Merge remote-tracking branch 'upstream/master'

algorithms-miscellaneous-3/README.md

@@ -13,6 +13,5 @@ This module contains articles about algorithms. Some classes of algorithms, e.g.
 - [Checking if a Java Graph has a Cycle](https://www.baeldung.com/java-graph-has-a-cycle)
 - [A Guide to the Folding Technique in Java](https://www.baeldung.com/folding-hashing-technique)
 - [Creating a Triangle with for Loops in Java](https://www.baeldung.com/java-print-triangle)
-- [Efficient Word Frequency Calculator in Java](https://www.baeldung.com/java-word-frequency)
 - [The K-Means Clustering Algorithm in Java](https://www.baeldung.com/java-k-means-clustering-algorithm)
 - More articles: [[<-- prev]](/algorithms-miscellaneous-2) [[next -->]](/algorithms-miscellaneous-4)

algorithms-miscellaneous-6/README.md

@@ -0,0 +1,4 @@
+### Relevant Articles:
+
+- [Boruvka’s Algorithm for Minimum Spanning Trees](https://www.baeldung.com/java-boruvka-algorithm)
+- [Gradient Descent in Java](https://www.baeldung.com/java-gradient-descent)

apache-olingo/olingo2/README.md

@@ -1,3 +0,0 @@
-### Relevant Articles:
-
-- [Intro to OData with Olingo](https://www.baeldung.com/olingo)

atomikos/README.md

@@ -0,0 +1,7 @@
+## Atomikos
+
+This module contains articles about Atomikos
+
+### Relevant Articles: 
+
+- [Guide Transactions Using Atomikos]()

atomikos/pom.xml

@@ -0,0 +1,119 @@
+<?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>atomikos</artifactId>
+	<name>atomikos</name>
+
+	<parent>
+		<groupId>com.baeldung</groupId>
+		<artifactId>parent-modules</artifactId>
+		<version>1.0.0-SNAPSHOT</version>
+	</parent>
+
+	<dependencies>
+		<dependency>
+			<groupId>com.atomikos</groupId>
+			<artifactId>transactions-jdbc</artifactId>
+			<version>${atomikos-version}</version>
+		</dependency>
+		<dependency>
+			<groupId>com.atomikos</groupId>
+			<artifactId>transactions-jms</artifactId>
+			<version>${atomikos-version}</version>
+		</dependency>
+		<dependency>
+			<groupId>com.atomikos</groupId>
+			<artifactId>transactions-hibernate4</artifactId>
+			<version>${atomikos-version}</version>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-context</artifactId>
+			<version>${spring-version}</version>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-tx</artifactId>
+			<version>${spring-version}</version>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.data</groupId>
+			<artifactId>spring-data-jpa</artifactId>
+			<version>1.11.23.RELEASE</version>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-test</artifactId>
+			<version>${spring-version}</version>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.hibernate</groupId>
+			<artifactId>hibernate-entitymanager</artifactId>
+			<version>${hibernate.version}</version>
+			<scope>provided</scope>
+			<exclusions>
+				<exclusion>
+					<groupId>javax.transaction</groupId>
+					<artifactId>jta</artifactId>
+				</exclusion>
+			</exclusions>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.activemq</groupId>
+			<artifactId>activemq-core</artifactId>
+			<version>5.7.0</version>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.derby</groupId>
+			<artifactId>derby</artifactId>
+			<version>10.8.1.2</version>
+		</dependency>
+		<dependency>
+			<groupId>junit</groupId>
+			<artifactId>junit</artifactId>
+			<version>4.12</version>
+			<scope>test</scope>
+		</dependency>
+		<!-- the JTA API -->
+		<dependency>
+			<groupId>javax.transaction</groupId>
+			<artifactId>jta</artifactId>
+			<version>1.1</version>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.geronimo.specs</groupId>
+			<artifactId>geronimo-jta_1.0.1B_spec</artifactId>
+			<version>1.0</version>
+		</dependency>
+		<dependency>
+			<groupId>javax.validation</groupId>
+			<artifactId>validation-api</artifactId>
+			<version>2.0.1.Final</version>
+		</dependency>
+		<dependency>
+			<groupId>org.hibernate.validator</groupId>
+			<artifactId>hibernate-validator</artifactId>
+			<version>6.1.2.Final</version>
+		</dependency>
+		<dependency>
+			<groupId>javax.el</groupId>
+			<artifactId>javax.el-api</artifactId>
+			<version>3.0.0</version>
+		</dependency>
+		<dependency>
+			<groupId>org.glassfish.web</groupId>
+			<artifactId>javax.el</artifactId>
+			<version>2.2.4</version>
+		</dependency>
+	</dependencies>
+
+	<properties>
+		<atomikos-version>5.0.6</atomikos-version>
+		<spring-version>5.1.6.RELEASE</spring-version>
+		<hibernate.version>5.4.3.Final</hibernate.version>
+	</properties>
+
+</project>

atomikos/src/main/java/com/baeldung/atomikos/direct/Application.java

@@ -0,0 +1,53 @@
+package com.baeldung.atomikos.direct;
+
+import java.sql.Connection;
+import java.sql.Statement;
+import java.util.UUID;
+
+import javax.sql.DataSource;
+
+import com.atomikos.icatch.jta.UserTransactionImp;
+
+public class Application {
+
+    private DataSource inventoryDataSource;
+    private DataSource orderDataSource;
+
+    public Application(DataSource inventoryDataSource, DataSource orderDataSource) {
+        this.inventoryDataSource = inventoryDataSource;
+        this.orderDataSource = orderDataSource;
+    }
+
+    public void placeOrder(String productId, int amount) throws Exception {
+
+        UserTransactionImp utx = new UserTransactionImp();
+        String orderId = UUID.randomUUID()
+            .toString();
+        boolean rollback = false;
+        try {
+            utx.begin();
+            Connection inventoryConnection = inventoryDataSource.getConnection();
+            Connection orderConnection = orderDataSource.getConnection();
+            Statement s1 = inventoryConnection.createStatement();
+            String q1 = "update Inventory set balance = balance - " + amount + " where productId ='" + productId + "'";
+            s1.executeUpdate(q1);
+            s1.close();
+            Statement s2 = orderConnection.createStatement();
+            String q2 = "insert into Orders values ( '" + orderId + "', '" + productId + "', " + amount + " )";
+            s2.executeUpdate(q2);
+            s2.close();
+            inventoryConnection.close();
+            orderConnection.close();
+        } catch (Exception e) {
+            System.out.println(e.getMessage());
+            rollback = true;
+        } finally {
+            if (!rollback)
+                utx.commit();
+            else
+                utx.rollback();
+        }
+
+    }
+
+}

atomikos/src/main/java/com/baeldung/atomikos/spring/Application.java

@@ -0,0 +1,41 @@
+package com.baeldung.atomikos.spring;
+
+import java.sql.Connection;
+import java.sql.Statement;
+import java.util.UUID;
+
+import javax.sql.DataSource;
+
+import org.springframework.transaction.annotation.Transactional;
+
+public class Application {
+
+    private DataSource inventoryDataSource;
+    private DataSource orderDataSource;
+
+    public Application(DataSource inventoryDataSource, DataSource orderDataSource) {
+        this.inventoryDataSource = inventoryDataSource;
+        this.orderDataSource = orderDataSource;
+    }
+
+    @Transactional(rollbackFor = Exception.class)
+    public void placeOrder(String productId, int amount) throws Exception {
+
+        String orderId = UUID.randomUUID()
+            .toString();
+        Connection inventoryConnection = inventoryDataSource.getConnection();
+        Connection orderConnection = orderDataSource.getConnection();
+        Statement s1 = inventoryConnection.createStatement();
+        String q1 = "update Inventory set balance = balance - " + amount + " where productId ='" + productId + "'";
+        s1.executeUpdate(q1);
+        s1.close();
+        Statement s2 = orderConnection.createStatement();
+        String q2 = "insert into Orders values ( '" + orderId + "', '" + productId + "', " + amount + " )";
+        s2.executeUpdate(q2);
+        s2.close();
+        inventoryConnection.close();
+        orderConnection.close();
+
+    }
+
+}

atomikos/src/main/java/com/baeldung/atomikos/spring/config/Config.java

@@ -0,0 +1,68 @@
+package com.baeldung.atomikos.spring.config;
+
+import java.util.Properties;
+
+import javax.transaction.SystemException;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.transaction.annotation.EnableTransactionManagement;
+import org.springframework.transaction.jta.JtaTransactionManager;
+
+import com.atomikos.icatch.jta.UserTransactionManager;
+import com.atomikos.jdbc.AtomikosDataSourceBean;
+import com.baeldung.atomikos.spring.Application;
+
+@Configuration
+@EnableTransactionManagement
+public class Config {
+
+    @Bean(initMethod = "init", destroyMethod = "close")
+    public AtomikosDataSourceBean inventoryDataSource() {
+        AtomikosDataSourceBean dataSource = new AtomikosDataSourceBean();
+        dataSource.setLocalTransactionMode(true);
+        dataSource.setUniqueResourceName("db1");
+        dataSource.setXaDataSourceClassName("org.apache.derby.jdbc.EmbeddedXADataSource");
+        Properties xaProperties = new Properties();
+        xaProperties.put("databaseName", "db1");
+        xaProperties.put("createDatabase", "create");
+        dataSource.setXaProperties(xaProperties);
+        dataSource.setPoolSize(10);
+        return dataSource;
+    }
+
+    @Bean(initMethod = "init", destroyMethod = "close")
+    public AtomikosDataSourceBean orderDataSource() {
+        AtomikosDataSourceBean dataSource = new AtomikosDataSourceBean();
+        dataSource.setLocalTransactionMode(true);
+        dataSource.setUniqueResourceName("db2");
+        dataSource.setXaDataSourceClassName("org.apache.derby.jdbc.EmbeddedXADataSource");
+        Properties xaProperties = new Properties();
+        xaProperties.put("databaseName", "db2");
+        xaProperties.put("createDatabase", "create");
+        dataSource.setXaProperties(xaProperties);
+        dataSource.setPoolSize(10);
+        return dataSource;
+    }
+
+    @Bean(initMethod = "init", destroyMethod = "close")
+    public UserTransactionManager userTransactionManager() throws SystemException {
+        UserTransactionManager userTransactionManager = new UserTransactionManager();
+        userTransactionManager.setTransactionTimeout(300);
+        userTransactionManager.setForceShutdown(true);
+        return userTransactionManager;
+    }
+
+    @Bean
+    public JtaTransactionManager jtaTransactionManager() throws SystemException {
+        JtaTransactionManager jtaTransactionManager = new JtaTransactionManager();
+        jtaTransactionManager.setTransactionManager(userTransactionManager());
+        jtaTransactionManager.setUserTransaction(userTransactionManager());
+        return jtaTransactionManager;
+    }
+
+    @Bean
+    public Application application() {
+        return new Application(inventoryDataSource(), orderDataSource());
+    }
+}

atomikos/src/main/java/com/baeldung/atomikos/spring/jpa/Application.java

@@ -0,0 +1,48 @@
+package com.baeldung.atomikos.spring.jpa;
+
+import java.util.Set;
+import java.util.UUID;
+
+import javax.validation.ConstraintViolation;
+import javax.validation.Validation;
+import javax.validation.Validator;
+import javax.validation.ValidatorFactory;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.transaction.annotation.Transactional;
+
+import com.baeldung.atomikos.spring.jpa.inventory.Inventory;
+import com.baeldung.atomikos.spring.jpa.inventory.InventoryRepository;
+import com.baeldung.atomikos.spring.jpa.order.Order;
+import com.baeldung.atomikos.spring.jpa.order.OrderRepository;
+
+public class Application {
+
+    @Autowired
+    private InventoryRepository inventoryRepository;
+
+    @Autowired
+    private OrderRepository orderRepository;
+
+    @Transactional(rollbackFor = Exception.class)
+    public void placeOrder(String productId, int amount) throws Exception {
+
+        String orderId = UUID.randomUUID()
+            .toString();
+        Inventory inventory = inventoryRepository.findOne(productId);
+        inventory.setBalance(inventory.getBalance() - amount);
+        inventoryRepository.save(inventory);
+        Order order = new Order();
+        order.setOrderId(orderId);
+        order.setProductId(productId);
+        order.setAmount(new Long(amount));
+        ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
+        Validator validator = factory.getValidator();
+        Set<ConstraintViolation<Order>> violations = validator.validate(order);
+        if (violations.size() > 0)
+            throw new Exception("Invalid instance of an order.");
+        orderRepository.save(order);
+
+    }
+
+}

atomikos/src/main/java/com/baeldung/atomikos/spring/jpa/config/Config.java

@@ -0,0 +1,38 @@
+package com.baeldung.atomikos.spring.jpa.config;
+
+import javax.transaction.SystemException;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.transaction.annotation.EnableTransactionManagement;
+import org.springframework.transaction.jta.JtaTransactionManager;
+
+import com.atomikos.icatch.jta.UserTransactionManager;
+import com.baeldung.atomikos.spring.jpa.Application;
+
+@Configuration
+@EnableTransactionManagement
+public class Config {
+
+    @Bean(initMethod = "init", destroyMethod = "close")
+    public UserTransactionManager userTransactionManager() throws SystemException {
+        UserTransactionManager userTransactionManager = new UserTransactionManager();
+        userTransactionManager.setTransactionTimeout(300);
+        userTransactionManager.setForceShutdown(true);
+        return userTransactionManager;
+    }
+
+    @Bean
+    public JtaTransactionManager transactionManager() throws SystemException {
+        JtaTransactionManager jtaTransactionManager = new JtaTransactionManager();
+        jtaTransactionManager.setTransactionManager(userTransactionManager());
+        jtaTransactionManager.setUserTransaction(userTransactionManager());
+        return jtaTransactionManager;
+    }
+
+    @Bean
+    public Application application() {
+        return new Application();
+    }
+
+}

atomikos/src/main/java/com/baeldung/atomikos/spring/jpa/inventory/Inventory.java

@@ -0,0 +1,31 @@
+package com.baeldung.atomikos.spring.jpa.inventory;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.Table;
+
+@Entity
+@Table(name = "INVENTORY")
+public class Inventory {
+
+    @Id
+    private String productId;
+    private Long balance;
+
+    public String getProductId() {
+        return productId;
+    }
+
+    public void setProductId(String productId) {
+        this.productId = productId;
+    }
+
+    public Long getBalance() {
+        return balance;
+    }
+
+    public void setBalance(Long balance) {
+        this.balance = balance;
+    }
+
+}

atomikos/src/main/java/com/baeldung/atomikos/spring/jpa/inventory/InventoryConfig.java

