Merge branch 'master' of https://github.com/Maiklins/tutorials into Java-1524-split-move-spring-boot-persistence

Conflicts: persistence-modules/spring-boot-persistence-2/README.md
2020-05-16 16:47:19 +02:00 · 2020-05-16 16:47:19 +02:00 · 8c1e57cc58
parent c2637f1509 6a7e086c4d
commit 8c1e57cc58
113 changed files with 2887 additions and 100 deletions
--- a/atomikos/README.md
+++ b/atomikos/README.md
@ -1,7 +1,6 @@
 ## Atomikos
-
 This module contains articles about Atomikos

 ### Relevant Articles: 

- [Guide Transactions Using Atomikos]()
+- [A Guide to Atomikos](https://www.baeldung.com/java-atomikos)
--- a/aws-app-sync/pom.xml
+++ b/aws-app-sync/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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>2.2.6.RELEASE</version>
+        <relativePath/> <!-- lookup parent from repository -->
+    </parent>
+
+    <groupId>com.baeldung</groupId>
+    <artifactId>aws-app-sync</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>aws-app-sync</name>
+
+    <description>Spring Boot using AWS App Sync</description>
+
+    <properties>
+        <java.version>1.8</java.version>
+    </properties>
+
+    <dependencies>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+            <exclusions>
+                <exclusion>
+                    <groupId>org.junit.vintage</groupId>
+                    <artifactId>junit-vintage-engine</artifactId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-webflux</artifactId>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>
--- a/aws-app-sync/src/main/java/com/baeldung/awsappsync/AppSyncClientHelper.java
+++ b/aws-app-sync/src/main/java/com/baeldung/awsappsync/AppSyncClientHelper.java
@ -0,0 +1,32 @@
+package com.baeldung.awsappsync;
+
+import org.springframework.http.HttpMethod;
+import org.springframework.http.MediaType;
+import org.springframework.web.reactive.function.BodyInserters;
+import org.springframework.web.reactive.function.client.WebClient;
+
+import java.nio.charset.StandardCharsets;
+import java.util.Map;
+
+public class AppSyncClientHelper {
+
+    static String apiUrl = "https://m4i3b6icrrb7livfbypfspiifi.appsync-api.us-east-2.amazonaws.com";
+    static String apiKey = "da2-bm4rpatkkrc5jfyhvvq7itjeke";
+    static String API_KEY_HEADER = "x-api-key";
+
+    public static WebClient.ResponseSpec getResponseBodySpec(Map<String, Object> requestBody) {
+        return WebClient
+                .builder()
+                .baseUrl(apiUrl)
+                .defaultHeader(API_KEY_HEADER, apiKey)
+                .defaultHeader("Content-Type", "application/json")
+                .build()
+                .method(HttpMethod.POST)
+                .uri("/graphql")
+                .body(BodyInserters.fromValue(requestBody))
+                .accept(MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML)
+                .acceptCharset(StandardCharsets.UTF_8)
+                .retrieve();
+    }
+
+}
--- a/aws-app-sync/src/main/java/com/baeldung/awsappsync/AwsAppSyncApplication.java
+++ b/aws-app-sync/src/main/java/com/baeldung/awsappsync/AwsAppSyncApplication.java
@ -0,0 +1,13 @@
+package com.baeldung.awsappsync;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class AwsAppSyncApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(AwsAppSyncApplication.class, args);
+    }
+
+}
--- a/aws-app-sync/src/test/java/com/baeldung/awsappsync/AwsAppSyncApplicationTests.java
+++ b/aws-app-sync/src/test/java/com/baeldung/awsappsync/AwsAppSyncApplicationTests.java
@ -0,0 +1,72 @@
+package com.baeldung.awsappsync;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.web.reactive.function.client.WebClient;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+@SpringBootTest
+class AwsAppSyncApplicationTests {
+
+    @Test
+    void givenGraphQuery_whenListEvents_thenReturnAllEvents() {
+
+        Map<String, Object> requestBody = new HashMap<>();
+        requestBody.put("query", "query ListEvents {"
+                + "  listEvents {"
+                + "    items {"
+                + "      id"
+                + "      name"
+                + "      where"
+                + "      when"
+                + "      description"
+                + "    }"
+                + "  }"
+                + "}");
+        requestBody.put("variables", "");
+        requestBody.put("operationName", "ListEvents");
+
+        String bodyString = AppSyncClientHelper.getResponseBodySpec(requestBody)
+                .bodyToMono(String.class).block();
+
+        assertNotNull(bodyString);
+        assertTrue(bodyString.contains("My First Event"));
+        assertTrue(bodyString.contains("where"));
+        assertTrue(bodyString.contains("when"));
+    }
+
+    @Test
+    void givenGraphAdd_whenMutation_thenReturnIdNameDesc() {
+
+        String queryString = "mutation add {"
+                + "    createEvent("
+                + "        name:\"My added GraphQL event\""
+                + "        where:\"Day 2\""
+                + "        when:\"Saturday night\""
+                + "        description:\"Studying GraphQL\""
+                + "    ){"
+                + "        id"
+                + "        name"
+                + "        description"
+                + "    }"
+                + "}";
+
+        Map<String, Object> requestBody = new HashMap<>();
+        requestBody.put("query", queryString);
+        requestBody.put("variables", "");
+        requestBody.put("operationName", "add");
+
+        WebClient.ResponseSpec response = AppSyncClientHelper.getResponseBodySpec(requestBody);
+
+        String bodyString = response.bodyToMono(String.class).block();
+
+        assertNotNull(bodyString);
+        assertTrue(bodyString.contains("My added GraphQL event"));
+        assertFalse(bodyString.contains("where"));
+        assertFalse(bodyString.contains("when"));
+    }
+}
--- a/bazel/bazelapp/README.md
+++ b/bazel/bazelapp/README.md
@ -1,3 +0,0 @@
-### Relevant Articles:
-
- [Building Java Applications with Bazel](https://www.baeldung.com/bazel-build-tool)
--- a/core-groovy/README.md
+++ b/core-groovy/README.md
@ -12,4 +12,5 @@ This module contains articles about core Groovy concepts
 - [Closures in Groovy](https://www.baeldung.com/groovy-closures)
 - [Converting a String to a Date in Groovy](https://www.baeldung.com/groovy-string-to-date)
 - [Guide to I/O in Groovy](https://www.baeldung.com/groovy-io)
- [[More -->]](/core-groovy-2)
+- [Convert String to Integer in Groovy](https://www.baeldung.com/groovy-convert-string-to-integer)
+- [[More -->]](/core-groovy-2)
--- a/core-java-modules/core-java-14/src/main/java/com/baeldung/java14/record/Person.java
+++ b/core-java-modules/core-java-14/src/main/java/com/baeldung/java14/record/Person.java
@ -0,0 +1,22 @@
+package com.baeldung.java14.record;
+
+import java.util.Objects;
+
+public record Person (String name, String address) {
+	
+	public static String UNKWOWN_ADDRESS = "Unknown";
+	public static String UNNAMED = "Unnamed";
+
+	public Person {
+		Objects.requireNonNull(name);
+		Objects.requireNonNull(address);
+	}
+	
+	public Person(String name) {
+		this(name, UNKWOWN_ADDRESS);
+	}
+	
+	public static Person unnamed(String address) {
+		return new Person(UNNAMED, address);
+	}
+}
--- a/core-java-modules/core-java-14/src/test/java/com/baeldung/java14/foreign/api/ForeignMemoryUnitTest.java
+++ b/core-java-modules/core-java-14/src/test/java/com/baeldung/java14/foreign/api/ForeignMemoryUnitTest.java
@ -0,0 +1,84 @@
+package com.baeldung.java14.foreign.api;
+
+import jdk.incubator.foreign.*;
+import org.junit.Test;
+
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+
+import java.lang.invoke.VarHandle;
+import java.nio.ByteOrder;
+
+public class ForeignMemoryUnitTest {
+
+    @Test
+    public void whenAValueIsSet_thenAccessTheValue() {
+        long value = 10;
+        MemoryAddress memoryAddress =
+          MemorySegment.allocateNative(8).baseAddress();
+        VarHandle varHandle = MemoryHandles.varHandle(long.class,
+          ByteOrder.nativeOrder());
+        varHandle.set(memoryAddress, value);
+        assertThat(varHandle.get(memoryAddress), is(value));
+    }
+
+    @Test
+    public void whenMultipleValuesAreSet_thenAccessAll() {
+        VarHandle varHandle = MemoryHandles.varHandle(int.class,
+          ByteOrder.nativeOrder());
+
+        try(MemorySegment memorySegment =
+          MemorySegment.allocateNative(100)) {
+            MemoryAddress base = memorySegment.baseAddress();
+            for(int i=0; i<25; i++) {
+                varHandle.set(base.addOffset((i*4)), i);
+            }
+            for(int i=0; i<25; i++) {
+                assertThat(varHandle.get(base.addOffset((i*4))), is(i));
+            }
+        }
+    }
+
+    @Test
+    public void whenSetValuesWithMemoryLayout_thenTheyCanBeRetrieved() {
+        SequenceLayout sequenceLayout =
+          MemoryLayout.ofSequence(25,
+            MemoryLayout.ofValueBits(64, ByteOrder.nativeOrder()));
+        VarHandle varHandle =
+          sequenceLayout.varHandle(long.class,
+            MemoryLayout.PathElement.sequenceElement());
+
+        try(MemorySegment memorySegment =
+          MemorySegment.allocateNative(sequenceLayout)) {
+            MemoryAddress base = memorySegment.baseAddress();
+            for(long i=0; i<sequenceLayout.elementCount().getAsLong(); i++) {
+                varHandle.set(base, i, i);
+            }
+            for(long i=0; i<sequenceLayout.elementCount().getAsLong(); i++) {
+                assertThat(varHandle.get(base, i), is(i));
+            }
+        }
+    }
+
+    @Test
+    public void whenSlicingMemorySegment_thenTheyCanBeAccessedIndividually() {
+        MemoryAddress memoryAddress =
+          MemorySegment.allocateNative(12).baseAddress();
+        MemoryAddress memoryAddress1 =
+          memoryAddress.segment().asSlice(0,4).baseAddress();
+        MemoryAddress memoryAddress2 =
+          memoryAddress.segment().asSlice(4,4).baseAddress();
+        MemoryAddress memoryAddress3 =
+          memoryAddress.segment().asSlice(8,4).baseAddress();
+
+        VarHandle intHandle =
+          MemoryHandles.varHandle(int.class, ByteOrder.nativeOrder());
+        intHandle.set(memoryAddress1, Integer.MIN_VALUE);
+        intHandle.set(memoryAddress2, 0);
+        intHandle.set(memoryAddress3, Integer.MAX_VALUE);
+
+        assertThat(intHandle.get(memoryAddress1), is(Integer.MIN_VALUE));
+        assertThat(intHandle.get(memoryAddress2), is(0));
+        assertThat(intHandle.get(memoryAddress3), is(Integer.MAX_VALUE));
+    }
+}
--- a/core-java-modules/core-java-14/src/test/java/com/baeldung/java14/record/PersonTest.java
+++ b/core-java-modules/core-java-14/src/test/java/com/baeldung/java14/record/PersonTest.java
@ -0,0 +1,150 @@
+package com.baeldung.java14.record;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+public class PersonTest {
+
+    @Test
+    public void givenSameNameAndAddress_whenEquals_thenPersonsEqual() {
+
+        String name = "John Doe";
+        String address = "100 Linda Ln.";
+
+        Person person1 = new Person(name, address);
+        Person person2 = new Person(name, address);
+
+        assertTrue(person1.equals(person2));
+    }
+    
+    @Test
+    public void givenDifferentObject_whenEquals_thenNotEqual() {
+
+        Person person = new Person("John Doe", "100 Linda Ln.");
+
+        assertFalse(person.equals(new Object()));
+    }
+
+    @Test
+    public void givenDifferentName_whenEquals_thenPersonsNotEqual() {
+    
+        String address = "100 Linda Ln.";
+    
+        Person person1 = new Person("Jane Doe", address);
+        Person person2 = new Person("John Doe", address);
+    
+        assertFalse(person1.equals(person2));
+    }
+    
+    @Test
+    public void givenDifferentAddress_whenEquals_thenPersonsNotEqual() {
+    
+        String name = "John Doe";
+    
+        Person person1 = new Person(name, "100 Linda Ln.");
+        Person person2 = new Person(name, "200 London Ave.");
+    
+        assertFalse(person1.equals(person2));
+    }
+
+    @Test
+    public void givenSameNameAndAddress_whenHashCode_thenPersonsEqual() {
+
+        String name = "John Doe";
+        String address = "100 Linda Ln.";
+
+        Person person1 = new Person(name, address);
+        Person person2 = new Person(name, address);
+
+        assertEquals(person1.hashCode(), person2.hashCode());
+    }
+    
+    @Test
+    public void givenDifferentObject_whenHashCode_thenNotEqual() {
+
+        Person person = new Person("John Doe", "100 Linda Ln.");
+
+        assertNotEquals(person.hashCode(), new Object().hashCode());
+    }
+
+    @Test
+    public void givenDifferentName_whenHashCode_thenPersonsNotEqual() {
+
+        String address = "100 Linda Ln.";
+
+        Person person1 = new Person("Jane Doe", address);
+        Person person2 = new Person("John Doe", address);
+
+        assertNotEquals(person1.hashCode(), person2.hashCode());
+    }
+
+    @Test
+    public void givenDifferentAddress_whenHashCode_thenPersonsNotEqual() {
+
+        String name = "John Doe";
+
+        Person person1 = new Person(name, "100 Linda Ln.");
+        Person person2 = new Person(name, "200 London Ave.");
+
+        assertNotEquals(person1.hashCode(), person2.hashCode());
+    }
+
+    @Test
+    public void givenValidNameAndAddress_whenGetNameAndAddress_thenExpectedValuesReturned() {
+
+        String name = "John Doe";
+        String address = "100 Linda Ln.";
+
+        Person person = new Person(name, address);
+
+        assertEquals(name, person.name());
+        assertEquals(address, person.address());
+    }
+
+    @Test
+    public void givenValidNameAndAddress_whenToString_thenCorrectStringReturned() {
+
+        String name = "John Doe";
+        String address = "100 Linda Ln.";
+
+        Person person = new Person(name, address);
+
+        assertEquals("Person[name=" + name + ", address=" + address + "]", person.toString());
+    }
+
+    @Test(expected = NullPointerException.class)
+    public void givenNullName_whenConstruct_thenErrorThrown() {
+        new Person(null, "100 Linda Ln.");
+    }
+
+    @Test(expected = NullPointerException.class)
+    public void givenNullAddress_whenConstruct_thenErrorThrown() {
+        new Person("John Doe", null);
+    }
+
+    @Test
+    public void givenUnknownAddress_whenConstructing_thenAddressPopulated() {
+
+        String name = "John Doe";
+
+        Person person = new Person(name);
+
+        assertEquals(name, person.name());
+        assertEquals(Person.UNKWOWN_ADDRESS, person.address());
+    }
+
+    @Test
+    public void givenUnnamed_whenConstructingThroughFactory_thenNamePopulated() {
+
+        String address = "100 Linda Ln.";
+
+        Person person = Person.unnamed(address);
+
+        assertEquals(Person.UNNAMED, person.name());
+        assertEquals(address, person.address());
+    }
+}
--- a/core-java-modules/core-java-collections-maps-3/README.md
+++ b/core-java-modules/core-java-collections-maps-3/README.md
@ -5,4 +5,5 @@ This module contains articles about Map data structures in Java.
 ### Relevant Articles: 
 - [Java TreeMap vs HashMap](https://www.baeldung.com/java-treemap-vs-hashmap)
 - [Comparing Two HashMaps in Java](https://www.baeldung.com/java-compare-hashmaps)
+- [The Map.computeIfAbsent() Method](https://www.baeldung.com/java-map-computeifabsent)
 - More articles: [[<-- prev]](/core-java-modules/core-java-collections-maps-2)
--- a/core-java-modules/core-java-concurrency-2/README.md
+++ b/core-java-modules/core-java-concurrency-2/README.md
@ -4,5 +4,5 @@

