Merge branch 'master' into master

2019-06-07 19:02:45 -05:00
parent c18bb8e188 0ece18c766
commit f9daccc5b2
68 changed files with 1845 additions and 197 deletions
@@ -0,0 +1,40 @@
+package com.baeldung.xml
+
+import groovy.xml.MarkupBuilder
+import groovy.xml.XmlUtil
+import spock.lang.Specification
+
+class MarkupBuilderUnitTest extends Specification {
+
+    def xmlFile = getClass().getResource("articles_short_formatted.xml")
+
+def "Should create XML properly"() {
+    given: "Node structures"
+
+    when: "Using MarkupBuilderUnitTest to create com.baeldung.xml structure"
+    def writer = new StringWriter()
+    new MarkupBuilder(writer).articles {
+        article {
+            title('First steps in Java')
+            author(id: '1') {
+                firstname('Siena')
+                lastname('Kerr')
+            }
+            'release-date'('2018-12-01')
+        }
+        article {
+            title('Dockerize your SpringBoot application')
+            author(id: '2') {
+                firstname('Jonas')
+                lastname('Lugo')
+            }
+            'release-date'('2018-12-01')
+        }
+    }
+
+    then: "Xml is created properly"
+    XmlUtil.serialize(writer.toString()) == XmlUtil.serialize(xmlFile.text)
+}
+
+
+}
@@ -0,0 +1,94 @@
+package com.baeldung.xml
+
+
+import spock.lang.Shared
+import spock.lang.Specification
+
+class XmlParserUnitTest extends Specification {
+
+    def xmlFile = getClass().getResourceAsStream("articles.xml")
+
+    @Shared
+    def parser = new XmlParser()
+
+    def "Should read XML file properly"() {
+        given: "XML file"
+
+        when: "Using XmlParser to read file"
+        def articles = parser.parse(xmlFile)
+
+        then: "Xml is loaded properly"
+        articles.'*'.size() == 4
+        articles.article[0].author.firstname.text() == "Siena"
+        articles.article[2].'release-date'.text() == "2018-06-12"
+        articles.article[3].title.text() == "Java 12 insights"
+        articles.article.find { it.author.'@id'.text() == "3" }.author.firstname.text() == "Daniele"
+    }
+
+
+    def "Should add node to existing com.baeldung.xml using NodeBuilder"() {
+        given: "XML object"
+        def articles = parser.parse(xmlFile)
+
+        when: "Adding node to com.baeldung.xml"
+        def articleNode = new NodeBuilder().article(id: '5') {
+            title('Traversing XML in the nutshell')
+            author {
+                firstname('Martin')
+                lastname('Schmidt')
+            }
+            'release-date'('2019-05-18')
+        }
+        articles.append(articleNode)
+
+        then: "Node is added to com.baeldung.xml properly"
+        articles.'*'.size() == 5
+        articles.article[4].title.text() == "Traversing XML in the nutshell"
+    }
+
+    def "Should replace node"() {
+        given: "XML object"
+        def articles = parser.parse(xmlFile)
+
+        when: "Adding node to com.baeldung.xml"
+        def articleNode = new NodeBuilder().article(id: '5') {
+            title('Traversing XML in the nutshell')
+            author {
+                firstname('Martin')
+                lastname('Schmidt')
+            }
+            'release-date'('2019-05-18')
+        }
+        articles.article[0].replaceNode(articleNode)
+
+        then: "Node is added to com.baeldung.xml properly"
+        articles.'*'.size() == 4
+        articles.article[0].title.text() == "Traversing XML in the nutshell"
+    }
+
+    def "Should modify node"() {
+        given: "XML object"
+        def articles = parser.parse(xmlFile)
+
+        when: "Changing value of one of the nodes"
+        articles.article.each { it.'release-date'[0].value = "2019-05-18" }
+
+        then: "XML is updated"
+        articles.article.findAll { it.'release-date'.text() != "2019-05-18" }.isEmpty()
+    }
+
+    def "Should remove article from com.baeldung.xml"() {
+        given: "XML object"
+        def articles = parser.parse(xmlFile)
+
+        when: "Removing all articles but with id==3"
+        articles.article
+          .findAll { it.author.'@id'.text() != "3" }
+          .each { articles.remove(it) }
+
+        then: "There is only one article left"
+        articles.children().size() == 1
+        articles.article[0].author.'@id'.text() == "3"
+    }
+
+}
@@ -0,0 +1,102 @@
+package com.baeldung.xml
+
+
+import groovy.xml.XmlUtil
+import spock.lang.Shared
+import spock.lang.Specification
+
+class XmlSlurperUnitTest extends Specification {
+
+    def xmlFile = getClass().getResourceAsStream("articles.xml")
+
+    @Shared
+    def parser = new XmlSlurper()
+
+    def "Should read XML file properly"() {
+        given: "XML file"
+
+        when: "Using XmlSlurper to read file"
+        def articles = parser.parse(xmlFile)
+
+        then: "Xml is loaded properly"
+        articles.'*'.size() == 4
+        articles.article[0].author.firstname == "Siena"
+        articles.article[2].'release-date' == "2018-06-12"
+        articles.article[3].title == "Java 12 insights"
+        articles.article.find { it.author.'@id' == "3" }.author.firstname == "Daniele"
+    }
+
+    def "Should add node to existing com.baeldung.xml"() {
+        given: "XML object"
+        def articles = parser.parse(xmlFile)
+
+        when: "Adding node to com.baeldung.xml"
+        articles.appendNode {
+            article(id: '5') {
+                title('Traversing XML in the nutshell')
+                author {
