Merge remote-tracking branch 'upstream/master'

algorithms/src/main/java/com/baeldung/algorithms/prime/PrimeGenerator.java

@@ -0,0 +1,59 @@
+package com.baeldung.algorithms.prime;
+
+import java.util.Arrays;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+public class PrimeGenerator {
+    public static List<Integer> sieveOfEratosthenes(int n) {
+        final boolean prime[] = new boolean[n + 1];
+        Arrays.fill(prime, true);
+
+        for (int p = 2; p * p <= n; p++) {
+            if (prime[p]) {
+                for (int i = p * 2; i <= n; i += p)
+                    prime[i] = false;
+            }
+        }
+
+        final List<Integer> primes = new LinkedList<>();
+        for (int i = 2; i <= n; i++) {
+            if (prime[i])
+                primes.add(i);
+        }
+        return primes;
+    }
+
+    public static List<Integer> primeNumbersBruteForce(int max) {
+        final List<Integer> primeNumbers = new LinkedList<Integer>();
+        for (int i = 2; i <= max; i++) {
+            if (isPrimeBruteForce(i)) {
+                primeNumbers.add(i);
+            }
+        }
+        return primeNumbers;
+    }
+
+    private static boolean isPrimeBruteForce(int x) {
+        for (int i = 2; i < x; i++) {
+            if (x % i == 0) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    public static List<Integer> primeNumbersTill(int max) {
+        return IntStream.rangeClosed(2, max)
+            .filter(x -> isPrime(x))
+            .boxed()
+            .collect(Collectors.toList());
+    }
+
+    private static boolean isPrime(int x) {
+        return IntStream.rangeClosed(2, (int) (Math.sqrt(x)))
+            .allMatch(n -> x % n != 0);
+    }
+}

algorithms/src/test/java/com/baeldung/algorithms/prime/PrimeGeneratorTest.java

@@ -0,0 +1,28 @@
+package com.baeldung.algorithms.prime;
+
+import static com.baeldung.algorithms.prime.PrimeGenerator.*;
+
+import java.util.Arrays;
+import java.util.List;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class PrimeGeneratorTest {
+    @Test
+    public void whenBruteForced_returnsSuccessfully() {
+        final List<Integer> primeNumbers = primeNumbersBruteForce(20);
+        assertEquals(Arrays.asList(new Integer[] { 2, 3, 5, 7, 11, 13, 17, 19 }), primeNumbers);
+    }
+
+    @Test
+    public void whenOptimized_returnsSuccessfully() {
+        final List<Integer> primeNumbers = primeNumbersTill(20);
+        assertEquals(Arrays.asList(new Integer[] { 2, 3, 5, 7, 11, 13, 17, 19 }), primeNumbers);
+    }
+
+    @Test
+    public void whenSieveOfEratosthenes_returnsSuccessfully() {
+        final List<Integer> primeNumbers = sieveOfEratosthenes(20);
+        assertEquals(Arrays.asList(new Integer[] { 2, 3, 5, 7, 11, 13, 17, 19 }), primeNumbers);
+    }
+}

core-java-8/src/main/java/com/baeldung/prime/PrimeGenerator.java

@@ -0,0 +1,59 @@
+package com.baeldung.prime;
+
+import java.util.Arrays;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+public class PrimeGenerator {
+    public static List<Integer> sieveOfEratosthenes(int n) {
+        final boolean prime[] = new boolean[n + 1];
+        Arrays.fill(prime, true);
+
+        for (int p = 2; p * p <= n; p++) {
+            if (prime[p]) {
+                for (int i = p * 2; i <= n; i += p)
+                    prime[i] = false;
+            }
+        }
+
+        final List<Integer> primes = new LinkedList<>();
+        for (int i = 2; i <= n; i++) {
+            if (prime[i])
+                primes.add(i);
+        }
+        return primes;
+    }
+
+    public static List<Integer> primeNumbersBruteForce(int max) {
+        final List<Integer> primeNumbers = new LinkedList<Integer>();
+        for (int i = 2; i <= max; i++) {
+            if (isPrimeBruteForce(i)) {
+                primeNumbers.add(i);
+            }
+        }
+        return primeNumbers;
+    }
+
+    private static boolean isPrimeBruteForce(int x) {
+        for (int i = 2; i < x; i++) {
+            if (x % i == 0) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    public static List<Integer> primeNumbersTill(int max) {
+        return IntStream.rangeClosed(2, max)
+            .filter(x -> isPrime(x))
+            .boxed()
+            .collect(Collectors.toList());
+    }
+
+    private static boolean isPrime(int x) {
+        return IntStream.rangeClosed(2, (int) (Math.sqrt(x)))
+            .allMatch(n -> x % n != 0);
+    }
+}

core-java-8/src/test/java/com/baeldung/prime/PrimeGeneratorTest.java

@@ -0,0 +1,28 @@
+package com.baeldung.prime;
+
+import static com.baeldung.prime.PrimeGenerator.*;
+
+import java.util.Arrays;
+import java.util.List;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class PrimeGeneratorTest {
+    @Test
+    public void whenBruteForced_returnsSuccessfully() {
+        final List<Integer> primeNumbers = primeNumbersBruteForce(20);
+        assertEquals(Arrays.asList(new Integer[] { 2, 3, 5, 7, 11, 13, 17, 19 }), primeNumbers);
+    }
+
+    @Test
+    public void whenOptimized_returnsSuccessfully() {
+        final List<Integer> primeNumbers = primeNumbersTill(20);
+        assertEquals(Arrays.asList(new Integer[] { 2, 3, 5, 7, 11, 13, 17, 19 }), primeNumbers);
+    }
+
+    @Test
+    public void whenSieveOfEratosthenes_returnsSuccessfully() {
+        final List<Integer> primeNumbers = sieveOfEratosthenes(20);
+        assertEquals(Arrays.asList(new Integer[] { 2, 3, 5, 7, 11, 13, 17, 19 }), primeNumbers);
+    }
+}

core-java/src/test/java/com/baeldung/stack/StackUnitTest.java

@@ -0,0 +1,137 @@
+package com.baeldung.stack;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.junit.Assert.*;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.ListIterator;
+import java.util.Stack;
+
+import org.junit.Test;
+public class StackUnitTest {
+
+    @Test
+    public void whenStackIsCreated_thenItHasSize0() {
+        Stack intStack = new Stack();
+        assertEquals(0, intStack.size());
+    }
+
+    @Test
+    public void givenEmptyStack_whenElementIsPushed_thenStackSizeisIncreased() {
+        Stack intStack = new Stack();
+        intStack.push(1);
+        assertEquals(1, intStack.size());
+    }
+
+    @Test
+    public void givenEmptyStack_whenMultipleElementsArePushed_thenStackSizeisIncreased() {
+        Stack intStack = new Stack();
+        List<Integer> intList = Arrays.asList(1, 2, 3, 4, 5, 6, 7);
+        boolean result = intStack.addAll(intList);
+        assertTrue(result);
+        assertEquals(7, intList.size());
+    }
+
+    @Test
+    public void whenElementIsPoppedFromStack_thenElementIsRemovedAndSizeChanges() {
+        Stack<Integer> intStack = new Stack();
+        intStack.push(5);
+        intStack.pop();
+        assertTrue(intStack.isEmpty());
+    }
+
+    @Test
+    public void whenElementIsPeeked_thenElementIsNotRemovedAndSizeDoesNotChange() {
+        Stack<Integer> intStack = new Stack();
+        intStack.push(5);
+        intStack.peek();
+        assertEquals(1, intStack.search(5));
+        assertEquals(1, intStack.size());
+    }
+
+    @Test
+    public void whenElementIsOnStack_thenSearchReturnsItsDistanceFromTheTop() {
+        Stack<Integer> intStack = new Stack();
+        intStack.push(5);
+        assertEquals(1, intStack.search(5));
+    }
+
+    @Test
+    public void whenElementIsOnStack_thenIndexOfReturnsItsIndex() {
+        Stack<Integer> intStack = new Stack();
+        intStack.push(5);
+        int indexOf = intStack.indexOf(5);
+        assertEquals(0, indexOf);
+    }
+
+    @Test
+    public void whenMultipleElementsAreOnStack_thenIndexOfReturnsLastElementIndex() {
+        Stack<Integer> intStack = new Stack();
+        intStack.push(5);
+        intStack.push(5);
+        intStack.push(5);
+        int lastIndexOf = intStack.lastIndexOf(5);
+        assertEquals(2, lastIndexOf);
+    }
+
+    @Test
+    public void givenElementOnStack_whenRemoveElementIsInvoked_thenElementIsRemoved() {
+        Stack<Integer> intStack = new Stack();
+        intStack.push(5);
+        intStack.push(5);
+        intStack.removeElement(5);
+        assertEquals(1, intStack.size());
+    }
+
+    @Test
+    public void givenElementOnStack_whenRemoveElementAtIsInvoked_thenElementIsRemoved() {
+        Stack<Integer> intStack = new Stack();
+        intStack.push(5);
+        intStack.push(7);
+        intStack.removeElementAt(1);
+        assertEquals(-1, intStack.search(7));
+    }
+
+    @Test
+    public void givenElementsOnStack_whenRemoveAllElementsIsInvoked_thenAllElementsAreRemoved() {
+        Stack<Integer> intStack = new Stack();
+        intStack.push(5);
+        intStack.push(7);
+        intStack.removeAllElements();
+        assertTrue(intStack.isEmpty());
+    }
+
+    @Test
+    public void givenElementsOnStack_whenRemoveAllIsInvoked_thenAllElementsFromCollectionAreRemoved() {
+        Stack<Integer> intStack = new Stack();
+        List<Integer> intList = Arrays.asList(1, 2, 3, 4, 5, 6, 7);
+        intStack.addAll(intList);
+        intStack.add(500);
+        intStack.removeAll(intList);
+        assertEquals(1, intStack.size());
+    }
+
+    @Test
+    public void givenElementsOnStack_whenRemoveIfIsInvoked_thenAllElementsSatysfyingConditionAreRemoved() {
+        Stack<Integer> intStack = new Stack();
+        List<Integer> intList = Arrays.asList(1, 2, 3, 4, 5, 6, 7);
+        intStack.addAll(intList);
+        intStack.removeIf(element -> element < 6);
+        assertEquals(2, intStack.size());
+    }
+
+    @Test
+    public void whenAnotherStackCreatedWhileTraversingStack_thenStacksAreEqual() {
+        Stack<Integer> intStack = new Stack<>();
+        List<Integer> intList = Arrays.asList(1, 2, 3, 4, 5, 6, 7);
+        intStack.addAll(intList);
+        ListIterator<Integer> it = intStack.listIterator();
+        Stack<Integer> result = new Stack();
+        while(it.hasNext()) {
+            result.push(it.next());
+        }
+
+        assertThat(result, equalTo(intStack));
+    }
+}

