "_id";
+
+    private static MongoClient mongoClient;
+    private static MongoDatabase database;
+    private static MongoCollection<Document> collection;
+    private static final String DATASET_JSON = "/employee.json";
+
+    @BeforeClass
+    public static void setUp() throws IOException {
+        if (mongoClient == null) {
+            mongoClient = new MongoClient("localhost", 27017);
+
+            database = mongoClient.getDatabase("baeldung");
+            collection = database.getCollection("employee");
+
+            collection.drop();
+
+            InputStream is = FindOperationLiveTest.class.getResourceAsStream(DATASET_JSON);
+            BufferedReader reader = new BufferedReader(new InputStreamReader(is));
+            reader.lines()
+              .forEach(line -> collection.insertOne(Document.parse(line)));
+            reader.close();
+        }
+    }
+
+    @Test
+    public void givenEmployeeCollection_whenFetchingDocumentsUsingObjectId_thenCheckingForDocuments() {
+        Document employee = collection.find()
+          .first();
+        ObjectId objectId = (ObjectId) employee.get(OBJECT_ID_FIELD);
+
+        FindIterable<Document> documents = collection.find(eq(OBJECT_ID_FIELD, objectId));
+        MongoCursor<Document> cursor = documents.iterator();
+
+        assertNotNull(cursor);
+        assertTrue(cursor.hasNext());
+    }
+
+    @Test
+    public void givenEmployeeCollection_whenFetchingFirstDocumentUsingObjectId_thenCheckingForDocument() {
+        Document employee = collection.find()
+          .first();
+        ObjectId objectId = (ObjectId) employee.get(OBJECT_ID_FIELD);
+
+        Document queriedEmployee = collection.find(eq(OBJECT_ID_FIELD, objectId))
+          .first();
+
+        assertNotNull(queriedEmployee);
+        assertEquals(employee.get(OBJECT_ID_FIELD), queriedEmployee.get(OBJECT_ID_FIELD));
+    }
+
+    @Test
+    public void givenEmployeeCollection_whenFetchingUsingRandomObjectId_thenCheckingForDocument() {
+        Document employee = collection.find(eq(OBJECT_ID_FIELD, new ObjectId()))
+          .first();
+
+        assertNull(employee);
+    }
+
+    @AfterClass
+    public static void cleanUp() {
+        mongoClient.close();
+    }
+}

persistence-modules/java-mongodb-queries/pom.xml

@@ -0,0 +1,33 @@
+<?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">
+  <parent>
+    <groupId>com.baeldung</groupId>
+    <artifactId>persistence-modules</artifactId>
+    <version>1.0.0-SNAPSHOT</version>
+  </parent>
+  <modelVersion>4.0.0</modelVersion>
+
+  <artifactId>java-mongodb-queries</artifactId>
+
+  <dependencies>
+    <dependency>
+      <groupId>org.mongodb</groupId>
+      <artifactId>mongodb-driver-sync</artifactId>
+      <version>4.6.0</version>
+    </dependency>
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-api</artifactId>
+      <version>5.8.1</version>
+      <scope>compile</scope>
+    </dependency>
+  </dependencies>
+
+  <properties>
+    <maven.compiler.source>8</maven.compiler.source>
+    <maven.compiler.target>8</maven.compiler.target>
+  </properties>
+
+</project>

persistence-modules/java-mongodb-queries/src/main/java/com/baeldung/mongo/crud/CrudClient.java