@@ -0,0 +1,53 @@
+package com.baeldung.atomikos.spring.jpa.inventory;
+
+import java.util.Properties;
+
+import javax.persistence.EntityManagerFactory;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
+import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
+import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
+
+import com.atomikos.jdbc.AtomikosDataSourceBean;
+
+@Configuration
+@EnableJpaRepositories(basePackages = "com.baeldung.atomikos.spring.jpa.inventory", entityManagerFactoryRef = "inventoryEntityManager", transactionManagerRef = "transactionManager")
+public class InventoryConfig {
+
+    @Bean(initMethod = "init", destroyMethod = "close")
+    public AtomikosDataSourceBean inventoryDataSource() {
+        AtomikosDataSourceBean dataSource = new AtomikosDataSourceBean();
+        dataSource.setLocalTransactionMode(true);
+        dataSource.setUniqueResourceName("db1");
+        dataSource.setXaDataSourceClassName("org.apache.derby.jdbc.EmbeddedXADataSource");
+        Properties xaProperties = new Properties();
+        xaProperties.put("databaseName", "db1");
+        xaProperties.put("createDatabase", "create");
+        dataSource.setXaProperties(xaProperties);
+        dataSource.setPoolSize(10);
+        return dataSource;
+    }
+
+    @Bean
+    public EntityManagerFactory inventoryEntityManager() {
+        HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
+        LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();
+        factory.setJpaVendorAdapter(vendorAdapter);
+        factory.setPackagesToScan("com.baeldung.atomikos.spring.jpa.inventory");
+        factory.setDataSource(inventoryDataSource());
+        Properties jpaProperties = new Properties();
+        //jpaProperties.put("hibernate.show_sql", "true");
+        //jpaProperties.put("hibernate.format_sql", "true");
+        jpaProperties.put("hibernate.dialect", "org.hibernate.dialect.DerbyDialect");
+        jpaProperties.put("hibernate.current_session_context_class", "jta");
+        jpaProperties.put("javax.persistence.transactionType", "jta");
+        jpaProperties.put("hibernate.transaction.manager_lookup_class", "com.atomikos.icatch.jta.hibernate3.TransactionManagerLookup");
+        jpaProperties.put("hibernate.hbm2ddl.auto", "create-drop");
+        factory.setJpaProperties(jpaProperties);
+        factory.afterPropertiesSet();
+        return factory.getObject();
+    }
+
+}

atomikos/src/main/java/com/baeldung/atomikos/spring/jpa/inventory/InventoryRepository.java

@@ -0,0 +1,9 @@
+package com.baeldung.atomikos.spring.jpa.inventory;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface InventoryRepository extends JpaRepository<Inventory, String> {
+
+}

atomikos/src/main/java/com/baeldung/atomikos/spring/jpa/order/Order.java

@@ -0,0 +1,42 @@
+package com.baeldung.atomikos.spring.jpa.order;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.Table;
+import javax.validation.constraints.Max;
+
+@Entity
+@Table(name = "ORDERS")
+public class Order {
+
+    @Id
+    private String orderId;
+    private String productId;
+    @Max(5)
+    private Long amount;
+
+    public String getOrderId() {
+        return orderId;
+    }
+
+    public void setOrderId(String orderId) {
+        this.orderId = orderId;
+    }
+
+    public String getProductId() {
+        return productId;
+    }
+
+    public void setProductId(String productId) {
+        this.productId = productId;
+    }
+
+    public Long getAmount() {
+        return amount;
+    }
+
+    public void setAmount(Long amount) {
+        this.amount = amount;
+    }
+
+}

atomikos/src/main/java/com/baeldung/atomikos/spring/jpa/order/OrderConfig.java

@@ -0,0 +1,53 @@
+package com.baeldung.atomikos.spring.jpa.order;
+
+import java.util.Properties;
+
+import javax.persistence.EntityManagerFactory;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
+import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
+import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
+
+import com.atomikos.jdbc.AtomikosDataSourceBean;
+
+@Configuration
+@EnableJpaRepositories(basePackages = "com.baeldung.atomikos.spring.jpa.order", entityManagerFactoryRef = "orderEntityManager", transactionManagerRef = "transactionManager")
+public class OrderConfig {
+
+    @Bean(initMethod = "init", destroyMethod = "close")
+    public AtomikosDataSourceBean orderDataSource() {
+        AtomikosDataSourceBean dataSource = new AtomikosDataSourceBean();
+        dataSource.setLocalTransactionMode(true);
+        dataSource.setUniqueResourceName("db2");
+        dataSource.setXaDataSourceClassName("org.apache.derby.jdbc.EmbeddedXADataSource");
+        Properties xaProperties = new Properties();
+        xaProperties.put("databaseName", "db2");
+        xaProperties.put("createDatabase", "create");
+        dataSource.setXaProperties(xaProperties);
+        dataSource.setPoolSize(10);
+        return dataSource;
+    }
+
+    @Bean
+    public EntityManagerFactory orderEntityManager() {
+        HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
+        LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();
+        factory.setJpaVendorAdapter(vendorAdapter);
+        factory.setPackagesToScan("com.baeldung.atomikos.spring.jpa.order");
+        factory.setDataSource(orderDataSource());
+        Properties jpaProperties = new Properties();
+        //jpaProperties.put("hibernate.show_sql", "true");
+        //jpaProperties.put("hibernate.format_sql", "true");
+        jpaProperties.put("hibernate.dialect", "org.hibernate.dialect.DerbyDialect");
+        jpaProperties.put("hibernate.current_session_context_class", "jta");
+        jpaProperties.put("javax.persistence.transactionType", "jta");
+        jpaProperties.put("hibernate.transaction.manager_lookup_class", "com.atomikos.icatch.jta.hibernate3.TransactionManagerLookup");
+        jpaProperties.put("hibernate.hbm2ddl.auto", "create-drop");
+        factory.setJpaProperties(jpaProperties);
+        factory.afterPropertiesSet();
+        return factory.getObject();
+    }
+
+}

atomikos/src/main/java/com/baeldung/atomikos/spring/jpa/order/OrderRepository.java

@@ -0,0 +1,9 @@
+package com.baeldung.atomikos.spring.jpa.order;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface OrderRepository extends JpaRepository<Order, String> {
+
+}

atomikos/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>

atomikos/src/main/resources/schema.sql

@@ -0,0 +1,10 @@
+CREATE TABLE INVENTORY (
+    productId VARCHAR PRIMARY KEY,
+    balance INT
+);
+
+CREATE TABLE ORDERS (
+    orderId VARCHAR PRIMARY KEY,
+    productId VARCHAR,
+    amount INT NOT NULL CHECK (amount <= 5)
+);

atomikos/src/main/resources/transactions.properties

@@ -0,0 +1 @@
+com.atomikos.icatch.file=logs

atomikos/src/test/java/com/baeldung/atomikos/direct/ApplicationUnitTest.java

@@ -0,0 +1,118 @@
+package com.baeldung.atomikos.direct;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.sql.Connection;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.Properties;
+import java.util.UUID;
+
+import javax.sql.DataSource;
+
+import org.junit.BeforeClass;
+import org.junit.Ignore;
+import org.junit.Test;
+
+import com.atomikos.icatch.jta.UserTransactionImp;
+import com.atomikos.jdbc.AtomikosDataSourceBean;
+
+public class ApplicationUnitTest {
+
+    private static DataSource inventoryDataSource;
+    private static DataSource orderDataSource;
+
+    private static String productId = UUID.randomUUID()
+        .toString();
+
+    @Test
+    @Ignore
+    public void testPlaceOrderSuccess() throws Exception {
+        int amount = 1;
+        long initialBalance = getBalance(inventoryDataSource, productId);
+        Application application = new Application(inventoryDataSource, orderDataSource);
+        application.placeOrder(productId, amount);
+        long finalBalance = getBalance(inventoryDataSource, productId);
+        assertEquals(initialBalance - amount, finalBalance);
+    }
+
+    @Test
+    @Ignore
+    public void testPlaceOrderFailure() throws Exception {
+        int amount = 10;
+        long initialBalance = getBalance(inventoryDataSource, productId);
+        Application application = new Application(inventoryDataSource, orderDataSource);
+        application.placeOrder(productId, amount);
+        long finalBalance = getBalance(inventoryDataSource, productId);
+        assertEquals(initialBalance, finalBalance);
+    }
+
+    @BeforeClass
+    public static void setUp() throws SQLException {
+
+        inventoryDataSource = getDataSource("db1");
+        orderDataSource = getDataSource("db2");
+        Connection inventoryConnection = inventoryDataSource.getConnection();
+        Connection orderConnection = orderDataSource.getConnection();
+        String createInventoryTable = "create table Inventory ( " + " productId VARCHAR ( 100 ) PRIMARY KEY, balance INT )";
+        String createInventoryRow = "insert into Inventory values ( '" + productId + "', 10000 )";
+        Statement s1 = inventoryConnection.createStatement();
+        try {
+            s1.executeUpdate(createInventoryTable);
+        } catch (Exception e) {
+            System.out.println("Inventory table exists");
+        }
+        try {
+            s1.executeUpdate(createInventoryRow);
+        } catch (Exception e) {
+            System.out.println("Product row exists");
+        }
+        s1.close();
+        String createOrderTable = "create table Orders ( orderId VARCHAR ( 100 ) PRIMARY KEY, productId VARCHAR ( 100 ), amount INT NOT NULL CHECK (amount <= 5) )";
+        Statement s2 = orderConnection.createStatement();
+        try {
+            s2.executeUpdate(createOrderTable);
+        } catch (Exception e) {
+            System.out.println("Orders table exists");
+        }
+        s2.close();
+        inventoryConnection.close();
+        orderConnection.close();
+    }
+
+    private static DataSource getDataSource(String db) {
+
+        DataSource ds;
+        AtomikosDataSourceBean ads = new AtomikosDataSourceBean();
+        ads.setXaDataSourceClassName("org.apache.derby.jdbc.EmbeddedXADataSource");
+        Properties properties = new Properties();
+        properties.put("databaseName", db);
+        properties.put("createDatabase", "create");
+        ads.setXaProperties(properties);
+        ads.setUniqueResourceName(db);
+        ads.setPoolSize(10); // optional
+        ads.setBorrowConnectionTimeout(10); // optional
+        ds = ads;
+        return ds;
+
+    }
+
+    private static long getBalance(DataSource inventoryDataSource, String productId) throws Exception {
+
+        UserTransactionImp utx = new UserTransactionImp();
+        utx.begin();
+        Connection inventoryConnection = inventoryDataSource.getConnection();
+        Statement s1 = inventoryConnection.createStatement();
+        String q1 = "select balance from Inventory where productId='" + productId + "'";
+        ResultSet rs1 = s1.executeQuery(q1);
+        if (rs1 == null || !rs1.next())
+            throw new Exception("Product not found: " + productId);
+        long balance = rs1.getLong(1);
+        inventoryConnection.close();
+        utx.commit();
+        return balance;
+
+    }
+
+}