 ### Relevant Articles: 
 - [Using a Mutex Object in Java](https://www.baeldung.com/java-mutex)
- [Testing Multi-Threaded Code in Java] (https://www.baeldung.com/java-testing-multithreaded)
+- [Testing Multi-Threaded Code in Java](https://www.baeldung.com/java-testing-multithreaded)

--- a/core-java-modules/core-java-concurrency-advanced-3/src/main/java/com/baeldung/lockfree/NonBlockingQueue.java
+++ b/core-java-modules/core-java-concurrency-advanced-3/src/main/java/com/baeldung/lockfree/NonBlockingQueue.java
@ -0,0 +1,81 @@
+package com.baeldung.lockfree;
+
+import java.util.NoSuchElementException;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicReference;
+
+public class NonBlockingQueue<T> {
+
+    private final AtomicReference<Node<T>> head, tail;
+    private final AtomicInteger size;
+
+    public NonBlockingQueue() {
+        head = new AtomicReference<>(null);
+        tail = new AtomicReference<>(null);
+        size = new AtomicInteger();
+        size.set(0);
+    }
+
+    public void add(T element) {
+        if (element == null) {
+            throw new NullPointerException();
+        }
+
+        Node<T> node = new Node<>(element);
+        Node<T> currentTail;
+        do {
+            currentTail = tail.get();
+            node.setPrevious(currentTail);
+        } while(!tail.compareAndSet(currentTail, node));
+
+        if(node.previous != null) {
+            node.previous.next = node;
+        }
+
+        head.compareAndSet(null, node); //if we are inserting the first element
+        size.incrementAndGet();
+    }
+
+    public T get() {
+        if(head.get() == null) {
+            throw new NoSuchElementException();
+        }
+
+        Node<T> currentHead;
+        Node<T> nextNode;
+        do {
+            currentHead = head.get();
+            nextNode = currentHead.getNext();
+        } while(!head.compareAndSet(currentHead, nextNode));
+
+        size.decrementAndGet();
+        return currentHead.getValue();
+    }
+
+    public int size() {
+        return this.size.get();
+    }
+
+    private class Node<T> {
+        private final T value;
+        private volatile Node<T> next;
+        private volatile Node<T> previous;
+
+        public Node(T value) {
+            this.value = value;
+            this.next = null;
+        }
+
+        public T getValue() {
+            return value;
+        }
+
+        public Node<T> getNext() {
+            return next;
+        }
+
+        public void setPrevious(Node<T> previous) {
+            this.previous = previous;
+        }
+    }
+}
--- a/core-java-modules/core-java-date-operations-2/src/main/java/com/baeldung/weeknumber/WeekNumberUsingCalendar.java
+++ b/core-java-modules/core-java-date-operations-2/src/main/java/com/baeldung/weeknumber/WeekNumberUsingCalendar.java
@ -0,0 +1,41 @@
+package com.baeldung.weeknumber;
+
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.Calendar;
+import java.util.Date;
+import java.util.Locale;
+
+public class WeekNumberUsingCalendar {
+
+    public int getWeekNumberFrom(String day, String dateFormat, Locale locale) throws ParseException {
+        SimpleDateFormat sdf = new SimpleDateFormat(dateFormat);
+
+        Calendar calendar = Calendar.getInstance(locale);
+        Date date = sdf.parse(day);
+        calendar.setTime(date);
+
+        return calendar.get(Calendar.WEEK_OF_YEAR);
+    }
+
+    public int getWeekNumberFrom(int year, int month, int day, Locale locale) {
+        Calendar calendar = Calendar.getInstance(locale);
+        calendar.set(year, month, day);
+
+        return calendar.get(Calendar.WEEK_OF_YEAR);
+    }
+
+    public int getWeekNumberFrom(int year, int month, int day, int firstDayOfWeek, int minimalDaysInFirstWeek, Locale locale) {
+        Calendar calendar = Calendar.getInstance(locale);
+        calendar.setFirstDayOfWeek(firstDayOfWeek);
+        calendar.setMinimalDaysInFirstWeek(minimalDaysInFirstWeek);
+        calendar.set(year, month, day);
+
+        return calendar.get(Calendar.WEEK_OF_YEAR);
+    }
+
+    public static void main(String[] args) {
+        WeekNumberUsingCalendar calendar = new WeekNumberUsingCalendar();
+        System.out.println(calendar.getWeekNumberFrom(2020, 2, 22, Locale.CANADA));
+    }
+}
--- a/core-java-modules/core-java-date-operations-2/src/main/java/com/baeldung/weeknumber/WeekNumberUsingLocalDate.java
+++ b/core-java-modules/core-java-date-operations-2/src/main/java/com/baeldung/weeknumber/WeekNumberUsingLocalDate.java
@ -0,0 +1,30 @@
+package com.baeldung.weeknumber;
+
+import java.time.LocalDate;
+import java.time.format.DateTimeFormatter;
+import java.time.temporal.ChronoField;
+import java.time.temporal.WeekFields;
+import java.util.Locale;
+
+public class WeekNumberUsingLocalDate {
+
+    public Integer getWeekNumberUsingWeekFiedsFrom(String day, String dayFormat, Locale locale) {
+        LocalDate date = LocalDate.parse(day, DateTimeFormatter.ofPattern(dayFormat));
+
+        return date.get(WeekFields.of(locale)
+            .weekOfYear());
+    }
+
+    public Integer getWeekNumberUsinWeekFieldsFrom(int year, int month, int day, Locale locale) {
+        LocalDate date = LocalDate.of(year, month, day);
+
+        return date.get(WeekFields.of(locale)
+            .weekOfYear());
+    }
+
+    public Integer getWeekNumberUsingChronoFieldFrom(int year, int month, int day) {
+        LocalDate date = LocalDate.of(year, month, day);
+
+        return date.get(ChronoField.ALIGNED_WEEK_OF_YEAR);
+    }
+}
--- a/core-java-modules/core-java-date-operations-2/src/test/java/com/baeldung/weeknumber/WeekNumberUsingCalendarUnitTest.java
+++ b/core-java-modules/core-java-date-operations-2/src/test/java/com/baeldung/weeknumber/WeekNumberUsingCalendarUnitTest.java
@ -0,0 +1,46 @@
+package com.baeldung.weeknumber;
+
+import static org.junit.Assert.assertEquals;
+
+import java.text.ParseException;
+import java.util.Calendar;
+import java.util.Locale;
+
+import org.junit.Test;
+
+public class WeekNumberUsingCalendarUnitTest {
+    @Test
+    public void givenDateInStringAndDateFormatUsingLocaleItaly_thenGettingWeekNumberUsingCalendarIsCorrectlyReturned() throws ParseException {
+        WeekNumberUsingCalendar calendar = new WeekNumberUsingCalendar();
+
+        assertEquals(12, calendar.getWeekNumberFrom("20200322", "yyyyMMdd", Locale.ITALY));
+    }
+
+    @Test
+    public void givenDateInStringAndDateFormatUsingLocaleCanada_thenGettingWeekNumberUsingCalendarIsCorrectlyReturned() throws ParseException {
+        WeekNumberUsingCalendar calendar = new WeekNumberUsingCalendar();
+
+        assertEquals(13, calendar.getWeekNumberFrom("20200322", "yyyyMMdd", Locale.CANADA));
+    }
+
+    @Test
+    public void givenDateInYearMonthDayNumbersLocaleItaly_thenGettingWeekNumberUsingCalendarIsCorrectlyReturned() {
+        WeekNumberUsingCalendar calendar = new WeekNumberUsingCalendar();
+
+        assertEquals(12, calendar.getWeekNumberFrom(2020, 2, 22, Locale.ITALY));
+    }
+
+    @Test
+    public void givenDateInYearMonthDayNumbersLocaleItalyChangingWeekCalculationSettings_thenGettingWeekNumberUsingCalendarIsCorrectlyReturned() {
+        WeekNumberUsingCalendar calendar = new WeekNumberUsingCalendar();
+
+        assertEquals(13, calendar.getWeekNumberFrom(2020, 2, 22, Calendar.SUNDAY, 4, Locale.ITALY));
+    }
+
+    @Test
+    public void givenDateInYearMonthDayNumbersLocaleCanada_thenGettingWeekNumberUsingCalendarIsCorrectlyReturned() {
+        WeekNumberUsingCalendar calendar = new WeekNumberUsingCalendar();
+
+        assertEquals(13, calendar.getWeekNumberFrom(2020, 2, 22, Locale.CANADA));
+    }
+}
--- a/core-java-modules/core-java-date-operations-2/src/test/java/com/baeldung/weeknumber/WeekNumberUsingLocalDateUnitTest.java
+++ b/core-java-modules/core-java-date-operations-2/src/test/java/com/baeldung/weeknumber/WeekNumberUsingLocalDateUnitTest.java
@ -0,0 +1,49 @@
+package com.baeldung.weeknumber;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.Locale;
+
+import org.junit.Test;
+
+public class WeekNumberUsingLocalDateUnitTest {
+    @Test
+    public void givenDateInStringAndDateFormatUsingWeekFieldsWithLocaleItaly_thenGettingWeekNumberUsingLocalDateIsCorrectlyReturned() {
+        WeekNumberUsingLocalDate localDate = new WeekNumberUsingLocalDate();
+
+        assertEquals(12, localDate.getWeekNumberUsingWeekFiedsFrom("20200322", "yyyyMMdd", Locale.ITALY)
+            .longValue());
+    }
+
+    @Test
+    public void givenDateInStringAndDateFormatUsingWeekFieldsWithLocaleCanada_thenGettingWeekNumberUsingLocalDateIsCorrectlyReturned() {
+        WeekNumberUsingLocalDate localDate = new WeekNumberUsingLocalDate();
+
+        assertEquals(13, localDate.getWeekNumberUsingWeekFiedsFrom("20200322", "yyyyMMdd", Locale.CANADA)
+            .longValue());
+    }
+
+    @Test
+    public void givenDateInStringAndDateFormatUsingChronoFieds_thenGettingWeekNumberUsingLocalDateIsCorrectlyReturned() {
+        WeekNumberUsingLocalDate localDate = new WeekNumberUsingLocalDate();
+
+        assertEquals(12, localDate.getWeekNumberUsingChronoFieldFrom(2020, 3, 22)
+            .longValue());
+    }
+
+    @Test
+    public void givenDateInYearMonthDayNumbersUsingWeekFieldsWithLocaleItaly_thenGettingWeekNumberUsingLocalDateIsCorrectlyReturned() {
+        WeekNumberUsingLocalDate localDate = new WeekNumberUsingLocalDate();
+
+        assertEquals(12, localDate.getWeekNumberUsinWeekFieldsFrom(2020, 3, 22, Locale.ITALY)
+            .longValue());
+    }
+
+    @Test
+    public void givenDateInYearMonthDayNumbersUsingWeekFieldsWithLocaleCanada_thenGettingWeekNumberUsingLocalDateIsCorrectlyReturned() {
+        WeekNumberUsingLocalDate localDate = new WeekNumberUsingLocalDate();
+
+        assertEquals(13, localDate.getWeekNumberUsinWeekFieldsFrom(2020, 3, 22, Locale.CANADA)
+            .longValue());
+    }
+}
--- a/core-java-modules/core-java-networking-2/README.md
+++ b/core-java-modules/core-java-networking-2/README.md
@ -11,4 +11,5 @@ This module contains articles about networking in Java
 - [Sending Emails with Java](https://www.baeldung.com/java-email)
 - [Authentication with HttpUrlConnection](https://www.baeldung.com/java-http-url-connection)
 - [Download a File from an URL in Java](https://www.baeldung.com/java-download-file)
+- [Handling java.net.ConnectException](https://www.baeldung.com/java-net-connectexception)
 - [[<-- Prev]](/core-java-modules/core-java-networking)
--- a/core-java-modules/core-java-regex/src/test/java/com/baeldung/regex/RegexUnitTest.java
+++ b/core-java-modules/core-java-regex/src/test/java/com/baeldung/regex/RegexUnitTest.java
@ -26,7 +26,6 @@ public class RegexUnitTest {
        while (matcher.find())
            matches++;
        assertEquals(matches, 2);
-
    }

    @Test
@ -452,7 +451,6 @@ public class RegexUnitTest {
        Matcher matcher = pattern.matcher("dogs are friendly");
        assertTrue(matcher.lookingAt());
        assertFalse(matcher.matches());
-
    }

    @Test
@ -460,7 +458,6 @@ public class RegexUnitTest {
        Pattern pattern = Pattern.compile("dog");
        Matcher matcher = pattern.matcher("dog");
        assertTrue(matcher.matches());
-
    }

    @Test
@ -469,7 +466,6 @@ public class RegexUnitTest {
        Matcher matcher = pattern.matcher("dogs are domestic animals, dogs are friendly");
        String newStr = matcher.replaceFirst("cat");
        assertEquals("cats are domestic animals, dogs are friendly", newStr);
-
    }