@@ -0,0 +1,183 @@
+package com.baeldung.mongo.crud;
+
+import com.baeldung.mongo.crud.model.Event;
+import com.mongodb.BasicDBObject;
+import com.mongodb.BasicDBObjectBuilder;
+import com.mongodb.MongoException;
+import com.mongodb.client.MongoClient;
+import com.mongodb.client.MongoClients;
+import com.mongodb.client.MongoCollection;
+import com.mongodb.client.MongoDatabase;
+import com.mongodb.client.model.UpdateOptions;
+import com.mongodb.client.model.Updates;
+import com.mongodb.client.result.InsertOneResult;
+import com.mongodb.client.result.DeleteResult;
+import com.mongodb.client.result.UpdateResult;
+import org.bson.BsonValue;
+import org.bson.Document;
+import org.bson.codecs.configuration.CodecProvider;
+import org.bson.codecs.configuration.CodecRegistry;
+import org.bson.codecs.pojo.PojoCodecProvider;
+import org.bson.conversions.Bson;
+
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.time.OffsetDateTime;
+import java.time.ZoneId;
+import java.time.ZoneOffset;
+import java.time.ZonedDateTime;
+import java.util.ArrayList;
+import java.util.List;
+
+import static com.mongodb.client.model.Filters.and;
+import static com.mongodb.client.model.Filters.eq;
+import static com.mongodb.MongoClientSettings.getDefaultCodecRegistry;
+import static com.mongodb.client.model.Filters.gte;
+import static com.mongodb.client.model.Filters.lt;
+import static org.bson.codecs.configuration.CodecRegistries.fromProviders;
+import static org.bson.codecs.configuration.CodecRegistries.fromRegistries;
+
+public class CrudClient {
+
+    private static String uri = "mongodb://localhost:27017";
+    private static MongoClient mongoClient = MongoClients.create(uri);
+    private static MongoDatabase db;
+    private static MongoCollection<Event> collection;
+
+    public static OffsetDateTime offsetDateTime = OffsetDateTime.of(LocalDateTime.of(2022, 6, 4, 11, 0, 0),
+            ZoneOffset.ofHours(2));
+
+    public static Event pianoLessons = new Event(
+            "Piano lessons",
+            "Foo Bvld",
+            LocalDateTime.of(2022, 6, 4, 11, 0, 0));
+
+    public static Event soccerGame = new Event(
+            "Soccer game",
+            "Bar Avenue",
+            LocalDateTime.of(2022, 6, 10, 17, 0, 0));
+
+    public static Event pianoLessonsTZ = new Event(
+            "Piano lessons",
+            "Baz Bvld",
+            LocalDateTime.of(2022, 12, 31, 12, 0, 0),
+            ZoneOffset.ofHours(2).toString());
+
+    public static LocalDateTime dateQuery = LocalDateTime.of(2022, 6, 10, 17, 0, 0);
+    public static LocalDateTime dateQueryEventWithTZ = LocalDateTime.of(2022, 12, 31, 12, 0, 0);
+
+    public static LocalDateTime from = LocalDateTime.of(2022, 06, 04, 12, 0, 0);
+    public static LocalDateTime to = LocalDateTime.of(2022, 06, 10, 17, 0, 0);
+
+    public static LocalDate updateManyFrom = LocalDate.of(2022, 1, 1);
+    public static LocalDate updateManyTo = LocalDate.of(2023, 1, 1);
+
+    public static LocalDate deleteFrom = LocalDate.of(2022, 1, 1);
+    public static LocalDate deleteTo = LocalDate.of(2023, 01, 01);
+
+    public static void setup() {
+        CodecProvider codecProvider = PojoCodecProvider.builder().automatic(true).build();
+        CodecRegistry codecRegistry = fromRegistries(getDefaultCodecRegistry(), fromProviders(codecProvider));
+
+        db = mongoClient.getDatabase("calendar").withCodecRegistry(codecRegistry);
+        collection = db.getCollection("my_events", Event.class);
+    }
+
+    public static void close() {
+        mongoClient.close();
+    }
+
+    public static BsonValue insertEventsWithDate(Event e) {