core-java/src/test/java/com/baeldung/stringpool/StringPoolUnitTest.java

@@ -0,0 +1,43 @@
+package com.baeldung.stringpool;
+
+import org.junit.Test;
+import static org.assertj.core.api.Assertions.*;
+
+public class StringPoolUnitTest {
+
+    @Test
+    public void whenCreatingConstantStrings_thenTheirAddressesAreEqual() {
+        String constantString1 = "Baeldung";
+        String constantString2 = "Baeldung";
+
+        assertThat(constantString1).isSameAs(constantString2);
+    }
+
+    @Test
+    public void whenCreatingStringsWithTheNewOperator_thenTheirAddressesAreDifferent() {
+        String newString1 = new String("Baeldung");
+        String newString2 = new String("Baeldung");
+
+        assertThat(newString1).isNotSameAs(newString2);
+    }
+
+    @Test
+    public void whenComparingConstantAndNewStrings_thenTheirAddressesAreDifferent() {
+        String constantString = "Baeldung";
+        String newString = new String("Baeldung");
+
+        assertThat(constantString).isNotSameAs(newString);
+    }
+
+    @Test
+    public void whenInterningAStringWithIdenticalValueToAnother_thenTheirAddressesAreEqual() {
+        String constantString = "interned Baeldung";
+        String newString = new String("interned Baeldung");
+
+        assertThat(constantString).isNotSameAs(newString);
+
+        String internedString = newString.intern();
+
+        assertThat(constantString).isSameAs(internedString);
+    }
+}

drools/backward-chaining/pom.xml

@@ -1,7 +1,6 @@
 <?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>drools-backward-chaining</artifactId>
@@ -17,7 +16,6 @@
 	<properties>
 		<runtime.version>6.4.0.Final</runtime.version>
 	</properties>
-
 	<dependencies>
 		<dependency>
 			<groupId>org.kie</groupId>
@@ -26,7 +24,6 @@
 		</dependency>
 		<dependency>
 			<groupId>org.drools</groupId>
-			<artifactId>drools-core</artifactId>
 			<version>${runtime.version}</version>
 		</dependency>
 		<dependency>

drools/backward-chaining/src/main/java/com/baeldung/drools/BackwardChaining.java

@@ -21,13 +21,11 @@ public class BackwardChaining {
         KieSession ksession = kContainer.newKieSession("ksession-backward-chaining");
         ksession.setGlobal("result", result);
         ksession.insert(new Fact("Asia", "Planet Earth"));
-//        ksession.insert(new Fact("China", "Asia"));
+        // ksession.insert(new Fact("China", "Asia"));
         ksession.insert(new Fact("Great Wall of China", "China"));
 
         ksession.fireAllRules();
 
         return result;
-
     }
-
 }

drools/backward-chaining/src/main/resources/com/baeldung/drools/backward_chaining/rules.drl

@@ -0,0 +1,27 @@
+package com.baeldung
+
+import com.baeldung.drools.model.Fact;
+
+global com.baeldung.drools.model.Result result;
+
+dialect  "mvel"
+
+query belongsTo(String x, String y)
+  Fact(x, y;)
+  or
+  (Fact(z, y;) and belongsTo(x, z;))
+end
+
+rule "Great Wall of China BELONGS TO Planet Earth"
+when
+    belongsTo("Great Wall of China", "Planet Earth";)
+then
+	result.setValue("Decision one taken: Great Wall of China BELONGS TO Planet Earth");
+end
+
+rule "print all facts"
+when
+    belongsTo(element, place;)
+then
+    result.addFact(element + " IS ELEMENT OF " + place);
+end

drools/backward-chaining/src/test/java/com/baeldung/test/BackwardChainingTest.java

@@ -2,8 +2,6 @@ package com.baeldung.test;
 
 import org.junit.Before;
 import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
 import org.kie.api.KieServices;
 import org.kie.api.runtime.KieContainer;
 import org.kie.api.runtime.KieSession;
@@ -13,7 +11,6 @@ import com.baeldung.drools.model.Result;
 
 import static junit.framework.TestCase.assertEquals;
 
-@RunWith(value = JUnit4.class)
 public class BackwardChainingTest {
     private Result result;
     private KieServices ks;

drools/pom.xml

@@ -8,6 +8,8 @@
     <artifactId>drools</artifactId>
     <version>1.0.0-SNAPSHOT</version>
 	
+	<packaging>pom</packaging>
+
     <parent>
         <groupId>com.baeldung</groupId>
         <artifactId>parent-modules</artifactId>

guest/spring-security/README.md

@@ -0,0 +1,17 @@
+## Building
+
+To build the module, use Maven's `package` goal:
+
+```
+mvn clean package
+```
+
+## Running
+
+To run the application, use Spring Boot's `run` goal:
+
+```
+mvn spring-boot:run
+```
+
+The application will be accessible at [http://localhost:8080/](http://localhost:8080/)

guest/spring-security/pom.xml

@@ -0,0 +1,77 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.stackify.guest</groupId>
+    <artifactId>spring-security</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>2.0.0.M6</version>
+        <relativePath/>
+    </parent>
+
+    <name>spring-security</name>
+    <description>Spring Security Sample Project</description>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-thymeleaf</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.thymeleaf</groupId>
+            <artifactId>thymeleaf-spring5</artifactId>
+            <version>3.0.8.RELEASE</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-security</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-jdbc</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+            <scope>runtime</scope>
+        </dependency>
+    </dependencies>
+
+    <repositories>
+        <repository>
+            <id>spring-milestones</id>
+            <name>Spring Milestones</name>
+            <url>https://repo.spring.io/milestone</url>
+            <snapshots>
+                <enabled>false</enabled>
+            </snapshots>
+        </repository>
+    </repositories>
+    <pluginRepositories>
+        <pluginRepository>
+            <id>spring-milestones</id>
+            <name>Spring Milestones</name>
+            <url>https://repo.spring.io/milestone</url>
+            <snapshots>
+                <enabled>false</enabled>
+            </snapshots>
+        </pluginRepository>
+    </pluginRepositories>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+        <java.version>1.8</java.version>
+    </properties>
+
+</project>

guest/spring-security/src/main/java/com/stackify/guest/springsecurity/Application.java

@@ -0,0 +1,15 @@
+package com.stackify.guest.springsecurity;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.ComponentScan;
+
+@SpringBootApplication
+@ComponentScan(basePackages = {"com.stackify.guest.springsecurity"})
+public class Application {
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+
+}

guest/spring-security/src/main/java/com/stackify/guest/springsecurity/config/WebMvcConfiguration.java

