Merge branch 'master' into master

README.md

@@ -32,7 +32,7 @@ Running a Spring Boot module
 ====================
 To run a Spring Boot module run the command: `mvn spring-boot:run` in the module directory
 
-#Running Tests
+###Running Tests
 
 The command `mvn clean install` will run the unit tests in a module.
 To run the integration tests, use the command `mvn clean install -Pintegration-lite-first`

algorithms-miscellaneous-3/README.md

@@ -6,4 +6,4 @@
 - [Practical Java Examples of the Big O Notation](http://www.baeldung.com/java-algorithm-complexity)
 - [Checking If a List Is Sorted in Java](https://www.baeldung.com/java-check-if-list-sorted)
 - [Checking if a Java Graph has a Cycle](https://www.baeldung.com/java-graph-has-a-cycle)
-- [A Guide to the Folding Technique](https://www.baeldung.com/folding-hashing-technique)
+- [A Guide to the Folding Technique in Java](https://www.baeldung.com/folding-hashing-technique)

core-groovy-2/src/main/groovy/com/baeldung/concatenate/Wonder.groovy

@@ -0,0 +1,52 @@
+package com.baeldung.concatenate
+
+class Wonder {
+
+    String numOfWonder = 'seven'
+
+    String operator_plus() {
+        return 'The ' + numOfWonder + ' wonders of the world'
+    }
+
+    String operator_left() {
+        return 'The ' << numOfWonder << ' wonders of ' << 'the world'
+    }
+
+    String interpolation_one() {
+        return "The $numOfWonder wonders of the world"
+
+    }
+
+    String interpolation_two() {
+        return "The ${numOfWonder} wonders of the world"
+    }
+
+    String multilineString() {
+        return """
+            There are $numOfWonder wonders of the world.
+            Can you name them all? 
+            1. The Great Pyramid of Giza
+            2. Hanging Gardens of Babylon
+            3. Colossus of Rhode
+            4. Lighthouse of Alexendra
+            5. Temple of Artemis
+            6. Status of Zeus at Olympia
+            7. Mausoleum at Halicarnassus
+        """
+    }
+
+    String method_concat() {
+        return 'The '.concat(numOfWonder).concat(' wonders of the world')
+
+    }
+
+    String method_builder() {
+        return new StringBuilder()
+                .append('The ').append(numOfWonder).append(' wonders of the world')
+    }
+
+    String method_buffer() {
+        return new StringBuffer()
+                .append('The ').append(numOfWonder).append(' wonders of the world')
+    }
+}

core-groovy-2/src/test/groovy/com/baeldung/concatenate/WonderUnitTest.groovy

@@ -0,0 +1,69 @@
+package com.baeldung.concatenate
+
+import org.junit.Before
+import org.junit.Test
+
+import static org.junit.Assert.*
+
+class WonderUnitTest {
+
+    static final String EXPECTED_SINGLE_LINE = "The seven wonders of the world"
+
+    Wonder wonder
+
+    @Before
+    void before() {
+        wonder = new Wonder()
+    }
+
+    @Test
+    void whenUsingOperatorPlus_thenConcatCorrectly() {
+        assertEquals(EXPECTED_SINGLE_LINE, wonder.operator_plus())
+    }
+
+    @Test
+    void whenUsingOperatorLeft_thenConcatCorrectly() {
+        assertEquals(EXPECTED_SINGLE_LINE, wonder.operator_left())
+    }
+
+    @Test
+    void whenUsingInterpolationOne_thenConcatCorrectly() {
+        assertEquals(EXPECTED_SINGLE_LINE, wonder.interpolation_one())
+    }
+
+    @Test
+    void whenUsingInterpolationTwo_thenConcatCorrectly() {
+        assertEquals(EXPECTED_SINGLE_LINE, wonder.interpolation_two())
+    }
+
+    @Test
+    void whenUsingMultiline_thenConcatCorrectly() {
+        def expectedMultiline = """
+            There are seven wonders of the world.
+            Can you name them all? 
+            1. The Great Pyramid of Giza
+            2. Hanging Gardens of Babylon
+            3. Colossus of Rhode
+            4. Lighthouse of Alexendra
+            5. Temple of Artemis
+            6. Status of Zeus at Olympia
+            7. Mausoleum at Halicarnassus
+        """
+        assertEquals(expectedMultiline, wonder.multilineString())
+    }
+
+    @Test
+    void whenUsingMethodConcat_thenConcatCorrectly() {
+        assertEquals(EXPECTED_SINGLE_LINE, wonder.method_concat())
+    }
+
+    @Test
+    void whenUsingMethodBuilder_thenConcatCorrectly() {
+        assertEquals(EXPECTED_SINGLE_LINE, wonder.method_builder())
+    }
+
+    @Test
+    void whenUsingMethodBuffer_thenConcatCorrectly() {
+        assertEquals(EXPECTED_SINGLE_LINE, wonder.method_buffer())
+    }
+}