+        try {
+            InsertOneResult insertResult = collection.insertOne(e);
+            return insertResult.getInsertedId();
+        } catch (MongoException me) {
+            System.err.println("Failed to insert with error: " + me);
+            throw me;
+        }
+    }
+
+    public static Event readEventsByDate(LocalDateTime localDateTime) {
+        try {
+            Event event = collection
+                    .find(eq("dateTime", localDateTime))
+                    .first();
+            return event;
+        } catch (MongoException me) {
+            System.err.println("Failed to read with error: " + me);
+            throw me;
+        }
+    }
+
+    public static List<Event> readEventsByDateRange(LocalDateTime from, LocalDateTime to) {
+        BasicDBObject object = new BasicDBObject();
+        object.put("dateTime", BasicDBObjectBuilder
+                .start("$gte", from)
+                .add("$lte", to)
+                .get());
+        try {
+            List<Event> list = new ArrayList<Event>(collection.find(object).into(new ArrayList<Event>()));
+            return list;
+        } catch (MongoException me) {
+            System.err.println("Failed to read with error: " + me);
+            throw me;
+        }
+    }
+
+    public static LocalDateTime readEventsByDateWithTZ(LocalDateTime localDateTime) {
+        try {
+            Event event = collection
+                    .find(eq("dateTime", localDateTime))
+                    .first();
+            OffsetDateTime offsetDateTime = OffsetDateTime.of(event.dateTime, ZoneOffset.of(pianoLessonsTZ.timeZoneOffset));
+            ZonedDateTime zoned = offsetDateTime.atZoneSameInstant(ZoneId.of("America/Toronto"));
+            return zoned.toLocalDateTime();
+        } catch (MongoException me) {
+            System.err.println("Failed to read with error: " + me);
+            throw me;
+        }
+    }
+
+    public static long updateDateField() {
+        Document document = new Document().append("title", "Piano lessons");
+        Bson update = Updates.currentDate("updatedAt");
+        UpdateOptions options = new UpdateOptions().upsert(false);
+        try {
+            UpdateResult result = collection.updateOne(document, update, options);
+            return result.getModifiedCount();
+        } catch (MongoException me) {
+            System.err.println("Failed to update with error: " + me);
+            throw me;
+        }
+    }
+
+    public static long updateManyEventsWithDateCriteria(LocalDate updateManyFrom, LocalDate updateManyTo) {
+        Bson query = and(gte("dateTime", updateManyFrom), lt("dateTime", updateManyTo));
+        Bson updates = Updates.currentDate("dateTime");
+        try {
+            UpdateResult result = collection.updateMany(query, updates);
+            return result.getModifiedCount();
+        } catch(MongoException me) {
+            System.err.println("Failed to replace/update with error: " + me);
+            throw me;
+        }
+    }
+
+    public static long deleteEventsByDate(LocalDate from, LocalDate to) {
+        Bson query = and(gte("dateTime", from), lt("dateTime", to));
+        try {
+            DeleteResult result = collection.deleteMany(query);
+            return result.getDeletedCount();
+        } catch (MongoException me) {
+            System.err.println("Failed to delete with error: " + me);
+            throw me;
+        }
+    }
+
+    public static void dropDb() {
+        db.drop();
+    }
+
+    public static void main(String[] args) {
+    }
+}