    @Test
@ -478,7 +474,6 @@ public class RegexUnitTest {
        Matcher matcher = pattern.matcher("dogs are domestic animals, dogs are friendly");
        String newStr = matcher.replaceAll("cat");
        assertEquals("cats are domestic animals, cats are friendly", newStr);
-
    }

    public synchronized static int runTest(String regex, String text) {
--- a/core-java-modules/core-java-regex/src/test/java/com/baeldung/regex/phonenumbers/PhoneNumbersRegexUnitTest.java
+++ b/core-java-modules/core-java-regex/src/test/java/com/baeldung/regex/phonenumbers/PhoneNumbersRegexUnitTest.java
@ -0,0 +1,129 @@
+package com.baeldung.regex.phonenumbers;
+
+import static org.junit.Assert.*;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import org.junit.Test;
+
+public class PhoneNumbersRegexUnitTest {
+
+    @Test
+    public void whenMatchesTenDigitsNumber_thenCorrect() {
+        Pattern pattern = Pattern.compile("^\\d{10}$");
+        Matcher matcher = pattern.matcher("2055550125");
+        assertTrue(matcher.matches());
+    }
+    
+    @Test
+    public void whenMOreThanTenDigits_thenNotCorrect() {
+        Pattern pattern = Pattern.compile("^\\d{10}$");
+        Matcher matcher = pattern.matcher("20555501251");
+        assertFalse(matcher.matches());
+    }
+
+    @Test
+    public void whenMatchesTenDigitsNumberWhitespacesDotHyphen_thenCorrect() {
+        Pattern pattern = Pattern.compile("^(\\d{3}[- .]?){2}\\d{4}$");
+        Matcher matcher = pattern.matcher("202 555 0125");
+        assertTrue(matcher.matches());
+    }
+    
+    @Test
+    public void whenIncludesBracket_thenNotCorrect() {
+        Pattern pattern = Pattern.compile("^(\\d{3}[- .]?){2}\\d{4}$");
+        Matcher matcher = pattern.matcher("202]555 0125");
+        assertFalse(matcher.matches());
+    }
+    
+    @Test
+    public void whenNotStartsWithBatchesOfThreeDigits_thenNotCorrect() {
+        Pattern pattern = Pattern.compile("^(\\d{3}[- .]?){2}\\d{4}$");
+        Matcher matcher = pattern.matcher("2021 555 0125");
+        assertFalse(matcher.matches());
+    }
+    
+    @Test
+    public void whenLastPartWithNoFourDigits_thenNotCorrect() {
+        Pattern pattern = Pattern.compile("^(\\d{3}[- .]?){2}\\d{4}$");
+        Matcher matcher = pattern.matcher("202 555 012");
+        assertFalse(matcher.matches());
+    }
+
+    @Test
+    public void whenMatchesTenDigitsNumberParenthesis_thenCorrect() {
+        Pattern pattern = Pattern.compile("^((\\(\\d{3}\\))|\\d{3})[- .]?\\d{3}[- .]?\\d{4}$");
+        Matcher matcher = pattern.matcher("(202) 555-0125");
+        assertTrue(matcher.matches());
+    }
+
+    @Test
+    public void whenJustOpeningParenthesis_thenNotCorrect() {
+        Pattern pattern = Pattern.compile("^((\\(\\d{3}\\))|\\d{3})[- .]?\\d{3}[- .]?\\d{4}$");
+        Matcher matcher = pattern.matcher("(202 555-0125");
+        assertFalse(matcher.matches());
+    }
+
+    @Test
+    public void whenJustClosingParenthesis_thenNotCorrect() {
+        Pattern pattern = Pattern.compile("^((\\(\\d{3}\\))|\\d{3})[- .]?\\d{3}[- .]?\\d{4}$");
+        Matcher matcher = pattern.matcher("202) 555-0125");
+        assertFalse(matcher.matches());
+    }
+
+    @Test
+    public void whenMatchesTenDigitsNumberPrefix_thenCorrect() {
+        Pattern pattern = Pattern.compile("^(\\+\\d{1,3}( )?)?((\\(\\d{3}\\))|\\d{3})[- .]?\\d{3}[- .]?\\d{4}$");
+        Matcher matcher = pattern.matcher("+111 (202) 555-0125");
+        assertTrue(matcher.matches());
+    }
+
+    @Test
+    public void whenIncorrectPrefix_thenNotCorrect() {
+        Pattern pattern = Pattern.compile("^(\\+\\d{1,3}( )?)?((\\(\\d{3}\\))|\\d{3})[- .]?\\d{3}[- .]?\\d{4}$");
+        Matcher matcher = pattern.matcher("-111 (202) 555-0125");
+        assertFalse(matcher.matches());
+    }
+
+    @Test
+    public void whenTooLongPrefix_thenNotCorrect() {
+        Pattern pattern = Pattern.compile("^(\\+\\d{1,3}( )?)?((\\(\\d{3}\\))|\\d{3})[- .]?\\d{3}[- .]?\\d{4}$");
+        Matcher matcher = pattern.matcher("+1111 (202) 555-0125");
+        assertFalse(matcher.matches());
+    }
+
+    @Test
+    public void whenMatchesPhoneNumber_thenCorrect() {
+        String patterns 
+          = "^(\\+\\d{1,3}( )?)?((\\(\\d{3}\\))|\\d{3})[- .]?\\d{3}[- .]?\\d{4}$"
+          + "|^(\\+\\d{1,3}( )?)?(\\d{3}[ ]?){2}\\d{3}$" 
+          + "|^(\\+\\d{1,3}( )?)?(\\d{3}[ ]?)(\\d{2}[ ]?){2}\\d{2}$";
+
+        String[] validPhoneNumbers 
+          = {"2055550125","202 555 0125", "(202) 555-0125", "+111 (202) 555-0125", "636 856 789", "+111 636 856 789", "636 85 67 89", "+111 636 85 67 89"};
+
+        Pattern pattern = Pattern.compile(patterns);
+        for(String phoneNumber : validPhoneNumbers) {
+            Matcher matcher = pattern.matcher(phoneNumber);
+            assertTrue(matcher.matches());
+        }
+    }
+
+    @Test
+    public void whenNotMatchesPhoneNumber_thenNotCorrect() {
+        String patterns 
+          = "^(\\+\\d{1,3}( )?)?((\\(\\d{3}\\))|\\d{3})[- .]?\\d{3}[- .]?\\d{4}$"
+          + "|^(\\+\\d{1,3}( )?)?(\\d{3}[ ]?){2}\\d{3}$" 
+          + "|^(\\+\\d{1,3}( )?)?(\\d{3}[ ]?)(\\d{2}[ ]?){2}\\d{2}$";
+
+        String[] invalidPhoneNumbers 
+          = {"20555501251","202]555 0125", "2021 555 012", "(202 555-0125", "202) 555-0125", "-111 (202) 555-0125", "+1111 (202) 555-0125", "636 85 789", "636 85 67 893"};
+
+        Pattern pattern = Pattern.compile(patterns);
+        for(String phoneNumber : invalidPhoneNumbers) {
+            Matcher matcher = pattern.matcher(phoneNumber);
+            assertFalse(matcher.matches());
+        }
+    }
+}
--- a/core-java-modules/core-java-streams-3/README.md
+++ b/core-java-modules/core-java-streams-3/README.md
@ -10,4 +10,5 @@ This module contains articles about the Stream API in Java.
 - [Primitive Type Streams in Java 8](https://www.baeldung.com/java-8-primitive-streams)
 - [Debugging Java 8 Streams with IntelliJ](https://www.baeldung.com/intellij-debugging-java-streams)
 - [Add BigDecimals using the Stream API](https://www.baeldung.com/java-stream-add-bigdecimals)
+- [Should We Close a Java Stream?](https://www.baeldung.com/java-stream-close)
 - More articles: [[<-- prev>]](/../core-java-streams-2)
--- a/core-kotlin-modules/core-kotlin-lang-2/src/test/kotlin/com/baeldung/late/LateInitUnitTest.kt
+++ b/core-kotlin-modules/core-kotlin-lang-2/src/test/kotlin/com/baeldung/late/LateInitUnitTest.kt
@ -0,0 +1,22 @@
+package com.baeldung.late
+
+import org.junit.Test
+import kotlin.test.assertFalse
+import kotlin.test.assertTrue
+
+class LateInitUnitTest {
+
+    private lateinit var answer: String
+
+    @Test(expected = UninitializedPropertyAccessException::class)
+    fun givenLateInit_WhenNotInitialized_ShouldThrowAnException() {
+        answer.length
+    }
+
+    @Test
+    fun givenLateInit_TheIsInitialized_ReturnsTheInitializationStatus() {
+        assertFalse { this::answer.isInitialized }
+        answer = "42"
+        assertTrue { this::answer.isInitialized }
+    }
+}
--- a/java-collections-conversions/src/main/java/com/baeldung/convertlisttomap/ConvertListToMapService.java
+++ b/java-collections-conversions/src/main/java/com/baeldung/convertlisttomap/ConvertListToMapService.java
@ -6,6 +6,7 @@ import org.apache.commons.collections4.MapUtils;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.function.Function;
 import java.util.stream.Collectors;

 public class ConvertListToMapService {
@ -21,7 +22,7 @@ public class ConvertListToMapService {
    }

    public Map<Integer, Animal> convertListAfterJava8(List<Animal> list) {
-        Map<Integer, Animal> map = list.stream().collect(Collectors.toMap(Animal::getId, animal -> animal));
+        Map<Integer, Animal> map = list.stream().collect(Collectors.toMap(Animal::getId, Function.identity()));
        return map;
    }

--- a/java-collections-conversions/src/test/java/com/baeldung/convertcollectiontoarraylist/CollectionToArrayListUnitTest.java
+++ b/java-collections-conversions/src/test/java/com/baeldung/convertcollectiontoarraylist/CollectionToArrayListUnitTest.java
@ -53,14 +53,14 @@ public class CollectionToArrayListUnitTest {

        verifyShallowCopy(srcCollection, newList);
    }
-    
+
    /**
     * Section 5. Deep Copy
     */
    @Test
    public void whenUsingDeepCopy_thenVerifyDeepCopy() {
        ArrayList<Foo> newList = srcCollection.stream()
-          .map(foo -> foo.deepCopy())
+          .map(Foo::deepCopy)
          .collect(toCollection(ArrayList::new));

        verifyDeepCopy(srcCollection, newList);
@ -83,13 +83,13 @@ public class CollectionToArrayListUnitTest {
     * @param a
     * @param b 
     */
-    private void verifyShallowCopy(Collection a, Collection b) {
+    private void verifyShallowCopy(Collection<Foo> a, Collection<Foo> b) {
        assertEquals("Collections have different lengths", a.size(), b.size());
        Iterator<Foo> iterA = a.iterator();
        Iterator<Foo> iterB = b.iterator();
        while (iterA.hasNext()) {
            // use '==' to test instance identity
-            assertTrue("Foo instances differ!", iterA.next() == iterB.next());
+            assertSame("Foo instances differ!", iterA.next(), iterB.next());
        }
    }
    
@ -98,7 +98,7 @@ public class CollectionToArrayListUnitTest {
     * @param a
     * @param b 
     */
-    private void verifyDeepCopy(Collection a, Collection b) {
+    private void verifyDeepCopy(Collection<Foo> a, Collection<Foo> b) {
        assertEquals("Collections have different lengths", a.size(), b.size());
        Iterator<Foo> iterA = a.iterator();
        Iterator<Foo> iterB = b.iterator();
@ -106,7 +106,7 @@ public class CollectionToArrayListUnitTest {
            Foo nextA = iterA.next();
            Foo nextB = iterB.next();
            // should not be same instance
-            assertFalse("Foo instances are the same!", nextA == nextB);
+            assertNotSame("Foo instances are the same!", nextA, nextB);
            // but should have same content
            assertFalse("Foo instances have different content!", fooDiff(nextA, nextB));
        }
--- a/java-collections-conversions/src/test/java/com/baeldung/convertiteratortolist/ConvertIteratorToListServiceUnitTest.java
+++ b/java-collections-conversions/src/test/java/com/baeldung/convertiteratortolist/ConvertIteratorToListServiceUnitTest.java
@ -23,7 +23,7 @@ public class ConvertIteratorToListServiceUnitTest {
    Iterator<Integer> iterator;

    @Before
-    public void setUp() throws Exception {
+    public void setUp() {
        iterator = Arrays.asList(1, 2, 3)
            .iterator();
    }
@ -31,7 +31,7 @@ public class ConvertIteratorToListServiceUnitTest {
    @Test
    public void givenAnIterator_whenConvertIteratorToListUsingWhileLoop_thenReturnAList() {

-        List<Integer> actualList = new ArrayList<Integer>();
+        List<Integer> actualList = new ArrayList<>();

        // Convert Iterator to List using while loop dsf
        while (iterator.hasNext()) {
@ -44,7 +44,7 @@ public class ConvertIteratorToListServiceUnitTest {

    @Test
    public void givenAnIterator_whenConvertIteratorToListAfterJava8_thenReturnAList() {
-        List<Integer> actualList = new ArrayList<Integer>();
+        List<Integer> actualList = new ArrayList<>();