+                    firstname('Martin')
+                    lastname('Schmidt')
+                }
+                'release-date'('2019-05-18')
+            }
+        }
+
+        articles = parser.parseText(XmlUtil.serialize(articles))
+
+        then: "Node is added to com.baeldung.xml properly"
+        articles.'*'.size() == 5
+        articles.article[4].title == "Traversing XML in the nutshell"
+    }
+
+    def "Should modify node"() {
+        given: "XML object"
+        def articles = parser.parse(xmlFile)
+
+        when: "Changing value of one of the nodes"
+        articles.article.each { it.'release-date' = "2019-05-18" }
+
+        then: "XML is updated"
+        articles.article.findAll { it.'release-date' != "2019-05-18" }.isEmpty()
+    }
+
+    def "Should replace node"() {
+        given: "XML object"
+        def articles = parser.parse(xmlFile)
+
+        when: "Replacing node"
+        articles.article[0].replaceNode {
+            article(id: '5') {
+                title('Traversing XML in the nutshell')
+                author {
+                    firstname('Martin')
+                    lastname('Schmidt')
+                }
+                'release-date'('2019-05-18')
+            }
+        }
+
+        articles = parser.parseText(XmlUtil.serialize(articles))
+
+        then: "Node is replaced properly"
+        articles.'*'.size() == 4
+        articles.article[0].title == "Traversing XML in the nutshell"
+    }
+
+    def "Should remove article from com.baeldung.xml"() {
+        given: "XML object"
+        def articles = parser.parse(xmlFile)
+
+        when: "Removing all articles but with id==3"
+        articles.article
+          .findAll { it.author.'@id' != "3" }
+          .replaceNode {}
+
+        articles = parser.parseText(XmlUtil.serialize(articles))
+
+        then: "There is only one article left"
+        articles.children().size() == 1
+        articles.article[0].author.'@id' == "3"
+    }
+
+}
@@ -0,0 +1,34 @@
+<articles>
+    <article>
+        <title>First steps in Java</title>
+        <author id='1'>
+            <firstname>Siena</firstname>
+            <lastname>Kerr</lastname>
+        </author>
+        <release-date>2018-12-01</release-date>
+    </article>
+    <article>
+        <title>Dockerize your SpringBoot application</title>
+        <author id='2'>
+            <firstname>Jonas</firstname>
+            <lastname>Lugo</lastname>
+        </author>
+        <release-date>2018-12-01</release-date>
+    </article>
+    <article>
+        <title>SpringBoot tutorial</title>
+        <author id='3'>
+            <firstname>Daniele</firstname>
+            <lastname>Ferguson</lastname>
+        </author>
+        <release-date>2018-06-12</release-date>
+    </article>
+    <article>
+        <title>Java 12 insights</title>
+        <author id='1'>
+            <firstname>Siena</firstname>
+            <lastname>Kerr</lastname>
+        </author>
+        <release-date>2018-07-22</release-date>
+    </article>
+</articles>
@@ -0,0 +1,18 @@
+<articles>
+  <article>
+    <title>First steps in Java</title>
+    <author id='1'>
+      <firstname>Siena</firstname>
+      <lastname>Kerr</lastname>
+    </author>
+    <release-date>2018-12-01</release-date>
+  </article>
+  <article>
+    <title>Dockerize your SpringBoot application</title>
+    <author id='2'>
+      <firstname>Jonas</firstname>
+      <lastname>Lugo</lastname>
+    </author>
+    <release-date>2018-12-01</release-date>
+  </article>
+</articles>
@@ -1,15 +0,0 @@
-package com.baeldung.error;
-
-public class ErrorGenerator {
-    public void throwException() throws Exception {
-        throw new Exception("checked");
-    }
-
-    public void throwRuntimeException() {
-        throw new RuntimeException("unchecked");
-    }
-
-    public void throwError() {
-        throw new Error("unchecked");
-    }
-}
@@ -1,51 +0,0 @@
-package com.baeldung.error;
-
-import org.junit.Assert;
-import org.junit.Before;
-import org.junit.Test;
-
-public class ErrorGeneratorUnitTest {
-
-    private ErrorGenerator errorGenerator;
-
-    @Before
-    public void setUp() {
-        errorGenerator = new ErrorGenerator();
-    }
-
-    @Test
-    public void whenCheckedException_thenIsCaughtByCatchException() {
-        try {
-            errorGenerator.throwException();
-        } catch (Exception e) {
-            // caught! -> test pass
-        }
-    }
-
-    @Test
-    public void whenUncheckedException_thenIsCaughtByCatchException() {
-        try {
-            errorGenerator.throwRuntimeException();
-        } catch (Exception e) {
-            // caught! -> test pass
-        }
-    }
-
-    @Test(expected = Error.class)
-    public void whenError_thenIsNotCaughtByCatchException() {
-        try {
-            errorGenerator.throwError();
-        } catch (Exception e) {
-            Assert.fail(); // errors are not caught by catch exception
-        }
-    }
-
-    @Test
-    public void whenError_thenIsCaughtByCatchError() {
-        try {
-            errorGenerator.throwError();
-        } catch (Error e) {
-            // caught! -> test pass
-        }
-    }
-}
@@ -22,6 +22,9 @@
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <icu.version>64.2</icu.version>
+        <hibernate.core.version>5.4.0.Final</hibernate.core.version>
+        <h2database.version>1.4.197</h2database.version>
+        <jackson.databind.version>2.9.8</jackson.databind.version>
    </properties>