core-java-modules/core-java-11/src/main/java/com/baeldung/predicate/not/README.md

@@ -0,0 +1,3 @@
+## Relevant articles:
+
+- [Negate a Predicate Method Reference with Java 11](https://www.baeldung.com/java-negate-predicate-method-reference)

core-java-modules/core-java-12/README.md

@@ -0,0 +1,3 @@
+## Relevant articles:
+
+- [String API Updates in Java 12](https://www.baeldung.com/java12-string-api)

core-java-modules/core-java-8/src/test/java/com/baeldung/java8/optional/OptionalUnitTest.java

@@ -259,4 +259,15 @@ public class OptionalUnitTest {
         LOG.debug("Getting default value...");
         return "Default Value";
     }
+    
+//    Uncomment code when code base is compatiable with Java 11     
+//    @Test
+//    public void givenAnEmptyOptional_thenIsEmptyBehavesAsExpected() {
+//        Optional<String> opt = Optional.of("Baeldung");
+//        assertFalse(opt.isEmpty());
+//     
+//        opt = Optional.ofNullable(null);
+//        assertTrue(opt.isEmpty());
+//    }
+
 }

core-java-modules/core-java-collections-array-list/src/test/java/org/baeldung/java/collections/CoreJavaCollectionsUnitTest.java

@@ -42,7 +42,7 @@ public class CoreJavaCollectionsUnitTest {
     @Test(expected = UnsupportedOperationException.class)
     public final void givenUsingGuavaBuilder_whenUnmodifiableListIsCreatedFromOriginal_thenNoLongerModifiable() {
         final List<String> list = new ArrayList<String>(Arrays.asList("one", "two", "three"));
-        final ImmutableList<Object> unmodifiableList = ImmutableList.builder().addAll(list).build();
+        final ImmutableList<String> unmodifiableList = ImmutableList.<String>builder().addAll(list).build();
         unmodifiableList.add("four");
     }
 

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

@@ -17,3 +17,4 @@
 - [Runnable vs. Callable in Java](http://www.baeldung.com/java-runnable-callable)
 - [What is Thread-Safety and How to Achieve it?](https://www.baeldung.com/java-thread-safety)
 - [How to Start a Thread in Java](https://www.baeldung.com/java-start-thread)
+- [How to Delay Code Execution in Java](https://www.baeldung.com/java-delay-code-execution)

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

@@ -0,0 +1,3 @@
+## Relevant articles:
+
+- [Will an Error Be Caught by Catch Block in Java?](https://www.baeldung.com/java-error-catch)