atomikos/src/test/java/com/baeldung/atomikos/spring/ApplicationUnitTest.java

@@ -0,0 +1,108 @@
+package com.baeldung.atomikos.spring;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.sql.Connection;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.UUID;
+
+import javax.sql.DataSource;
+
+import org.junit.Before;
+import org.junit.Ignore;
+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 com.baeldung.atomikos.spring.config.Config;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration(classes = { Config.class })
+public class ApplicationUnitTest {
+
+    private static String productId = UUID.randomUUID()
+        .toString();
+
+    @Autowired
+    Application application;
+
+    @Autowired
+    DataSource inventoryDataSource;
+
+    @Autowired
+    DataSource orderDataSource;
+
+    @Test
+    @Ignore
+    public void testPlaceOrderSuccess() throws Exception {
+        int amount = 1;
+        long initialBalance = getBalance(inventoryDataSource, productId);
+        application.placeOrder(productId, amount);
+        long finalBalance = getBalance(inventoryDataSource, productId);
+        assertEquals(initialBalance - amount, finalBalance);
+    }
+
+    @Test
+    @Ignore
+    public void testPlaceOrderFailure() throws Exception {
+        int amount = 10;
+        long initialBalance = getBalance(inventoryDataSource, productId);
+        try {
+            application.placeOrder(productId, amount);
+        } catch (Exception e) {
+            System.out.println(e.getMessage());
+        }
+        long finalBalance = getBalance(inventoryDataSource, productId);
+        assertEquals(initialBalance, finalBalance);
+    }
+
+    @Before
+    public void setUp() throws SQLException {
+
+        Connection inventoryConnection = inventoryDataSource.getConnection();
+        Connection orderConnection = orderDataSource.getConnection();
+        String createInventoryTable = "create table Inventory ( " + " productId VARCHAR ( 100 ) PRIMARY KEY, balance INT )";
+        String createInventoryRow = "insert into Inventory values ( '" + productId + "', 10000 )";
+        Statement s1 = inventoryConnection.createStatement();
+        try {
+            s1.executeUpdate(createInventoryTable);
+        } catch (Exception e) {
+            System.out.println("Inventory table exists");
+        }
+        try {
+            s1.executeUpdate(createInventoryRow);
+        } catch (Exception e) {
+            System.out.println("Product row exists");
+        }
+        s1.close();
+        String createOrderTable = "create table Orders ( orderId VARCHAR ( 100 ) PRIMARY KEY, productId VARCHAR ( 100 ), amount INT NOT NULL CHECK (amount <= 5) )";
+        Statement s2 = orderConnection.createStatement();
+        try {
+            s2.executeUpdate(createOrderTable);
+        } catch (Exception e) {
+            System.out.println("Orders table exists");
+        }
+        s2.close();
+        inventoryConnection.close();
+        orderConnection.close();
+    }
+
+    private static long getBalance(DataSource inventoryDataSource, String productId) throws Exception {
+
+        Connection inventoryConnection = inventoryDataSource.getConnection();
+        Statement s1 = inventoryConnection.createStatement();
+        String q1 = "select balance from Inventory where productId='" + productId + "'";
+        ResultSet rs1 = s1.executeQuery(q1);
+        if (rs1 == null || !rs1.next())
+            throw new Exception("Product not found: " + productId);
+        long balance = rs1.getLong(1);
+        inventoryConnection.close();
+        return balance;
+
+    }
+
+}

atomikos/src/test/java/com/baeldung/atomikos/spring/jpa/ApplicationUnitTest.java

@@ -0,0 +1,80 @@
+package com.baeldung.atomikos.spring.jpa;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.sql.SQLException;
+import java.util.UUID;
+
+import org.junit.Before;
+import org.junit.Ignore;
+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 com.baeldung.atomikos.spring.jpa.config.Config;
+import com.baeldung.atomikos.spring.jpa.inventory.Inventory;
+import com.baeldung.atomikos.spring.jpa.inventory.InventoryConfig;
+import com.baeldung.atomikos.spring.jpa.inventory.InventoryRepository;
+import com.baeldung.atomikos.spring.jpa.order.OrderConfig;
+import com.baeldung.atomikos.spring.jpa.order.OrderRepository;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration(classes = { Config.class, InventoryConfig.class, OrderConfig.class })
+public class ApplicationUnitTest {
+
+    private static String productId = UUID.randomUUID()
+        .toString();
+
+    @Autowired
+    Application application;
+
+    @Autowired
+    InventoryRepository inventoryRepository;
+
+    @Autowired
+    OrderRepository orderRepository;
+
+    @Test
+    @Ignore
+    public void testPlaceOrderSuccess() throws Exception {
+        int amount = 1;
+        long initialBalance = getBalance(inventoryRepository, productId);
+        application.placeOrder(productId, amount);
+        long finalBalance = getBalance(inventoryRepository, productId);
+        assertEquals(initialBalance - amount, finalBalance);
+    }
+
+    @Test
+    @Ignore
+    public void testPlaceOrderFailure() throws Exception {
+        int amount = 10;
+        long initialBalance = getBalance(inventoryRepository, productId);
+        try {
+            application.placeOrder(productId, amount);
+        } catch (Exception e) {
+            System.out.println(e.getMessage());
+        }
+        long finalBalance = getBalance(inventoryRepository, productId);
+        assertEquals(initialBalance, finalBalance);
+    }
+
+    @Before
+    public void setUp() throws SQLException {
+
+        Inventory inventory = new Inventory();
+        inventory.setProductId(productId);
+        inventory.setBalance(new Long(10000));
+        inventoryRepository.save(inventory);
+
+    }
+
+    private static long getBalance(InventoryRepository inventoryRepository, String productId) throws Exception {
+
+        return inventoryRepository.findOne(productId)
+            .getBalance();
+
+    }
+
+}

atomikos/src/test/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>

atomikos/src/test/resources/transactions.properties

@@ -0,0 +1 @@
+com.atomikos.icatch.file=logs

cas/cas-server/README.md

@@ -1,146 +0,0 @@
-CAS Overlay Template [![Build Status](https://travis-ci.org/apereo/cas-overlay-template.svg?branch=master)](https://travis-ci.org/apereo/cas-overlay-template)
-=======================
-
-Generic CAS WAR overlay to exercise the latest versions of CAS. This overlay could be freely used as a starting template for local CAS war overlays.
-
-# Versions
-
-- CAS `6.1.x`
-- JDK `11`
-
-# Overview
-
-To build the project, use:
-
-```bash
-# Use --refresh-dependencies to force-update SNAPSHOT versions
-./gradlew[.bat] clean build
-```
-
-To see what commands are available to the build script, run:
-
-```bash
-./gradlew[.bat] tasks
-```
-
-To launch into the CAS command-line shell:
-
-```bash
-./gradlew[.bat] downloadShell runShell
-```
-
-To fetch and overlay a CAS resource or view, use:
-
-```bash
-./gradlew[.bat] getResource -PresourceName=[resource-name]
-```
-
-To list all available CAS views and templates:
-
-```bash
-./gradlew[.bat] listTemplateViews
-```
-
-To unzip and explode the CAS web application file and the internal resources jar:
-
-```bash
-./gradlew[.bat] explodeWar
-```
-
-# Configuration
-
-- The `etc` directory contains the configuration files and directories that need to be copied to `/etc/cas/config`.
-
-```bash
-./gradlew[.bat] copyCasConfiguration
-```
-
-- The specifics of the build are controlled using the `gradle.properties` file.
-
-## Adding Modules
-
-CAS modules may be specified under the `dependencies` block of the [Gradle build script](build.gradle):
-
-```gradle
-dependencies {
-    compile "org.apereo.cas:cas-server-some-module:${project.casVersion}"
-    ...
-}
-```
-
-To collect the list of all project modules and dependencies:
-
-```bash
-./gradlew[.bat] allDependencies
-```
-
-### Clear Gradle Cache
-
-If you need to, on Linux/Unix systems, you can delete all the existing artifacts (artifacts and metadata) Gradle has downloaded using:
-
-```bash
-# Only do this when absolutely necessary
-rm -rf $HOME/.gradle/caches/
-```
-
-Same strategy applies to Windows too, provided you switch `$HOME` to its equivalent in the above command.
-
-# Deployment
-
-- Create a keystore file `thekeystore` under `/etc/cas`. Use the password `changeit` for both the keystore and the key/certificate entries. This can either be done using the JDK's `keytool` utility or via the following command:
-
-```bash
-./gradlew[.bat] createKeystore
-```
-
-- Ensure the keystore is loaded up with keys and certificates of the server.
-
-On a successful deployment via the following methods, CAS will be available at:
-
-* `https://cas.server.name:8443/cas`
-
-## Executable WAR
-
-Run the CAS web application as an executable WAR:
-
-```bash
-./gradlew[.bat] run
-```
-
-Debug the CAS web application as an executable WAR:
-
-```bash
-./gradlew[.bat] debug
-```
-
-Run the CAS web application as a *standalone* executable WAR:
-
-```bash
-./gradlew[.bat] clean executable
-```
-
-## External
-
-Deploy the binary web application file `cas.war` after a successful build to a servlet container of choice.
-
-## Docker
-
-The following strategies outline how to build and deploy CAS Docker images.
-
-### Jib
-
-The overlay embraces the [Jib Gradle Plugin](https://github.com/GoogleContainerTools/jib) to provide easy-to-use out-of-the-box tooling for building CAS docker images. Jib is an open-source Java containerizer from Google that lets Java developers build containers using the tools they know. It is a container image builder that handles all the steps of packaging your application into a container image. It does not require you to write a Dockerfile or have Docker installed, and it is directly integrated into the overlay.
-
-```bash
-./gradlew build jibDockerBuild
-```
-
-### Dockerfile
-
-You can also use the native Docker tooling and the provided `Dockerfile` to build and run CAS.
-
-```bash
-chmod +x *.sh
-./docker-build.sh
-./docker-run.sh
-```

core-java-modules/core-java-14/README.md

@@ -7,3 +7,4 @@ This module contains articles about Java 14.
 - [Guide to the @Serial Annotation in Java 14](https://www.baeldung.com/java-14-serial-annotation)
 - [Java Text Blocks](https://www.baeldung.com/java-text-blocks)
 - [Pattern Matching for instanceof in Java 14](https://www.baeldung.com/java-pattern-matching-instanceof)
+- [Helpful NullPointerExceptions in Java 14](https://www.baeldung.com/java-14-nullpointerexception)

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

@@ -4,7 +4,6 @@ This module contains articles about Java 8 core features
 
 ### Relevant Articles: 
 
-- [How to Delay Code Execution in Java](https://www.baeldung.com/java-delay-code-execution)
 - [Run a Java Application from the Command Line](https://www.baeldung.com/java-run-jar-with-arguments)
 - [Java 8 Stream skip() vs limit()](https://www.baeldung.com/java-stream-skip-vs-limit)
 - [Guide to Java BiFunction Interface](https://www.baeldung.com/java-bifunction-interface)

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

@@ -12,4 +12,3 @@
 - [Sorting in Java](https://www.baeldung.com/java-sorting)
 - [Getting the Size of an Iterable in Java](https://www.baeldung.com/java-iterable-size)
 - [Java Null-Safe Streams from Collections](https://www.baeldung.com/java-null-safe-streams-from-collections)
-- [Operating on and Removing an Item from Stream](https://www.baeldung.com/java-use-remove-item-stream)

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

@@ -4,7 +4,6 @@ This module contains articles about Map data structures in Java.
 