    <dependencies>
@@ -30,7 +33,21 @@
            <artifactId>icu4j</artifactId>
            <version>${icu.version}</version>
        </dependency>
-
+        <dependency>
+            <groupId>org.hibernate</groupId>
+            <artifactId>hibernate-core</artifactId>
+            <version>${hibernate.core.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+            <version>${h2database.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>${jackson.databind.version}</version>
+        </dependency>
    </dependencies>

    <build>
@@ -0,0 +1,41 @@
+package com.baeldung.optionalReturnType;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+
+public class HandleOptionalTypeExample {
+    static Map<String, User> usersByName = new HashMap();
+    static {
+        User user1 = new User();
+        user1.setUserId(1l);
+        user1.setFirstName("baeldung");
+        usersByName.put("baeldung", user1);
+    }
+
+    public static void main(String[] args) {
+        changeUserName("baeldung", "baeldung-new");
+        changeUserName("user", "user-new");
+    }
+
+    public static void changeUserName(String oldFirstName, String newFirstName) {
+        Optional<User> userOpt = findUserByName(oldFirstName);
+        if (userOpt.isPresent()) {
+            User user = userOpt.get();
+            user.setFirstName(newFirstName);
+
+            System.out.println("user with name " + oldFirstName + " is changed to " + user.getFirstName());
+        } else {
+            // user is missing
+            System.out.println("user with name " + oldFirstName + " is not found.");
+        }
+    }
+
+    public static Optional<User> findUserByName(String name) {
+        // look up the user in the database, the user object below could be null
+        User user = usersByName.get(name);
+        Optional<User> opt = Optional.ofNullable(user);
+
+        return opt;
+    }
+}
@@ -0,0 +1,19 @@
+package com.baeldung.optionalReturnType;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+public class OptionalToJsonExample {
+    public static void main(String[] args) {
+        UserOptional user = new UserOptional();
+        user.setUserId(1l);
+        user.setFirstName("Bael Dung");
+
+        ObjectMapper om = new ObjectMapper();
+        try {
+            System.out.print("user in json is:" + om.writeValueAsString(user));
+        } catch (JsonProcessingException e) {
+            e.printStackTrace();
+        }
+    }
+}
@@ -0,0 +1,26 @@
+package com.baeldung.optionalReturnType;
+
+import java.util.Optional;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.Persistence;
+
+public class PersistOptionalTypeExample {
+    static String persistenceUnit = "com.baeldung.optionalReturnType";
+    static EntityManagerFactory emf = Persistence.createEntityManagerFactory(persistenceUnit);
+
+    static EntityManager entityManager = emf.createEntityManager();
+
+    // to run this app, uncomment the follow line in META-INF/persistence.xml
+    // <class>com.baeldung.optionalReturnType.UserOptionalField</class>
+    public static void main(String[] args) {
+        UserOptionalField user1 = new UserOptionalField();
+        user1.setUserId(1l);
+        user1.setFirstName(Optional.of("Bael Dung"));
+        entityManager.persist(user1);
+
+        UserOptional user2 = entityManager.find(UserOptional.class, 1l);
+        System.out.print("User2.firstName:" + user2.getFirstName());
+    }
+}
@@ -0,0 +1,22 @@
+package com.baeldung.optionalReturnType;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.Persistence;
+
+public class PersistOptionalTypeExample2 {
+    static String persistenceUnit = "com.baeldung.optionalReturnType";
+    static EntityManagerFactory emf = Persistence.createEntityManagerFactory(persistenceUnit);
+
+    static EntityManager em = emf.createEntityManager();
+
+    public static void main(String[] args) {
+        UserOptional user1 = new UserOptional();
+        user1.setUserId(1l);
+        user1.setFirstName("Bael Dung");
+        em.persist(user1);
+
+        UserOptional user2 = em.find(UserOptional.class, 1l);
+        System.out.print("User2.firstName:" + user2.getFirstName());
+    }
+}
@@ -0,0 +1,22 @@
+package com.baeldung.optionalReturnType;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.Persistence;
+
+public class PersistUserExample {
+    static String persistenceUnit = "com.baeldung.optionalReturnType";
+    static EntityManagerFactory emf = Persistence.createEntityManagerFactory(persistenceUnit);
+
+    static EntityManager em = emf.createEntityManager();
+
+    public static void main(String[] args) {
+        User user1 = new User();
+        user1.setUserId(1l);
+        user1.setFirstName("Bael Dung");
+        em.persist(user1);
+
+        User user2 = em.find(User.class, 1l);
+        System.out.print("User2.firstName:" + user2.getFirstName());
+    }
+}
@@ -0,0 +1,41 @@
+package com.baeldung.optionalReturnType;
+
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.ObjectOutputStream;
+import java.util.Optional;
+
+public class SerializeOptionalTypeExample {
+    public static void main(String[] args) {
+        User user1 = new User();
+        user1.setUserId(1l);
+        user1.setFirstName("baeldung");
+
+        serializeObject(user1, "user1.ser");
+
+        UserOptionalField user2 = new UserOptionalField();
+        user2.setUserId(1l);
+        user2.setFirstName(Optional.of("baeldung"));
+
+        serializeObject(user2, "user2.ser");
+
+    }
+
+    public static void serializeObject(Object object, String fileName) {
+        // Serialization
+        try {
+            FileOutputStream file = new FileOutputStream(fileName);
+            ObjectOutputStream out = new ObjectOutputStream(file);
+
+            out.writeObject(object);