persistence-modules/java-mongodb-queries/src/main/java/com/baeldung/mongo/crud/model/Event.java

@@ -0,0 +1,28 @@
+package com.baeldung.mongo.crud.model;
+
+import java.time.LocalDateTime;
+
+public class Event {
+    public String title;
+    public String location;
+    public LocalDateTime dateTime;
+    public String timeZoneOffset;
+
+    public Event() {}
+    public Event(String title, String location, LocalDateTime dateTime) {
+        this.title = title;
+        this.location = location;
+        this.dateTime = dateTime;
+    }
+
+    public Event(String title, String location, LocalDateTime dateTime, String timeZoneOffset) {
+        this.title = title;
+        this.location = location;
+        this.dateTime = dateTime;
+        this.timeZoneOffset = timeZoneOffset;
+    }
+
+    @Override
+    public String toString() { return "\nEvent: " + title + "\nWhere: " + location + "\nWhen: " + dateTime; }
+}
+

persistence-modules/java-mongodb-queries/src/test/java/com/baeldung/mongo/crud/CrudClientLiveTest.java

@@ -0,0 +1,95 @@
+package com.baeldung.mongo.crud;
+
+import com.baeldung.mongo.crud.model.Event;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.MethodOrderer;
+import org.junit.jupiter.api.Order;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.TestMethodOrder;
+
+import java.io.IOException;
+import java.util.List;
+
+@TestMethodOrder(MethodOrderer.OrderAnnotation.class)
+public class CrudClientLiveTest {
+
+    @BeforeAll
+    public static void setup() {
+        CrudClient.setup();
+    }
+
+    @Test
+    @Order(1)
+    public void whenInsertingEventsWithDate_thenCheckForDocument() {
+        Assertions.assertNotNull(CrudClient.insertEventsWithDate(CrudClient.pianoLessons));
+        Assertions.assertNotNull(CrudClient.insertEventsWithDate(CrudClient.soccerGame));
+    }
+
+    @Test
+    @Order(2)
+    public void whenReadingEventsByDate_thenCheckForReturnedDocument() {
+        Assertions.assertNotNull(CrudClient.readEventsByDate(CrudClient.dateQuery));
+        Event event = CrudClient.readEventsByDate(CrudClient.dateQuery);
+        Assertions.assertNotNull(event);
+        Assertions.assertEquals("Soccer game", event.title);
+        Assertions.assertEquals("Bar Avenue", event.location);
+        Assertions.assertEquals(CrudClient.soccerGame.dateTime, event.dateTime);
+    }
+
+    @Test
+    @Order(3)
+    public void whenReadingEventsByDateRange_thenCheckForReturnedDocument() {
+        List<Event> events = CrudClient.readEventsByDateRange(CrudClient.from, CrudClient.to);
+        Assertions.assertNotNull(events);
+        Assertions.assertEquals(1, events.size());
+        Assertions.assertEquals("Soccer game", events.get(0).title);
+        Assertions.assertEquals("Bar Avenue", events.get(0).location);
+        Assertions.assertEquals(CrudClient.soccerGame.dateTime, events.get(0).dateTime);
+    }
+
+    @Test
+    @Order(5)
+    public void whenUpdatingEventsDateField_thenCheckUpdatedCount() {
+        Assertions.assertEquals(1, CrudClient.updateDateField());
+    }
+
+    @Test
+    @Order(6)
+    public void whenUpdatingManyEvents_thenCheckUpdatedCount() {
+        long updates = CrudClient.updateManyEventsWithDateCriteria(CrudClient.updateManyFrom, CrudClient.updateManyTo);
+        Assertions.assertTrue(1 < updates);
+    }
+
+    @Test
+    @Order(7)
+    public void whenDeletingEventsWithDate_thenCheckDeletedCount() {
+        Assertions.assertEquals(2, CrudClient.deleteEventsByDate(CrudClient.deleteFrom, CrudClient.deleteTo));
+    }
+
+    @Test
+    @Order(8)
+    public void whenInsertingEventWithDateAndTimeZone_thenCheckForDocument() {
+        Assertions.assertNotNull(CrudClient.insertEventsWithDate(CrudClient.pianoLessonsTZ));
+    }
+
+    @Test
+    @Order(9)
+    public void whenReadingEventsWithDateAndTimeZone_thenCheckInsertedCount() {
+        Assertions.assertNotEquals(CrudClient.pianoLessonsTZ.dateTime, CrudClient.readEventsByDateWithTZ(CrudClient.dateQueryEventWithTZ));
+    }
+
+    @Test
+    @Order(10)
+    public void whenDeletingEventsWithDateAndTimeZone_thenCheckDeletedCount() {
+        Assertions.assertEquals(1, CrudClient.deleteEventsByDate(CrudClient.deleteFrom, CrudClient.deleteTo));
+    }
+
+    @AfterAll
+    public static void close() throws IOException {
+        CrudClient.dropDb();
+        CrudClient.close();
+    }
+
+}

persistence-modules/pom.xml

@@ -45,6 +45,7 @@
         <module>java-mongodb</module> <!-- long running -->
         <module>java-mongodb-2</module> <!-- long running -->
         <module>java-mongodb-3</module> <!-- long running -->
+        <module>java-mongodb-queries</module> <!-- long running -->
         <module>jnosql</module> <!-- long running -->
         <module>jooq</module>
         <module>jpa-hibernate-cascade-type</module>

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

@@ -11,6 +11,7 @@
 - [Spring Data MongoDB: Projections and Aggregations](http://www.baeldung.com/spring-data-mongodb-projections-aggregations)
 - [Spring Data Annotations](http://www.baeldung.com/spring-data-annotations)
 - [Spring Data MongoDB Transactions](https://www.baeldung.com/spring-data-mongodb-transactions)
+- [UUID as Entity ID in MongoDB](https://www.baeldung.com/java-mongodb-uuid)
 