 ### Relevant Articles: 
 - [Guide to the Guava BiMap](https://www.baeldung.com/guava-bimap)
-- [A Guide to Java HashMap](https://www.baeldung.com/java-hashmap)
 - [A Guide to LinkedHashMap in Java](https://www.baeldung.com/java-linked-hashmap)
 - [A Guide to TreeMap in Java](https://www.baeldung.com/java-treemap)
 - [How to Store Duplicate Keys in a Map in Java?](https://www.baeldung.com/java-map-duplicate-keys)

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

@@ -3,7 +3,6 @@
 This module contains articles about Java collections
 
 ### Relevant Articles: 
-- [Collect a Java Stream to an Immutable Collection](https://www.baeldung.com/java-stream-immutable-collection)
 - [Introduction to the Java ArrayDeque](https://www.baeldung.com/java-array-deque)
 - [An Introduction to Java.util.Hashtable Class](https://www.baeldung.com/java-hash-table)
 - [Thread Safe LIFO Data Structure Implementations](https://www.baeldung.com/java-lifo-thread-safe)

core-java-modules/core-java-concurrency-advanced-3/README.md

@@ -10,4 +10,5 @@ This module contains articles about advanced topics about multithreading with co
 - [Guide to RejectedExecutionHandler](https://www.baeldung.com/java-rejectedexecutionhandler)
 - [Guide to Work Stealing in Java](https://www.baeldung.com/java-work-stealing)
 - [Asynchronous Programming in Java](https://www.baeldung.com/java-asynchronous-programming)
+- [Java Thread Deadlock and Livelock](https://www.baeldung.com/java-deadlock-livelock)
 - [[<-- previous]](/core-java-modules/core-java-concurrency-advanced-2)

core-java-modules/core-java-concurrency-basic-2/README.md

@@ -8,4 +8,5 @@ This module contains articles about basic Java concurrency
 - [Difference Between Wait and Sleep in Java](https://www.baeldung.com/java-wait-and-sleep)
 - [Guide to the Synchronized Keyword in Java](https://www.baeldung.com/java-synchronized)
 - [Life Cycle of a Thread in Java](https://www.baeldung.com/java-thread-lifecycle)
+- [Guide to AtomicMarkableReference](https://www.baeldung.com/java-atomicmarkablereference)
 - [[<-- Prev]](/core-java-modules/core-java-concurrency-basic)

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

@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Introduction to Lock Striping](https://www.baeldung.com/java-lock-stripping)

core-java-modules/core-java-date-operations-2/README.md

@@ -7,4 +7,5 @@ This module contains articles about date operations in Java.
 - [Checking If Two Java Dates Are on the Same Day](https://www.baeldung.com/java-check-two-dates-on-same-day)
 - [Converting Java Date to OffsetDateTime](https://www.baeldung.com/java-convert-date-to-offsetdatetime)
 - [How to Set the JVM Time Zone](https://www.baeldung.com/java-jvm-time-zone)
+- [How to determine day of week by passing specific date in Java?](https://www.baeldung.com/java-get-day-of-week)
 - [[<-- Prev]](/core-java-modules/core-java-date-operations-1)

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

@@ -12,4 +12,5 @@ This module contains articles about core Java input and output (IO)
 - [Java – Append Data to a File](https://www.baeldung.com/java-append-to-file)
 - [How to Copy a File with Java](https://www.baeldung.com/java-copy-file)
 - [Create a Directory in Java](https://www.baeldung.com/java-create-directory) 
+- [Java IO vs NIO](https://www.baeldung.com/java-io-vs-nio)
 - [[<-- Prev]](/core-java-modules/core-java-io)

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

@@ -10,4 +10,5 @@ This module contains articles about core features in the Java language
 - [How to Return Multiple Values From a Java Method](https://www.baeldung.com/java-method-return-multiple-values)
 - [Guide to the Java finally Keyword](https://www.baeldung.com/java-finally-keyword)
 - [The Java Headless Mode](https://www.baeldung.com/java-headless-mode)
+- [Comparing Long Values in Java](https://www.baeldung.com/java-compare-long-values)
 - [[<-- Prev]](/core-java-modules/core-java-lang)

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

@@ -9,3 +9,4 @@
 - [Pre-compile Regex Patterns Into Pattern Objects](https://www.baeldung.com/java-regex-pre-compile)
 - [Difference Between Java Matcher find() and matches()](https://www.baeldung.com/java-matcher-find-vs-matches)
 - [How to Use Regular Expressions to Replace Tokens in Strings](https://www.baeldung.com/java-regex-token-replacement)
+- [Regular Expressions \s and \s+ in Java](https://www.baeldung.com/java-regex-s-splus)

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

@@ -8,4 +8,5 @@ This module contains articles about core Java Security
 - [MD5 Hashing in Java](http://www.baeldung.com/java-md5)
 - [Hashing a Password in Java](https://www.baeldung.com/java-password-hashing)
 - [SHA-256 and SHA3-256 Hashing in Java](https://www.baeldung.com/sha-256-hashing-java)
+- [Checksums in Java](https://www.baeldung.com/java-checksums)
 - More articles: [[<-- prev]](/core-java-modules/core-java-security)

core-java-modules/core-java-streams-3/README.md

@@ -9,4 +9,5 @@ This module contains articles about the Stream API in Java.
 - [Guide to Java 8’s Collectors](https://www.baeldung.com/java-8-collectors)
 - [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)
 - More articles: [[<-- prev>]](/../core-java-streams-2)

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

@@ -13,4 +13,5 @@ This module contains articles about string operations.
 - [Adding a Newline Character to a String in Java](https://www.baeldung.com/java-string-newline)
 - [Check If a String Contains a Substring](https://www.baeldung.com/java-string-contains-substring)
 - [Java Base64 Encoding and Decoding](https://www.baeldung.com/java-base64-encode-and-decode)
+- [Java Convert PDF to Base64](https://www.baeldung.com/java-convert-pdf-to-base64)
 - More articles: [[next -->]](../core-java-string-operations-2)

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

@@ -12,3 +12,4 @@ This module contains articles about strings in Java.
 - [Java String Interview Questions and Answers](https://www.baeldung.com/java-string-interview-questions)
 - [Java Multi-line String](https://www.baeldung.com/java-multiline-string)
 - [Guide to Java String Pool](https://www.baeldung.com/java-string-pool)
+- [Fixing “constant string too long” Build Error](https://www.baeldung.com/java-constant-string-too-long-error)

core-kotlin-modules/core-kotlin-collections/README.md

@@ -8,3 +8,4 @@ This module contains articles about core Kotlin collections.
 - [Overview of Kotlin Collections API](https://www.baeldung.com/kotlin-collections-api)
 - [Converting a List to Map in Kotlin](https://www.baeldung.com/kotlin-list-to-map)
 - [Filtering Kotlin Collections](https://www.baeldung.com/kotlin-filter-collection)
+- [Collection Transformations in Kotlin](https://www.baeldung.com/kotlin-collection-transformations)

core-kotlin-modules/core-kotlin/README.md

@@ -3,7 +3,7 @@
 This module contains articles about Kotlin core features.
 
 ### Relevant articles:
-- [Introduction to the Kotlin Language](https://www.baeldung.com/kotlin-intro)
+- [Introduction to the Kotlin Language](https://www.baeldung.com/kotlin/tutorial)
 - [Kotlin Java Interoperability](https://www.baeldung.com/kotlin-java-interoperability)
 - [Get a Random Number in Kotlin](https://www.baeldung.com/kotlin-random-number)
 - [Create a Java and Kotlin Project with Maven](https://www.baeldung.com/kotlin-maven-java-project)

core-scala/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Pattern Matching in Scala](https://www.baeldung.com/scala/pattern-matching)

guava-collections-map/README.md

@@ -10,3 +10,4 @@ This module contains articles about map collections in Guava
 - [Guide to Guava RangeMap](https://www.baeldung.com/guava-rangemap)
 - [Initialize a HashMap in Java](https://www.baeldung.com/java-initialize-hashmap)
 - [Guide to Guava ClassToInstanceMap](https://www.baeldung.com/guava-class-to-instance-map)
+- [Using Guava’s MapMaker](https://www.baeldung.com/guava-mapmaker)

guava/README.md

@@ -12,4 +12,4 @@ This module contains articles a Google Guava
 - [Guide to Mathematical Utilities in Guava](https://www.baeldung.com/guava-math)
 - [Bloom Filter in Java using Guava](https://www.baeldung.com/guava-bloom-filter)
 - [Quick Guide to the Guava RateLimiter](https://www.baeldung.com/guava-rate-limiter)
-
+- [Introduction to Guava Throwables](https://www.baeldung.com/guava-throwables)

java-collections-maps-3/README.md

@@ -0,0 +1,8 @@
+## Java Collections Cookbooks and Examples
+
+This module contains articles about Map data structures in Java.
+
+### Relevant Articles: 
+
+- More articles: [[<-- prev>]](/../java-collections-maps)
+- More articles: [[<-- prev>]](/../java-collections-maps-2)

java-collections-maps-3/pom.xml

@@ -0,0 +1,43 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-java</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../parent-java</relativePath>
+    </parent>
+
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>java-collections-maps-3</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>java-collections-maps-3</name>
+    <packaging>jar</packaging>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-core</artifactId>
+            <version>${spring.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
+    <dependency>
+        <groupId>org.apache.commons</groupId>
+        <artifactId>commons-collections4</artifactId>
+        <version>${commons-collections4.version}</version>
+    </dependency>
+    </dependencies>
+
+    <properties>
+        <commons-collections4.version>4.1</commons-collections4.version>
+        <assertj.version>3.6.1</assertj.version>
+        <spring.version>5.2.5.RELEASE</spring.version>
+    </properties>
+</project>

java-collections-maps-3/src/test/java/com/baeldung/map/caseinsensitivekeys/CaseInsensitiveMapUnitTest.java

@@ -0,0 +1,94 @@
+package com.baeldung.map.caseinsensitivekeys;
+
+import org.apache.commons.collections4.map.CaseInsensitiveMap;
+import org.junit.Test;
+import org.springframework.util.LinkedCaseInsensitiveMap;
+import java.util.Map;
+import java.util.TreeMap;
+import static org.junit.Assert.*;
+
+public class CaseInsensitiveMapUnitTest {
+    @Test
+    public void givenCaseInsensitiveTreeMap_whenTwoEntriesAdded_thenSizeIsOne(){
+        Map<String, Integer> treeMap = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
+        treeMap.put("abc", 1);
+        treeMap.put("ABC", 2);
+
+        assertEquals(1, treeMap.size());
+    }
+
+    @Test
+    public void givenCommonsCaseInsensitiveMap_whenTwoEntriesAdded_thenSizeIsOne(){
+        Map<String, Integer> commonsHashMap = new CaseInsensitiveMap<>();
+        commonsHashMap.put("abc", 1);
+        commonsHashMap.put("ABC", 2);
+
+        assertEquals(1, commonsHashMap.size());
+    }
+
+    @Test
+    public void givenLinkedCaseInsensitiveMap_whenTwoEntriesAdded_thenSizeIsOne(){
+        Map<String, Integer> linkedHashMap = new LinkedCaseInsensitiveMap<>();
+        linkedHashMap.put("abc", 1);
+        linkedHashMap.put("ABC", 2);
+
+        assertEquals(1, linkedHashMap.size());
+    }
+
+    @Test
+    public void givenCaseInsensitiveTreeMap_whenSameEntryAdded_thenValueUpdated(){
+        Map<String, Integer> treeMap = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
+        treeMap.put("abc", 1);
+        treeMap.put("ABC", 2);
+
+        assertEquals(2, treeMap.get("aBc").intValue());
+        assertEquals(2, treeMap.get("ABc").intValue());
+    }
+
+    @Test
+    public void givenCommonsCaseInsensitiveMap_whenSameEntryAdded_thenValueUpdated(){
+        Map<String, Integer> commonsHashMap = new CaseInsensitiveMap<>();
+        commonsHashMap.put("abc", 1);
+        commonsHashMap.put("ABC", 2);
+
+        assertEquals(2, commonsHashMap.get("aBc").intValue());
+        assertEquals(2, commonsHashMap.get("ABc").intValue());
+    }
+
+    @Test
+    public void givenLinkedCaseInsensitiveMap_whenSameEntryAdded_thenValueUpdated(){
+        Map<String, Integer> linkedHashMap = new LinkedCaseInsensitiveMap<>();
+        linkedHashMap.put("abc", 1);
+        linkedHashMap.put("ABC", 2);
+
+        assertEquals(2, linkedHashMap.get("aBc").intValue());
+        assertEquals(2, linkedHashMap.get("ABc").intValue());
+    }
+
+    @Test
+    public void givenCaseInsensitiveTreeMap_whenEntryRemoved_thenSizeIsZero(){
+        Map<String, Integer> treeMap = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
+        treeMap.put("abc", 3);
+        treeMap.remove("aBC");
+
+        assertEquals(0, treeMap.size());
+    }
+
+    @Test
+    public void givenCommonsCaseInsensitiveMap_whenEntryRemoved_thenSizeIsZero(){
+        Map<String, Integer> commonsHashMap = new CaseInsensitiveMap<>();
+        commonsHashMap.put("abc", 3);
+        commonsHashMap.remove("aBC");
+
+        assertEquals(0, commonsHashMap.size());
+    }
+
+    @Test
+    public void givenLinkedCaseInsensitiveMap_whenEntryRemoved_thenSizeIsZero(){
+        Map<String, Integer> linkedHashMap = new LinkedCaseInsensitiveMap<>();
+        linkedHashMap.put("abc", 3);
+        linkedHashMap.remove("aBC");
+
+        assertEquals(0, linkedHashMap.size());
+    }
+}

java-numbers-3/README.md

@@ -10,4 +10,5 @@ This module contains articles about numbers in Java.
 - [Generating Random Numbers in a Range in Java](https://www.baeldung.com/java-generating-random-numbers-in-range)
 - [Listing Numbers Within a Range in Java](https://www.baeldung.com/java-listing-numbers-within-a-range)
 - [Fibonacci Series in Java](https://www.baeldung.com/java-fibonacci)
+- [Guide to the Number Class in Java](https://www.baeldung.com/java-number-class)
 - More articles: [[<-- prev]](/java-numbers-2)

java-numbers/README.md

@@ -12,4 +12,5 @@ This module contains articles about numbers in Java.
 - [Calculating the nth Root in Java](https://www.baeldung.com/java-nth-root)
 - [Convert Double to String, Removing Decimal Places](https://www.baeldung.com/java-double-to-string)
 - [Changing the Order in a Sum Operation Can Produce Different Results?](https://www.baeldung.com/java-floating-point-sum-order)
+- [Using Math.sin with Degrees](https://www.baeldung.com/java-math-sin-degrees)
 - More articles: [[next -->]](/../java-numbers-2)

jhipster-5/bookstore-monolith/src/test/java/com/baeldung/jhipster5/service/mapper/UserMapperIntegrationTest.java