+
+            out.close();
+            file.close();
+
+            System.out.println("Object " + object.toString() + " has been serialized to file " + fileName);
+
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+}
@@ -0,0 +1,31 @@
+package com.baeldung.optionalReturnType;
+
+import java.io.Serializable;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+
+@Entity
+public class User implements Serializable {
+    @Id
+    private long userId;
+
+    private String firstName;
+
+    public long getUserId() {
+        return userId;
+    }
+
+    public void setUserId(long userId) {
+        this.userId = userId;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+
+}
@@ -0,0 +1,35 @@
+package com.baeldung.optionalReturnType;
+
+import java.io.Serializable;
+import java.util.Optional;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.Id;
+
+@Entity
+public class UserOptional implements Serializable {
+    @Id
+    private long userId;
+
+    @Column(nullable = true)
+    private String firstName;
+
+    public long getUserId() {
+        return userId;
+    }
+
+    public void setUserId(long userId) {
+        this.userId = userId;
+    }
+
+    public Optional<String> getFirstName() {
+        return Optional.ofNullable(firstName);
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+        Optional.ofNullable(firstName);
+    }
+
+}
@@ -0,0 +1,31 @@
+package com.baeldung.optionalReturnType;
+
+import java.io.Serializable;
+import java.util.Optional;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+
+@Entity
+public class UserOptionalField implements Serializable {
+    @Id
+    private long userId;
+
+    private Optional<String> firstName;
+
+    public long getUserId() {
+        return userId;
+    }
+
+    public void setUserId(long userId) {
+        this.userId = userId;
+    }
+
+    public Optional<String> getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(Optional<String> firstName) {
+        this.firstName = firstName;
+    }
+}
@@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<persistence xmlns="http://java.sun.com/xml/ns/persistence"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
+	version="2.0">
+
+	<persistence-unit
+		name="com.baeldung.optionalReturnType"
+		transaction-type="RESOURCE_LOCAL">
+		<description>Persist Optional Return Type Demo</description>
+		<provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
+		<class>com.baeldung.optionalReturnType.User</class>
+		<class>com.baeldung.optionalReturnType.UserOptional</class>
+		<!-- 
+		<class>com.baeldung.optionalReturnType.UserOptionalField</class>
+		-->
+		<exclude-unlisted-classes>true</exclude-unlisted-classes>
+
+		<properties>
+			<property name="javax.persistence.jdbc.driver"
+				value="org.h2.Driver" />
+			<property name="javax.persistence.jdbc.url"
+				value="jdbc:h2:mem:test" />
+			<property name="javax.persistence.jdbc.user" value="sa" />
+			<property name="javax.persistence.jdbc.password" value="" />
+			<property name="hibernate.dialect"
+				value="org.hibernate.dialect.H2Dialect" />
+			<property name="hibernate.hbm2ddl.auto" value="create-drop" />
+			<property name="show_sql" value="true" />
+			<property name="hibernate.temp.use_jdbc_metadata_defaults"
+				value="false" />
+		</properties>
+	</persistence-unit>
+</persistence>
@@ -0,0 +1,26 @@
+package com.baeldung.error;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+public class ErrorGeneratorUnitTest {
+
+    @Test(expected = AssertionError.class)
+    public void whenError_thenIsNotCaughtByCatchException() {
+        try {
+            throw new AssertionError();
+        } catch (Exception e) {
+            Assert.fail(); // errors are not caught by catch exception
+        }
+    }
+
+    @Test
+    public void whenError_thenIsCaughtByCatchError() {
+        try {
+            throw new AssertionError();
+        } catch (Error e) {
+            // caught! -> test pass
+        }
+    }
+}
@@ -0,0 +1,61 @@
+version: '3'
+
+services:
+
+## VOLUME CONTAINER-TO-CONTAINER AND HOST-TO-CONTAINER TEST ##
+
+  volumes-example-service:
+    image: alpine:latest
+    container_name: volumes-example-service
+    volumes: 
+      - /tmp:/my-volumes/host-volume
+      - /home:/my-volumes/readonly-host-volume:ro
+      - my-named-global-volume:/my-volumes/named-global-volume    
+    tty: true # Needed to keep the container running
+
+  another-volumes-example-service:
+    image: alpine:latest
+    container_name: another-volumes-example-service
+    volumes: 
+      - my-named-global-volume:/another-path/the-same-named-global-volume
+    tty: true # Needed to keep the container running
+
+## NETWORK CONTAINER-TO-CONTAINER TEST ##
+
+  network-example-service:
+    image: karthequian/helloworld:latest
+    container_name: network-example-service
+    networks:
+      - my-shared-network
+
+  another-service-in-the-same-network:
+    image: alpine:latest
+    container_name: another-service-in-the-same-network
+    networks: 
+      - my-shared-network
+
+    tty: true # Needed to keep the container running
+
+  another-service-in-its-own-network:
+    image: alpine:latest
+    container_name: another-service-in-its-own-network
+    networks: 
+      - my-private-network
+    tty: true # Needed to keep the container running
+
+## NETWORK HOST-TO-CONTAINER TEST ##
+
+  network-example-service-available-to-host-on-port-1337:
+    image: karthequian/helloworld:latest
+    container_name: network-example-service-available-to-host-on-port-1337
+    networks: 
+      - my-shared-network
+    ports:
+      - "1337:80"
+
+volumes:
+  my-named-global-volume:
+
+networks:
+  my-shared-network: {}
+  my-private-network: {}
@@ -15,8 +15,7 @@ public class ConvertToMap {
    }