        // Convert Iterator to List using Java 8
        iterator.forEachRemaining(actualList::add);
--- a/java-collections-maps-3/README.md
+++ b/java-collections-maps-3/README.md
@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Java Map With Case-Insensitive Keys](https://www.baeldung.com/java-map-with-case-insensitive-keys)
--- a/java-python-interop/README.md
+++ b/java-python-interop/README.md
@ -0,0 +1,5 @@
+## Java Python Interop
+
+This module contains articles about Java and Python interoperability.  
+
+### Relevant Articles:
--- a/java-python-interop/pom.xml
+++ b/java-python-interop/pom.xml
@ -0,0 +1,55 @@
+<?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>java-python-interop</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>java-python-interop</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.python</groupId>
+            <artifactId>jython-slim</artifactId>
+            <version>${jython.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-exec</artifactId>
+            <version>${commons-exec.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>java-python-interop</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+            <resource>
+                <directory>src/test/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+    </build>
+
+    <properties>
+        <jython.version>2.7.2</jython.version>
+        <commons-exec.version>1.3</commons-exec.version>
+        <assertj.version>3.6.1</assertj.version>
+    </properties>
+
+</project>
--- a/java-python-interop/src/main/java/com/baeldung/python/interop/ScriptEngineManagerUtils.java
+++ b/java-python-interop/src/main/java/com/baeldung/python/interop/ScriptEngineManagerUtils.java
@ -0,0 +1,34 @@
+package com.baeldung.python.interop;
+
+import java.util.List;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.script.ScriptEngineFactory;
+import javax.script.ScriptEngineManager;
+
+public class ScriptEngineManagerUtils {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(ScriptEngineManagerUtils.class);
+
+    private ScriptEngineManagerUtils() {
+    }
+
+    public static void listEngines() {
+        ScriptEngineManager manager = new ScriptEngineManager();
+        List<ScriptEngineFactory> engines = manager.getEngineFactories();
+
+        for (ScriptEngineFactory engine : engines) {
+            LOGGER.info("Engine name: {}", engine.getEngineName());
+            LOGGER.info("Version: {}", engine.getEngineVersion());
+            LOGGER.info("Language: {}", engine.getLanguageName());
+
+            LOGGER.info("Short Names:");
+            for (String names : engine.getNames()) {
+                LOGGER.info(names);
+            }
+        }
+    }
+
+}
--- a/java-python-interop/src/main/resources/logback.xml
+++ b/java-python-interop/src/main/resources/logback.xml
@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>
--- a/java-python-interop/src/test/java/com/baeldung/python/interop/JavaPythonInteropUnitTest.java
+++ b/java-python-interop/src/test/java/com/baeldung/python/interop/JavaPythonInteropUnitTest.java
@ -0,0 +1,131 @@
+package com.baeldung.python.interop;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.empty;
+import static org.hamcrest.Matchers.hasItem;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.not;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
+
+import java.io.BufferedReader;
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.StringWriter;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import javax.script.ScriptContext;
+import javax.script.ScriptEngine;
+import javax.script.ScriptEngineManager;
+import javax.script.SimpleScriptContext;
+
+import org.apache.commons.exec.CommandLine;
+import org.apache.commons.exec.DefaultExecutor;
+import org.apache.commons.exec.ExecuteException;
+import org.apache.commons.exec.PumpStreamHandler;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.python.core.PyException;
+import org.python.core.PyObject;
+import org.python.util.PythonInterpreter;
+
+public class JavaPythonInteropUnitTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    @Test
+    public void givenPythonScript_whenPythonProcessInvoked_thenSuccess() throws Exception {
+        ProcessBuilder processBuilder = new ProcessBuilder("python", resolvePythonScriptPath("hello.py"));
+        processBuilder.redirectErrorStream(true);
+
+        Process process = processBuilder.start();
+        List<String> results = readProcessOutput(process.getInputStream());
+
+        assertThat("Results should not be empty", results, is(not(empty())));
+        assertThat("Results should contain output of script: ", results, hasItem(containsString("Hello Baeldung Readers!!")));
+
+        int exitCode = process.waitFor();
+        assertEquals("No errors should be detected", 0, exitCode);
+    }
+
+    @Test
+    public void givenPythonScriptEngineIsAvailable_whenScriptInvoked_thenOutputDisplayed() throws Exception {
+        StringWriter output = new StringWriter();
+        ScriptContext context = new SimpleScriptContext();
+        context.setWriter(output);
+
+        ScriptEngineManager manager = new ScriptEngineManager();
+        ScriptEngine engine = manager.getEngineByName("python");
+        engine.eval(new FileReader(resolvePythonScriptPath("hello.py")), context);
+        assertEquals("Should contain script output: ", "Hello Baeldung Readers!!", output.toString()
+            .trim());
+    }
+
+    @Test
+    public void givenPythonInterpreter_whenPrintExecuted_thenOutputDisplayed() {
+        try (PythonInterpreter pyInterp = new PythonInterpreter()) {
+            StringWriter output = new StringWriter();
+            pyInterp.setOut(output);
+
+            pyInterp.exec("print('Hello Baeldung Readers!!')");
+            assertEquals("Should contain script output: ", "Hello Baeldung Readers!!", output.toString()
+                .trim());
+        }
+    }
+
+    @Test
+    public void givenPythonInterpreter_whenNumbersAdded_thenOutputDisplayed() {
+        try (PythonInterpreter pyInterp = new PythonInterpreter()) {
+            pyInterp.exec("x = 10+10");
+            PyObject x = pyInterp.get("x");
+            assertEquals("x: ", 20, x.asInt());
+        }
+    }
+
+    @Test
+    public void givenPythonInterpreter_whenErrorOccurs_thenExceptionIsThrown() {
+        thrown.expect(PyException.class);
+        thrown.expectMessage("ImportError: No module named syds");
+
+        try (PythonInterpreter pyInterp = new PythonInterpreter()) {
+            pyInterp.exec("import syds");
+        }
+    }
+
+    @Test
+    public void givenPythonScript_whenPythonProcessExecuted_thenSuccess() throws ExecuteException, IOException {
+        String line = "python " + resolvePythonScriptPath("hello.py");
+        CommandLine cmdLine = CommandLine.parse(line);
+
+        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+        PumpStreamHandler streamHandler = new PumpStreamHandler(outputStream);
+
+        DefaultExecutor executor = new DefaultExecutor();
+        executor.setStreamHandler(streamHandler);
+
+        int exitCode = executor.execute(cmdLine);
+        assertEquals("No errors should be detected", 0, exitCode);
+        assertEquals("Should contain script output: ", "Hello Baeldung Readers!!", outputStream.toString()
+            .trim());
+    }
+
+    private List<String> readProcessOutput(InputStream inputStream) throws IOException {
+        try (BufferedReader output = new BufferedReader(new InputStreamReader(inputStream))) {
+            return output.lines()
+                .collect(Collectors.toList());
+        }
+    }
+
+    private String resolvePythonScriptPath(String filename) {
+        File file = new File("src/test/resources/" + filename);
+        return file.getAbsolutePath();
+    }
+
+}
--- a/java-python-interop/src/test/resources/hello.py
+++ b/java-python-interop/src/test/resources/hello.py
@ -0,0 +1 @@
+print("Hello Baeldung Readers!!")
--- a/jsoup/src/test/java/com/baeldung/jsonproxy/JsoupProxyLiveTest.java
+++ b/jsoup/src/test/java/com/baeldung/jsonproxy/JsoupProxyLiveTest.java
@ -0,0 +1,27 @@
+package com.baeldung.jsonproxy;
+
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.net.Proxy;
+
+import org.jsoup.Jsoup;
+import org.junit.Test;
+
+public class JsoupProxyLiveTest {
+
+    @Test
+    public void whenUsingHostAndPort_thenConnect() throws IOException {
+        Jsoup.connect("https://spring.io/blog")
+            .proxy("200.216.227.141", 53281)
+            .get();
+    }
+
+    @Test
+    public void whenUsingProxyClass_thenConnect() throws IOException {
+        Proxy proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress("200.216.227.141", 53281));
+
+        Jsoup.connect("https://spring.io/blog")
+            .proxy(proxy)
+            .get();
+    }
+}
--- a/libraries-3/README.md
+++ b/libraries-3/README.md
@ -17,4 +17,4 @@ Remember, for advanced libraries like [Jackson](/jackson) and [JUnit](/testing-m
 - [Using NullAway to Avoid NullPointerExceptions](https://www.baeldung.com/java-nullaway)
 - [Introduction to Alibaba Arthas](https://www.baeldung.com/java-alibaba-arthas-intro)
 - [Quick Guide to Spring Cloud Circuit Breaker](https://www.baeldung.com/spring-cloud-circuit-breaker)
- More articles [[<-- prev]](/libraries-2) [[next -->]](/libraries-4)
+- More articles [[<-- prev]](/libraries-2) [[next -->]](/libraries-4)
--- a/libraries-rpc/pom.xml
+++ b/libraries-rpc/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/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>libraries-rpc</artifactId>
+    <name>libraries-rpc</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+      <dependency>
+        <groupId>com.twitter</groupId>
+        <artifactId>finagle-core_2.13</artifactId>
+        <version>${finagle.core.version}</version>
+      </dependency>
+      <dependency>
+          <groupId>com.twitter</groupId>
+          <artifactId>finagle-http_2.13</artifactId>
+          <version>${finagle.http.version}</version>
+      </dependency>
+
+    </dependencies>
+
+    <properties>
+        <finagle.core.version>20.4.0</finagle.core.version>
+        <finagle.http.version>20.4.0</finagle.http.version>
+    </properties>
+
+
+</project>
--- a/libraries-rpc/src/main/java/com/baeldung/rpc/finagle/GreetingService.java
+++ b/libraries-rpc/src/main/java/com/baeldung/rpc/finagle/GreetingService.java
@ -0,0 +1,18 @@
+package com.baeldung.rpc.finagle;
+
+import com.twitter.finagle.Service;
+import com.twitter.finagle.http.Request;
+import com.twitter.finagle.http.Response;
+import com.twitter.finagle.http.Status;
+import com.twitter.io.Buf;
+import com.twitter.io.Reader;
+import com.twitter.util.Future;
+
+public class GreetingService extends Service<Request, Response> {
+    @Override
+    public Future<Response> apply(Request request) {
+        String greeting = "Hello " + request.getParam("name");
+        Reader<Buf> reader = Reader.fromBuf(new Buf.ByteArray(greeting.getBytes(), 0, greeting.length()));
+        return Future.value(Response.apply(request.version(), Status.Ok(), reader));
+    }
+}
--- a/libraries-rpc/src/main/java/com/baeldung/rpc/finagle/LogFilter.java
+++ b/libraries-rpc/src/main/java/com/baeldung/rpc/finagle/LogFilter.java
@ -0,0 +1,22 @@
+package com.baeldung.rpc.finagle;
+
+import com.twitter.finagle.Service;
+import com.twitter.finagle.SimpleFilter;
+import com.twitter.finagle.http.Request;
+import com.twitter.finagle.http.Response;
+import com.twitter.util.Future;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class LogFilter extends SimpleFilter<Request, Response> {
+
+    private static final Logger logger = LoggerFactory.getLogger(LogFilter.class);
+
+    @Override
+    public Future<Response> apply(Request request, Service<Request, Response> service) {
+        logger.info("Request host:" + request.host().getOrElse(() -> ""));
+        logger.info("Request params:");
+        request.getParams().forEach(entry -> logger.info("\t" + entry.getKey() + " : " + entry.getValue()));
+        return service.apply(request);
+    }
+}
--- a/libraries-rpc/src/main/resources/logback.xml
+++ b/libraries-rpc/src/main/resources/logback.xml
@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>
--- a/libraries-rpc/src/test/java/com/baeldung/rpc/finagle/FinagleIntegrationTest.java
+++ b/libraries-rpc/src/test/java/com/baeldung/rpc/finagle/FinagleIntegrationTest.java
@ -0,0 +1,40 @@
+package com.baeldung.rpc.finagle;
+
+import com.twitter.finagle.Http;
+import com.twitter.finagle.Service;
+import com.twitter.finagle.http.Method;
+import com.twitter.finagle.http.Request;
+import com.twitter.finagle.http.Response;
+import com.twitter.util.Await;
+import com.twitter.util.Future;
+import org.junit.Test;
+import scala.runtime.BoxedUnit;
+
+import static org.junit.Assert.assertEquals;
+
+public class FinagleIntegrationTest {
+    @Test
+    public void givenServerAndClient_whenRequestSent_thenClientShouldReceiveResponseFromServer() throws Exception {
+        // given
+        Service serverService = new LogFilter().andThen(new GreetingService());
+        Http.serve(":8080", serverService);
+
+        Service<Request, Response> clientService = new LogFilter().andThen(Http.newService(":8080"));
+
+        // when
+        Request request = Request.apply(Method.Get(), "/?name=John");
+        request.host("localhost");
+        Future<Response> response = clientService.apply(request);
+
+        // then
+        Await.result(response
+                .onSuccess(r -> {
+                    assertEquals("Hello John", r.getContentString());
+                    return BoxedUnit.UNIT;
+                })
+                .onFailure(r -> {
+                    throw new RuntimeException(r);
+                })
+        );
+    }
+}
--- a/libraries-testing/README.md
+++ b/libraries-testing/README.md
@ -11,4 +11,4 @@ This module contains articles about test libraries.
 - [Introduction to Awaitlity](https://www.baeldung.com/awaitlity-testing)
 - [Introduction to Hoverfly in Java](https://www.baeldung.com/hoverfly)
 - [Testing with Hamcrest](https://www.baeldung.com/java-junit-hamcrest-guide)
- [Introduction To DBUnit](https://www.baeldung.com/dbunit)
+- [Introduction To DBUnit](https://www.baeldung.com/java-dbunit)
--- a/logging-modules/log4j2/src/main/java/com/baeldung/logging/log4j2/plugins/DockerPatternConverter.java
+++ b/logging-modules/log4j2/src/main/java/com/baeldung/logging/log4j2/plugins/DockerPatternConverter.java
@ -0,0 +1,30 @@
+package com.baeldung.logging.log4j2.plugins;
+
+import org.apache.logging.log4j.core.LogEvent;
+import org.apache.logging.log4j.core.config.plugins.Plugin;
+import org.apache.logging.log4j.core.pattern.ConverterKeys;
+import org.apache.logging.log4j.core.pattern.LogEventPatternConverter;
+import org.apache.logging.log4j.core.pattern.PatternConverter;
+
+@Plugin(name = "DockerPatternConverter", category = PatternConverter.CATEGORY)
+@ConverterKeys({"docker", "container"})
+public class DockerPatternConverter extends LogEventPatternConverter {
+
+    private DockerPatternConverter(String[] options) {
+        super("Docker", "docker");
+    }
+
+    public static DockerPatternConverter newInstance(String[] options) {
+        return new DockerPatternConverter(options);
+    }
+
+    @Override
+    public void format(LogEvent event, StringBuilder toAppendTo) {
+        toAppendTo.append(dockerContainer());
+    }
+
+    private String dockerContainer() {
+        //get docker container ID inside which application is running here
+        return "container-1";
+    }
+}
--- a/logging-modules/log4j2/src/main/java/com/baeldung/logging/log4j2/plugins/KafkaAppender.java
+++ b/logging-modules/log4j2/src/main/java/com/baeldung/logging/log4j2/plugins/KafkaAppender.java
@ -0,0 +1,133 @@
+package com.baeldung.logging.log4j2.plugins;
+
+import org.apache.logging.log4j.core.Core;
+import org.apache.logging.log4j.core.Filter;
+import org.apache.logging.log4j.core.Layout;
+import org.apache.logging.log4j.core.LogEvent;
+import org.apache.logging.log4j.core.appender.AbstractAppender;
+import org.apache.logging.log4j.core.config.plugins.Plugin;
+import org.apache.logging.log4j.core.config.plugins.PluginBuilderAttribute;
+import org.apache.logging.log4j.core.config.plugins.PluginBuilderFactory;
+import org.apache.logging.log4j.core.config.plugins.PluginElement;
+import org.apache.logging.log4j.core.config.plugins.validation.constraints.Required;
+
+import java.io.Serializable;
+
+@Plugin(name = "Kafka2", category = Core.CATEGORY_NAME)
+public class KafkaAppender extends AbstractAppender {
+
+    @PluginBuilderFactory
+    public static Builder newBuilder() {
+        return new Builder();
+    }
+
+    public static class Builder implements org.apache.logging.log4j.core.util.Builder<KafkaAppender> {
+
+        @PluginBuilderAttribute("name")
+        @Required
+        private String name;
+
+        @PluginBuilderAttribute("ip")
+        private String ipAddress;
+
+        @PluginBuilderAttribute("port")
+        private int port;
+
+        @PluginBuilderAttribute("topic")
+        private String topic;
+
+        @PluginBuilderAttribute("partition")
+        private String partition;
+
+        @PluginElement("Layout")
+        private Layout<? extends Serializable> layout;
+
+        @PluginElement("Filter")
+        private Filter filter;
+
+        public Layout<? extends Serializable> getLayout() {
+            return layout;
+        }
+
+        public Builder setLayout(Layout<? extends Serializable> layout) {
+            this.layout = layout;
+            return this;
+        }
+
+        public Filter getFilter() {
+            return filter;
+        }
+
+        public String getName() {
+            return name;
+        }
+
+        public Builder setName(String name) {
+            this.name = name;
+            return this;
+        }
+
+        public Builder setFilter(Filter filter) {
+            this.filter = filter;
+            return this;
+        }
+
+        public String getIpAddress() {
+            return ipAddress;
+        }
+
+        public Builder setIpAddress(String ipAddress) {
+            this.ipAddress = ipAddress;
+            return this;
+        }
+
+        public int getPort() {
+            return port;
+        }
+
+        public Builder setPort(int port) {
+            this.port = port;
+            return this;
+        }
+
+        public String getTopic() {
+            return topic;
+        }
+
+        public Builder setTopic(String topic) {
+            this.topic = topic;
+            return this;
+        }
+
+        public String getPartition() {
+            return partition;
+        }
+
+        public Builder setPartition(String partition) {
+            this.partition = partition;
+            return this;
+        }
+
+        @Override
+        public KafkaAppender build() {
+            return new KafkaAppender(getName(), getFilter(), getLayout(), true, new KafkaBroker(ipAddress, port, topic, partition));
+        }
+    }
+
+    private KafkaBroker broker;
+
+    private KafkaAppender(String name, Filter filter, Layout<? extends Serializable> layout, boolean ignoreExceptions, KafkaBroker broker) {
+        super(name, filter, layout, ignoreExceptions);
+        this.broker = broker;
+    }
+
+    @Override
+    public void append(LogEvent event) {
+
+        connectAndSendToKafka(broker, event);
+    }
+
+    private void connectAndSendToKafka(KafkaBroker broker, LogEvent event) {
+        //send to Kafka
+    }
+}
--- a/logging-modules/log4j2/src/main/java/com/baeldung/logging/log4j2/plugins/KafkaBroker.java
+++ b/logging-modules/log4j2/src/main/java/com/baeldung/logging/log4j2/plugins/KafkaBroker.java
@ -0,0 +1,38 @@
+package com.baeldung.logging.log4j2.plugins;
+
+import java.io.Serializable;
+
+public class KafkaBroker implements Serializable {
+
+    private final String ipAddress;
+    private final int port;
+
+    public KafkaBroker(String ipAddress, int port, String topic, String partition) {
+        this.ipAddress = ipAddress;
+        this.port = port;
+        this.topic = topic;
+        this.partition = partition;
+    }
+
+    public String getTopic() {
+        return topic;
+    }
+
+    public String getPartition() {
+        return partition;
+    }
+
+    private final String topic;
+    private final String partition;
+
+
+    public String getIpAddress() {
+        return ipAddress;
+    }
+
+    public int getPort() {
+        return port;
+    }
+
+
+}
--- a/logging-modules/log4j2/src/main/java/com/baeldung/logging/log4j2/plugins/KafkaLookup.java
+++ b/logging-modules/log4j2/src/main/java/com/baeldung/logging/log4j2/plugins/KafkaLookup.java
@ -0,0 +1,24 @@
+package com.baeldung.logging.log4j2.plugins;
+
+import org.apache.logging.log4j.core.LogEvent;
+import org.apache.logging.log4j.core.config.plugins.Plugin;
+import org.apache.logging.log4j.core.lookup.StrLookup;
+
+@Plugin(name = "kafka", category = StrLookup.CATEGORY)
+public class KafkaLookup implements StrLookup {
+
+    @Override
+    public String lookup(String key) {
+        return getFromKafka(key);
+    }
+
+    @Override
+    public String lookup(LogEvent event, String key) {
+        return getFromKafka(key);
+    }
+
+    private String getFromKafka(String topicName) {
+        //kafka search logic should go here
+        return "topic1-p1";
+    }
+}
--- a/logging-modules/log4j2/src/main/java/com/baeldung/logging/log4j2/plugins/ListAppender.java
+++ b/logging-modules/log4j2/src/main/java/com/baeldung/logging/log4j2/plugins/ListAppender.java
@ -0,0 +1,48 @@
+/**
+ *
+ */
+package com.baeldung.logging.log4j2.plugins;
+
+import org.apache.logging.log4j.Level;
+import org.apache.logging.log4j.core.Appender;
+import org.apache.logging.log4j.core.Core;
+import org.apache.logging.log4j.core.Filter;
+import org.apache.logging.log4j.core.LogEvent;
+import org.apache.logging.log4j.core.appender.AbstractAppender;
+import org.apache.logging.log4j.core.config.plugins.Plugin;
+import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
+import org.apache.logging.log4j.core.config.plugins.PluginElement;
+import org.apache.logging.log4j.core.config.plugins.PluginFactory;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+import static java.util.Collections.synchronizedList;
+
+@Plugin(name = "ListAppender", category = Core.CATEGORY_NAME, elementType = Appender.ELEMENT_TYPE)
+public class ListAppender extends AbstractAppender {
+
+    private List<LogEvent> logList;
+
+    protected ListAppender(String name, Filter filter) {
+        super(name, filter, null);
+        logList = synchronizedList(new ArrayList<>());
+    }
+
+    @PluginFactory
+    public static ListAppender createAppender(@PluginAttribute("name") String name, @PluginElement("Filter") final Filter filter) {
+        return new ListAppender(name, filter);
+    }
+
+    @Override
+    public void append(LogEvent event) {
+        if (event.getLevel()
+                .isLessSpecificThan(Level.WARN)) {
+            error("Unable to log less than WARN level.");
+            return;
+        }
+        logList.add(event);
+    }
+
+}
--- a/logging-modules/log4j2/src/test/resources/log4j2.xml
+++ b/logging-modules/log4j2/src/test/resources/log4j2.xml
@ -50,6 +50,12 @@
            </Policies>
        </RollingFile>
        <MapAppender name="MapAppender"/>
+        <Console name="DockerConsoleLogger" target="SYSTEM_OUT">
+            <PatternLayout pattern="%pid %docker" />
+        </Console>
+        <Kafka2 name="KafkaLogger" ip ="127.0.0.1" port="9010" topic="log" partition="p-1">
+            <PatternLayout pattern="%pid%style{%message}{red}%n" />
+        </Kafka2>
    </Appenders>
    <Loggers>
        <Logger name="CONSOLE_PATTERN_APPENDER_MARKER" level="TRACE"
@ -80,6 +86,9 @@
            additivity="false">
            <AppenderRef ref="ConsoleJSONAppender" />
        </Logger>
+        <Logger name="com.baeldung.logging.log4j2.plugins" level="INFO">
+            <AppenderRef ref="KafkaLogger" />
+        </Logger>
        <Root level="DEBUG">
            <AppenderRef ref="ConsoleAppender" />
            <AppenderRef ref="MapAppender" />
--- a/netty/README.md
+++ b/netty/README.md
@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [HTTP/2 in Netty](https://www.baeldung.com/netty-http2)
--- a/oauth2-framework-impl/oauth2-authorization-server/README.md
+++ b/oauth2-framework-impl/oauth2-authorization-server/README.md
@ -1,3 +0,0 @@
-### Relevant Articles:
-
- [Implementing The OAuth 2.0 Authorization Framework Using Jakarta EE](https://www.baeldung.com/java-ee-oauth2-implementation)
--- a/oauth2-framework-impl/oauth2-resource-server/README.md
+++ b/oauth2-framework-impl/oauth2-resource-server/README.md
@ -1,3 +0,0 @@
-### Relevant Articles:
-
- [Implementing The OAuth 2.0 Authorization Framework Using Jakarta EE](https://www.baeldung.com/java-ee-oauth2-implementation)
--- a/pdf/pom.xml
+++ b/pdf/pom.xml
@ -60,6 +60,16 @@
            <artifactId>poi-ooxml</artifactId>
            <version>${poi-ooxml.version}</version>
        </dependency>
+        <dependency>
+            <groupId>org.thymeleaf</groupId>
+            <artifactId>thymeleaf</artifactId>
+            <version>3.0.11.RELEASE</version>
+        </dependency>
+        <dependency>
+            <groupId>org.xhtmlrenderer</groupId>
+            <artifactId>flying-saucer-pdf</artifactId>
+            <version>9.1.20</version>
+        </dependency>
    </dependencies>