@@ -0,0 +1,16 @@
+package com.stackify.guest.springsecurity.config;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+
+@Configuration
+public class WebMvcConfiguration implements WebMvcConfigurer {
+
+    @Override
+    public void addViewControllers(ViewControllerRegistry registry) {
+        registry.addViewController("/customLogin").setViewName("customLogin");
+        registry.addViewController("/loginSuccess").setViewName("index");
+    }
+
+}

guest/spring-security/src/main/java/com/stackify/guest/springsecurity/config/WebSecurityConfig.java

@@ -0,0 +1,40 @@
+package com.stackify.guest.springsecurity.config;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.security.config.annotation.web.builders.HttpSecurity;
+import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
+import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
+import org.springframework.security.core.userdetails.UserDetailsService;
+import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
+import org.springframework.security.crypto.password.PasswordEncoder;
+import org.springframework.security.provisioning.JdbcUserDetailsManager;
+
+import javax.sql.DataSource;
+
+@EnableWebSecurity
+public class WebSecurityConfig extends WebSecurityConfigurerAdapter {
+
+    @Bean
+    public UserDetailsService jdbcUserDetailsService(DataSource dataSource) {
+        JdbcUserDetailsManager manager = new JdbcUserDetailsManager();
+        manager.setDataSource(dataSource);
+        return manager;
+    }
+
+    @Bean
+    public PasswordEncoder passwordEncoder() {
+        return new BCryptPasswordEncoder();
+    }
+
+    @Override
+    protected void configure(HttpSecurity http) throws Exception {
+        http.authorizeRequests()
+                .antMatchers("/css/**").permitAll()
+                .anyRequest().authenticated()
+                .and().formLogin()
+                .loginPage("/customLogin")
+                .defaultSuccessUrl("/loginSuccess", true)
+                .permitAll();
+    }
+
+}

guest/spring-security/src/main/resources/data.sql

@@ -0,0 +1,2 @@
+INSERT INTO users VALUES ('jill', '$2a$04$qUlqAEEYF1YvrpJMosodoewgL6aO.qgHytl2k5L7kdXEWnJsFdxvq', TRUE);
+INSERT INTO authorities VALUES ('jill', 'USERS');

guest/spring-security/src/main/resources/schema.sql

@@ -0,0 +1,10 @@
+CREATE TABLE users (
+  username VARCHAR(256) PRIMARY KEY,
+  password VARCHAR(256),
+  enabled  BOOLEAN
+);
+
+CREATE TABLE authorities (
+  username  VARCHAR(256) REFERENCES users (username),
+  authority VARCHAR(256)
+);

guest/spring-security/src/main/resources/static/css/styles.css

@@ -0,0 +1,3 @@
+.bad-login {
+  color: red;
+}

guest/spring-security/src/main/resources/templates/customLogin.html

@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<html xmlns="http://www.w3.org/1999/xhtml"
+      xmlns:th="http://www.thymeleaf.org">
+<head>
+    <link rel="stylesheet" href="/css/styles.css">
+</head>
+<body>
+<form th:action="@{/customLogin}" method="post">
+    <fieldset>
+        <label for="username">Login:</label>
+        <input id="username" name="username">
+        <label for="password">Password:</label>
+        <input id="password" name="password" type="password">
+    </fieldset>
+    <input type="hidden" th:name="${_csrf.parameterName}" th:value="${_csrf.token}"/>
+    <input type="submit" value="Login">
+    <div th:if="${param.error}" class="bad-login">Bad login or password.</div>
+    <div th:if="${param.logout}">Log out successful.</div>
+</form>
+</body>
+</html>

guest/spring-security/src/main/resources/templates/index.html

@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html xmlns="http://www.w3.org/1999/xhtml"
+      xmlns:th="http://www.thymeleaf.org">
+<p>Hello, <span th:text="${
+    T(org.springframework.security.core.context.SecurityContextHolder)
+      .context.authentication.principal.username}"></span>!</p>
+<form action="/logout" method="post">
+    <input type="hidden" th:name="${_csrf.parameterName}" th:value="${_csrf.token}"/>
+    <input type="submit" value="Log Out">
+</form>
+</html>

hibernate5/src/main/java/com/baeldung/hibernate/HibernateUtil.java

@@ -2,8 +2,17 @@ package com.baeldung.hibernate;
 
 import com.baeldung.hibernate.pojo.Employee;
 import com.baeldung.hibernate.pojo.EntityDescription;
+import com.baeldung.hibernate.pojo.OrderEntry;
+import com.baeldung.hibernate.pojo.OrderEntryIdClass;
+import com.baeldung.hibernate.pojo.OrderEntryPK;
+import com.baeldung.hibernate.pojo.Product;
 import com.baeldung.hibernate.pojo.Phone;
 import com.baeldung.hibernate.pojo.TemporalValues;
+import com.baeldung.hibernate.pojo.Course;
+import com.baeldung.hibernate.pojo.Student;
+import com.baeldung.hibernate.pojo.User;
+import com.baeldung.hibernate.pojo.UserProfile;
+
 import org.hibernate.SessionFactory;
 import org.hibernate.boot.Metadata;
 import org.hibernate.boot.MetadataSources;
@@ -33,6 +42,14 @@ public class HibernateUtil {
         metadataSources.addAnnotatedClass(Phone.class);
         metadataSources.addAnnotatedClass(EntityDescription.class);
         metadataSources.addAnnotatedClass(TemporalValues.class);
+        metadataSources.addAnnotatedClass(User.class);
+        metadataSources.addAnnotatedClass(Student.class);
+        metadataSources.addAnnotatedClass(Course.class);
+        metadataSources.addAnnotatedClass(Product.class);
+        metadataSources.addAnnotatedClass(OrderEntryPK.class);
+        metadataSources.addAnnotatedClass(OrderEntry.class);
+        metadataSources.addAnnotatedClass(OrderEntryIdClass.class);
+        metadataSources.addAnnotatedClass(UserProfile.class);
 
         Metadata metadata = metadataSources.buildMetadata();
         return metadata.getSessionFactoryBuilder()

hibernate5/src/main/java/com/baeldung/hibernate/pojo/Course.java

@@ -0,0 +1,27 @@
+package com.baeldung.hibernate.pojo;
+
+import java.util.UUID;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+
+@Entity
+public class Course {
+
+    @Id
+    @GeneratedValue
+    private UUID courseId;
+
+    public UUID getCourseId() {
+        return courseId;
+    }
+
+    public void setCourseId(UUID courseId) {
+        this.courseId = courseId;
+    }
+    
+    
+
+   
+}

hibernate5/src/main/java/com/baeldung/hibernate/pojo/Department.java

@@ -0,0 +1,25 @@
+package com.baeldung.hibernate.pojo;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.TableGenerator;
+
+@Entity
+public class Department {
+    @Id
+    @GeneratedValue(strategy = GenerationType.TABLE, generator="table-generator")
+    @TableGenerator (name="table-generator", table="dep_ids", pkColumnName="seq_id", valueColumnName="seq_value")
+    private long depId;
+
+    public long getDepId() {
+        return depId;
+    }
+
+    public void setDepId(long depId) {
+        this.depId = depId;
+    }
+    
+    
+}

hibernate5/src/main/java/com/baeldung/hibernate/pojo/OrderEntry.java

@@ -0,0 +1,20 @@
+package com.baeldung.hibernate.pojo;
+
+import javax.persistence.EmbeddedId;
+import javax.persistence.Entity;
+
+@Entity
+public class OrderEntry {
+
+    @EmbeddedId
+    private OrderEntryPK entryId;
+
+    public OrderEntryPK getEntryId() {
+        return entryId;
+    }
+
+    public void setEntryId(OrderEntryPK entryId) {
+        this.entryId = entryId;
+    }
+
+}

hibernate5/src/main/java/com/baeldung/hibernate/pojo/OrderEntryIdClass.java

@@ -0,0 +1,31 @@
+package com.baeldung.hibernate.pojo;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.IdClass;
+
+@Entity
+@IdClass(OrderEntryPK.class)
+public class OrderEntryIdClass {
+    @Id
+    private long orderId;
+    @Id
+    private long productId;
+
+    public long getOrderId() {
+        return orderId;
+    }
+
+    public void setOrderId(long orderId) {
+        this.orderId = orderId;
+    }
+
+    public long getProductId() {
+        return productId;
+    }
+
+    public void setProductId(long productId) {
+        this.productId = productId;
+    }
+
+}