    public Map<Integer, Book> listToMapWithDupKey(List<Book> books) {
-        return books.stream().collect(Collectors.toMap(Book::getReleaseYear, Function.identity(),
-                (o1, o2) -> o1));
+        return books.stream().collect(Collectors.toMap(Book::getReleaseYear, Function.identity(), (existing, replacement) -> existing));
    }

    public Map<Integer, Book> listToConcurrentMap(List<Book> books) {
@@ -2,6 +2,7 @@ package com.baeldung.convertToMap;

 import java.util.ArrayList;
 import java.util.List;
+import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;

 import static org.junit.Assert.*;
@@ -34,8 +35,10 @@ public class ConvertToMapUnitTest {
    }

    @Test
-    public void whenMapHasDuplicateKey_with_merge_function() {
-        assertTrue(convertToMap.listToMapWithDupKey(bookList).size() == 2);
+    public void whenMapHasDuplicateKeyThenMergeFunctionHandlesCollision() {
+        Map<Integer, Book> booksByYear = convertToMap.listToMapWithDupKey(bookList);
+        assertEquals(2, booksByYear.size());
+        assertEquals("0395489318", booksByYear.get(1954).getIsbn());
    }

    @Test
@@ -82,6 +82,12 @@
 			<scope>test</scope>
 		</dependency>

+        <dependency>
+            <groupId>edu.uci.ics</groupId>
+            <artifactId>crawler4j</artifactId>
+            <version>${crawler4j.version}</version>
+        </dependency
+          
 	</dependencies>