@@ -26,7 +26,7 @@ import static org.assertj.core.api.Assertions.assertThat;
  */
 @RunWith(SpringRunner.class)
 @SpringBootTest(classes = BookstoreApp.class)
-public class UserMapperUnitTest {
+public class UserMapperIntegrationTest {
 
     private static final String DEFAULT_LOGIN = "johndoe";
 

libraries-3/README.md

@@ -15,4 +15,5 @@ Remember, for advanced libraries like [Jackson](/jackson) and [JUnit](/testing-m
 - [Introduction to the jcabi-aspects AOP Annotations Library](https://www.baeldung.com/java-jcabi-aspects)
 - [Introduction to Takes](https://www.baeldung.com/java-takes)
 - [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)

libraries-concurrency/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Intro to Coroutines with Quasar](https://www.baeldung.com/java-quasar-coroutines)

linux-bash/command-line-arguments/src/main/bash/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [How to Use Command Line Arguments in a Bash Script](https://www.baeldung.com/linux/use-command-line-arguments-in-bash-script)

linux-bash/functions/src/main/bash/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles
+
+- [Bash Functions in Linux](https://www.baeldung.com/linux/bash-functions)

linux-bash/read/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Guide to the Linux read Command](https://www.baeldung.com/linux/read-command)

linux-bash/text/README.md

@@ -1,3 +1,4 @@
 ### Relevant Articles:
 
 - [Linux Commands – Remove All Text After X](https://www.baeldung.com/linux/tr-manipulate-strings)
+- [Linux Commands for Appending Multiple Lines to a File](https://www.baeldung.com/linux/appending-multiple-lines-to-file2)

logging-modules/log-mdc/README.md

@@ -1,7 +1,7 @@
 ### Relevant Articles:
 - TBD
 - [Improved Java Logging with Mapped Diagnostic Context (MDC)](https://www.baeldung.com/mdc-in-log4j-2-logback)
-- [Java Logging with Nested Diagnostic Context (NDC)](https:www.baeldung.com/java-logging-ndc-log4j)
+- [Java Logging with Nested Diagnostic Context (NDC)](https://www.baeldung.com/java-logging-ndc-log4j)
 - [Drools Using Rules from Excel Files](https://www.baeldung.com/drools-excel)
 
 ### References

lombok/src/main/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Guide to the Linux wc Command](https://www.baeldung.com/linux/wc-command)

persistence-modules/hibernate-jpa/README.md

@@ -13,3 +13,4 @@ This module contains articles specific to use of Hibernate as a JPA implementati
 - [Enabling Transaction Locks in Spring Data JPA](https://www.baeldung.com/java-jpa-transaction-locks)
 - [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)

persistence-modules/java-cassandra/pom.xml

@@ -18,6 +18,12 @@
             <artifactId>cassandra-driver-core</artifactId>
             <version>${cassandra-driver-core.version}</version>
             <optional>true</optional>
+            <exclusions>
+                <exclusion>
+                    <groupId>com.google.guava</groupId>
+                    <artifactId>guava</artifactId>
+                </exclusion>
+            </exclusions>
         </dependency>
 
         <!-- https://mvnrepository.com/artifact/org.cassandraunit/cassandra-unit -->

persistence-modules/java-cassandra/src/test/resources/cassandra.yaml

@@ -0,0 +1,51 @@
+cluster_name: 'Test Cluster'
+hinted_handoff_enabled: true
+max_hint_window_in_ms: 10800000
+hinted_handoff_throttle_in_kb: 1024
+max_hints_delivery_threads: 2
+hints_directory: target/embeddedCassandra/hints
+authenticator: AllowAllAuthenticator
+authorizer: AllowAllAuthorizer
+permissions_validity_in_ms: 2000
+partitioner: RandomPartitioner
+data_file_directories:
+  - target/embeddedCassandra/data
+commitlog_directory: target/embeddedCassandra/commitlog
+cdc_raw_directory: target/embeddedCassandra/cdc
+disk_failure_policy: stop
+key_cache_size_in_mb:
+key_cache_save_period: 14400
+row_cache_size_in_mb: 0
+row_cache_save_period: 0
+saved_caches_directory: target/embeddedCassandra/saved_caches
+commitlog_sync: periodic
+commitlog_sync_period_in_ms: 10000
+commitlog_segment_size_in_mb: 32
+concurrent_reads: 32
+concurrent_writes: 32
+trickle_fsync: false
+trickle_fsync_interval_in_kb: 10240
+thrift_framed_transport_size_in_mb: 15
+thrift_max_message_length_in_mb: 16
+incremental_backups: false
+snapshot_before_compaction: false
+auto_snapshot: false
+column_index_size_in_kb: 64
+compaction_throughput_mb_per_sec: 16
+read_request_timeout_in_ms: 5000
+range_request_timeout_in_ms: 10000
+write_request_timeout_in_ms: 2000
+cas_contention_timeout_in_ms: 1000
+truncate_request_timeout_in_ms: 60000
+request_timeout_in_ms: 10000
+cross_node_timeout: false
+endpoint_snitch: SimpleSnitch
+dynamic_snitch_update_interval_in_ms: 100
+dynamic_snitch_reset_interval_in_ms: 600000
+dynamic_snitch_badness_threshold: 0.1
+request_scheduler: org.apache.cassandra.scheduler.NoScheduler
+index_interval: 128
+seed_provider:
+  - class_name: org.apache.cassandra.locator.SimpleSeedProvider
+    parameters:
+      - seeds: "127.0.0.1"

persistence-modules/spring-boot-persistence-h2/README.md

@@ -2,3 +2,4 @@
 - [Access the Same In-Memory H2 Database in Multiple Spring Boot Applications](https://www.baeldung.com/spring-boot-access-h2-database-multiple-apps)
 - [Spring Boot With H2 Database](https://www.baeldung.com/spring-boot-h2-database)
 - [Hibernate @NotNull vs @Column(nullable = false)](https://www.baeldung.com/hibernate-notnull-vs-nullable)
+- [Quick Guide to Hibernate enable_lazy_load_no_trans Property](https://www.baeldung.com/hibernate-lazy-loading-workaround)

persistence-modules/spring-data-jpa-4/create.sql

@@ -0,0 +1,2 @@
+create table PERSON (ID int8 not null, FIRST_NAME varchar(255), LAST_NAME varchar(255), primary key (ID))
+create table person (id int8 not null, first_name varchar(255), last_name varchar(255), primary key (id))

persistence-modules/spring-data-jpa-4/pom.xml

@@ -33,6 +33,11 @@
             <artifactId>mysql-connector-java</artifactId>
         </dependency>
 
+        <dependency>
+            <groupId>org.postgresql</groupId>
+            <artifactId>postgresql</artifactId>
+        </dependency>
+
         <dependency>
             <groupId>com.h2database</groupId>
             <artifactId>h2</artifactId>

persistence-modules/spring-data-jpa-4/src/main/java/com/baeldung/namingstrategy/Person.java

@@ -0,0 +1,35 @@
+package com.baeldung.namingstrategy;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.Id;
+
+@Entity
+public class Person {
+    @Id
+    private Long id;
+
+    private String firstName;
+
+    private String lastName;
+
+    public Person() {}
+
+    public Person(Long id, String firstName, String lastName) {
+        this.id = id;
+        this.firstName = firstName;
+        this.lastName = lastName;
+    }
+
+    public Long id() {
+        return id;
+    }
+
+    public String firstName() {
+        return firstName;
+    }
+
+    public String lastName() {
+        return lastName;
+    }
+}

persistence-modules/spring-data-jpa-4/src/main/java/com/baeldung/namingstrategy/PersonRepository.java

@@ -0,0 +1,6 @@
+package com.baeldung.namingstrategy;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface PersonRepository extends JpaRepository<Person, Long> {
+}

persistence-modules/spring-data-jpa-4/src/main/java/com/baeldung/namingstrategy/QuotedLowerCaseNamingStrategy.java

@@ -0,0 +1,12 @@
+package com.baeldung.namingstrategy;
+
+import org.hibernate.boot.model.naming.Identifier;
+import org.hibernate.engine.jdbc.env.spi.JdbcEnvironment;
+import org.springframework.boot.orm.jpa.hibernate.SpringPhysicalNamingStrategy;
+
+public class QuotedLowerCaseNamingStrategy extends SpringPhysicalNamingStrategy {
+    @Override
+    protected Identifier getIdentifier(String name, boolean quoted, JdbcEnvironment jdbcEnvironment) {
+        return new Identifier(name.toLowerCase(), true);
+    }
+}

persistence-modules/spring-data-jpa-4/src/main/java/com/baeldung/namingstrategy/QuotedUpperCaseNamingStrategy.java

@@ -0,0 +1,12 @@
+package com.baeldung.namingstrategy;
+
+import org.hibernate.boot.model.naming.Identifier;
+import org.hibernate.engine.jdbc.env.spi.JdbcEnvironment;
+import org.springframework.boot.orm.jpa.hibernate.SpringPhysicalNamingStrategy;
+
+public class QuotedUpperCaseNamingStrategy extends SpringPhysicalNamingStrategy {
+    @Override
+    protected Identifier getIdentifier(String name, boolean quoted, JdbcEnvironment jdbcEnvironment) {
+        return new Identifier(name.toUpperCase(), true);
+    }
+}

persistence-modules/spring-data-jpa-4/src/main/java/com/baeldung/namingstrategy/SpringDataJpaNamingConventionApplication.java

@@ -0,0 +1,7 @@
+package com.baeldung.namingstrategy;
+
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SpringDataJpaNamingConventionApplication {
+}

persistence-modules/spring-data-jpa-4/src/main/java/com/baeldung/namingstrategy/UnquotedLowerCaseNamingStrategy.java

@@ -0,0 +1,12 @@
+package com.baeldung.namingstrategy;
+
+import org.hibernate.boot.model.naming.Identifier;
+import org.hibernate.engine.jdbc.env.spi.JdbcEnvironment;
+import org.springframework.boot.orm.jpa.hibernate.SpringPhysicalNamingStrategy;
+
+public class UnquotedLowerCaseNamingStrategy extends SpringPhysicalNamingStrategy {
+    @Override
+    protected Identifier getIdentifier(String name, boolean quoted, JdbcEnvironment jdbcEnvironment) {
+        return new Identifier(name.toLowerCase(), false);
+    }
+}

persistence-modules/spring-data-jpa-4/src/main/java/com/baeldung/namingstrategy/UnquotedUpperCaseNamingStrategy.java

@@ -0,0 +1,12 @@
+package com.baeldung.namingstrategy;
+
+import org.hibernate.boot.model.naming.Identifier;
+import org.hibernate.engine.jdbc.env.spi.JdbcEnvironment;
+import org.springframework.boot.orm.jpa.hibernate.SpringPhysicalNamingStrategy;
+
+public class UnquotedUpperCaseNamingStrategy extends SpringPhysicalNamingStrategy {
+    @Override
+    protected Identifier getIdentifier(String name, boolean quoted, JdbcEnvironment jdbcEnvironment) {
+        return new Identifier(name.toUpperCase(), false);
+    }
+}

persistence-modules/spring-data-jpa-4/src/test/java/com/baeldung/namingstrategy/QuotedLowerCaseNamingStrategyH2IntegrationTest.java