 ## Spring Data MongoDB Live Testing
 

pom.xml

@@ -1246,6 +1246,7 @@
                  <module>core-java-modules/core-java-networking-3</module>
                  <module>core-java-modules/core-java-strings</module>
                  <module>core-java-modules/core-java-httpclient</module>
+                 <module>spring-core-6</module>
                  <module>ddd-contexts</module>
                  <module>docker-modules</module>
                  <module>apache-httpclient-2</module>
@@ -1328,6 +1329,7 @@
                 <module>testing-modules/testing-assertions</module>
                 <module>persistence-modules/fauna</module>
                 <module>lightrun</module>
+                <module>spring-core-6</module>
             </modules>
         </profile>
     </profiles>
@@ -1398,6 +1400,7 @@
         <lombok.version>1.18.20</lombok.version>
         <h2.version>1.4.200</h2.version>
         <guava.version>31.0.1-jre</guava.version>
+        <maven-jar-plugin.version>3.2.2</maven-jar-plugin.version>
     </properties>
 
 </project>

spring-boot-modules/pom.xml

@@ -44,6 +44,7 @@
         <module>spring-boot-groovy</module>
         <!-- <module>spring-boot-gradle</module> --> <!-- Not a maven project -->
         <module>spring-boot-jasypt</module>
+        <module>spring-boot-jsp</module>
         <module>spring-boot-keycloak</module>
         <module>spring-boot-keycloak-2</module>
         <module>spring-boot-libraries</module>

spring-boot-modules/spring-boot-jsp/pom.xml

@@ -9,9 +9,9 @@
     <packaging>war</packaging>
 
     <parent>
-        <groupId>com.baeldung</groupId>
-        <artifactId>spring-web-modules</artifactId>
-        <version>0.0.1-SNAPSHOT</version>
+        <groupId>com.baeldung.spring-boot-modules</groupId>
+        <artifactId>spring-boot-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
     </parent>
 
     <dependencyManagement>

spring-cloud-modules/spring-cloud-gateway/README.md

@@ -10,3 +10,4 @@ This module contains articles about Spring Cloud Gateway
 - [Spring Cloud Gateway WebFilter Factories](https://www.baeldung.com/spring-cloud-gateway-webfilter-factories)
 - [Using Spring Cloud Gateway with OAuth 2.0 Patterns](https://www.baeldung.com/spring-cloud-gateway-oauth2)
 - [URL Rewriting With Spring Cloud Gateway](https://www.baeldung.com/spring-cloud-gateway-url-rewriting)
+- [Processing the Response Body in Spring Cloud Gateway](https://www.baeldung.com/spring-cloud-gateway-response-body)

spring-core-6/pom.xml

@@ -0,0 +1,76 @@
+<?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>
+
+    <groupId>com.baeldung</groupId>
+    <artifactId>spring-core-6</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>spring-core-6</name>
+    <url>http://www.baeldung.com</url>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <maven.compiler.source>11</maven.compiler.source>
+        <maven.compiler.target>11</maven.compiler.target>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.11</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+            <version>2.0.0.RELEASE</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <pluginManagement>
+            <plugins>
+                <plugin>
+                    <artifactId>maven-clean-plugin</artifactId>
+                    <version>3.1.0</version>
+                </plugin>
+                <plugin>
+                    <artifactId>maven-resources-plugin</artifactId>
+                    <version>3.0.2</version>
+                </plugin>
+                <plugin>
+                    <artifactId>maven-compiler-plugin</artifactId>
+                    <version>3.8.0</version>
+                </plugin>
+                <plugin>
+                    <artifactId>maven-surefire-plugin</artifactId>
+                    <version>2.22.1</version>
+                </plugin>
+                <plugin>
+                    <artifactId>maven-jar-plugin</artifactId>
+                    <version>3.0.2</version>
+                </plugin>
+                <plugin>
+                    <artifactId>maven-install-plugin</artifactId>
+                    <version>2.5.2</version>
+                </plugin>
+                <plugin>
+                    <artifactId>maven-deploy-plugin</artifactId>
+                    <version>2.8.2</version>
+                </plugin>
+
+                <plugin>
+                    <artifactId>maven-site-plugin</artifactId>
+                    <version>3.7.1</version>
+                </plugin>
+                <plugin>
+                    <artifactId>maven-project-info-reports-plugin</artifactId>
+                    <version>3.0.0</version>
+                </plugin>
+            </plugins>
+        </pluginManagement>
+    </build>
+</project>

spring-core-6/src/main/java/com/baeldung/multibeaninstantiation/solution1/Person.java