 	<properties>
@@ -89,6 +95,7 @@
 		<classgraph.version>4.8.28</classgraph.version>
 		<jbpm.version>6.0.0.Final</jbpm.version>
 		<picocli.version>3.9.6</picocli.version>
+        <crawler4j.version>4.4.0</crawler4j.version>
 		<spring-boot-starter.version>2.1.4.RELEASE</spring-boot-starter.version>
 	</properties>
 </project>
@@ -0,0 +1,22 @@
+package com.baeldung.crawler4j;
+
+public class CrawlerStatistics {
+    private int processedPageCount = 0;
+    private int totalLinksCount = 0;
+    
+    public void incrementProcessedPageCount() {
+        processedPageCount++;
+    }
+    
+    public void incrementTotalLinksCount(int linksCount) {
+        totalLinksCount += linksCount;
+    }
+    
+    public int getProcessedPageCount() {
+        return processedPageCount;
+    }
+    
+    public int getTotalLinksCount() {
+        return totalLinksCount;
+    }
+}
@@ -0,0 +1,48 @@
+package com.baeldung.crawler4j;
+
+import java.util.Set;
+import java.util.regex.Pattern;
+
+import edu.uci.ics.crawler4j.crawler.Page;
+import edu.uci.ics.crawler4j.crawler.WebCrawler;
+import edu.uci.ics.crawler4j.parser.HtmlParseData;
+import edu.uci.ics.crawler4j.url.WebURL;
+
+public class HtmlCrawler extends WebCrawler {
+
+    private final static Pattern EXCLUSIONS = Pattern.compile(".*(\\.(css|js|xml|gif|jpg|png|mp3|mp4|zip|gz|pdf))$");
+    
+    private CrawlerStatistics stats;
+    
+    public HtmlCrawler(CrawlerStatistics stats) {
+        this.stats = stats;
+    }
+
+    @Override
+    public boolean shouldVisit(Page referringPage, WebURL url) {
+        String urlString = url.getURL().toLowerCase();
+        return !EXCLUSIONS.matcher(urlString).matches() 
+            && urlString.startsWith("https://www.baeldung.com/");
+    }
+
+    @Override
+    public void visit(Page page) {
+        String url = page.getWebURL().getURL();
+        stats.incrementProcessedPageCount();
+
+        if (page.getParseData() instanceof HtmlParseData) {
+            HtmlParseData htmlParseData = (HtmlParseData) page.getParseData();
+            String title = htmlParseData.getTitle();
+            String text = htmlParseData.getText();
+            String html = htmlParseData.getHtml();
+            Set<WebURL> links = htmlParseData.getOutgoingUrls();
+            stats.incrementTotalLinksCount(links.size());
+
+            System.out.printf("Page with title '%s' %n", title);
+            System.out.printf("    Text length: %d %n", text.length());
+            System.out.printf("    HTML length: %d %n", html.length());
+            System.out.printf("    %d outbound links %n", links.size());
+        }
+    }
+
+}
@@ -0,0 +1,36 @@
+package com.baeldung.crawler4j;
+
+import java.io.File;
+
+import edu.uci.ics.crawler4j.crawler.CrawlConfig;
+import edu.uci.ics.crawler4j.crawler.CrawlController;
+import edu.uci.ics.crawler4j.fetcher.PageFetcher;
+import edu.uci.ics.crawler4j.robotstxt.RobotstxtConfig;
+import edu.uci.ics.crawler4j.robotstxt.RobotstxtServer;
+
+public class HtmlCrawlerController {
+
+    public static void main(String[] args) throws Exception {
+        File crawlStorage = new File("src/test/resources/crawler4j");
+        CrawlConfig config = new CrawlConfig();
+        config.setCrawlStorageFolder(crawlStorage.getAbsolutePath());
+        config.setMaxDepthOfCrawling(2);
+
+        int numCrawlers = 12;
+
+        PageFetcher pageFetcher = new PageFetcher(config);
+        RobotstxtConfig robotstxtConfig = new RobotstxtConfig();
+        RobotstxtServer robotstxtServer = new RobotstxtServer(robotstxtConfig, pageFetcher);
+        CrawlController controller = new CrawlController(config, pageFetcher, robotstxtServer);
+
+        controller.addSeed("https://www.baeldung.com/");
+
+        CrawlerStatistics stats = new CrawlerStatistics();
+        CrawlController.WebCrawlerFactory<HtmlCrawler> factory = () -> new HtmlCrawler(stats);
+
+        controller.start(factory, numCrawlers);
+        System.out.printf("Crawled %d pages %n", stats.getProcessedPageCount());
+        System.out.printf("Total Number of outbound links = %d %n", stats.getTotalLinksCount());
+    }
+
+}
@@ -0,0 +1,49 @@
+package com.baeldung.crawler4j;
+
+import java.io.File;
+import java.util.regex.Pattern;
+
+import edu.uci.ics.crawler4j.crawler.Page;
+import edu.uci.ics.crawler4j.crawler.WebCrawler;
+import edu.uci.ics.crawler4j.parser.BinaryParseData;
+import edu.uci.ics.crawler4j.url.WebURL;
+
+public class ImageCrawler extends WebCrawler {
+    private final static Pattern EXCLUSIONS = Pattern.compile(".*(\\.(css|js|xml|gif|png|mp3|mp4|zip|gz|pdf))$");
+
+    private static final Pattern IMG_PATTERNS = Pattern.compile(".*(\\.(jpg|jpeg))$");
+
+    private File saveDir;
+
+    public ImageCrawler(File saveDir) {
+        this.saveDir = saveDir;
+    }
+
+    @Override