    <build>
--- a/pdf/src/main/java/com/baeldung/pdf/PDFThymeleafExample.java
+++ b/pdf/src/main/java/com/baeldung/pdf/PDFThymeleafExample.java
@ -0,0 +1,48 @@
+package com.baeldung.pdf;
+
+import com.lowagie.text.DocumentException;
+import org.thymeleaf.TemplateEngine;
+import org.thymeleaf.context.Context;
+import org.thymeleaf.templatemode.TemplateMode;
+import org.thymeleaf.templateresolver.ClassLoaderTemplateResolver;
+import org.xhtmlrenderer.pdf.ITextRenderer;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+
+public class PDFThymeleafExample {
+
+    public static void main(String[] args) throws IOException, DocumentException {
+        PDFThymeleafExample thymeleaf2Pdf = new PDFThymeleafExample();
+        String html = thymeleaf2Pdf.parseThymeleafTemplate();
+        thymeleaf2Pdf.generatePdfFromHtml(html);
+    }
+
+    public void generatePdfFromHtml(String html) throws IOException, DocumentException {
+        String outputFolder = System.getProperty("user.home") + File.separator + "thymeleaf.pdf";
+        OutputStream outputStream = new FileOutputStream(outputFolder);
+
+        ITextRenderer renderer = new ITextRenderer();
+        renderer.setDocumentFromString(html);
+        renderer.layout();
+        renderer.createPDF(outputStream);
+
+        outputStream.close();
+    }
+
+    private String parseThymeleafTemplate() {
+        ClassLoaderTemplateResolver templateResolver = new ClassLoaderTemplateResolver();
+        templateResolver.setSuffix(".html");
+        templateResolver.setTemplateMode(TemplateMode.HTML);
+
+        TemplateEngine templateEngine = new TemplateEngine();
+        templateEngine.setTemplateResolver(templateResolver);
+
+        Context context = new Context();
+        context.setVariable("to", "Baeldung.com");
+
+        return templateEngine.process("thymeleaf_template", context);
+    }
+}
--- a/pdf/src/main/resources/thymeleaf_template.html
+++ b/pdf/src/main/resources/thymeleaf_template.html
@ -0,0 +1,7 @@
+<html lang="en" xmlns:th="http://www.thymeleaf.org">
+  <body>
+    <h3 style="text-align: center; color: green">
+      <span th:text="'Welcome to ' + ${to} + '!'"></span>
+    </h3>
+  </body>
+</html>
--- a/pdf/src/test/java/com/baeldung/pdf/PDFThymeleafUnitTest.java
+++ b/pdf/src/test/java/com/baeldung/pdf/PDFThymeleafUnitTest.java
@ -0,0 +1,52 @@
+package com.baeldung.pdf;
+
+import com.lowagie.text.DocumentException;
+import org.junit.Test;
+import org.thymeleaf.TemplateEngine;
+import org.thymeleaf.context.Context;
+import org.thymeleaf.templatemode.TemplateMode;
+import org.thymeleaf.templateresolver.ClassLoaderTemplateResolver;
+import org.xhtmlrenderer.pdf.ITextRenderer;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+
+import static org.junit.Assert.assertTrue;
+
+public class PDFThymeleafUnitTest {
+
+    @Test
+    public void givenThymeleafTemplate_whenParsedAndRenderedToPDF_thenItShouldNotBeEmpty() throws DocumentException, IOException {
+        String html = parseThymeleafTemplate();
+
+        ByteArrayOutputStream outputStream = generatePdfOutputStreamFromHtml(html);
+
+        assertTrue(outputStream.size() > 0);
+    }
+
+    private ByteArrayOutputStream generatePdfOutputStreamFromHtml(String html) throws IOException, DocumentException {
+        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+
+        ITextRenderer renderer = new ITextRenderer();
+        renderer.setDocumentFromString(html);
+        renderer.layout();
+        renderer.createPDF(outputStream);
+
+        outputStream.close();
+        return outputStream;
+    }
+
+    private String parseThymeleafTemplate() {
+        ClassLoaderTemplateResolver templateResolver = new ClassLoaderTemplateResolver();
+        templateResolver.setSuffix(".html");
+        templateResolver.setTemplateMode(TemplateMode.HTML);
+
+        TemplateEngine templateEngine = new TemplateEngine();
+        templateEngine.setTemplateResolver(templateResolver);
+
+        Context context = new Context();
+        context.setVariable("to", "Baeldung.com");
+
+        return templateEngine.process("thymeleaf_template", context);
+    }
+}
--- a/persistence-modules/hibernate-jpa/README.md
+++ b/persistence-modules/hibernate-jpa/README.md
@ -14,3 +14,4 @@ This module contains articles specific to use of Hibernate as a JPA implementati
 - [TransactionRequiredException Error](https://www.baeldung.com/jpa-transaction-required-exception)
 - [JPA/Hibernate Persistence Context](https://www.baeldung.com/jpa-hibernate-persistence-context)
 - [Quick Guide to EntityManager#getReference()](https://www.baeldung.com/jpa-entity-manager-get-reference)
+- [Hibernate Error “No Persistence Provider for EntityManager”](https://www.baeldung.com/hibernate-no-persistence-provider)
--- a/persistence-modules/java-mongodb/README.md
+++ b/persistence-modules/java-mongodb/README.md
@ -11,3 +11,4 @@ This module contains articles about MongoDB in Java.
 - [Introduction to Morphia – Java ODM for MongoDB](https://www.baeldung.com/mongodb-morphia)
 - [MongoDB Aggregations Using Java](https://www.baeldung.com/java-mongodb-aggregations)
 - [MongoDB BSON to JSON](https://www.baeldung.com/bson-to-json)
+- [BSON to JSON Document Conversion in Java](https://www.baeldung.com/java-convert-bson-to-json)
--- a/persistence-modules/java-mongodb/src/main/java/com/baeldung/bsontojson/Book.java
+++ b/persistence-modules/java-mongodb/src/main/java/com/baeldung/bsontojson/Book.java
@ -0,0 +1,168 @@
+package com.baeldung.bsontojson;
+
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.util.HashSet;
+import java.util.Set;
+
+import dev.morphia.annotations.Embedded;
+import dev.morphia.annotations.Entity;
+import dev.morphia.annotations.Field;
+import dev.morphia.annotations.Id;
+import dev.morphia.annotations.Index;
+import dev.morphia.annotations.IndexOptions;
+import dev.morphia.annotations.Indexes;
+import dev.morphia.annotations.Property;
+import dev.morphia.annotations.Reference;
+import dev.morphia.annotations.Validation;
+
+@Entity("Books")
+@Indexes({ @Index(fields = @Field("title"), options = @IndexOptions(name = "book_title")) })
+@Validation("{ price : { $gt : 0 } }")
+public class Book {
+    @Id
+    private String isbn;
+    @Property
+    private String title;
+    private String author;
+    @Embedded
+    private Publisher publisher;
+    @Property("price")
+    private double cost;
+    @Reference
+    private Set<Book> companionBooks;
+    @Property
+    private LocalDateTime publishDate;
+
+    public Book() {
+
+    }
+
+    public Book(String isbn, String title, String author, double cost, Publisher publisher) {
+        this.isbn = isbn;
+        this.title = title;
+        this.author = author;
+        this.cost = cost;
+        this.publisher = publisher;
+        this.companionBooks = new HashSet<>();
+    }
+
+    // Getters and setters ...
+    public String getIsbn() {
+        return isbn;
+    }
+
+    public Book setIsbn(String isbn) {
+        this.isbn = isbn;
+        return this;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public Book setTitle(String title) {
+        this.title = title;
+        return this;
+    }
+
+    public String getAuthor() {
+        return author;
+    }
+
+    public Book setAuthor(String author) {
+        this.author = author;
+        return this;
+    }
+
+    public Publisher getPublisher() {
+        return publisher;
+    }
+
+    public Book setPublisher(Publisher publisher) {
+        this.publisher = publisher;
+        return this;
+    }
+
+    public double getCost() {
+        return cost;
+    }
+
+    public Book setCost(double cost) {
+        this.cost = cost;
+        return this;
+    }
+
+    public LocalDateTime getPublishDate() {
+        return publishDate;
+    }
+
+    public Book setPublishDate(LocalDateTime publishDate) {
+        this.publishDate = publishDate;
+        return this;
+    }
+
+    public Set<Book> getCompanionBooks() {
+        return companionBooks;
+    }
+
+    public Book addCompanionBooks(Book book) {
+        if (companionBooks != null)
+            this.companionBooks.add(book);
+        return this;
+    }
+
+    @Override
+    public String toString() {
+        return "Book [isbn=" + isbn + ", title=" + title + ", author=" + author + ", publisher=" + publisher + ", cost=" + cost + "]";
+    }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + ((author == null) ? 0 : author.hashCode());
+        long temp;
+        temp = Double.doubleToLongBits(cost);
+        result = prime * result + (int) (temp ^ (temp >>> 32));
+        result = prime * result + ((isbn == null) ? 0 : isbn.hashCode());
+        result = prime * result + ((publisher == null) ? 0 : publisher.hashCode());
+        result = prime * result + ((title == null) ? 0 : title.hashCode());
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj)
+            return true;
+        if (obj == null)
+            return false;
+        if (getClass() != obj.getClass())
+            return false;
+        Book other = (Book) obj;
+        if (author == null) {
+            if (other.author != null)
+                return false;
+        } else if (!author.equals(other.author))
+            return false;
+        if (Double.doubleToLongBits(cost) != Double.doubleToLongBits(other.cost))
+            return false;
+        if (isbn == null) {
+            if (other.isbn != null)
+                return false;
+        } else if (!isbn.equals(other.isbn))
+            return false;
+        if (publisher == null) {
+            if (other.publisher != null)
+                return false;
+        } else if (!publisher.equals(other.publisher))
+            return false;
+        if (title == null) {
+            if (other.title != null)
+                return false;
+        } else if (!title.equals(other.title))
+            return false;
+        return true;
+    }
+
+}
--- a/persistence-modules/java-mongodb/src/main/java/com/baeldung/bsontojson/Publisher.java
+++ b/persistence-modules/java-mongodb/src/main/java/com/baeldung/bsontojson/Publisher.java
@ -0,0 +1,70 @@
+package com.baeldung.bsontojson;
+
+import org.bson.types.ObjectId;
+
+import dev.morphia.annotations.Entity;
+import dev.morphia.annotations.Id;
+
+@Entity
+public class Publisher {
+
+    @Id
+    private ObjectId id;
+    private String name;
+
+    public Publisher() {
+
+    }
+
+    public Publisher(ObjectId id, String name) {
+        this.id = id;
+        this.name = name;
+    }
+
+    public ObjectId getId() {
+        return id;
+    }
+
+    public void setId(ObjectId id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public String toString() {
+        return "Catalog [id=" + id + ", name=" + name + "]";
+    }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + ((name == null) ? 0 : name.hashCode());
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj)
+            return true;
+        if (obj == null)
+            return false;
+        if (getClass() != obj.getClass())
+            return false;
+        Publisher other = (Publisher) obj;
+        if (name == null) {
+            if (other.name != null)
+                return false;
+        } else if (!name.equals(other.name))
+            return false;
+        return true;
+    }
+
+}
--- a/persistence-modules/java-mongodb/src/test/java/com/baeldung/bsontojson/BsonToJsonLiveTest.java
+++ b/persistence-modules/java-mongodb/src/test/java/com/baeldung/bsontojson/BsonToJsonLiveTest.java
@ -2,32 +2,18 @@ package com.baeldung.bsontojson;