@@ -0,0 +1,17 @@
+package com.baeldung.multibeaninstantiation.solution1;
+
+public class Person {
+    private String firstName;
+    private String lastName;
+
+    public Person(String firstName, String secondName) {
+        super();
+        this.firstName = firstName;
+        this.lastName = secondName;
+    }
+
+    @Override
+    public String toString() {
+        return "Person [firstName=" + firstName + ", secondName=" + lastName + "]";
+    }
+}

spring-core-6/src/main/java/com/baeldung/multibeaninstantiation/solution1/PersonConfig.java

@@ -0,0 +1,17 @@
+package com.baeldung.multibeaninstantiation.solution1;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class PersonConfig {
+    @Bean
+    public Person personOne() {
+        return new Person("Harold", "Finch");
+    }
+
+    @Bean
+    public Person personTwo() {
+        return new Person("John", "Reese");
+    }
+}

spring-core-6/src/main/java/com/baeldung/multibeaninstantiation/solution1/SpringApp1.java

@@ -0,0 +1,11 @@
+package com.baeldung.multibeaninstantiation.solution1;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SpringApp1 {
+    public static void main(String[] args) {
+        SpringApplication.run(SpringApp1.class, args);
+    }
+}

spring-core-6/src/main/java/com/baeldung/multibeaninstantiation/solution2/Person.java

@@ -0,0 +1,17 @@
+package com.baeldung.multibeaninstantiation.solution2;
+
+public class Person {
+    private String firstName;
+    private String lastName;
+
+    public Person(String firstName, String secondName) {
+        super();
+        this.firstName = firstName;
+        this.lastName = secondName;
+    }
+
+    @Override
+    public String toString() {
+        return "Person [firstName=" + firstName + ", secondName=" + lastName + "]";
+    }
+}

spring-core-6/src/main/java/com/baeldung/multibeaninstantiation/solution2/PersonConfig.java

@@ -0,0 +1,10 @@
+package com.baeldung.multibeaninstantiation.solution2;
+
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@ComponentScan("com.baeldung.multibeaninstantiation.solution2")
+public class PersonConfig {
+
+}

spring-core-6/src/main/java/com/baeldung/multibeaninstantiation/solution2/PersonOne.java

@@ -0,0 +1,13 @@
+package com.baeldung.multibeaninstantiation.solution2;
+
+import org.springframework.stereotype.Component;
+
+import com.baeldung.multibeaninstantiation.solution2.Person;
+
+@Component
+public class PersonOne extends Person {
+
+    public PersonOne() {
+        super("Harold", "Finch");
+    }
+}

spring-core-6/src/main/java/com/baeldung/multibeaninstantiation/solution2/PersonTwo.java

@@ -0,0 +1,13 @@
+package com.baeldung.multibeaninstantiation.solution2;
+
+import org.springframework.stereotype.Component;
+
+import com.baeldung.multibeaninstantiation.solution2.Person;
+
+@Component
+public class PersonTwo extends Person {
+
+    public PersonTwo() {
+        super("John", "Reese");
+    }
+}

spring-core-6/src/main/java/com/baeldung/multibeaninstantiation/solution2/SpringApp2.java

@@ -0,0 +1,11 @@
+package com.baeldung.multibeaninstantiation.solution2;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SpringApp2 {
+    public static void main(String[] args) {
+        SpringApplication.run(SpringApp2.class, args);
+    }
+}

spring-core-6/src/main/java/com/baeldung/multibeaninstantiation/solution3/Human.java

@@ -0,0 +1,33 @@
+package com.baeldung.multibeaninstantiation.solution3;
+
+import org.springframework.beans.factory.InitializingBean;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.util.Assert;
+
+public class Human implements InitializingBean {
+
+    private Person personOne;
+
+    private Person personTwo;
+
+    @Override
+    public void afterPropertiesSet() throws Exception {
+        Assert.notNull(personOne, "Harold is alive!");
+        Assert.notNull(personTwo, "John is alive!");
+    }
+
+    /* Setter injection */
+    @Autowired
+    public void setPersonOne(Person personOne) {
+        this.personOne = personOne;
+        this.personOne.setFirstName("Harold");
+        this.personOne.setSecondName("Finch");
+    }
+
+    @Autowired
+    public void setPersonTwo(Person personTwo) {
+        this.personTwo = personTwo;
+        this.personTwo.setFirstName("John");
+        this.personTwo.setSecondName("Reese");
+    }
+}

spring-core-6/src/main/java/com/baeldung/multibeaninstantiation/solution3/MultiBeanFactory.java