+    public boolean shouldVisit(Page referringPage, WebURL url) {
+        String urlString = url.getURL().toLowerCase();
+        if (EXCLUSIONS.matcher(urlString).matches()) {
+            return false;
+        }
+
+        if (IMG_PATTERNS.matcher(urlString).matches() 
+            || urlString.startsWith("https://www.baeldung.com/")) {
+            return true;
+        }
+
+        return false;
+    }
+
+    @Override
+    public void visit(Page page) {
+        String url = page.getWebURL().getURL();
+        if (IMG_PATTERNS.matcher(url).matches() 
+            && page.getParseData() instanceof BinaryParseData) {
+            String extension = url.substring(url.lastIndexOf("."));
+            int contentLength = page.getContentData().length;
+
+            System.out.printf("Extension is '%s' with content length %d %n", extension, contentLength);
+        }
+    }
+
+}
@@ -0,0 +1,36 @@
+package com.baeldung.crawler4j;
+
+import java.io.File;
+
+import edu.uci.ics.crawler4j.crawler.CrawlConfig;
+import edu.uci.ics.crawler4j.crawler.CrawlController;
+import edu.uci.ics.crawler4j.fetcher.PageFetcher;
+import edu.uci.ics.crawler4j.robotstxt.RobotstxtConfig;
+import edu.uci.ics.crawler4j.robotstxt.RobotstxtServer;
+
+public class ImageCrawlerController {
+
+    public static void main(String[] args) throws Exception {
+        File crawlStorage = new File("src/test/resources/crawler4j");
+        CrawlConfig config = new CrawlConfig();
+        config.setCrawlStorageFolder(crawlStorage.getAbsolutePath());
+        config.setIncludeBinaryContentInCrawling(true);
+        config.setMaxPagesToFetch(500);
+        
+        File saveDir = new File("src/test/resources/crawler4j");
+        
+        int numCrawlers = 12;
+        
+        PageFetcher pageFetcher = new PageFetcher(config);
+        RobotstxtConfig robotstxtConfig = new RobotstxtConfig();
+        RobotstxtServer robotstxtServer = new RobotstxtServer(robotstxtConfig, pageFetcher);
+        CrawlController controller = new CrawlController(config, pageFetcher, robotstxtServer);
+        
+        controller.addSeed("https://www.baeldung.com/");
+        
+        CrawlController.WebCrawlerFactory<ImageCrawler> factory = () -> new ImageCrawler(saveDir);
+        
+        controller.start(factory, numCrawlers);
+    }
+
+}
@@ -0,0 +1,54 @@
+package com.baeldung.crawler4j;
+
+import java.io.File;
+
+import edu.uci.ics.crawler4j.crawler.CrawlConfig;
+import edu.uci.ics.crawler4j.crawler.CrawlController;
+import edu.uci.ics.crawler4j.fetcher.PageFetcher;
+import edu.uci.ics.crawler4j.robotstxt.RobotstxtConfig;
+import edu.uci.ics.crawler4j.robotstxt.RobotstxtServer;
+
+public class MultipleCrawlerController {
+    public static void main(String[] args) throws Exception {
+        File crawlStorageBase = new File("src/test/resources/crawler4j");
+        CrawlConfig htmlConfig = new CrawlConfig();
+        CrawlConfig imageConfig = new CrawlConfig();
+        
+        htmlConfig.setCrawlStorageFolder(new File(crawlStorageBase, "html").getAbsolutePath());
+        imageConfig.setCrawlStorageFolder(new File(crawlStorageBase, "image").getAbsolutePath());
+        imageConfig.setIncludeBinaryContentInCrawling(true);
+        
+        htmlConfig.setMaxPagesToFetch(500);
+        imageConfig.setMaxPagesToFetch(1000);
+        
+        PageFetcher pageFetcherHtml = new PageFetcher(htmlConfig);
+        PageFetcher pageFetcherImage = new PageFetcher(imageConfig);
+        
+        RobotstxtConfig robotstxtConfig = new RobotstxtConfig();
+        RobotstxtServer robotstxtServer = new RobotstxtServer(robotstxtConfig, pageFetcherHtml);
+
+        CrawlController htmlController = new CrawlController(htmlConfig, pageFetcherHtml, robotstxtServer);
+        CrawlController imageController = new CrawlController(imageConfig, pageFetcherImage, robotstxtServer);
+        
+        htmlController.addSeed("https://www.baeldung.com/");
+        imageController.addSeed("https://www.baeldung.com/");
+        
+        CrawlerStatistics stats = new CrawlerStatistics();
+        CrawlController.WebCrawlerFactory<HtmlCrawler> htmlFactory = () -> new HtmlCrawler(stats);
+        
+        File saveDir = new File("src/test/resources/crawler4j");
+        CrawlController.WebCrawlerFactory<ImageCrawler> imageFactory = () -> new ImageCrawler(saveDir);
+        
+        imageController.startNonBlocking(imageFactory, 7);
+        htmlController.startNonBlocking(htmlFactory, 10);
+        
+
+        htmlController.waitUntilFinish();
+        System.out.printf("Crawled %d pages %n", stats.getProcessedPageCount());
+        System.out.printf("Total Number of outbound links = %d %n", stats.getTotalLinksCount());
+
+        imageController.waitUntilFinish();
+        System.out.printf("Image Crawler is finished.");
+        
+    }
+}
@@ -5,9 +5,9 @@