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

@@ -0,0 +1,3 @@
+## Relevant articles:
+
+- [Why Do Local Variables Used in Lambdas Have to Be Final or Effectively Final?](https://www.baeldung.com/java-lambda-effectively-final-local-variables)

java-strings-2/README.MD

@@ -4,3 +4,4 @@
 - [Check If a String Contains a Substring](https://www.baeldung.com/java-string-contains-substring)
 - [Removing Stopwords from a String in Java](https://www.baeldung.com/java-string-remove-stopwords)
 - [Blank and Empty Strings in Java](https://www.baeldung.com/java-blank-empty-strings)
+- [String Initialization in Java](https://www.baeldung.com/java-string-initialization)

jhipster/README.md

@@ -1,6 +0,0 @@
-## Relevant articles:
-
-- [JHipster with a Microservice Architecture](http://www.baeldung.com/jhipster-microservices)
-- [Intro to JHipster](http://www.baeldung.com/jhipster)
-- [Building a Basic UAA-Secured JHipster Microservice](https://www.baeldung.com/jhipster-uaa-secured-micro-service)
-- [Creating New Roles and Authorities in JHipster](https://www.baeldung.com/jhipster-new-roles)

morphia/README.md

@@ -1,3 +0,0 @@
-### Relevant Articles:
-
-- [Intro to Morphia](http://www.baeldung.com/intro-to-morphia)

morphia/pom.xml

@@ -1,43 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xmlns="http://maven.apache.org/POM/4.0.0"
-	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-	<modelVersion>4.0.0</modelVersion>
-	<groupId>com.baeldung.morphia</groupId>
-	<artifactId>morphia</artifactId>
-	<name>morphia</name>
-
-	<parent>
-		<groupId>com.baeldung</groupId>
-		<artifactId>parent-modules</artifactId>
-		<version>1.0.0-SNAPSHOT</version>
-		<relativePath>..</relativePath>
-	</parent>
-
-	<dependencies>
-		<dependency>
-			<groupId>dev.morphia.morphia</groupId>
-			<artifactId>core</artifactId>
-			<version>${morphia.version}</version>
-		</dependency>
-
-	</dependencies>
-
-	<build>
-		<pluginManagement>
-			<plugins>
-				<plugin>
-					<groupId>org.springframework.boot</groupId>
-					<artifactId>spring-boot-maven-plugin</artifactId>
-					<version>${spring-boot-maven-plugin.version}</version>
-				</plugin>
-			</plugins>
-		</pluginManagement>
-	</build>
-
-	<properties>
-		<spring-boot-maven-plugin.version>1.4.2.RELEASE</spring-boot-maven-plugin.version>
-		<morphia.version>1.5.3</morphia.version>
-	</properties>
-
-</project>

persistence-modules/hibernate-mapping/README.md

@@ -4,3 +4,4 @@
 - [Persisting Maps with Hibernate](https://www.baeldung.com/hibernate-persisting-maps)
 - [Difference Between @Size, @Length, and @Column(length=value)](https://www.baeldung.com/jpa-size-length-column-differences)
 - [Hibernate Validator Specific Constraints](https://www.baeldung.com/hibernate-validator-constraints)
+- [Hibernate One to Many Annotation Tutorial](http://www.baeldung.com/hibernate-one-to-many)

persistence-modules/hibernate-mapping/pom.xml

@@ -58,7 +58,7 @@
         <finalName>hibernate-mapping</finalName>
         <resources>
             <resource>
-                <directory>src/test/resources</directory>
+                <directory>src/main/resources</directory>
                 <filtering>true</filtering>
             </resource>
         </resources>

persistence-modules/hibernate-mapping/src/main/java/com/baeldung/hibernate/oneToMany/config/HibernateAnnotationUtil.java

@@ -1,8 +1,9 @@
 package com.baeldung.hibernate.oneToMany.config;
 
 import org.hibernate.SessionFactory;
+import org.hibernate.boot.Metadata;
+import org.hibernate.boot.MetadataSources;
 import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
-import org.hibernate.cfg.Configuration;
 import org.hibernate.service.ServiceRegistry;
 