@@ -0,0 +1,81 @@
+package com.baeldung.namingstrategy;
+
+import org.hibernate.exception.SQLGrammarException;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.jdbc.TestDatabaseAutoConfiguration;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.test.context.TestPropertySource;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import javax.persistence.Query;
+import java.math.BigInteger;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+@DataJpaTest(excludeAutoConfiguration = TestDatabaseAutoConfiguration.class)
+@TestPropertySource("quoted-lower-case-naming-strategy.properties")
+class QuotedLowerCaseNamingStrategyH2IntegrationTest {
+
+    @PersistenceContext
+    private EntityManager entityManager;
+
+    @Autowired
+    private PersonRepository personRepository;
+
+    @BeforeEach
+    void insertPeople() {
+        personRepository.saveAll(Arrays.asList(
+          new Person(1L, "John", "Doe"),
+          new Person(2L, "Jane", "Doe"),
+          new Person(3L, "Ted", "Mosby")
+        ));
+    }
+
+    @ParameterizedTest
+    @ValueSource(strings = {"person", "PERSON", "Person"})
+    void givenPeopleAndLowerCaseNamingStrategy_whenQueryPersonUnquoted_thenException(String tableName) {
+        Query query = entityManager.createNativeQuery("select * from " + tableName);
+
+        // Unexpected result
+        assertThrows(SQLGrammarException.class, query::getResultStream);
+    }
+
+    @Test
+    void givenPeopleAndLowerCaseNamingStrategy_whenQueryPersonQuotedUpperCase_thenException() {
+        Query query = entityManager.createNativeQuery("select * from \"PERSON\"");
+
+        // Expected result
+        assertThrows(SQLGrammarException.class, query::getResultStream);
+    }
+
+    @Test
+    void givenPeopleAndLowerCaseNamingStrategy_whenQueryPersonQuotedLowerCase_thenResult() {
+        Query query = entityManager.createNativeQuery("select * from \"person\"");
+
+        // Expected result
+        List<Person> result = (List<Person>) query.getResultStream()
+          .map(this::fromDatabase)
+          .collect(Collectors.toList());
+
+        assertThat(result).isNotEmpty();
+    }
+
+    public Person fromDatabase(Object databaseRow) {
+        Object[] typedDatabaseRow = (Object[]) databaseRow;
+
+        return new Person(
+          ((BigInteger) typedDatabaseRow[0]).longValue(),
+          (String) typedDatabaseRow[1],
+          (String) typedDatabaseRow[2]
+        );
+    }
+}

persistence-modules/spring-data-jpa-4/src/test/java/com/baeldung/namingstrategy/QuotedLowerCaseNamingStrategyPostgresLiveTest.java

@@ -0,0 +1,85 @@
+package com.baeldung.namingstrategy;
+
+import org.hibernate.exception.SQLGrammarException;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.jdbc.TestDatabaseAutoConfiguration;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.test.context.TestPropertySource;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import javax.persistence.Query;
+import java.math.BigInteger;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+@DataJpaTest(excludeAutoConfiguration = TestDatabaseAutoConfiguration.class)
+@TestPropertySource("quoted-lower-case-naming-strategy-on-postgres.properties")
+class QuotedLowerCaseNamingStrategyPostgresLiveTest {
+
+    @PersistenceContext
+    private EntityManager entityManager;
+
+    @Autowired
+    private PersonRepository personRepository;
+
+    @BeforeEach
+    void insertPeople() {
+        personRepository.saveAll(Arrays.asList(
+          new Person(1L, "John", "Doe"),
+          new Person(2L, "Jane", "Doe"),
+          new Person(3L, "Ted", "Mosby")
+        ));
+    }
+
+    @ParameterizedTest
+    @ValueSource(strings = {"person", "PERSON", "Person"})
+    void givenPeopleAndLowerCaseNamingStrategy_whenQueryPersonUnquoted_thenResult(String tableName) {
+        Query query = entityManager.createNativeQuery("select * from " + tableName);
+
+        // Expected result
+        List<Person> result = (List<Person>) query.getResultStream()
+          .map(this::fromDatabase)
+          .collect(Collectors.toList());
+
+        assertThat(result).isNotEmpty();
+    }
+
+    @Test
+    void givenPeopleAndLowerCaseNamingStrategy_whenQueryPersonQuotedUpperCase_thenException() {
+        Query query = entityManager.createNativeQuery("select * from \"PERSON\"");
+
+        // Expected result
+        assertThrows(SQLGrammarException.class, query::getResultStream);
+    }
+
+    @Test
+    void givenPeopleAndLowerCaseNamingStrategy_whenQueryPersonQuotedLowerCase_thenResult() {
+        Query query = entityManager.createNativeQuery("select * from \"person\"");
+
+        // Expected result
+        List<Person> result = (List<Person>) query.getResultStream()
+          .map(this::fromDatabase)
+          .collect(Collectors.toList());
+
+        assertThat(result).isNotEmpty();
+    }
+
+    public Person fromDatabase(Object databaseRow) {
+        Object[] typedDatabaseRow = (Object[]) databaseRow;
+
+        return new Person(
+          ((BigInteger) typedDatabaseRow[0]).longValue(),
+          (String) typedDatabaseRow[1],
+          (String) typedDatabaseRow[2]
+        );
+    }
+}

persistence-modules/spring-data-jpa-4/src/test/java/com/baeldung/namingstrategy/QuotedUpperCaseNamingStrategyH2IntegrationTest.java

@@ -0,0 +1,85 @@
+package com.baeldung.namingstrategy;
+
+import org.hibernate.exception.SQLGrammarException;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.jdbc.TestDatabaseAutoConfiguration;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.test.context.TestPropertySource;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import javax.persistence.Query;
+import java.math.BigInteger;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+@DataJpaTest(excludeAutoConfiguration = TestDatabaseAutoConfiguration.class)
+@TestPropertySource("quoted-upper-case-naming-strategy.properties")
+class QuotedUpperCaseNamingStrategyH2IntegrationTest {
+
+    @PersistenceContext
+    private EntityManager entityManager;
+
+    @Autowired
+    private PersonRepository personRepository;
+
+    @BeforeEach
+    void insertPeople() {
+        personRepository.saveAll(Arrays.asList(
+          new Person(1L, "John", "Doe"),
+          new Person(2L, "Jane", "Doe"),
+          new Person(3L, "Ted", "Mosby")
+        ));
+    }
+
+    @ParameterizedTest
+    @ValueSource(strings = {"person", "PERSON", "Person"})
+    void givenPeopleAndUpperCaseNamingStrategy_whenQueryPersonUnquoted_thenException(String tableName) {
+        Query query = entityManager.createNativeQuery("select * from " + tableName);
+
+        // Expected result
+        List<Person> result = (List<Person>) query.getResultStream()
+          .map(this::fromDatabase)
+          .collect(Collectors.toList());
+
+        assertThat(result).isNotEmpty();
+    }
+
+    @Test
+    void givenPeopleAndUpperCaseNamingStrategy_whenQueryPersonQuotedUpperCase_thenResult() {
+        Query query = entityManager.createNativeQuery("select * from \"PERSON\"");
+
+        // Expected result
+        List<Person> result = (List<Person>) query.getResultStream()
+          .map(this::fromDatabase)
+          .collect(Collectors.toList());
+
+        assertThat(result).isNotEmpty();
+    }
+
+    @Test
+    void givenPeopleAndUpperCaseNamingStrategy_whenQueryPersonQuotedLowerCase_thenException() {
+        Query query = entityManager.createNativeQuery("select * from \"person\"");
+
+        // Expected result
+        assertThrows(SQLGrammarException.class, query::getResultStream);
+    }
+
+    public Person fromDatabase(Object databaseRow) {
+        Object[] typedDatabaseRow = (Object[]) databaseRow;
+
+        return new Person(
+          ((BigInteger) typedDatabaseRow[0]).longValue(),
+          (String) typedDatabaseRow[1],
+          (String) typedDatabaseRow[2]
+        );
+    }
+}

persistence-modules/spring-data-jpa-4/src/test/java/com/baeldung/namingstrategy/QuotedUpperCaseNamingStrategyPostgresLiveTest.java

@@ -0,0 +1,81 @@
+package com.baeldung.namingstrategy;
+
+import org.hibernate.exception.SQLGrammarException;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.jdbc.TestDatabaseAutoConfiguration;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.test.context.TestPropertySource;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import javax.persistence.Query;
+import java.math.BigInteger;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+@DataJpaTest(excludeAutoConfiguration = TestDatabaseAutoConfiguration.class)
+@TestPropertySource("quoted-upper-case-naming-strategy-on-postgres.properties")
+class QuotedUpperCaseNamingStrategyPostgresLiveTest {
+
+    @PersistenceContext
+    private EntityManager entityManager;
+
+    @Autowired
+    private PersonRepository personRepository;
+
+    @BeforeEach
+    void insertPeople() {
+        personRepository.saveAll(Arrays.asList(
+          new Person(1L, "John", "Doe"),
+          new Person(2L, "Jane", "Doe"),
+          new Person(3L, "Ted", "Mosby")
+        ));
+    }
+
+    @ParameterizedTest
+    @ValueSource(strings = {"person", "PERSON", "Person"})
+    void givenPeopleAndUpperCaseNamingStrategy_whenQueryPersonUnquoted_thenResult(String tableName) {
+        Query query = entityManager.createNativeQuery("select * from " + tableName);
+
+        // Unexpected result
+        assertThrows(SQLGrammarException.class, query::getResultStream);
+    }
+
+    @Test
+    void givenPeopleAndUpperCaseNamingStrategy_whenQueryPersonQuotedUpperCase_thenException() {
+        Query query = entityManager.createNativeQuery("select * from \"PERSON\"");
+
+        // Expected result
+        List<Person> result = (List<Person>) query.getResultStream()
+          .map(this::fromDatabase)
+          .collect(Collectors.toList());
+
+        assertThat(result).isNotEmpty();
+    }
+
+    @Test
+    void givenPeopleAndUpperCaseNamingStrategy_whenQueryPersonQuotedLowerCase_thenResult() {
+        Query query = entityManager.createNativeQuery("select * from \"person\"");
+
+        // Expected result
+        assertThrows(SQLGrammarException.class, query::getResultStream);
+    }
+
+    public Person fromDatabase(Object databaseRow) {
+        Object[] typedDatabaseRow = (Object[]) databaseRow;
+
+        return new Person(
+          ((BigInteger) typedDatabaseRow[0]).longValue(),
+          (String) typedDatabaseRow[1],
+          (String) typedDatabaseRow[2]
+        );
+    }
+}

persistence-modules/spring-data-jpa-4/src/test/java/com/baeldung/namingstrategy/SpringPhysicalNamingStrategyH2IntegrationTest.java

@@ -0,0 +1,85 @@
+package com.baeldung.namingstrategy;
+
+import org.hibernate.exception.SQLGrammarException;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.jdbc.TestDatabaseAutoConfiguration;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.test.context.TestPropertySource;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import javax.persistence.Query;
+import java.math.BigInteger;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+@DataJpaTest(excludeAutoConfiguration = TestDatabaseAutoConfiguration.class)
+@TestPropertySource("spring-physical-naming-strategy.properties")
+class SpringPhysicalNamingStrategyH2IntegrationTest {
+
+    @PersistenceContext
+    private EntityManager entityManager;
+
+    @Autowired
+    private PersonRepository personRepository;
+
+    @BeforeEach
+    void insertPeople() {
+        personRepository.saveAll(Arrays.asList(
+          new Person(1L, "John", "Doe"),
+          new Person(2L, "Jane", "Doe"),
+          new Person(3L, "Ted", "Mosby")
+        ));
+    }
+
+    @ParameterizedTest
+    @ValueSource(strings = {"person", "PERSON", "Person"})
+    void givenPeopleAndSpringNamingStrategy_whenQueryPersonUnquoted_thenResult(String tableName) {
+        Query query = entityManager.createNativeQuery("select * from " + tableName);
+
+        // Expected result
+        List<Person> result = (List<Person>) query.getResultStream()
+          .map(this::fromDatabase)
+          .collect(Collectors.toList());
+
+        assertThat(result).isNotEmpty();
+    }
+
+    @Test
+    void givenPeopleAndSpringNamingStrategy_whenQueryPersonQuotedUpperCase_thenResult() {
+        Query query = entityManager.createNativeQuery("select * from \"PERSON\"");
+
+        // Unexpected result
+        List<Person> result = (List<Person>) query.getResultStream()
+          .map(this::fromDatabase)
+          .collect(Collectors.toList());
+
+        assertThat(result).isNotEmpty();
+    }
+
+    @Test
+    void givenPeopleAndSpringNamingStrategy_whenQueryPersonQuotedLowerCase_thenException() {
+        Query query = entityManager.createNativeQuery("select * from \"person\"");
+
+        // Unexpected result
+        assertThrows(SQLGrammarException.class, query::getResultStream);
+    }
+
+    public Person fromDatabase(Object databaseRow) {
+        Object[] typedDatabaseRow = (Object[]) databaseRow;
+
+        return new Person(
+          ((BigInteger) typedDatabaseRow[0]).longValue(),
+          (String) typedDatabaseRow[1],
+          (String) typedDatabaseRow[2]
+        );
+    }
+}

persistence-modules/spring-data-jpa-4/src/test/java/com/baeldung/namingstrategy/SpringPhysicalNamingStrategyPostgresLiveTest.java