 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertTrue;

-import java.sql.Timestamp;
-import java.time.Instant;
 import java.time.LocalDateTime;
 import java.time.format.DateTimeFormatter;
-import java.util.Date;
-import java.util.TimeZone;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;

 import org.bson.Document;
-import org.bson.json.Converter;
 import org.bson.json.JsonMode;
 import org.bson.json.JsonWriterSettings;
-import org.bson.json.StrictJsonWriter;
 import org.bson.types.ObjectId;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
 import org.junit.Test;
-import org.junit.jupiter.api.AfterEach;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;

-import com.baeldung.morphia.domain.Book;
-import com.baeldung.morphia.domain.Publisher;
 import com.mongodb.MongoClient;
 import com.mongodb.client.MongoDatabase;

@ -42,7 +28,7 @@ public class BsonToJsonLiveTest {
    @BeforeClass
    public static void setUp() {
        Morphia morphia = new Morphia();
-        morphia.mapPackage("com.baeldung.morphia");
+        morphia.mapPackage("com.baeldung.bsontojson");
        datastore = morphia.createDatastore(new MongoClient(), DB_NAME);
        datastore.ensureIndexes();
        
@ -72,7 +58,7 @@ public class BsonToJsonLiveTest {
        }
        
        String expectedJson = "{\"_id\": \"isbn\", " + 
-            "\"className\": \"com.baeldung.morphia.domain.Book\", " + 
+            "\"className\": \"com.baeldung.bsontojson.Book\", " + 
            "\"title\": \"title\", " + 
            "\"author\": \"author\", " + 
            "\"publisher\": {\"_id\": {\"$oid\": \"fffffffffffffffffffffffa\"}, " + 
@ -100,7 +86,7 @@ public class BsonToJsonLiveTest {
        }
        
        String expectedJson = "{\"_id\": \"isbn\", " + 
-            "\"className\": \"com.baeldung.morphia.domain.Book\", " + 
+            "\"className\": \"com.baeldung.bsontojson.Book\", " + 
            "\"title\": \"title\", " + 
            "\"author\": \"author\", " + 
            "\"publisher\": {\"_id\": {\"$oid\": \"fffffffffffffffffffffffa\"}, " + 
@ -127,7 +113,7 @@ public class BsonToJsonLiveTest {
        }

        String expectedJson = "{\"_id\": \"isbn\", " + 
-            "\"className\": \"com.baeldung.morphia.domain.Book\", " + 
+            "\"className\": \"com.baeldung.bsontojson.Book\", " + 
            "\"title\": \"title\", " + 
            "\"author\": \"author\", " + 
            "\"publisher\": {\"_id\": {\"$oid\": \"fffffffffffffffffffffffa\"}, " + 
--- a/persistence-modules/spring-boot-persistence-2/README.md
+++ b/persistence-modules/spring-boot-persistence-2/README.md
@ -4,4 +4,5 @@
 - [Configuring a Tomcat Connection Pool in Spring Boot](https://www.baeldung.com/spring-boot-tomcat-connection-pool)
 - [Integrating Spring Boot with HSQLDB](https://www.baeldung.com/spring-boot-hsqldb)
 - [List of In-Memory Databases](http://www.baeldung.com/java-in-memory-databases)
- More articles: [[<-- prev]](../spring-boot-persistence)
+- [Oracle Connection Pooling With Spring](https://www.baeldung.com/spring-oracle-connection-pooling)
+- More articles: [[<-- prev]](../spring-boot-persistence)
--- a/persistence-modules/spring-boot-persistence-2/src/main/java/com/baeldung/spring/transactional/TransactionalCompareApplication.java
+++ b/persistence-modules/spring-boot-persistence-2/src/main/java/com/baeldung/spring/transactional/TransactionalCompareApplication.java
@ -0,0 +1,12 @@
+package com.baeldung.spring.transactional;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+class TransactionalCompareApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(TransactionalCompareApplication.class, args);
+    }
+}
--- a/persistence-modules/spring-boot-persistence-2/src/main/java/com/baeldung/spring/transactional/entity/Car.java
+++ b/persistence-modules/spring-boot-persistence-2/src/main/java/com/baeldung/spring/transactional/entity/Car.java
@ -0,0 +1,60 @@
+package com.baeldung.spring.transactional.entity;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+
+@Entity
+public class Car {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    private Long id;
+
+    private String make;
+
+    private String model;
+
+    public Car() {
+    }
+
+    public Car(Long id, String make, String model) {
+        this.id = id;
+        this.make = make;
+        this.model = model;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getMake() {
+        return make;
+    }
+
+    public void setMake(String make) {
+        this.make = make;
+    }
+
+    public String getModel() {
+        return model;
+    }
+
+    public void setModel(String model) {
+        this.model = model;
+    }
+
+    @Override
+    public String toString() {
+        return "Car{" +
+                "id=" + id +
+                ", make='" + make + '\'' +
+                ", model='" + model + '\'' +
+                '}';
+    }
+}
--- a/persistence-modules/spring-boot-persistence-2/src/main/java/com/baeldung/spring/transactional/repository/CarRepository.java
+++ b/persistence-modules/spring-boot-persistence-2/src/main/java/com/baeldung/spring/transactional/repository/CarRepository.java
@ -0,0 +1,7 @@
+package com.baeldung.spring.transactional.repository;
+
+import com.baeldung.spring.transactional.entity.Car;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface CarRepository extends JpaRepository<Car, Long> {
+}
--- a/persistence-modules/spring-boot-persistence-2/src/main/java/com/baeldung/spring/transactional/service/CarService.java
+++ b/persistence-modules/spring-boot-persistence-2/src/main/java/com/baeldung/spring/transactional/service/CarService.java
@ -0,0 +1,25 @@
+package com.baeldung.spring.transactional.service;
+
+import com.baeldung.spring.transactional.entity.Car;
+import com.baeldung.spring.transactional.repository.CarRepository;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Isolation;
+import org.springframework.transaction.annotation.Propagation;
+import org.springframework.transaction.annotation.Transactional;
+
+import javax.persistence.EntityExistsException;
+
+@Service
+@Transactional(isolation = Isolation.READ_COMMITTED, propagation = Propagation.SUPPORTS, readOnly = false, timeout = 30)
+public class CarService {
+
+    @Autowired
+    private CarRepository carRepository;
+
+    @Transactional(rollbackFor = IllegalArgumentException.class, noRollbackFor = EntityExistsException.class,
+      rollbackForClassName = "IllegalArgumentException", noRollbackForClassName = "EntityExistsException")
+    public Car save(Car car) {
+        return carRepository.save(car);
+    }
+}
--- a/persistence-modules/spring-boot-persistence-2/src/main/java/com/baeldung/spring/transactional/service/RentalService.java
+++ b/persistence-modules/spring-boot-persistence-2/src/main/java/com/baeldung/spring/transactional/service/RentalService.java
@ -0,0 +1,22 @@
+package com.baeldung.spring.transactional.service;
+
+import com.baeldung.spring.transactional.entity.Car;
+import com.baeldung.spring.transactional.repository.CarRepository;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+import javax.persistence.EntityExistsException;
+import javax.transaction.Transactional;
+
+@Service
+@Transactional(Transactional.TxType.SUPPORTS)
+public class RentalService {
+
+    @Autowired
+    private CarRepository carRepository;
+
+    @Transactional(rollbackOn = IllegalArgumentException.class, dontRollbackOn = EntityExistsException.class)
+    public Car rent(Car car) {
+        return carRepository.save(car);
+    }
+}
--- a/persistence-modules/spring-data-jpa-4/README.md
+++ b/persistence-modules/spring-data-jpa-4/README.md
@ -6,6 +6,7 @@
 - [JPA Entity Lifecycle Events](https://www.baeldung.com/jpa-entity-lifecycle-events)
 - [Working with Lazy Element Collections in JPA](https://www.baeldung.com/java-jpa-lazy-collections)
 - [Calling Stored Procedures from Spring Data JPA Repositories](https://www.baeldung.com/spring-data-jpa-stored-procedures)
+- [Custom Naming Convention with Spring Data JPA](https://www.baeldung.com/spring-data-jpa-custom-naming)

 ### Eclipse Config 
 After importing the project into Eclipse, you may see the following error:  
--- a/pom.xml
+++ b/pom.xml
@ -461,7 +461,8 @@
                <module>java-lite</module>
                <module>java-numbers</module>
                <module>java-numbers-2</module>
-                <module>java-numbers-3</module>
+		<module>java-numbers-3</module>
+		<module>java-python-interop</module>
                <module>java-rmi</module>
                <module>java-spi</module>
                <module>java-vavr-stream</module>
@ -508,6 +509,7 @@
                <module>libraries-http-2</module>
                <module>libraries-io</module>
                <module>libraries-primitive</module>
+                <module>libraries-rpc</module>
                <module>libraries-security</module>
                <module>libraries-server</module>
                <module>libraries-testing</module>
@ -896,6 +898,7 @@
                <module>atomix</module>

                <module>aws</module>
+                <module>aws-app-sync</module>
                <module>aws-lambda</module>
                <module>aws-reactive</module>

--- a/reactor-core/README.md
+++ b/reactor-core/README.md
@ -7,3 +7,4 @@ This module contains articles about Reactor Core.
 - [Intro To Reactor Core](https://www.baeldung.com/reactor-core)
 - [Combining Publishers in Project Reactor](https://www.baeldung.com/reactor-combine-streams)
 - [Programmatically Creating Sequences with Project Reactor](https://www.baeldung.com/flux-sequences-reactor)
+- [How to Extract a Mono’s Content in Java](https://www.baeldung.com/java-string-from-mono)
--- a/spring-boot-modules/spring-boot-properties/src/main/resources/configForDbProperties.xml
+++ b/spring-boot-modules/spring-boot-properties/src/main/resources/configForDbProperties.xml
@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
+       xmlns:util="http://www.springframework.org/schema/util"
+       xsi:schemaLocation="
+      http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
+      http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.2.xsd
+      http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.2.xsd"
+>
+
+    <context:property-placeholder location="classpath:database.properties"/>
+
+
+    <bean id="dataSource" class="com.baeldung.configurationproperties.Database">
+        <property name="url" value="${jdbc.url}" />
+        <property name="username" value="${database.username}" />
+        <property name="password" value="${database.password}" />
+    </bean>
+
+</beans>
--- a/spring-boot-modules/spring-boot-properties/src/main/resources/configForProperties.xml
+++ b/spring-boot-modules/spring-boot-properties/src/main/resources/configForProperties.xml
@ -7,7 +7,8 @@
      http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.2.xsd"
 >

-    <context:property-placeholder location="classpath:foo.properties,classpath:bar.properties, classpath:database.properties"/>
+
+    <context:property-placeholder location="classpath:foo.properties,classpath:bar.properties,classpath:database.properties"/>

    <bean id="componentInXmlUsingProperties" class="com.baeldung.properties.core.ComponentInXmlUsingProperties">
        <constructor-arg value="${key.something}"/>
--- a/spring-boot-modules/spring-boot-properties/src/main/resources/database.properties
+++ b/spring-boot-modules/spring-boot-properties/src/main/resources/database.properties
@ -1,4 +1,5 @@
-database.url=jdbc:postgresql:/localhost:5432/instance
+
+jdbc.url=jdbc:postgresql:/localhost:5432
 database.username=foo
 database.password=bar
-jdbc.url=jdbc:postgresql:/localhost:5432
+
--- a/spring-boot-modules/spring-boot-properties/src/test/java/com/baeldung/properties/multiple/MultiplePropertiesXmlConfigIntegrationTest.java
+++ b/spring-boot-modules/spring-boot-properties/src/test/java/com/baeldung/properties/multiple/MultiplePropertiesXmlConfigIntegrationTest.java
@ -6,7 +6,7 @@ import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;

 import static org.assertj.core.api.Assertions.assertThat;

-@SpringJUnitConfig(locations = "classpath:configForProperties.xml")
+@SpringJUnitConfig(locations = {"classpath:configForProperties.xml", "classpath:configForDbProperties.xml"})
 public class MultiplePropertiesXmlConfigIntegrationTest {

    @Value("${key.something}") private String something;
--- a/spring-boot-modules/spring-boot/src/test/resources/README.md
+++ b/spring-boot-modules/spring-boot/src/test/resources/README.md
@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [How to Test GraphQL Using Postman](https://www.baeldung.com/graphql-postman)
--- a/spring-cloud/spring-cloud-circuit-breaker/README.md
+++ b/spring-cloud/spring-cloud-circuit-breaker/README.md
@ -3,3 +3,5 @@
 This module contains articles about Spring Cloud Circuit Breaker

 ### Relevant Articles:
+
+- [Quick Guide to Spring Cloud Circuit Breaker](https://www.baeldung.com/spring-cloud-circuit-breaker)
--- a/spring-cloud/spring-cloud-gateway/pom.xml
+++ b/spring-cloud/spring-cloud-gateway/pom.xml
@ -1,7 +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">
+    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>
    <artifactId>spring-cloud-gateway</artifactId>
    <name>spring-cloud-gateway</name>
@ -49,6 +49,26 @@
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>

+        <!-- Circuit Breaker -->
+        <dependency>
+            <groupId>org.springframework.cloud</groupId>
+            <artifactId>spring-cloud-starter-circuitbreaker-reactor-resilience4j</artifactId>
+        </dependency>
+
+        <!-- Redis -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-redis-reactive</artifactId>
+        </dependency>
+
+        <!-- Embedded Redis -->
+        <dependency>
+            <groupId>it.ozimov</groupId>
+            <artifactId>embedded-redis</artifactId>
+            <version>${redis.version}</version>
+            <scope>test</scope>
+        </dependency>
+
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-validator-cdi</artifactId>
@ -69,8 +89,8 @@
            <scope>test</scope>
        </dependency>
        <dependency>
-        	<groupId>org.springframework.boot</groupId>
-        	<artifactId>spring-boot-devtools</artifactId>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
    </dependencies>