hibernate5/src/main/java/com/baeldung/hibernate/pojo/OrderEntryPK.java

@@ -0,0 +1,46 @@
+package com.baeldung.hibernate.pojo;
+
+import java.io.Serializable;
+import java.util.Objects;
+
+import javax.persistence.Embeddable;
+
+@Embeddable
+public class OrderEntryPK implements Serializable {
+
+    private long orderId;
+    private long productId;
+
+    public long getOrderId() {
+        return orderId;
+    }
+
+    public void setOrderId(long orderId) {
+        this.orderId = orderId;
+    }
+
+    public long getProductId() {
+        return productId;
+    }
+
+    public void setProductId(long productId) {
+        this.productId = productId;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        OrderEntryPK pk = (OrderEntryPK) o;
+        return Objects.equals(orderId, pk.orderId) && Objects.equals(productId, pk.productId);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(orderId, productId);
+    }
+}

hibernate5/src/main/java/com/baeldung/hibernate/pojo/Product.java

@@ -0,0 +1,26 @@
+package com.baeldung.hibernate.pojo;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+
+import org.hibernate.annotations.GenericGenerator;
+import org.hibernate.annotations.Parameter;
+
+@Entity
+public class Product {
+
+    @Id
+    @GeneratedValue(generator = "prod-generator")
+    @GenericGenerator(name = "prod-generator", parameters = @Parameter(name = "prefix", value = "prod"), strategy = "com.baeldung.hibernate.pojo.generator.MyGenerator")
+    private String prodId;
+
+    public String getProdId() {
+        return prodId;
+    }
+
+    public void setProdId(String prodId) {
+        this.prodId = prodId;
+    }
+
+}

hibernate5/src/main/java/com/baeldung/hibernate/pojo/Student.java

@@ -0,0 +1,23 @@
+package com.baeldung.hibernate.pojo;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+
+@Entity
+public class Student {
+
+    @Id
+    @GeneratedValue (strategy = GenerationType.SEQUENCE)
+    private long studentId;
+
+    public long getStudentId() {
+        return studentId;
+    }
+
+    public void setStudent_id(long studentId) {
+        this.studentId = studentId;
+    }
+    
+}

hibernate5/src/main/java/com/baeldung/hibernate/pojo/User.java

@@ -0,0 +1,24 @@
+package com.baeldung.hibernate.pojo;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.SequenceGenerator;
+
+@Entity
+public class User {
+    @Id
+    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "sequence-generator")
+    @SequenceGenerator(name = "sequence-generator", sequenceName = "user_sequence", initialValue = 4)
+    private long userId;
+
+    public long getUserId() {
+        return userId;
+    }
+
+    public void setUserId(long userId) {
+        this.userId = userId;
+    }
+
+}

hibernate5/src/main/java/com/baeldung/hibernate/pojo/UserProfile.java

@@ -0,0 +1,34 @@
+package com.baeldung.hibernate.pojo;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.MapsId;
+import javax.persistence.OneToOne;
+
+@Entity
+public class UserProfile {
+
+    @Id
+    private long profileId;
+
+    @OneToOne
+    @MapsId
+    private User user;
+
+    public long getProfileId() {
+        return profileId;
+    }
+
+    public void setProfileId(long profileId) {
+        this.profileId = profileId;
+    }
+    
+    public User getUser() {
+        return user;
+    }
+
+    public void setUser(User user) {
+        this.user = user;
+    }
+    
+}

hibernate5/src/main/java/com/baeldung/hibernate/pojo/generator/MyGenerator.java

@@ -0,0 +1,41 @@
+package com.baeldung.hibernate.pojo.generator;
+
+import java.io.Serializable;
+import java.util.Properties;
+import java.util.stream.Stream;
+
+import org.hibernate.HibernateException;
+import org.hibernate.MappingException;
+import org.hibernate.engine.spi.SharedSessionContractImplementor;
+import org.hibernate.id.Configurable;
+import org.hibernate.id.IdentifierGenerator;
+import org.hibernate.service.ServiceRegistry;
+import org.hibernate.type.Type;
+
+public class MyGenerator implements IdentifierGenerator, Configurable {
+
+    private String prefix;
+
+    @Override
+    public Serializable generate(SharedSessionContractImplementor session, Object obj) throws HibernateException {
+
+        String query = String.format("select %s from %s", 
+            session.getEntityPersister(obj.getClass().getName(), obj).getIdentifierPropertyName(),
+            obj.getClass().getSimpleName());
+
+        Stream<String> ids = session.createQuery(query).stream();
+
+        Long max = ids.map(o -> o.replace(prefix + "-", ""))
+            .mapToLong(Long::parseLong)
+            .max()
+            .orElse(0L);
+
+        return prefix + "-" + (max + 1);
+    }
+
+    @Override
+    public void configure(Type type, Properties properties, ServiceRegistry serviceRegistry) throws MappingException {
+        prefix = properties.getProperty("prefix");
+    }
+
+}

hibernate5/src/test/java/com/baeldung/hibernate/IdentifiersIntegrationTest.java

@@ -0,0 +1,100 @@
+package com.baeldung.hibernate;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.hibernate.Transaction;
+import java.io.IOException;
+import org.hibernate.Session;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import com.baeldung.hibernate.pojo.Product;
+import com.baeldung.hibernate.pojo.Course;
+import com.baeldung.hibernate.pojo.OrderEntry;
+import com.baeldung.hibernate.pojo.OrderEntryIdClass;
+import com.baeldung.hibernate.pojo.OrderEntryPK;
+import com.baeldung.hibernate.pojo.Student;
+import com.baeldung.hibernate.pojo.User;
+import com.baeldung.hibernate.pojo.UserProfile;
+
+public class IdentifiersIntegrationTest {
+    private Session session;
+
+    private Transaction transaction;
+
+    @Before
+    public void setUp() throws IOException {
+        session = HibernateUtil.getSessionFactory()
+            .openSession();
+        transaction = session.beginTransaction();
+    }
+
+    @After
+    public void tearDown() {
+        transaction.rollback();
+        session.close();
+    }
+
+    @Test
+    public void whenSaveSimpleIdEntities_thenOk() {
+        Student student = new Student();
+        session.save(student);
+        User user = new User();
+        session.save(user);
+       
+        assertThat(student.getStudentId()).isEqualTo(1L);
+        assertThat(user.getUserId()).isEqualTo(4L);
+
+        Course course = new Course();
+        session.save(course);
+
+    }
+
+    @Test
+    public void whenSaveCustomGeneratedId_thenOk() {
+        Product product = new Product();
+        session.save(product);
+        Product product2 = new Product();
+        session.save(product2);
+
+        assertThat(product2.getProdId()).isEqualTo("prod-2");
+    }
+
+    @Test
+    public void whenSaveCompositeIdEntity_thenOk() {
+        OrderEntryPK entryPK = new OrderEntryPK();
+        entryPK.setOrderId(1L);
+        entryPK.setProductId(30L);
+
+        OrderEntry entry = new OrderEntry();
+        entry.setEntryId(entryPK);
+        session.save(entry);
+
+        assertThat(entry.getEntryId()
+            .getOrderId()).isEqualTo(1L);
+    }
+
+    @Test
+    public void whenSaveIdClassEntity_thenOk() {
+        OrderEntryIdClass entry = new OrderEntryIdClass();
+        entry.setOrderId(1L);
+        entry.setProductId(30L);
+        session.save(entry);
+
+        assertThat(entry.getOrderId()).isEqualTo(1L);
+    }
+
+    @Test
+    public void whenSaveDerivedIdEntity_thenOk() {
+        User user = new User();
+        session.save(user);
+
+        UserProfile profile = new UserProfile();
+        profile.setUser(user);
+        session.save(profile);
+
+        assertThat(profile.getProfileId()).isEqualTo(user.getUserId());
+    }
+
+}

jsonb/.gitignore

@@ -0,0 +1,12 @@
+#folders#
+.idea
+/target
+/neoDb*
+/data
+/src/main/webapp/WEB-INF/classes
+*/META-INF/*
+
+# Packaged files #
+*.jar
+*.war
+*.ear