@@ -0,0 +1,9 @@
+package com.baeldung.multibeaninstantiation.solution3;
+
+import java.util.List;
+
+public interface MultiBeanFactory<T> {
+    List<T> getObject(String name) throws Exception;
+
+    Class<?> getObjectType();
+}

spring-core-6/src/main/java/com/baeldung/multibeaninstantiation/solution3/Person.java

@@ -0,0 +1,49 @@
+package com.baeldung.multibeaninstantiation.solution3;
+
+import org.springframework.beans.factory.FactoryBean;
+import org.springframework.beans.factory.annotation.Qualifier;
+
+@Qualifier(value = "personOne, personTwo")
+public class Person implements FactoryBean<Object> {
+    private String firstName;
+    private String secondName;
+
+    public Person() {
+        // initialization code (optional)
+    }
+
+    @Override
+    public Class<Person> getObjectType() {
+        return Person.class;
+    }
+
+    @Override
+    public Object getObject() throws Exception {
+        return new Person();
+    }
+
+    public boolean isSingleton() {
+        return true;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+
+    public String getSecondName() {
+        return secondName;
+    }
+
+    public void setSecondName(String secondName) {
+        this.secondName = secondName;
+    }
+
+    @Override
+    public String toString() {
+        return "Person [firstName=" + firstName + ", secondName=" + secondName + "]";
+    }
+}

spring-core-6/src/main/java/com/baeldung/multibeaninstantiation/solution3/PersonConfig.java

@@ -0,0 +1,22 @@
+package com.baeldung.multibeaninstantiation.solution3;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class PersonConfig {
+    @Bean
+    public PersonFactoryPostProcessor PersonFactoryPostProcessor() {
+        return new PersonFactoryPostProcessor();
+    }
+
+    @Bean
+    public Person person() {
+        return new Person();
+    }
+
+    @Bean
+    public Human human() {
+        return new Human();
+    }
+}

spring-core-6/src/main/java/com/baeldung/multibeaninstantiation/solution3/PersonFactoryPostProcessor.java

@@ -0,0 +1,33 @@
+package com.baeldung.multibeaninstantiation.solution3;
+
+import java.util.Map;
+
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
+import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
+
+public class PersonFactoryPostProcessor implements BeanFactoryPostProcessor {
+
+    @Override
+    public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
+        Map<String, Object> map = beanFactory.getBeansWithAnnotation(Qualifier.class);
+        for (Map.Entry<String, Object> entry : map.entrySet()) {
+            createInstances(beanFactory, entry.getKey(), entry.getValue());
+        }
+    }
+
+    private void createInstances(ConfigurableListableBeanFactory beanFactory, String beanName, Object bean) {
+        Qualifier qualifier = bean.getClass()
+            .getAnnotation(Qualifier.class);
+        for (String name : extractNames(qualifier)) {
+            Object newBean = beanFactory.getBean(beanName);
+            beanFactory.registerSingleton(name.trim(), newBean);
+        }
+    }
+
+    private String[] extractNames(Qualifier qualifier) {
+        return qualifier.value()
+            .split(",");
+    }
+}

spring-core-6/src/main/java/com/baeldung/multibeaninstantiation/solution3/SpringApp3.java

@@ -0,0 +1,11 @@
+package com.baeldung.multibeaninstantiation.solution3;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SpringApp3 {
+    public static void main(String[] args) {
+        SpringApplication.run(SpringApp3.class, args);
+    }
+}

spring-web-modules/pom.xml

@@ -47,7 +47,6 @@
         <module>spring-thymeleaf-3</module>
         <module>spring-thymeleaf-4</module>
         <module>spring-thymeleaf-5</module>
-        <module>spring-boot-jsp</module>
         <module>spring-web-url</module>
     </modules>