@ -84,11 +104,10 @@
    </build>

    <properties>
-        <spring-cloud-dependencies.version>Greenwich.SR3</spring-cloud-dependencies.version>
-
-        <!-- Spring Boot version compatible with Spring Cloud Release train -->
-        <spring-boot.version>2.1.9.RELEASE</spring-boot.version>
+        <spring-cloud-dependencies.version>Hoxton.SR3</spring-cloud-dependencies.version>
+        <spring-boot.version>2.2.6.RELEASE</spring-boot.version>
        <hibernate-validator.version>6.0.2.Final</hibernate-validator.version>
+        <redis.version>0.7.2</redis.version>
    </properties>

 </project>
--- a/spring-cloud/spring-cloud-gateway/src/main/java/com/baeldung/springcloudgateway/webfilters/WebFilterGatewayApplication.java
+++ b/spring-cloud/spring-cloud-gateway/src/main/java/com/baeldung/springcloudgateway/webfilters/WebFilterGatewayApplication.java
@ -0,0 +1,15 @@
+package com.baeldung.springcloudgateway.webfilters;
+
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+
+@SpringBootApplication
+public class WebFilterGatewayApplication {
+
+    public static void main(String[] args) {
+        new SpringApplicationBuilder(WebFilterGatewayApplication.class)
+          .profiles("webfilters")
+          .run(args);
+    }
+
+}
--- a/spring-cloud/spring-cloud-gateway/src/main/java/com/baeldung/springcloudgateway/webfilters/config/ModifyBodyRouteConfig.java
+++ b/spring-cloud/spring-cloud-gateway/src/main/java/com/baeldung/springcloudgateway/webfilters/config/ModifyBodyRouteConfig.java
@ -0,0 +1,49 @@
+package com.baeldung.springcloudgateway.webfilters.config;
+
+import org.springframework.cloud.gateway.route.RouteLocator;
+import org.springframework.cloud.gateway.route.builder.RouteLocatorBuilder;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.http.MediaType;
+
+import reactor.core.publisher.Mono;
+
+@Configuration
+public class ModifyBodyRouteConfig {
+
+    @Bean
+    public RouteLocator routes(RouteLocatorBuilder builder) {
+        return builder.routes()
+          .route("modify_request_body", r -> r.path("/post")
+            .filters(f -> f.modifyRequestBody(String.class, Hello.class, MediaType.APPLICATION_JSON_VALUE,
+              (exchange, s) -> Mono.just(new Hello(s.toUpperCase())))).uri("https://httpbin.org"))
+          .build();
+    }  
+
+    @Bean
+    public RouteLocator responseRoutes(RouteLocatorBuilder builder) {
+        return builder.routes()
+          .route("modify_response_body", r -> r.path("/put/**")
+            .filters(f -> f.modifyResponseBody(String.class, Hello.class, MediaType.APPLICATION_JSON_VALUE,
+              (exchange, s) -> Mono.just(new Hello("New Body")))).uri("https://httpbin.org"))
+          .build();
+    } 
+
+    static class Hello {
+        String message;
+
+        public Hello() { }
+
+        public Hello(String message) {
+            this.message = message;
+        }
+
+        public String getMessage() {
+            return message;
+        }
+
+        public void setMessage(String message) {
+            this.message = message;
+        }
+    } 
+}
--- a/spring-cloud/spring-cloud-gateway/src/main/java/com/baeldung/springcloudgateway/webfilters/config/RequestRateLimiterResolverConfig.java
+++ b/spring-cloud/spring-cloud-gateway/src/main/java/com/baeldung/springcloudgateway/webfilters/config/RequestRateLimiterResolverConfig.java
@ -0,0 +1,16 @@
+package com.baeldung.springcloudgateway.webfilters.config;
+
+import org.springframework.cloud.gateway.filter.ratelimit.KeyResolver;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import reactor.core.publisher.Mono;
+
+@Configuration
+public class RequestRateLimiterResolverConfig {
+    
+    @Bean
+    KeyResolver userKeyResolver() {
+        return exchange -> Mono.just("1");
+    }
+}
--- a/spring-cloud/spring-cloud-gateway/src/main/resources/application-webfilters.yml
+++ b/spring-cloud/spring-cloud-gateway/src/main/resources/application-webfilters.yml
@ -0,0 +1,102 @@
+logging:
+  level:
+    org.springframework.cloud.gateway: INFO
+    reactor.netty.http.client: INFO
+    
+spring:
+  redis:
+    host: localhost
+    port: 6379
+  cloud:
+    gateway:
+      routes:
+      - id: request_header_route
+        uri: https://httpbin.org
+        predicates:
+        - Path=/get/**
+        filters:
+        - AddRequestHeader=My-Header-Good,Good
+        - AddRequestHeader=My-Header-Remove,Remove
+        - AddRequestParameter=var, good
+        - AddRequestParameter=var2, remove
+        - MapRequestHeader=My-Header-Good, My-Header-Bad
+        - MapRequestHeader=My-Header-Set, My-Header-Bad
+        - SetRequestHeader=My-Header-Set, Set 
+        - RemoveRequestHeader=My-Header-Remove
+        - RemoveRequestParameter=var2
+        - PreserveHostHeader
+        
+      - id: response_header_route
+        uri: https://httpbin.org
+        predicates:
+        - Path=/header/post/**
+        filters:
+        - AddResponseHeader=My-Header-Good,Good
+        - AddResponseHeader=My-Header-Set,Good
+        - AddResponseHeader=My-Header-Rewrite, password=12345678
+        - DedupeResponseHeader=Access-Control-Allow-Credentials Access-Control-Allow-Origin
+        - AddResponseHeader=My-Header-Remove,Remove
+        - SetResponseHeader=My-Header-Set, Set
+        - RemoveResponseHeader=My-Header-Remove
+        - RewriteResponseHeader=My-Header-Rewrite, password=[^&]+, password=***
+        - RewriteLocationResponseHeader=AS_IN_REQUEST, Location, ,
+        - StripPrefix=1
+        
+      - id: path_route
+        uri: https://httpbin.org
+        predicates:
+        - Path=/new/post/**
+        filters:
+        - RewritePath=/new(?<segment>/?.*), $\{segment}
+        - SetPath=/post
+        
+      - id: redirect_route
+        uri: https://httpbin.org
+        predicates:
+        - Path=/fake/post/**
+        filters:
+        - RedirectTo=302, https://httpbin.org
+        
+      - id: status_route
+        uri: https://httpbin.org
+        predicates:
+        - Path=/delete/**
+        filters:
+        - SetStatus=401
+        
+      - id: size_route
+        uri: https://httpbin.org
+        predicates:
+        - Path=/anything
+        filters:
+        - name: RequestSize
+          args:
+            maxSize: 5000000
+ 
+      - id: retry_test
+        uri: https://httpbin.org
+        predicates:
+        - Path=/status/502
+        filters:
+        - name: Retry
+          args:
+            retries: 3
+            statuses: BAD_GATEWAY
+            methods: GET,POST
+            backoff:
+              firstBackoff: 10ms
+              maxBackoff: 50ms
+              factor: 2
+              basedOnPreviousValue: false
+              
+      - id: request_rate_limiter
+        uri: https://httpbin.org
+        predicates:
+        - Path=/redis/get/**
+        filters:
+        - StripPrefix=1
+        - name: RequestRateLimiter
+          args:
+            redis-rate-limiter.replenishRate: 10
+            redis-rate-limiter.burstCapacity: 5
+            key-resolver: "#{@userKeyResolver}"
--- a/spring-cloud/spring-cloud-gateway/src/test/java/com/baeldung/springcloudgateway/webfilters/RedisWebFilterFactoriesLiveTest.java
+++ b/spring-cloud/spring-cloud-gateway/src/test/java/com/baeldung/springcloudgateway/webfilters/RedisWebFilterFactoriesLiveTest.java
@ -0,0 +1,64 @@
+package com.baeldung.springcloudgateway.webfilters;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.jupiter.api.RepeatedTest;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
+import org.springframework.boot.test.context.TestConfiguration;
+import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.boot.web.server.LocalServerPort;
+import org.springframework.http.ResponseEntity;
+import org.springframework.test.context.ActiveProfiles;
+
+import redis.embedded.RedisServer;
+
+@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
+@ActiveProfiles("webfilters")
+@TestConfiguration
+public class RedisWebFilterFactoriesLiveTest {
+    
+    private static final Logger LOGGER = LoggerFactory.getLogger(RedisWebFilterFactoriesLiveTest.class);
+    
+    private RedisServer redisServer;
+    
+    public RedisWebFilterFactoriesLiveTest() {
+    }
+
+    @Before
+    public void postConstruct() {
+        this.redisServer = new RedisServer(6379);
+        redisServer.start();    
+    }
+    
+    @LocalServerPort
+    String port;
+
+    @Autowired
+    private TestRestTemplate restTemplate;
+
+    @Autowired
+    TestRestTemplate template;
+ 
+    @RepeatedTest(25)
+    public void whenCallRedisGetThroughGateway_thenOKStatusOrIsReceived() {
+        String url = "http://localhost:" + port + "/redis/get";
+
+        ResponseEntity<String> r = restTemplate.getForEntity(url, String.class);
+        // assertThat(response.getStatusCode()).isEqualTo(HttpStatus.OK);
+
+        LOGGER.info("Received: status->{}, reason->{}, remaining->{}", 
+          r.getStatusCodeValue(), r.getStatusCode().getReasonPhrase(), 
+          r.getHeaders().get("X-RateLimit-Remaining"));
+    }
+    
+    @After
+    public void preDestroy() {
+        redisServer.stop();
+    }
+
+}
--- a/spring-cloud/spring-cloud-gateway/src/test/java/com/baeldung/springcloudgateway/webfilters/WebFilterFactoriesLiveTest.java
+++ b/spring-cloud/spring-cloud-gateway/src/test/java/com/baeldung/springcloudgateway/webfilters/WebFilterFactoriesLiveTest.java
@ -0,0 +1,136 @@
+package com.baeldung.springcloudgateway.webfilters;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+
+import org.assertj.core.api.Condition;
+import org.json.JSONException;
+import org.json.JSONObject;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
+import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.boot.web.server.LocalServerPort;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpMethod;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.test.context.ActiveProfiles;
+import org.springframework.test.web.reactive.server.WebTestClient;
+import org.springframework.test.web.reactive.server.WebTestClient.ResponseSpec;
+
+@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
+@ActiveProfiles("webfilters")
+public class WebFilterFactoriesLiveTest {
+
+    @LocalServerPort
+    String port;
+
+    @Autowired
+    private WebTestClient client;
+
+    @Autowired
+    private TestRestTemplate restTemplate;
+
+    @BeforeEach
+    public void configureClient() {
+        client = WebTestClient.bindToServer()
+          .baseUrl("http://localhost:" + port)
+          .build();
+    }
+
+    @Test
+    public void whenCallGetThroughGateway_thenAllHTTPRequestHeadersParametersAreSet() throws JSONException {
+        String url = "http://localhost:" + port + "/get";
+        ResponseEntity<String> response = restTemplate.getForEntity(url, String.class);
+        assertThat(response.getStatusCode()).isEqualTo(HttpStatus.OK);
+
+        JSONObject json = new JSONObject(response.getBody());
+        JSONObject headers = json.getJSONObject("headers");
+        assertThat(headers.getString("My-Header-Good")).isEqualTo("Good");
+        assertThat(headers.getString("My-Header-Bad")).isEqualTo("Good");
+        assertThat(headers.getString("My-Header-Set")).isEqualTo("Set");
+        assertTrue(headers.isNull("My-Header-Remove"));
+        JSONObject vars = json.getJSONObject("args");
+        assertThat(vars.getString("var")).isEqualTo("good");
+    }
+
+    @Test
+    public void whenCallHeaderPostThroughGateway_thenAllHTTPResponseHeadersAreSet() {
+        ResponseSpec response = client.post()
+          .uri("/header/post")
+          .exchange();
+
+        response.expectStatus()
+          .isOk()
+          .expectHeader()
+          .valueEquals("My-Header-Rewrite", "password=***")
+          .expectHeader()
+          .valueEquals("My-Header-Set", "Set")
+          .expectHeader()
+          .valueEquals("My-Header-Good", "Good")
+          .expectHeader()
+          .doesNotExist("My-Header-Remove");
+    }
+
+    @Test
+    public void whenCallPostThroughGateway_thenBodyIsRetrieved() throws JSONException {
+        String url = "http://localhost:" + port + "/post";
+
+        HttpEntity<String> entity = new HttpEntity<>("content", new HttpHeaders());
+
+        ResponseEntity<String> response = restTemplate.exchange(url, HttpMethod.POST, entity, String.class);
+        assertThat(response.getStatusCode()).isEqualTo(HttpStatus.OK);
+
+        JSONObject json = new JSONObject(response.getBody());
+        JSONObject data = json.getJSONObject("json");
+        assertThat(data.getString("message")).isEqualTo("CONTENT");
+    }
+
+    @Test
+    public void whenCallPutThroughGateway_thenBodyIsRetrieved() throws JSONException {
+        String url = "http://localhost:" + port + "/put";
+
+        HttpEntity<String> entity = new HttpEntity<>("CONTENT", new HttpHeaders());
+
+        ResponseEntity<String> response = restTemplate.exchange(url, HttpMethod.PUT, entity, String.class);
+        assertThat(response.getStatusCode()).isEqualTo(HttpStatus.OK);
+
+        JSONObject json = new JSONObject(response.getBody());
+        assertThat(json.getString("message")).isEqualTo("New Body");
+    }
+
+    @Test
+    public void whenCallDeleteThroughGateway_thenIsUnauthorizedCodeIsSet() {
+        ResponseSpec response = client.delete()
+          .uri("/delete")
+          .exchange();
+
+        response.expectStatus()
+          .isUnauthorized();
+    }
+
+    @Test
+    public void whenCallFakePostThroughGateway_thenIsUnauthorizedCodeIsSet() {
+        ResponseSpec response = client.post()
+          .uri("/fake/post")
+          .exchange();
+
+        response.expectStatus()
+          .is3xxRedirection();
+    }
+
+    @Test
+    public void whenCallStatus504ThroughGateway_thenCircuitBreakerIsExecuted() throws JSONException {
+        String url = "http://localhost:" + port + "/status/504";
+        ResponseEntity<String> response = restTemplate.getForEntity(url, String.class);
+
+        JSONObject json = new JSONObject(response.getBody());
+        assertThat(json.getString("url")).contains("anything");
+    }
+}
--- a/spring-cloud/spring-cloud-gateway/src/test/resources/logback-test.xml
+++ b/spring-cloud/spring-cloud-gateway/src/test/resources/logback-test.xml
@ -3,7 +3,15 @@
    <appender name="LISTAPPENDER"
        class="com.baeldung.springcloudgateway.customfilters.gatewayapp.utils.LoggerListAppender">
    </appender>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
+        </encoder>
+    </appender>
    <root level="info">
        <appender-ref ref="LISTAPPENDER" />
    </root>
+    <root level="info">
+        <appender-ref ref="STDOUT" />
+    </root>
 </configuration> 
--- a/spring-core-2/README.md
+++ b/spring-core-2/README.md
@ -14,4 +14,5 @@ This module contains articles about core Spring functionality
 - [Spring Events](https://www.baeldung.com/spring-events)
 - [Spring Null-Safety Annotations](https://www.baeldung.com/spring-null-safety-annotations)
 - [Using @Autowired in Abstract Classes](https://www.baeldung.com/spring-autowired-abstract-class)
+- [Running Setup Data on Startup in Spring](https://www.baeldung.com/running-setup-logic-on-startup-in-spring)
 - More articles: [[<-- prev]](/spring-core)[[next -->]](/spring-core-3)
--- a/spring-core-4/src/main/java/com/baeldung/dynamic/autowire/BeanFactoryDynamicAutowireService.java
+++ b/spring-core-4/src/main/java/com/baeldung/dynamic/autowire/BeanFactoryDynamicAutowireService.java
@ -0,0 +1,27 @@
+package com.baeldung.dynamic.autowire;
+
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+@Service
+public class BeanFactoryDynamicAutowireService {
+    private static final String SERVICE_NAME_SUFFIX = "regionService";
+    private final BeanFactory beanFactory;
+
+    @Autowired
+    public BeanFactoryDynamicAutowireService(BeanFactory beanFactory) {
+        this.beanFactory = beanFactory;
+    }
+
+    public boolean isServerActive(String isoCountryCode, int serverId) {
+        RegionService service = beanFactory.getBean(getRegionServiceBeanName(isoCountryCode), RegionService.class);
+
+        return service.isServerActive(serverId);
+    }
+
+    private String getRegionServiceBeanName(String isoCountryCode) {
+        return isoCountryCode + SERVICE_NAME_SUFFIX;
+    }
+
+}
--- a/spring-core-4/src/main/java/com/baeldung/dynamic/autowire/CustomMapFromListDynamicAutowireService.java
+++ b/spring-core-4/src/main/java/com/baeldung/dynamic/autowire/CustomMapFromListDynamicAutowireService.java
@ -0,0 +1,26 @@
+package com.baeldung.dynamic.autowire;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+import java.util.List;
+import java.util.Map;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+@Service
+public class CustomMapFromListDynamicAutowireService {
+    private final Map<String, RegionService> servicesByCountryCode;
+
+    @Autowired
+    public CustomMapFromListDynamicAutowireService(List<RegionService> regionServices) {
+        servicesByCountryCode = regionServices.stream()
+                .collect(Collectors.toMap(RegionService::getISOCountryCode, Function.identity()));
+    }
+
+    public boolean isServerActive(String isoCountryCode, int serverId) {
+        RegionService service = servicesByCountryCode.get(isoCountryCode);
+
+        return service.isServerActive(serverId);
+    }
+}
--- a/spring-core-4/src/main/java/com/baeldung/dynamic/autowire/DynamicAutowireConfig.java
+++ b/spring-core-4/src/main/java/com/baeldung/dynamic/autowire/DynamicAutowireConfig.java
@ -0,0 +1,9 @@
+package com.baeldung.dynamic.autowire;
+
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@ComponentScan("com.baeldung.dynamic.autowire")
+public class DynamicAutowireConfig {
+}
--- a/spring-core-4/src/main/java/com/baeldung/dynamic/autowire/GBRegionService.java
+++ b/spring-core-4/src/main/java/com/baeldung/dynamic/autowire/GBRegionService.java
@ -0,0 +1,16 @@
+package com.baeldung.dynamic.autowire;
+
+import org.springframework.stereotype.Service;
+
+@Service("GBregionService")
+public class GBRegionService implements RegionService {
+    @Override
+    public boolean isServerActive(int serverId) {
+        return false;
+    }
+
+    @Override
+    public String getISOCountryCode() {
+        return "GB";
+    }
+}
--- a/spring-core-4/src/main/java/com/baeldung/dynamic/autowire/RegionService.java
+++ b/spring-core-4/src/main/java/com/baeldung/dynamic/autowire/RegionService.java
@ -0,0 +1,7 @@
+package com.baeldung.dynamic.autowire;
+
+public interface RegionService {
+    boolean isServerActive(int serverId);
+
+    String getISOCountryCode();
+}
--- a/spring-core-4/src/main/java/com/baeldung/dynamic/autowire/USRegionService.java
+++ b/spring-core-4/src/main/java/com/baeldung/dynamic/autowire/USRegionService.java
@ -0,0 +1,16 @@
+package com.baeldung.dynamic.autowire;
+
+import org.springframework.stereotype.Service;
+
+@Service("USregionService")
+public class USRegionService implements RegionService {
+    @Override
+    public boolean isServerActive(int serverId) {
+        return true;
+    }
+
+    @Override
+    public String getISOCountryCode() {
+        return "US";
+    }
+}
--- a/spring-core-4/src/test/java/com/baeldung/dynamic/autowire/DynamicAutowireIntegrationTest.java
+++ b/spring-core-4/src/test/java/com/baeldung/dynamic/autowire/DynamicAutowireIntegrationTest.java
@ -0,0 +1,33 @@
+package com.baeldung.dynamic.autowire;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertThat;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration(classes = DynamicAutowireConfig.class)
+public class DynamicAutowireIntegrationTest {
+
+    @Autowired
+    private BeanFactoryDynamicAutowireService beanFactoryDynamicAutowireService;
+
+    @Autowired
+    private CustomMapFromListDynamicAutowireService customMapFromListDynamicAutowireService;
+
+    @Test
+    public void givenDynamicallyAutowiredBean_whenCheckingServerInGB_thenServerIsNotActive() {
+        assertThat(beanFactoryDynamicAutowireService.isServerActive("GB", 101), is(false));
+        assertThat(customMapFromListDynamicAutowireService.isServerActive("GB", 101), is(false));
+    }
+
+    @Test
+    public void givenDynamicallyAutowiredBean_whenCheckingServerInUS_thenServerIsActive() {
+        assertThat(beanFactoryDynamicAutowireService.isServerActive("US", 101), is(true));
+        assertThat(customMapFromListDynamicAutowireService.isServerActive("US", 101), is(true));
+    }
+}
--- a/spring-mobile/pom.xml
+++ b/spring-mobile/pom.xml
@ -10,9 +10,9 @@