jsonb/README.md

@@ -0,0 +1 @@
+## JSON B

jsonb/pom.xml

@@ -0,0 +1,106 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+
+	<groupId>com.baeldung</groupId>
+	<artifactId>json-b</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<packaging>jar</packaging>
+
+	<name>json-b</name>
+	<description>json-b sample project</description>
+	<profiles>
+		<profile>
+			<id>yasson</id>
+			<activation>
+				<activeByDefault>true</activeByDefault>
+			</activation>
+			<dependencies>
+				<!-- Dependencies for Yasson -->
+				<dependency>
+					<groupId>org.eclipse</groupId>
+					<artifactId>yasson</artifactId>
+					<version>${yasson.version}</version>
+				</dependency>
+				<dependency>
+					<groupId>org.glassfish</groupId>
+					<artifactId>javax.json</artifactId>
+					<version>${javax.json.version}</version>
+				</dependency>
+			</dependencies>
+		</profile>
+		<profile>
+			<id>johnzon</id>
+			<dependencies>
+				<!-- Dependencies for Johnzon -->
+				<dependency>
+					<groupId>org.apache.geronimo.specs</groupId>
+					<artifactId>geronimo-json_1.1_spec</artifactId>
+					<version>${geronimo-json_1.1_spec.version}</version>
+				</dependency>
+				<dependency>
+					<groupId>org.apache.johnzon</groupId>
+					<artifactId>johnzon-jsonb</artifactId>
+					<version>${johnzon.version}</version>
+				</dependency>
+			</dependencies>
+		</profile>
+	</profiles>
+	<dependencies>
+		<dependency>
+			<groupId>javax.json.bind</groupId>
+			<artifactId>javax.json.bind-api</artifactId>
+			<version>${jsonb-api.version}</version>
+		</dependency>
+		<!-- utils -->
+		<dependency>
+			<groupId>org.apache.commons</groupId>
+			<artifactId>commons-collections4</artifactId>
+			<version>${commons-collections4.version}</version>
+			<scope>test</scope>
+		</dependency>
+
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-api</artifactId>
+			<version>${junit.jupiter.version}</version>
+		</dependency>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-engine</artifactId>
+			<version>${junit.jupiter.version}</version>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.junit.platform</groupId>
+			<artifactId>junit-platform-surefire-provider</artifactId>
+			<version>${junit.platform.version}</version>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.junit.platform</groupId>
+			<artifactId>junit-platform-runner</artifactId>
+			<version>${junit.platform.version}</version>
+			<scope>test</scope>
+		</dependency>
+
+	</dependencies>
+
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+		<maven.compiler.source>1.8</maven.compiler.source>
+		<maven.compiler.target>1.8</maven.compiler.target>
+		<junit.platform.version>1.0.0</junit.platform.version>
+		<junit.jupiter.version>5.0.0</junit.jupiter.version>
+		<maven-surefire-plugin.version>2.20</maven-surefire-plugin.version>
+		<jsonb-api.version>1.0</jsonb-api.version>
+		<johnzon.version>1.1.3</johnzon.version>
+		<geronimo-json_1.1_spec.version>1.0</geronimo-json_1.1_spec.version>
+		<yasson.version>1.0</yasson.version>
+		<javax.json.version>1.1.2</javax.json.version>
+		<commons-collections4.version>4.1</commons-collections4.version>
+	</properties>
+
+</project>

jsonb/src/main/java/com/baeldung/jsonb/Person.java

@@ -0,0 +1,127 @@
+package com.baeldung.jsonb;
+
+import java.math.BigDecimal;
+import java.time.LocalDate;
+
+import javax.json.bind.annotation.JsonbDateFormat;
+import javax.json.bind.annotation.JsonbNumberFormat;
+import javax.json.bind.annotation.JsonbProperty;
+import javax.json.bind.annotation.JsonbTransient;
+
+public class Person {
+
+    private int id;
+    @JsonbProperty("person-name")
+    private String name;
+    @JsonbProperty(nillable = true)
+    private String email;
+    @JsonbTransient
+    private int age;
+    @JsonbDateFormat("dd-MM-yyyy")
+    private LocalDate registeredDate;
+    private BigDecimal salary;
+
+    public Person() {
+    }
+
+    public Person(int id, String name, String email, int age, LocalDate registeredDate, BigDecimal salary) {
+        super();
+        this.id = id;
+        this.name = name;
+        this.email = email;
+        this.age = age;
+        this.registeredDate = registeredDate;
+        this.salary = salary;
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public int getAge() {
+        return age;
+    }
+
+    public void setAge(int age) {
+        this.age = age;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+
+    public void setEmail(String email) {
+        this.email = email;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    @JsonbNumberFormat(locale = "en_US", value = "#0.0")
+    public BigDecimal getSalary() {
+        return salary;
+    }
+
+    public void setSalary(BigDecimal salary) {
+        this.salary = salary;
+    }
+
+    public LocalDate getRegisteredDate() {
+        return registeredDate;
+    }
+
+    public void setRegisteredDate(LocalDate registeredDate) {
+        this.registeredDate = registeredDate;
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder builder = new StringBuilder();
+        builder.append("Person [id=");
+        builder.append(id);
+        builder.append(", name=");
+        builder.append(name);
+        builder.append(", email=");
+        builder.append(email);
+        builder.append(", age=");
+        builder.append(age);
+        builder.append(", registeredDate=");
+        builder.append(registeredDate);
+        builder.append(", salary=");
+        builder.append(salary);
+        builder.append("]");
+        return builder.toString();
+    }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + id;
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj)
+            return true;
+        if (obj == null)
+            return false;
+        if (getClass() != obj.getClass())
+            return false;
+        Person other = (Person) obj;
+        if (id != other.id)
+            return false;
+        return true;
+    }
+
+}