@@ -0,0 +1,85 @@
+package com.baeldung.namingstrategy;
+
+import org.hibernate.exception.SQLGrammarException;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.jdbc.TestDatabaseAutoConfiguration;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.test.context.TestPropertySource;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import javax.persistence.Query;
+import java.math.BigInteger;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+@DataJpaTest(excludeAutoConfiguration = TestDatabaseAutoConfiguration.class)
+@TestPropertySource("spring-physical-naming-strategy-on-postgres.properties")
+class SpringPhysicalNamingStrategyPostgresLiveTest {
+
+    @PersistenceContext
+    private EntityManager entityManager;
+
+    @Autowired
+    private PersonRepository personRepository;
+
+    @BeforeEach
+    void insertPeople() {
+        personRepository.saveAll(Arrays.asList(
+          new Person(1L, "John", "Doe"),
+          new Person(2L, "Jane", "Doe"),
+          new Person(3L, "Ted", "Mosby")
+        ));
+    }
+
+    @ParameterizedTest
+    @ValueSource(strings = {"person", "PERSON", "Person"})
+    void givenPeopleAndSpringNamingStrategy_whenQueryPersonUnquoted_thenResult(String tableName) {
+        Query query = entityManager.createNativeQuery("select * from " + tableName);
+
+        // Expected result
+        List<Person> result = (List<Person>) query.getResultStream()
+          .map(this::fromDatabase)
+          .collect(Collectors.toList());
+
+        assertThat(result).isNotEmpty();
+    }
+
+    @Test
+    void givenPeopleAndSpringNamingStrategy_whenQueryPersonQuotedUpperCase_thenException() {
+        Query query = entityManager.createNativeQuery("select * from \"PERSON\"");
+
+        // Expected result
+        assertThrows(SQLGrammarException.class, query::getResultStream);
+    }
+
+    @Test
+    void givenPeopleAndSpringNamingStrategy_whenQueryPersonQuotedLowerCase_thenResult() {
+        Query query = entityManager.createNativeQuery("select * from \"person\"");
+
+        // Expected result
+        List<Person> result = (List<Person>) query.getResultStream()
+          .map(this::fromDatabase)
+          .collect(Collectors.toList());
+
+        assertThat(result).isNotEmpty();
+    }
+
+    public Person fromDatabase(Object databaseRow) {
+        Object[] typedDatabaseRow = (Object[]) databaseRow;
+
+        return new Person(
+          ((BigInteger) typedDatabaseRow[0]).longValue(),
+          (String) typedDatabaseRow[1],
+          (String) typedDatabaseRow[2]
+        );
+    }
+}

persistence-modules/spring-data-jpa-4/src/test/java/com/baeldung/namingstrategy/UnquotedLowerCaseNamingStrategyH2IntegrationTest.java

@@ -0,0 +1,86 @@
+package com.baeldung.namingstrategy;
+
+import org.hibernate.exception.SQLGrammarException;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.jdbc.TestDatabaseAutoConfiguration;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.test.context.TestPropertySource;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import javax.persistence.Query;
+import java.math.BigInteger;
+import java.sql.SQLException;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+@DataJpaTest(excludeAutoConfiguration = TestDatabaseAutoConfiguration.class)
+@TestPropertySource("unquoted-lower-case-naming-strategy.properties")
+class UnquotedLowerCaseNamingStrategyH2IntegrationTest {
+
+    @PersistenceContext
+    private EntityManager entityManager;
+
+    @Autowired
+    private PersonRepository personRepository;
+
+    @BeforeEach
+    void insertPeople() {
+        personRepository.saveAll(Arrays.asList(
+          new Person(1L, "John", "Doe"),
+          new Person(2L, "Jane", "Doe"),
+          new Person(3L, "Ted", "Mosby")
+        ));
+    }
+
+    @ParameterizedTest
+    @ValueSource(strings = {"person", "PERSON", "Person"})
+    void givenPeopleAndLowerCaseNamingStrategy_whenQueryPersonUnquoted_thenResult(String tableName) {
+        Query query = entityManager.createNativeQuery("select * from " + tableName);
+
+        // Expected result
+        List<Person> result = (List<Person>) query.getResultStream()
+          .map(this::fromDatabase)
+          .collect(Collectors.toList());
+
+        assertThat(result).isNotEmpty();
+    }
+
+    @Test
+    void givenPeopleAndLowerCaseNamingStrategy_whenQueryPersonQuotedUpperCase_thenResult() {
+        Query query = entityManager.createNativeQuery("select * from \"PERSON\"");
+
+        // Unexpected result
+        List<Person> result = (List<Person>) query.getResultStream()
+          .map(this::fromDatabase)
+          .collect(Collectors.toList());
+
+        assertThat(result).isNotEmpty();
+    }
+
+    @Test
+    void givenPeopleAndLowerCaseNamingStrategy_whenQueryPersonQuotedLowerCase_thenException() {
+        Query query = entityManager.createNativeQuery("select * from \"person\"");
+
+        // Unexpected result
+        assertThrows(SQLGrammarException.class, query::getResultStream);
+    }
+
+    public Person fromDatabase(Object databaseRow) {
+        Object[] typedDatabaseRow = (Object[]) databaseRow;
+
+        return new Person(
+          ((BigInteger) typedDatabaseRow[0]).longValue(),
+          (String) typedDatabaseRow[1],
+          (String) typedDatabaseRow[2]
+        );
+    }
+}

persistence-modules/spring-data-jpa-4/src/test/java/com/baeldung/namingstrategy/UnquotedLowerCaseNamingStrategyPostgresLiveTest.java

@@ -0,0 +1,85 @@
+package com.baeldung.namingstrategy;
+
+import org.hibernate.exception.SQLGrammarException;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.jdbc.TestDatabaseAutoConfiguration;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.test.context.TestPropertySource;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import javax.persistence.Query;
+import java.math.BigInteger;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+@DataJpaTest(excludeAutoConfiguration = TestDatabaseAutoConfiguration.class)
+@TestPropertySource("unquoted-lower-case-naming-strategy-on-postgres.properties")
+class UnquotedLowerCaseNamingStrategyPostgresLiveTest {
+
+    @PersistenceContext
+    private EntityManager entityManager;
+
+    @Autowired
+    private PersonRepository personRepository;
+
+    @BeforeEach
+    void insertPeople() {
+        personRepository.saveAll(Arrays.asList(
+          new Person(1L, "John", "Doe"),
+          new Person(2L, "Jane", "Doe"),
+          new Person(3L, "Ted", "Mosby")
+        ));
+    }
+
+    @ParameterizedTest
+    @ValueSource(strings = {"person", "PERSON", "Person"})
+    void givenPeopleAndLowerCaseNamingStrategy_whenQueryPersonUnquoted_thenResult(String tableName) {
+        Query query = entityManager.createNativeQuery("select * from " + tableName);
+
+        // Expected result
+        List<Person> result = (List<Person>) query.getResultStream()
+          .map(this::fromDatabase)
+          .collect(Collectors.toList());
+
+        assertThat(result).isNotEmpty();
+    }
+
+    @Test
+    void givenPeopleAndLowerCaseNamingStrategy_whenQueryPersonQuotedUpperCase_thenException() {
+        Query query = entityManager.createNativeQuery("select * from \"PERSON\"");
+
+        // Expected result
+        assertThrows(SQLGrammarException.class, query::getResultStream);
+    }
+
+    @Test
+    void givenPeopleAndLowerCaseNamingStrategy_whenQueryPersonQuotedLowerCase_thenResult() {
+        Query query = entityManager.createNativeQuery("select * from \"person\"");
+
+        // Expected result
+        List<Person> result = (List<Person>) query.getResultStream()
+          .map(this::fromDatabase)
+          .collect(Collectors.toList());
+
+        assertThat(result).isNotEmpty();
+    }
+
+    public Person fromDatabase(Object databaseRow) {
+        Object[] typedDatabaseRow = (Object[]) databaseRow;
+
+        return new Person(
+          ((BigInteger) typedDatabaseRow[0]).longValue(),
+          (String) typedDatabaseRow[1],
+          (String) typedDatabaseRow[2]
+        );
+    }
+}

persistence-modules/spring-data-jpa-4/src/test/java/com/baeldung/namingstrategy/UnquotedUpperCaseNamingStrategyH2IntegrationTest.java

@@ -0,0 +1,85 @@
+package com.baeldung.namingstrategy;
+
+import org.hibernate.exception.SQLGrammarException;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.jdbc.TestDatabaseAutoConfiguration;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.test.context.TestPropertySource;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import javax.persistence.Query;
+import java.math.BigInteger;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+@DataJpaTest(excludeAutoConfiguration = TestDatabaseAutoConfiguration.class)
+@TestPropertySource("unquoted-upper-case-naming-strategy.properties")
+class UnquotedUpperCaseNamingStrategyH2IntegrationTest {
+
+    @PersistenceContext
+    private EntityManager entityManager;
+
+    @Autowired
+    private PersonRepository personRepository;
+
+    @BeforeEach
+    void insertPeople() {
+        personRepository.saveAll(Arrays.asList(
+          new Person(1L, "John", "Doe"),
+          new Person(2L, "Jane", "Doe"),
+          new Person(3L, "Ted", "Mosby")
+        ));
+    }
+
+    @ParameterizedTest
+    @ValueSource(strings = {"person", "PERSON", "Person"})
+    void givenPeopleAndUpperCaseNamingStrategy_whenQueryPersonUnquoted_thenResult(String tableName) {
+        Query query = entityManager.createNativeQuery("select * from " + tableName);
+
+        // Expected result
+        List<Person> result = (List<Person>) query.getResultStream()
+          .map(this::fromDatabase)
+          .collect(Collectors.toList());
+
+        assertThat(result).isNotEmpty();
+    }
+
+    @Test
+    void givenPeopleAndUpperCaseNamingStrategy_whenQueryPersonQuotedUpperCase_thenResult() {
+        Query query = entityManager.createNativeQuery("select * from \"PERSON\"");
+
+        // Expected result
+        List<Person> result = (List<Person>) query.getResultStream()
+          .map(this::fromDatabase)
+          .collect(Collectors.toList());
+
+        assertThat(result).isNotEmpty();
+    }
+
+    @Test
+    void givenPeopleAndUpperCaseNamingStrategy_whenQueryPersonQuotedLowerCase_thenException() {
+        Query query = entityManager.createNativeQuery("select * from \"person\"");
+
+        // Expected result
+        assertThrows(SQLGrammarException.class, query::getResultStream);
+    }
+
+    public Person fromDatabase(Object databaseRow) {
+        Object[] typedDatabaseRow = (Object[]) databaseRow;
+
+        return new Person(
+          ((BigInteger) typedDatabaseRow[0]).longValue(),
+          (String) typedDatabaseRow[1],
+          (String) typedDatabaseRow[2]
+        );
+    }
+}

persistence-modules/spring-data-jpa-4/src/test/java/com/baeldung/namingstrategy/UnquotedUpperCaseNamingStrategyPostgresLiveTest.java

@@ -0,0 +1,85 @@
+package com.baeldung.namingstrategy;
+
+import org.hibernate.exception.SQLGrammarException;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.jdbc.TestDatabaseAutoConfiguration;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.test.context.TestPropertySource;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import javax.persistence.Query;
+import java.math.BigInteger;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+@DataJpaTest(excludeAutoConfiguration = TestDatabaseAutoConfiguration.class)
+@TestPropertySource("unquoted-upper-case-naming-strategy-on-postgres.properties")
+class UnquotedUpperCaseNamingStrategyPostgresLiveTest {
+
+    @PersistenceContext
+    private EntityManager entityManager;
+
+    @Autowired
+    private PersonRepository personRepository;
+
+    @BeforeEach
+    void insertPeople() {
+        personRepository.saveAll(Arrays.asList(
+          new Person(1L, "John", "Doe"),
+          new Person(2L, "Jane", "Doe"),
+          new Person(3L, "Ted", "Mosby")
+        ));
+    }
+
+    @ParameterizedTest
+    @ValueSource(strings = {"person", "PERSON", "Person"})
+    void givenPeopleAndUpperCaseNamingStrategy_whenQueryPersonUnquoted_thenResult(String tableName) {
+        Query query = entityManager.createNativeQuery("select * from " + tableName);
+
+        // Expected result
+        List<Person> result = (List<Person>) query.getResultStream()
+          .map(this::fromDatabase)
+          .collect(Collectors.toList());
+
+        assertThat(result).isNotEmpty();
+    }
+
+    @Test
+    void givenPeopleAndUpperCaseNamingStrategy_whenQueryPersonQuotedUpperCase_thenException() {
+        Query query = entityManager.createNativeQuery("select * from \"PERSON\"");
+
+        // Unexpected result
+        assertThrows(SQLGrammarException.class, query::getResultStream);
+    }
+
+    @Test
+    void givenPeopleAndUpperCaseNamingStrategy_whenQueryPersonQuotedLowerCase_thenResult() {
+        Query query = entityManager.createNativeQuery("select * from \"person\"");
+
+        // Unexpected result
+        List<Person> result = (List<Person>) query.getResultStream()
+          .map(this::fromDatabase)
+          .collect(Collectors.toList());
+
+        assertThat(result).isNotEmpty();
+    }
+
+    public Person fromDatabase(Object databaseRow) {
+        Object[] typedDatabaseRow = (Object[]) databaseRow;
+
+        return new Person(
+          ((BigInteger) typedDatabaseRow[0]).longValue(),
+          (String) typedDatabaseRow[1],
+          (String) typedDatabaseRow[2]
+        );
+    }
+}

persistence-modules/spring-data-jpa-4/src/test/resources/com/baeldung/namingstrategy/quoted-lower-case-naming-strategy-on-postgres.properties