 public class HibernateAnnotationUtil {
@@ -12,16 +13,12 @@ public class HibernateAnnotationUtil {
     private static SessionFactory buildSessionFactory() {
         try {
             // Create the SessionFactory from hibernate-annotation.cfg.xml
-            Configuration configuration = new Configuration();
-            configuration.configure("hibernate-annotation.cfg.xml");
-            System.out.println("Hibernate Annotation Configuration loaded");
-
-            ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties()).build();
-            System.out.println("Hibernate Annotation serviceRegistry created");
-
-            SessionFactory sessionFactory = configuration.buildSessionFactory(serviceRegistry);
+            ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().configure("hibernate-annotation.cfg.xml").build();
+            Metadata metadata = new MetadataSources(serviceRegistry).getMetadataBuilder().build();
+            SessionFactory sessionFactory = metadata.getSessionFactoryBuilder().build();
 
             return sessionFactory;
+
         } catch (Throwable ex) {
             System.err.println("Initial SessionFactory creation failed." + ex);
             ex.printStackTrace();

persistence-modules/hibernate-mapping/src/main/resources/hibernate-annotation.cfg.xml

@@ -4,11 +4,11 @@
 		"http://hibernate.org/dtd/hibernate-configuration-3.0.dtd">
 <hibernate-configuration>
     <session-factory>
-        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
-        <property name="hibernate.connection.password">mypassword</property>
-        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/spring_hibernate_one_to_many?createDatabaseIfNotExist=true</property>
-        <property name="hibernate.connection.username">myuser</property>
-        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
+        <property name="hibernate.connection.driver_class">org.h2.Driver</property>
+        <property name="hibernate.connection.password"></property>
+        <property name="hibernate.connection.url">jdbc:h2:mem:spring_hibernate_one_to_many</property>
+        <property name="hibernate.connection.username">sa</property>
+        <property name="hibernate.dialect">org.hibernate.dialect.H2Dialect</property>
         <property name="hbm2ddl.auto">create</property>
         <property name="hibernate.current_session_context_class">thread</property>
         <property name="hibernate.show_sql">true</property>

persistence-modules/hibernate-mapping/src/test/java/com/baeldung/hibernate/oneToMany/main/HibernateOneToManyAnnotationMainIntegrationTest.java

@@ -10,7 +10,7 @@ import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
 import org.hibernate.cfg.Configuration;
-import org.hibernate.dialect.HSQLDialect;
+import org.hibernate.dialect.H2Dialect;
 import org.hibernate.service.ServiceRegistry;
 import org.junit.After;
 import org.junit.AfterClass;
@@ -18,6 +18,7 @@ import org.junit.Assert;
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Test;
+
 import com.baeldung.hibernate.oneToMany.model.Cart;
 import com.baeldung.hibernate.oneToMany.model.Items;
 
@@ -33,9 +34,9 @@ public class HibernateOneToManyAnnotationMainIntegrationTest {
 	@BeforeClass
 	public static void beforeTests() {
 		Configuration configuration = new Configuration().addAnnotatedClass(Cart.class).addAnnotatedClass(Items.class)
-				.setProperty("hibernate.dialect", HSQLDialect.class.getName())
-				.setProperty("hibernate.connection.driver_class", org.hsqldb.jdbcDriver.class.getName())
-				.setProperty("hibernate.connection.url", "jdbc:hsqldb:mem:test")
+				.setProperty("hibernate.dialect", H2Dialect.class.getName())
+				.setProperty("hibernate.connection.driver_class", org.h2.Driver.class.getName())
+				.setProperty("hibernate.connection.url", "jdbc:h2:mem:test")
 				.setProperty("hibernate.connection.username", "sa").setProperty("hibernate.connection.password", "")
 				.setProperty("hibernate.hbm2ddl.auto", "update");
 		ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()

persistence-modules/java-jpa/README.md

@@ -13,3 +13,4 @@
 - [Defining JPA Entities](https://www.baeldung.com/jpa-entities)
 - [JPA @Basic Annotation](https://www.baeldung.com/jpa-basic-annotation)
 - [Default Column Values in JPA](https://www.baeldung.com/jpa-default-column-values)
+- [Persisting Enums in JPA](https://www.baeldung.com/jpa-persisting-enums-in-jpa)