jsonb/src/test/java/com/baeldung/jsonb/JsonbTest.java

@@ -0,0 +1,158 @@
+package com.baeldung.jsonb;
+
+import static org.junit.Assert.assertTrue;
+
+import java.math.BigDecimal;
+import java.time.LocalDate;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import javax.json.bind.Jsonb;
+import javax.json.bind.JsonbBuilder;
+import javax.json.bind.JsonbConfig;
+import javax.json.bind.config.PropertyNamingStrategy;
+import javax.json.bind.config.PropertyOrderStrategy;
+
+import org.apache.commons.collections4.ListUtils;
+import org.junit.Test;
+
+public class JsonbTest {
+
+    @Test
+    public void givenPersonList_whenSerializeWithJsonb_thenGetPersonJsonArray() {
+        Jsonb jsonb = JsonbBuilder.create();
+        // @formatter:off
+        List<Person> personList = Arrays.asList(
+            new Person(1, "Jhon", "jhon@test.com", 20, LocalDate.of(2019, 9, 9), BigDecimal.valueOf(1000)), 
+            new Person(2, "Jhon", "jhon1@test.com", 20, LocalDate.of(2019, 9, 9), BigDecimal.valueOf(1500)), 
+            new Person(3, "Jhon", null, 20, LocalDate.of(2019, 9, 9), BigDecimal.valueOf(1000)),  
+            new Person(4, "Tom", "tom@test.com", 21, LocalDate.of(2019, 9, 9), BigDecimal.valueOf(1500)));            
+        // @formatter:on
+        String jsonArrayPerson = jsonb.toJson(personList);
+        // @formatter:off
+        String jsonExpected = "[" + 
+          "{\"email\":\"jhon@test.com\"," + 
+           "\"id\":1,\"person-name\":\"Jhon\"," + 
+           "\"registeredDate\":\"09-09-2019\"," + 
+           "\"salary\":\"1000.0\"}," +
+          "{\"email\":\"jhon1@test.com\"," +
+           "\"id\":2,\"person-name\":\"Jhon\"," +
+           "\"registeredDate\":\"09-09-2019\"," +
+           "\"salary\":\"1500.0\"},{\"email\":null," +
+           "\"id\":3,\"person-name\":\"Jhon\"," +
+           "\"registeredDate\":\"09-09-2019\"," +
+           "\"salary\":\"1000.0\"}," +
+          "{\"email\":\"tom@test.com\"," +
+           "\"id\":4,\"person-name\":\"Tom\"," +
+           "\"registeredDate\":\"09-09-2019\"," +
+           "\"salary\":\"1500.0\"}"
+           + "]";
+        // @formatter:on
+        assertTrue(jsonArrayPerson.equals(jsonExpected));
+    }
+
+    @Test
+    public void givenPersonJsonArray_whenDeserializeWithJsonb_thenGetPersonList() {
+        Jsonb jsonb = JsonbBuilder.create();
+        // @formatter:off
+        String personJsonArray =
+            "[" + 
+                "{\"email\":\"jhon@test.com\"," + 
+                 "\"id\":1,\"person-name\":\"Jhon\"," + 
+                 "\"registeredDate\":\"09-09-2019\"," + 
+                 "\"salary\":\"1000.0\"}," +
+                "{\"email\":\"jhon1@test.com\"," +
+                 "\"id\":2,\"person-name\":\"Jhon\"," +
+                 "\"registeredDate\":\"09-09-2019\"," +
+                 "\"salary\":\"1500.0\"},{\"email\":null," +
+                 "\"id\":3,\"person-name\":\"Jhon\"," +
+                 "\"registeredDate\":\"09-09-2019\"," +
+                 "\"salary\":\"1000.0\"}," +
+                "{\"email\":\"tom@test.com\"," +
+                 "\"id\":4,\"person-name\":\"Tom\"," +
+                 "\"registeredDate\":\"09-09-2019\"," +
+                 "\"salary\":\"1500.0\"}"
+                 + "]";
+        // @formatter:on        
+        @SuppressWarnings("serial")
+        List<Person> personList = jsonb.fromJson(personJsonArray, new ArrayList<Person>() {
+        }.getClass()
+            .getGenericSuperclass());
+        // @formatter:off
+        List<Person> personListExpected = Arrays.asList(
+            new Person(1, "Jhon", "jhon@test.com", 20, LocalDate.of(2019, 9, 9), BigDecimal.valueOf(1000)), 
+            new Person(2, "Jhon", "jhon1@test.com", 20, LocalDate.of(2019, 9, 9), BigDecimal.valueOf(1500)), 
+            new Person(3, "Jhon", null, 20, LocalDate.of(2019, 9, 9), BigDecimal.valueOf(1000)),  
+            new Person(4, "Tom", "tom@test.com", 21, LocalDate.of(2019, 9, 9), BigDecimal.valueOf(1500)));            
+        // @formatter:on
+        assertTrue(ListUtils.isEqualList(personList, personListExpected));
+    }
+
+    @Test
+    public void givenPersonObject_whenNamingStrategy_thenGetCustomPersonJson() {
+        JsonbConfig config = new JsonbConfig().withPropertyNamingStrategy(PropertyNamingStrategy.LOWER_CASE_WITH_UNDERSCORES);
+        Jsonb jsonb = JsonbBuilder.create(config);
+        Person person = new Person(1, "Jhon", "jhon@test.com", 20, LocalDate.of(2019, 9, 7), BigDecimal.valueOf(1000));
+        String jsonPerson = jsonb.toJson(person);
+        // @formatter:off
+        String jsonExpected = 
+            "{\"email\":\"jhon@test.com\"," +
+             "\"id\":1," +
+             "\"person-name\":\"Jhon\"," +
+             "\"registered_date\":\"07-09-2019\"," +
+             "\"salary\":\"1000.0\"}";
+        // @formatter:on
+        assertTrue(jsonExpected.equals(jsonPerson));
+    }
+
+    @Test
+    public void givenPersonObject_whenWithPropertyOrderStrategy_thenGetReversePersonJson() {
+        JsonbConfig config = new JsonbConfig().withPropertyOrderStrategy(PropertyOrderStrategy.REVERSE);
+        Jsonb jsonb = JsonbBuilder.create(config);
+        Person person = new Person(1, "Jhon", "jhon@test.com", 20, LocalDate.of(2019, 9, 7), BigDecimal.valueOf(1000));
+        String jsonPerson = jsonb.toJson(person);
+        // @formatter:off
+        String jsonExpected = 
+            "{\"salary\":\"1000.0\","+
+             "\"registeredDate\":\"07-09-2019\"," +
+             "\"person-name\":\"Jhon\"," +
+             "\"id\":1," +
+             "\"email\":\"jhon@test.com\"}";
+        // @formatter:on
+        assertTrue(jsonExpected.equals(jsonPerson));
+    }
+
+    @Test
+    public void givenPersonObject_whenSerializeWithJsonb_thenGetPersonJson() {
+        Jsonb jsonb = JsonbBuilder.create();
+        Person person = new Person(1, "Jhon", "jhon@test.com", 20, LocalDate.of(2019, 9, 7), BigDecimal.valueOf(1000));
+        String jsonPerson = jsonb.toJson(person);
+        // @formatter:off
+        String jsonExpected = 
+            "{\"email\":\"jhon@test.com\"," +
+             "\"id\":1," +
+             "\"person-name\":\"Jhon\"," +
+             "\"registeredDate\":\"07-09-2019\"," +
+             "\"salary\":\"1000.0\"}";
+        // @formatter:on
+        assertTrue(jsonExpected.equals(jsonPerson));
+    }
+
+    @Test
+    public void givenPersonJson_whenDeserializeWithJsonb_thenGetPersonObject() {
+        Jsonb jsonb = JsonbBuilder.create();
+        Person person = new Person(1, "Jhon", "jhon@test.com", 0, LocalDate.of(2019, 9, 7), BigDecimal.valueOf(1000.0));
+        // @formatter:off
+        String jsonPerson = 
+            "{\"email\":\"jhon@test.com\"," + 
+             "\"id\":1," + 
+             "\"person-name\":\"Jhon\"," + 
+             "\"registeredDate\":\"07-09-2019\"," + 
+             "\"salary\":\"1000.0\"}";
+        // @formatter:on
+        assertTrue(jsonb.fromJson(jsonPerson, Person.class)
+            .equals(person));
+    }
+
+}

patterns/template-method/src/main/java/com/baeldung/templatemethodpattern/model/Computer.java

@@ -1,32 +1,31 @@
 package com.baeldung.templatemethodpattern.model;
 
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
 import java.util.HashMap;
 import java.util.Map;
 
 public abstract class Computer {
     
     protected Map<String, String> computerParts = new HashMap<>();
+    protected List<String> moterboardSetupStatus = new ArrayList<>();
     
     public final void buildComputer() {
          addMotherboard();
+         setupMotherboard();
          addProcessor();
-         addMemory();
-         addHardDrive();
-         addGraphicCard();
-         addSoundCard();        
     }
     
-    public abstract void addProcessor();
-    
     public abstract void addMotherboard();
     
-    public abstract void addMemory();
+     public abstract void setupMotherboard();
     
-    public abstract void addHardDrive();
+    public abstract void addProcessor();
     
-    public abstract void addGraphicCard();
+    public List<String> getMotherboardSetupStatus() {
-    
+        return moterboardSetupStatus;
-    public abstract void addSoundCard();
+    }
         
     public Map<String, String> getComputerParts() {
         return computerParts;

patterns/template-method/src/main/java/com/baeldung/templatemethodpattern/model/HighEndComputer.java

@@ -2,33 +2,25 @@ package com.baeldung.templatemethodpattern.model;
 
 public class HighEndComputer extends Computer {
 
+    @Override
+    public void addMotherboard() {
+         computerParts.put("Motherboard", "High-end Motherboard");
+    }
+    
+    @Override
+    public void setupMotherboard() {
+        moterboardSetupStatus.add("Screwing the high-end motherboard to the case.");
+        moterboardSetupStatus.add("Pluging in the power supply connectors.");
+        moterboardSetupStatus.forEach(step -> System.out.println(step));
+    }
+    
     @Override
     public void addProcessor() {
-         computerParts.put("Processor", "High End Processor");
+         computerParts.put("Processor", "High-end Processor");
     }
     
     @Override
     public void addMotherboard() {
          computerParts.put("Motherboard", "High End Motherboard");
     }
-
-    @Override
-    public void addMemory() {
-         computerParts.put("Memory", "16GB");
-    }
-
-    @Override
-    public void addHardDrive() {
-         computerParts.put("Hard Drive", "2TB Hard Drive");
-    }
-
-    @Override
-    public void addGraphicCard() {
-         computerParts.put("Graphic Card", "High End Graphic Card");
-    }
-
-    @Override
-    public void addSoundCard() {
-         computerParts.put("Sound Card", "High End Sound Card");
-    }  
 }

patterns/template-method/src/main/java/com/baeldung/templatemethodpattern/model/StandardComputer.java

@@ -2,6 +2,17 @@ package com.baeldung.templatemethodpattern.model;
  
 public class StandardComputer extends Computer {
     
+    public void addMotherboard() {
+        computerParts.put("Motherboard", "Standard Motherboard");
+    }
+    
+    @Override
+    public void setupMotherboard() {
+        moterboardSetupStatus.add("Screwing the standard motherboard to the case.");
+        moterboardSetupStatus.add("Pluging in the power supply connectors.");
+        moterboardSetupStatus.forEach(step -> System.out.println(step));
+    }
+    
     @Override
     public void addProcessor() {
         computerParts.put("Processor", "Standard Processor");
@@ -11,24 +22,4 @@ public class StandardComputer extends Computer {
     public void addMotherboard() {
         computerParts.put("Motherboard", "Standard Motherboard");
     }
-
-    @Override
-    public void addMemory() {
-        computerParts.put("Memory", "8GB");
-    }
-
-    @Override
-    public void addHardDrive() {
-        computerParts.put("Hard Drive", "1TB Hard Drive");
-    }
-
-    @Override
-    public void addGraphicCard() {
-        computerParts.put("Graphic Card", "Standard Graphic Card");
-    }
-
-    @Override
-    public void addSoundCard() {
-        computerParts.put("Sound Card", "Standard Sound Card");
-    }
 }

patterns/template-method/src/test/java/com/baeldung/templatemethodpatterntest/TemplateMethodPatternTest.java

@@ -3,6 +3,7 @@ package com.baeldung.templatemethodpatterntest;
 import com.baeldung.templatemethodpattern.model.HighEndComputer;
 import com.baeldung.templatemethodpattern.model.StandardComputer;
 import org.junit.Assert;
+import static org.junit.Assert.assertEquals;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
@@ -21,100 +22,53 @@ public class TemplateMethodPatternTest {
         highEndComputer = new HighEndComputer();
     }
 