    <parent>
        <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
+        <artifactId>persistence-modules</artifactId>
        <version>1.0.0-SNAPSHOT</version>
-        <relativePath>../../</relativePath>
+        <relativePath>..</relativePath>
    </parent>

    <artifactId>hibernate-mapping</artifactId>
@@ -31,22 +31,28 @@
            <artifactId>h2</artifactId>
            <version>${h2.version}</version>
        </dependency>
-	    <!-- validation -->
+        <!-- validation -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-validator</artifactId>
            <version>${hibernate-validator.version}</version>
        </dependency>
-        <dependency>
-            <groupId>javax.el</groupId>
-            <artifactId>javax.el-api</artifactId>
-            <version>${javax.el-api.version}</version>
-	    </dependency>
        <dependency>
            <groupId>org.glassfish</groupId>
            <artifactId>javax.el</artifactId>
            <version>${org.glassfish.javax.el.version}</version>
        </dependency>
+        <dependency>
+            <groupId>javax.money</groupId>
+            <artifactId>money-api</artifactId>
+            <version>1.0.3</version>
+        </dependency>
+        <dependency>
+            <groupId>org.javamoney</groupId>
+            <artifactId>moneta</artifactId>
+            <version>1.3</version>
+            <type>pom</type>
+        </dependency>
    </dependencies>

    <build>
@@ -60,11 +66,10 @@
    </build>

    <properties>
-        <hibernate.version>5.3.7.Final</hibernate.version>
+        <hibernate.version>5.3.10.Final</hibernate.version>
        <assertj-core.version>3.8.0</assertj-core.version>
-        <hibernate-validator.version>5.3.3.Final</hibernate-validator.version>
-        <javax.el-api.version>2.2.5</javax.el-api.version>
-        <org.glassfish.javax.el.version>3.0.1-b08</org.glassfish.javax.el.version>
+        <hibernate-validator.version>6.0.16.Final</hibernate-validator.version>
+        <org.glassfish.javax.el.version>3.0.1-b11</org.glassfish.javax.el.version>
    </properties>

-</project>
+</project>
--- a/Show More
+++ b/Show More