    <parent>
        <groupId>com.baeldung</groupId>
-        <artifactId>parent-boot-1</artifactId>
+        <artifactId>parent-boot-2</artifactId>
        <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../parent-boot-1</relativePath>
+        <relativePath>../parent-boot-2</relativePath>
    </parent>

    <dependencies>
@ -23,11 +23,24 @@
        <dependency>
            <groupId>org.springframework.mobile</groupId>
            <artifactId>spring-mobile-device</artifactId>
+            <version>${spring-mobile-device.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-freemarker</artifactId>
        </dependency>
    </dependencies>
-
+    <repositories>
+        <repository>
+            <id>spring-milestones</id>
+            <name>Spring Milestones</name>
+            <url>https://repo.spring.io/libs-milestone</url>
+            <snapshots>
+                <enabled>false</enabled>
+            </snapshots>
+        </repository>
+    </repositories>
+    <properties>
+        <spring-mobile-device.version>2.0.0.M3</spring-mobile-device.version>
+    </properties>
 </project>
--- a/spring-mobile/src/main/java/com/baeldung/AppConfig.java
+++ b/spring-mobile/src/main/java/com/baeldung/AppConfig.java
@ -0,0 +1,36 @@
+package com.baeldung;
+
+import java.util.List;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.mobile.device.DeviceHandlerMethodArgumentResolver;
+import org.springframework.mobile.device.DeviceResolverHandlerInterceptor;
+import org.springframework.web.method.support.HandlerMethodArgumentResolver;
+import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+
+@Configuration
+public class AppConfig implements WebMvcConfigurer {
+
+    @Bean
+    public DeviceResolverHandlerInterceptor deviceResolverHandlerInterceptor() {
+        return new DeviceResolverHandlerInterceptor();
+    }
+
+    @Bean
+    public DeviceHandlerMethodArgumentResolver deviceHandlerMethodArgumentResolver() {
+        return new DeviceHandlerMethodArgumentResolver();
+    }
+
+    @Override
+    public void addInterceptors(InterceptorRegistry registry) {
+        registry.addInterceptor(deviceResolverHandlerInterceptor());
+    }
+
+    @Override
+    public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
+        argumentResolvers.add(deviceHandlerMethodArgumentResolver());
+    }
+
+}
--- a/spring-mobile/src/main/java/com/baeldung/controller/IndexController.java
+++ b/spring-mobile/src/main/java/com/baeldung/controller/IndexController.java
@ -16,13 +16,16 @@ public class IndexController {

 		String deviceType = "browser";
 		String platform = "browser";
+		String viewName = "index";

 		if (device.isNormal()) {
 			deviceType = "browser";
 		} else if (device.isMobile()) {
 			deviceType = "mobile";
+			viewName = "mobile/index";
 		} else if (device.isTablet()) {
 			deviceType = "tablet";
+			viewName = "tablet/index";
 		}

 		platform = device.getDevicePlatform().name();
@ -33,7 +36,7 @@ public class IndexController {

 		LOGGER.info("Client Device Type: " + deviceType + ", Platform: " + platform);

-		return "index";
+		return viewName;
 	}

 }
--- a/spring-mobile/src/main/resources/application.properties
+++ b/spring-mobile/src/main/resources/application.properties
@ -1 +1,3 @@
-spring.mobile.devicedelegatingviewresolver.enabled: true
+spring.mobile.devicedelegatingviewresolver.enabled: true
+spring.freemarker.template-loader-path: classpath:/templates
+spring.freemarker.suffix: .ftl
--- a/spring-mvc-basics-2/README.md
+++ b/spring-mvc-basics-2/README.md
@ -9,7 +9,7 @@ This module contains articles about Spring MVC
 - [Servlet Redirect vs Forward](https://www.baeldung.com/servlet-redirect-forward)
 - [Apache Tiles Integration with Spring MVC](https://www.baeldung.com/spring-mvc-apache-tiles)
 - [Guide to Spring Email](https://www.baeldung.com/spring-email)
- [Using ThymeLeaf and FreeMarker Emails Templates with Spring](https://www.baeldung.com/thymeleaf-freemarker-email)
+- [Using ThymeLeaf and FreeMarker Emails Templates with Spring](https://www.baeldung.com/spring-email-templates)
 - [Request Method Not Supported (405) in Spring](https://www.baeldung.com/spring-request-method-not-supported-405)
 - [Spring @RequestParam Annotation](https://www.baeldung.com/spring-request-param)
 - More articles: [[more -->]](/spring-mvc-basics-3)
--- a/spring-rest-hal-browser/pom.xml
+++ b/spring-rest-hal-browser/pom.xml
@ -9,9 +9,9 @@

    <parent>
        <groupId>com.baeldung</groupId>
-        <artifactId>parent-boot-1</artifactId>
+        <artifactId>parent-boot-2</artifactId>
        <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../parent-boot-1</relativePath>
+        <relativePath>../parent-boot-2</relativePath>
    </parent>

    <dependencies>
@ -19,25 +19,26 @@
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
-            <version>${spring-boot.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-data-jpa -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
-            <version>${spring-boot.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework.data/spring-data-rest-hal-browser -->
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-rest-hal-browser</artifactId>
-            <version>${spring-data.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.h2database/h2 -->
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
-            <version>${h2.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>net.bytebuddy</groupId>
+            <artifactId>byte-buddy-dep</artifactId>
+            <version>${bytebuddy.version}</version>
        </dependency>
    </dependencies>

@ -55,9 +56,7 @@
    </build>

    <properties>
-        <spring-boot.version>2.0.3.RELEASE</spring-boot.version>
-        <spring-data.version>3.0.8.RELEASE</spring-data.version>
-        <h2.version>1.4.197</h2.version>
+        <bytebuddy.version>1.10.10</bytebuddy.version>
        <source.version>1.8</source.version>
        <target.version>1.8</target.version>
    </properties>
--- a/spring-security-modules/pom.xml
+++ b/spring-security-modules/pom.xml
@ -31,6 +31,7 @@
        <module>spring-security-mvc-persisted-remember-me</module>
        <module>spring-security-mvc-socket</module>
        <module>spring-security-oidc</module>
+        <module>spring-security-okta</module>
        <module>spring-security-react</module>   
        <module>spring-security-rest</module>
        <module>spring-security-rest-basic-auth</module>
--- a/spring-security-modules/spring-security-okta/pom.xml
+++ b/spring-security-modules/spring-security-okta/pom.xml
@ -0,0 +1,62 @@
+<?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/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>spring-security-okta</artifactId>
+    <version>1.0-SNAPSHOT</version>
+    <name>spring-security-okta</name>
+    <packaging>war</packaging>
+
+    <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-web</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>com.okta.spring</groupId>
+            <artifactId>okta-spring-boot-starter</artifactId>
+            <version>${okta.spring.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.okta.spring</groupId>
+            <artifactId>okta-spring-sdk</artifactId>
+            <version>${okta.spring.version}</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>spring-security-okta</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+            </resource>
+        </resources>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+                <configuration>
+                    <addResources>true</addResources>
+                </configuration>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>repackage</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+    
+    <properties>
+        <okta.spring.version>1.4.0</okta.spring.version>
+    </properties>
+</project>
--- a/spring-security-modules/spring-security-okta/src/main/java/com/baeldung/okta/Application.java
+++ b/spring-security-modules/spring-security-okta/src/main/java/com/baeldung/okta/Application.java
@ -0,0 +1,13 @@
+package com.baeldung.okta;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Application {
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+
+}
--- a/spring-security-modules/spring-security-okta/src/main/java/com/baeldung/okta/controller/AdminController.java
+++ b/spring-security-modules/spring-security-okta/src/main/java/com/baeldung/okta/controller/AdminController.java
@ -0,0 +1,43 @@
+package com.baeldung.okta.controller;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.okta.sdk.client.Client;
+import com.okta.sdk.resource.user.User;
+import com.okta.sdk.resource.user.UserBuilder;
+import com.okta.sdk.resource.user.UserList;
+
+@RestController
+public class AdminController {
+
+    @Autowired
+    public Client client;
+
+    @GetMapping("/users")
+    public UserList getUsers() {
+        return client.listUsers();
+    }
+
+    @GetMapping("/user")
+    public UserList searchUserByEmail(@RequestParam String query) {
+        return client.listUsers(query, null, null, null, null);
+    }
+    
+    @GetMapping("/createUser")
+    public User createUser() {
+        char[] tempPassword = {'P','a','$','$','w','0','r','d'};
+        User user = UserBuilder.instance()
+            .setEmail("norman.lewis@email.com")
+            .setFirstName("Norman")
+            .setLastName("Lewis")
+            .setPassword(tempPassword)
+            .setActive(true)
+            .buildAndCreate(client);
+        return user;
+    }
+    
+}
+
--- a/spring-security-modules/spring-security-okta/src/main/java/com/baeldung/okta/controller/HomeController.java
+++ b/spring-security-modules/spring-security-okta/src/main/java/com/baeldung/okta/controller/HomeController.java
@ -0,0 +1,16 @@
+package com.baeldung.okta.controller;
+
+import org.springframework.security.core.annotation.AuthenticationPrincipal;
+import org.springframework.security.oauth2.core.oidc.user.OidcUser;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class HomeController {
+
+    @GetMapping("/")
+    public String home(@AuthenticationPrincipal OidcUser user) {
+        return "Welcome, "+ user.getFullName() +"!";
+    }
+    
+}
--- a/Show More
+++ b/Show More