-    @Test
-    public void givenStandardProcessor_whenAddingProcessor_thenEqualAssertion() {
-        standardComputer.addProcessor();
-        Assert.assertEquals("Standard Processor", standardComputer
-          .getComputerParts().get("Processor"));
-    }
-    
     @Test
     public void givenStandardMotherBoard_whenAddingMotherBoard_thenEqualAssertion() {
         standardComputer.addMotherboard();
-        Assert.assertEquals("Standard Motherboard", standardComputer
+        assertEquals("Standard Motherboard", standardComputer.getComputerParts().get("Motherboard"));
-          .getComputerParts().get("Motherboard"));
     }
 
     @Test
-    public void givenStandardMemory_whenAddingMemory_thenEqualAssertion() {
+    public void givenStandardMotheroboard_whenSetup_thenTwoEqualAssertions() {
-        standardComputer.addMemory();
+        standardComputer.setupMotherboard();
-        Assert.assertEquals("8GB", standardComputer
+        assertEquals("Screwing the standard motherboard to the case.", standardComputer.getMotherboardSetupStatus().get(0));
-          .getComputerParts().get("Memory"));
+        assertEquals("Plugin in the power supply connectors.",  standardComputer.getMotherboardSetupStatus().get(1));
     }
     
     @Test
-    public void givenStandardHardDrive_whenAddingHardDrive_thenEqualAssertion() {
+    public void givenStandardProcessor_whenAddingProcessor_thenEqualAssertion() {
-        standardComputer.addHardDrive();
+        standardComputer.addProcessor();
-        Assert.assertEquals("1TB Hard Drive", standardComputer
+        assertEquals("Standard Processor", standardComputer.getComputerParts().get("Processor"));
-          .getComputerParts().get("Hard Drive"));
     }
 
     @Test
-    public void givenStandardGraphicaCard_whenAddingGraphicCard_thenEqualAssertion() {
+    public void givenAllStandardParts_whenBuildingComputer_thenTwoParts() {
-        standardComputer.addGraphicCard();
-        Assert.assertEquals("Standard Graphic Card", standardComputer
-          .getComputerParts().get("Graphic Card"));
-    }
-    
-    @Test
-    public void givenStandardSoundCard_whenAddingSoundCard_thenEqualAssertion() {
-        standardComputer.addSoundCard();
-        Assert.assertEquals("Standard Sound Card", standardComputer
-          .getComputerParts().get("Sound Card"));
-    }
-    
-    @Test
-    public void givenAllStandardParts_whenBuildingComputer_thenSixParts() {
         standardComputer.buildComputer();
-        Assert.assertEquals(6, standardComputer
+        assertEquals(2, standardComputer.getComputerParts().size());
-          .getComputerParts().size());
-    }
-    
-    @Test
-    public void givenHightEndProcessor_whenAddingProcessor_thenEqualAssertion() {
-        highEndComputer.addProcessor();
-        Assert.assertEquals("High End Processor", highEndComputer
-          .getComputerParts().get("Processor"));
     }
 
     @Test
     public void givenHighEnddMotherBoard_whenAddingMotherBoard_thenEqualAssertion() {
         highEndComputer.addMotherboard();
-        Assert.assertEquals("High End Motherboard", highEndComputer
+        Assert.assertEquals("High-end Motherboard", highEndComputer.getComputerParts().get("Motherboard"));
-          .getComputerParts().get("Motherboard"));
     }
     
     @Test
-    public void givenHighEndMemory_whenAddingMemory_thenEqualAssertion() {
+    public void givenHighEnddMotheroboard_whenSetup_thenTwoEqualAssertions() {
-        highEndComputer.addMemory();
+        highEndComputer.setupMotherboard();
-        Assert.assertEquals("16GB", highEndComputer
+        assertEquals("Screwing the high-end motherboard to the case.", highEndComputer.getMotherboardSetupStatus().get(0));
-          .getComputerParts().get("Memory"));
+        assertEquals("Plugin in the power supply connectors.", highEndComputer.getMotherboardSetupStatus().get(1));
     }
     
     @Test
-    public void givenHighEndHardDrive_whenAddingHardDrive_thenEqualAssertion() {
+    public void givenHightEndProcessor_whenAddingProcessor_thenEqualAssertion() {
-        highEndComputer.addHardDrive();
+        highEndComputer.addProcessor();
-        Assert.assertEquals("2TB Hard Drive", highEndComputer
+        Assert.assertEquals("High-end Processor", highEndComputer.getComputerParts().get("Processor"));
-          .getComputerParts().get("Hard Drive"));
     }
     
     @Test
-    public void givenHighEndGraphicCard_whenAddingGraphicCard_thenEqualAssertion() {
+    public void givenAllHighEnddParts_whenBuildingComputer_thenTwoParts() {
-        highEndComputer.addGraphicCard();
-        Assert.assertEquals("High End Graphic Card", highEndComputer
-          .getComputerParts().get("Graphic Card"));
-    }
-    
-    @Test
-    public void givenHighEndSoundCard_whenAddingSoundCard_thenEqualAssertion() {
-        highEndComputer.addSoundCard();
-        Assert.assertEquals("High End Sound Card", highEndComputer
-          .getComputerParts().get("Sound Card"));
-    }
-    
-    @Test
-    public void givenAllHighEndParts_whenBuildingComputer_thenSixParts() {
         highEndComputer.buildComputer();
-        Assert.assertEquals(6, highEndComputer.getComputerParts().size());
+        assertEquals(2, highEndComputer.getComputerParts().size());
     }  
 }

spring-5/pom.xml

@@ -49,6 +49,18 @@
 			<artifactId>javax.json.bind-api</artifactId>
 			<version>${jsonb-api.version}</version>
 		</dependency>
+		<!-- Dependencies for Yasson -->
+		<!-- <dependency> -->
+		<!-- <groupId>org.eclipse</groupId> -->
+		<!-- <artifactId>yasson</artifactId> -->
+		<!-- <version>1.0</version> -->
+		<!-- </dependency> -->
+		<!-- <dependency> -->
+		<!-- <groupId>org.glassfish</groupId> -->
+		<!-- <artifactId>javax.json</artifactId> -->
+		<!-- <version>1.1.2</version> -->
+		<!-- </dependency> -->
+		<!-- Dependencies for Johnzon -->
 		<dependency>
 			<groupId>org.apache.geronimo.specs</groupId>
 			<artifactId>geronimo-json_1.1_spec</artifactId>
@@ -88,6 +100,13 @@
 			<scope>test</scope>
 		</dependency>
 
+		<dependency>
+			<groupId>org.apache.commons</groupId>
+			<artifactId>commons-collections4</artifactId>
+			<version>4.1</version>
+			<scope>test</scope>
+		</dependency>
+
 		<dependency>
 			<groupId>org.junit.jupiter</groupId>
 			<artifactId>junit-jupiter-api</artifactId>

spring-5/src/test/java/com/baeldung/jsonb/JsonbTest.java

@@ -1,38 +0,0 @@
-package com.baeldung.jsonb;
-
-import static org.junit.Assert.assertTrue;
-
-import java.math.BigDecimal;
-import java.time.LocalDate;
-
-import javax.json.bind.Jsonb;
-import javax.json.bind.JsonbBuilder;
-
-import org.junit.Before;
-import org.junit.Test;
-
-public class JsonbTest {
-
-    private Jsonb jsonb;
-
-    @Before
-    public void setup() {
-        jsonb = JsonbBuilder.create();
-    }
-
-    @Test
-    public void givenPersonObject_whenSerializeWithJsonb_thenGetPersonJson() {
-        Person person = new Person(1, "Jhon", "jhon@test.com", 20, LocalDate.of(2019, 9, 7), BigDecimal.valueOf(1000));
-        String jsonPerson = jsonb.toJson(person);
-        assertTrue("{\"email\":\"jhon@test.com\",\"id\":1,\"person-name\":\"Jhon\",\"registeredDate\":\"07-09-2019\",\"salary\":\"1000.0\"}".equals(jsonPerson));
-    }
-
-    @Test
-    public void givenPersonJson_whenDeserializeWithJsonb_thenGetPersonObject() {
-        Person person = new Person(1, "Jhon", "jhon@test.com", 0, LocalDate.of(2019, 9, 7), BigDecimal.valueOf(1000.0));
-        String jsonPerson = "{\"email\":\"jhon@test.com\",\"id\":1,\"person-name\":\"Jhon\",\"registeredDate\":\"07-09-2019\",\"salary\":\"1000.0\"}";
-        assertTrue(jsonb.fromJson(jsonPerson, Person.class)
-            .equals(person));
-    }
-
-}