@@ -0,0 +1,9 @@
+spring.datasource.url=jdbc:postgresql://localhost:5432/quoted-lower-case-strategy
+spring.datasource.username=postgres
+spring.datasource.password=root
+
+spring.jpa.hibernate.ddl-auto=create-drop
+spring.jpa.hibernate.naming.physical-strategy=com.baeldung.namingstrategy.QuotedLowerCaseNamingStrategy
+#spring.jpa.properties.javax.persistence.schema-generation.create-source=metadata
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.action=create
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.create-target=upper-case-naming-strategy-ddl.sql

persistence-modules/spring-data-jpa-4/src/test/resources/com/baeldung/namingstrategy/quoted-lower-case-naming-strategy.properties

@@ -0,0 +1,9 @@
+spring.datasource.url=jdbc:h2:mem:quoted-lower-case-strategy
+spring.datasource.username=sa
+spring.datasource.password=
+
+spring.jpa.hibernate.ddl-auto=create-drop
+spring.jpa.hibernate.naming.physical-strategy=com.baeldung.namingstrategy.QuotedLowerCaseNamingStrategy
+#spring.jpa.properties.javax.persistence.schema-generation.create-source=metadata
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.action=create
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.create-target=upper-case-naming-strategy-ddl.sql

persistence-modules/spring-data-jpa-4/src/test/resources/com/baeldung/namingstrategy/quoted-upper-case-naming-strategy-on-postgres.properties

@@ -0,0 +1,9 @@
+spring.datasource.url=jdbc:postgresql://localhost:5432/quoted-upper-case-strategy
+spring.datasource.username=postgres
+spring.datasource.password=root
+
+spring.jpa.hibernate.ddl-auto=create-drop
+spring.jpa.hibernate.naming.physical-strategy=com.baeldung.namingstrategy.QuotedUpperCaseNamingStrategy
+#spring.jpa.properties.javax.persistence.schema-generation.create-source=metadata
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.action=create
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.create-target=upper-case-naming-strategy-ddl.sql

persistence-modules/spring-data-jpa-4/src/test/resources/com/baeldung/namingstrategy/quoted-upper-case-naming-strategy.properties

@@ -0,0 +1,9 @@
+spring.datasource.url=jdbc:h2:mem:quoted-upper-case-strategy
+spring.datasource.username=sa
+spring.datasource.password=
+
+spring.jpa.hibernate.ddl-auto=create-drop
+spring.jpa.hibernate.naming.physical-strategy=com.baeldung.namingstrategy.QuotedUpperCaseNamingStrategy
+#spring.jpa.properties.javax.persistence.schema-generation.create-source=metadata
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.action=create
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.create-target=upper-case-naming-strategy-ddl.sql

persistence-modules/spring-data-jpa-4/src/test/resources/com/baeldung/namingstrategy/spring-physical-naming-strategy-on-postgres.properties

@@ -0,0 +1,9 @@
+spring.datasource.url=jdbc:postgresql://localhost:5432/spring-strategy
+spring.datasource.username=postgres
+spring.datasource.password=root
+
+spring.jpa.hibernate.ddl-auto=create-drop
+spring.jpa.hibernate.naming.physical-strategy=org.springframework.boot.orm.jpa.hibernate.SpringPhysicalNamingStrategy
+#spring.jpa.properties.javax.persistence.schema-generation.create-source=metadata
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.action=create
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.create-target=default-naming-strategy-ddl.sql

persistence-modules/spring-data-jpa-4/src/test/resources/com/baeldung/namingstrategy/spring-physical-naming-strategy.properties

@@ -0,0 +1,9 @@
+spring.datasource.url=jdbc:h2:mem:spring-strategy
+spring.datasource.username=sa
+spring.datasource.password=
+
+spring.jpa.hibernate.ddl-auto=create-drop
+spring.jpa.hibernate.naming.physical-strategy=org.springframework.boot.orm.jpa.hibernate.SpringPhysicalNamingStrategy
+#spring.jpa.properties.javax.persistence.schema-generation.create-source=metadata
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.action=create
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.create-target=default-naming-strategy-ddl.sql

persistence-modules/spring-data-jpa-4/src/test/resources/com/baeldung/namingstrategy/unquoted-lower-case-naming-strategy-on-postgres.properties

@@ -0,0 +1,9 @@
+spring.datasource.url=jdbc:postgresql://localhost:5432/unquoted-lower-case-strategy
+spring.datasource.username=postgres
+spring.datasource.password=root
+
+spring.jpa.hibernate.ddl-auto=create-drop
+spring.jpa.hibernate.naming.physical-strategy=com.baeldung.namingstrategy.UnquotedLowerCaseNamingStrategy
+#spring.jpa.properties.javax.persistence.schema-generation.create-source=metadata
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.action=create
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.create-target=upper-case-naming-strategy-ddl.sql

persistence-modules/spring-data-jpa-4/src/test/resources/com/baeldung/namingstrategy/unquoted-lower-case-naming-strategy.properties

@@ -0,0 +1,9 @@
+spring.datasource.url=jdbc:h2:mem:unquoted-lower-case-strategy
+spring.datasource.username=sa
+spring.datasource.password=
+
+spring.jpa.hibernate.ddl-auto=create-drop
+spring.jpa.hibernate.naming.physical-strategy=com.baeldung.namingstrategy.UnquotedLowerCaseNamingStrategy
+#spring.jpa.properties.javax.persistence.schema-generation.create-source=metadata
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.action=create
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.create-target=upper-case-naming-strategy-ddl.sql

persistence-modules/spring-data-jpa-4/src/test/resources/com/baeldung/namingstrategy/unquoted-upper-case-naming-strategy-on-postgres.properties

@@ -0,0 +1,9 @@
+spring.datasource.url=jdbc:postgresql://localhost:5432/unquoted-upper-case-strategy
+spring.datasource.username=postgres
+spring.datasource.password=root
+
+spring.jpa.hibernate.ddl-auto=create-drop
+spring.jpa.hibernate.naming.physical-strategy=com.baeldung.namingstrategy.UnquotedUpperCaseNamingStrategy
+#spring.jpa.properties.javax.persistence.schema-generation.create-source=metadata
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.action=create
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.create-target=upper-case-naming-strategy-ddl.sql

persistence-modules/spring-data-jpa-4/src/test/resources/com/baeldung/namingstrategy/unquoted-upper-case-naming-strategy.properties

@@ -0,0 +1,9 @@
+spring.datasource.url=jdbc:h2:mem:unquoted-upper-case-strategy
+spring.datasource.username=sa
+spring.datasource.password=
+
+spring.jpa.hibernate.ddl-auto=create-drop
+spring.jpa.hibernate.naming.physical-strategy=com.baeldung.namingstrategy.UnquotedUpperCaseNamingStrategy
+#spring.jpa.properties.javax.persistence.schema-generation.create-source=metadata
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.action=create
+#spring.jpa.properties.javax.persistence.schema-generation.scripts.create-target=upper-case-naming-strategy-ddl.sql

persistence-modules/spring-hibernate4/README.md

@@ -9,7 +9,6 @@ This module contains articles about Spring with Hibernate 4
 - [Stored Procedures with Hibernate](https://www.baeldung.com/stored-procedures-with-hibernate-tutorial)
 - [Hibernate: save, persist, update, merge, saveOrUpdate](https://www.baeldung.com/hibernate-save-persist-update-merge-saveorupdate)
 - [Eager/Lazy Loading In Hibernate](https://www.baeldung.com/hibernate-lazy-eager-loading)
-- [The DAO with Spring and Hibernate](https://www.baeldung.com/persistence-layer-with-spring-and-hibernate)
 - [Auditing with JPA, Hibernate, and Spring Data JPA](https://www.baeldung.com/database-auditing-jpa)
 
 ### Quick Start

persistence-modules/spring-persistence-simple-2/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Spring JdbcTemplate Unit Testing](https://www.baeldung.com/spring-jdbctemplate-testing)

pom.xml

@@ -453,6 +453,7 @@
 
                 <module>java-collections-conversions</module>
                 <module>java-collections-conversions-2</module>
+                <module>java-collections-maps-3</module>
                 <!-- <module>java-ee-8-security-api</module> --> <!-- long running -->
 
                 <module>javafx</module>
@@ -564,6 +565,8 @@
                 <module>rxjava-libraries</module>
                 <module>rxjava-observables</module>
                 <module>rxjava-operators</module>
+
+				<module>atomikos</module>
             </modules>
 
         </profile>
@@ -803,7 +806,7 @@
 
                 <module>jenkins/plugins</module>
                 <module>jhipster</module>
-                <module>jws</module>
+                <!-- <module>jws</module> --> <!-- Failing the build. Fixing in http://jira.baeldung.com/browse/BAEL-3992 -->
 
                 <module>libraries</module> <!-- very long running -->
 
@@ -963,6 +966,7 @@
 
                 <module>java-collections-conversions</module>
                 <module>java-collections-conversions-2</module>
+                <module>java-collections-maps-3</module>
                 <!-- <module>java-ee-8-security-api</module> --> <!-- long running -->
 
                 <module>javafx</module>
@@ -1073,6 +1077,8 @@
                 <module>rxjava-libraries</module>
                 <module>rxjava-observables</module>
                 <module>rxjava-operators</module>
+
+				<module>atomikos</module>
             </modules>
 
         </profile>
@@ -1296,7 +1302,7 @@
 
                 <module>jenkins/plugins</module>
                 <module>jhipster</module>
-                <module>jws</module>
+                <!-- <module>jws</module> --> <!-- Failing the build. Fixing in http://jira.baeldung.com/browse/BAEL-3992 -->
 
                 <module>libraries</module> <!-- very long running -->
 

spring-5-mvc/README.md

@@ -6,3 +6,4 @@ This module contains articles about Spring 5 model-view-controller (MVC) pattern
 - [Spring Boot and Kotlin](https://www.baeldung.com/spring-boot-kotlin)
 - [Spring MVC Streaming and SSE Request Processing](https://www.baeldung.com/spring-mvc-sse-streams)
 - [Interface Driven Controllers in Spring](https://www.baeldung.com/spring-interface-driven-controllers)
+- [Returning Plain HTML From a Spring MVC Controller](https://www.baeldung.com/spring-mvc-return-html)

spring-batch/README.md

@@ -3,6 +3,7 @@
 This module contains articles about Spring Batch
 
 ### Relevant Articles: 
+
 - [Introduction to Spring Batch](https://www.baeldung.com/introduction-to-spring-batch)
 - [Spring Batch using Partitioner](https://www.baeldung.com/spring-batch-partitioner)
 - [Spring Batch – Tasklets vs Chunks](https://www.baeldung.com/spring-batch-tasklet-chunk)
@@ -10,3 +11,4 @@ This module contains articles about Spring Batch
 - [Configuring Skip Logic in Spring Batch](https://www.baeldung.com/spring-batch-skip-logic)
 - [Testing a Spring Batch Job](https://www.baeldung.com/spring-batch-testing-job)
 - [Configuring Retry Logic in Spring Batch](https://www.baeldung.com/spring-batch-retry-logic)
+- [Conditional Flow in Spring Batch](https://www.baeldung.com/spring-batch-conditional-flow)

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

@@ -28,6 +28,10 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-tomcat</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-jpa</artifactId>
+        </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>

spring-boot-modules/spring-boot-libraries/src/main/java/com/baeldung/scheduling/shedlock/SpringBootShedlockApplication.java

@@ -1,4 +1,4 @@
-package com.baeldung;
+package com.baeldung.scheduling.shedlock;
 
 import net.javacrumbs.shedlock.spring.annotation.EnableSchedulerLock;
 import org.springframework.boot.SpringApplication;
@@ -8,8 +8,8 @@ import org.springframework.scheduling.annotation.EnableScheduling;
 @SpringBootApplication
 @EnableScheduling
 @EnableSchedulerLock(defaultLockAtMostFor = "PT30S")
-public class Application {
+public class SpringBootShedlockApplication {
     public static void main(String[] args) {
-        SpringApplication.run(Application.class, args);
+        SpringApplication.run(SpringBootShedlockApplication.class, args);
     }
 }