spring-boot/src/main/java/org/baeldung/dsrouting/ClientDao.java

@@ -0,0 +1,29 @@
+package org.baeldung.dsrouting;
+
+import javax.sql.DataSource;
+
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.jdbc.core.RowMapper;
+
+/**
+ * Database access code for datasource routing example.
+ */
+public class ClientDao {
+
+    private static final String SQL_GET_CLIENT_NAME = "select name from client";
+
+    private final JdbcTemplate jdbcTemplate;
+
+    public ClientDao(DataSource datasource) {
+        this.jdbcTemplate = new JdbcTemplate(datasource);
+    }
+
+    public String getClientName() {
+        return this.jdbcTemplate.query(SQL_GET_CLIENT_NAME, rowMapper)
+            .get(0);
+    }
+
+    private static RowMapper<String> rowMapper = (rs, rowNum) -> {
+        return rs.getString("name");
+    };
+}

spring-boot/src/main/java/org/baeldung/dsrouting/ClientDataSourceRouter.java

@@ -0,0 +1,14 @@
+package org.baeldung.dsrouting;
+
+import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
+
+/**
+ * Returns thread bound client lookup key for current context.
+ */
+public class ClientDataSourceRouter extends AbstractRoutingDataSource {
+
+    @Override
+    protected Object determineCurrentLookupKey() {
+        return ClientDatabaseContextHolder.getClientDatabase();
+    }
+}

spring-boot/src/main/java/org/baeldung/dsrouting/ClientDatabase.java

@@ -0,0 +1,7 @@
+package org.baeldung.dsrouting;
+
+public enum ClientDatabase {
+
+    ACME_WIDGETS, WIDGETS_ARE_US, WIDGET_DEPOT
+
+}

spring-boot/src/main/java/org/baeldung/dsrouting/ClientDatabaseContextHolder.java

@@ -0,0 +1,26 @@
+package org.baeldung.dsrouting;
+
+import org.springframework.util.Assert;
+
+/**
+ * Thread shared context to point to the datasource which should be used. This
+ * enables context switches between different clients.
+ */
+public class ClientDatabaseContextHolder {
+
+    private static final ThreadLocal<ClientDatabase> CONTEXT = new ThreadLocal<>();
+
+    public static void set(ClientDatabase clientDatabase) {
+        Assert.notNull(clientDatabase, "clientDatabase cannot be null");
+        CONTEXT.set(clientDatabase);
+    }
+
+    public static ClientDatabase getClientDatabase() {
+        return CONTEXT.get();
+    }
+
+    public static void clear() {
+        CONTEXT.remove();
+    }
+
+}

spring-boot/src/main/java/org/baeldung/dsrouting/ClientService.java

@@ -0,0 +1,21 @@
+package org.baeldung.dsrouting;
+
+/**
+ * Service layer code for datasource routing example.  Here, the service methods are responsible
+ * for setting and clearing the context.
+ */
+public class ClientService {
+
+    private final ClientDao clientDao;
+
+    public ClientService(ClientDao clientDao) {
+        this.clientDao = clientDao;
+    }
+
+    public String getClientName(ClientDatabase clientDb) {
+        ClientDatabaseContextHolder.set(clientDb);
+        String clientName = this.clientDao.getClientName();
+        ClientDatabaseContextHolder.clear();
+        return clientName;
+    }
+}

spring-boot/src/test/java/org/baeldung/dsrouting/DataSourceRoutingTestConfiguration.java

@@ -0,0 +1,64 @@
+package org.baeldung.dsrouting;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import javax.sql.DataSource;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.jdbc.datasource.embedded.EmbeddedDatabase;
+import org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseBuilder;
+import org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseType;
+
+@Configuration
+public class DataSourceRoutingTestConfiguration {
+
+    @Bean
+    public ClientService clientService() {
+        return new ClientService(new ClientDao(clientDatasource()));
+    }
+
+    @Bean
+    public DataSource clientDatasource() {
+        Map<Object, Object> targetDataSources = new HashMap<>();
+        DataSource acmeWidgetsDatasource = acmeWidgetsDatasource();
+        DataSource widgetsAreUsDatasource = widgetsAreUsDatasource();
+        DataSource widgetsDepotDatasource = widgetsDepotDatasource();
+        targetDataSources.put(ClientDatabase.ACME_WIDGETS, acmeWidgetsDatasource);
+        targetDataSources.put(ClientDatabase.WIDGETS_ARE_US, widgetsAreUsDatasource);
+        targetDataSources.put(ClientDatabase.WIDGET_DEPOT, widgetsDepotDatasource);
+
+        ClientDataSourceRouter clientRoutingDatasource = new ClientDataSourceRouter();
+        clientRoutingDatasource.setTargetDataSources(targetDataSources);
+        clientRoutingDatasource.setDefaultTargetDataSource(acmeWidgetsDatasource);
+        return clientRoutingDatasource;
+    }
+
+    private DataSource acmeWidgetsDatasource() {
+        EmbeddedDatabaseBuilder dbBuilder = new EmbeddedDatabaseBuilder();
+        EmbeddedDatabase embeddedDb = dbBuilder.setType(EmbeddedDatabaseType.H2)
+            .setName("ACMEWIDGETS")
+            .addScript("classpath:dsrouting-db.sql")
+            .build();
+        return embeddedDb;
+    }
+
+    private DataSource widgetsAreUsDatasource() {
+        EmbeddedDatabaseBuilder dbBuilder = new EmbeddedDatabaseBuilder();
+        EmbeddedDatabase embeddedDb = dbBuilder.setType(EmbeddedDatabaseType.H2)
+            .setName("WIDGETSAREUS")
+            .addScript("classpath:dsrouting-db.sql")
+            .build();
+        return embeddedDb;
+    }
+
+    private DataSource widgetsDepotDatasource() {
+        EmbeddedDatabaseBuilder dbBuilder = new EmbeddedDatabaseBuilder();
+        EmbeddedDatabase embeddedDb = dbBuilder.setType(EmbeddedDatabaseType.H2)
+            .setName("WIDGETDEPOT")
+            .addScript("classpath:dsrouting-db.sql")
+            .build();
+        return embeddedDb;
+    }
+}

spring-boot/src/test/java/org/baeldung/dsrouting/DataSourceRoutingTests.java

@@ -0,0 +1,62 @@
+package org.baeldung.dsrouting;
+
+import static org.junit.Assert.assertEquals;
+
+import javax.sql.DataSource;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringRunner;
+
+@RunWith(SpringRunner.class)
+@ContextConfiguration(classes = DataSourceRoutingTestConfiguration.class)
+public class DataSourceRoutingTests {
+
+    @Autowired
+    DataSource routingDatasource;
+
+    @Autowired
+    ClientService clientService;
+
+    @Before
+    public void setup() {
+        final String SQL_ACME_WIDGETS = "insert into client (id, name) values (1, 'ACME WIDGETS')";
+        final String SQL_WIDGETS_ARE_US = "insert into client (id, name) values (2, 'WIDGETS ARE US')";
+        final String SQL_WIDGET_DEPOT = "insert into client (id, name) values (3, 'WIDGET DEPOT')";
+
+        JdbcTemplate jdbcTemplate = new JdbcTemplate();
+        jdbcTemplate.setDataSource(routingDatasource);
+
+        ClientDatabaseContextHolder.set(ClientDatabase.ACME_WIDGETS);
+        jdbcTemplate.execute(SQL_ACME_WIDGETS);
+        ClientDatabaseContextHolder.clear();
+
+        ClientDatabaseContextHolder.set(ClientDatabase.WIDGETS_ARE_US);
+        jdbcTemplate.execute(SQL_WIDGETS_ARE_US);
+        ClientDatabaseContextHolder.clear();
+
+        ClientDatabaseContextHolder.set(ClientDatabase.WIDGET_DEPOT);
+        jdbcTemplate.execute(SQL_WIDGET_DEPOT);
+        ClientDatabaseContextHolder.clear();
+    }
+
+    @Test
+    public void givenClientDbs_whenContextsSwitch_thenRouteToCorrectDatabase() throws Exception {
+
+        // test ACME WIDGETS
+        String clientName = clientService.getClientName(ClientDatabase.ACME_WIDGETS);
+        assertEquals(clientName, "ACME WIDGETS");
+
+        // test WIDGETS_ARE_US
+        clientName = clientService.getClientName(ClientDatabase.WIDGETS_ARE_US);
+        assertEquals(clientName, "WIDGETS ARE US");
+
+        // test WIDGET_DEPOT
+        clientName = clientService.getClientName(ClientDatabase.WIDGET_DEPOT);
+        assertEquals(clientName, "WIDGET DEPOT");
+    }
+}

spring-boot/src/test/resources/dsrouting-db.sql

@@ -0,0 +1,5 @@
+create table client (
+  id numeric,
+  name  varchar(50),
+  constraint pk_client primary key (id)
+);