From 552b2b2fa941f313d38ae44588dec44d3b0d82df Mon Sep 17 00:00:00 2001
From: Liesheng Long <liesheng.long@gmail.com>
Date: Mon, 20 May 2019 02:24:51 -0400
Subject: [PATCH 1/5] sample code for article "Java Optional As Return Type"

---
 core-java-modules/core-java-8-2/pom.xml       | 16 ++++++-
 .../HandleOptionalTypeExample.java            | 41 ++++++++++++++++++
 .../OptionalToJsonExample.java                | 20 +++++++++
 .../PersistOptionalTypeExample.java           | 24 +++++++++++
 .../PersistOptionalTypeExample2.java          | 22 ++++++++++
 .../PersistUserNoOptionalExample.java         | 22 ++++++++++
 .../SerializeOptionalTypeExample.java         | 42 +++++++++++++++++++
 .../com/baeldung/optionalReturnType/User.java | 31 ++++++++++++++
 .../optionalReturnType/UserOptional.java      | 35 ++++++++++++++++
 .../optionalReturnType/UserOptionalField.java | 31 ++++++++++++++
 .../main/resources/META-INF/persistence.xml   | 32 ++++++++++++++
 11 files changed, 315 insertions(+), 1 deletion(-)
 create mode 100644 core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/HandleOptionalTypeExample.java
 create mode 100644 core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/OptionalToJsonExample.java
 create mode 100644 core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistOptionalTypeExample.java
 create mode 100644 core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistOptionalTypeExample2.java
 create mode 100644 core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistUserNoOptionalExample.java
 create mode 100644 core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/SerializeOptionalTypeExample.java
 create mode 100644 core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/User.java
 create mode 100644 core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/UserOptional.java
 create mode 100644 core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/UserOptionalField.java
 create mode 100644 core-java-modules/core-java-8-2/src/main/resources/META-INF/persistence.xml

diff --git a/core-java-modules/core-java-8-2/pom.xml b/core-java-modules/core-java-8-2/pom.xml
index fbaf795b95..862b739530 100644
--- a/core-java-modules/core-java-8-2/pom.xml
+++ b/core-java-modules/core-java-8-2/pom.xml
@@ -30,7 +30,21 @@
             <artifactId>icu4j</artifactId>
             <version>${icu.version}</version>
         </dependency>
-
+		<dependency>
+    		<groupId>org.hibernate</groupId>
+    		<artifactId>hibernate-core</artifactId>
+    		<version>5.4.0.Final</version>
+		</dependency>
+		<dependency>
+    		<groupId>com.h2database</groupId>
+    		<artifactId>h2</artifactId>
+    		<version>1.4.197</version>
+		</dependency>
+		<dependency>
+    		<groupId>com.fasterxml.jackson.core</groupId>
+    		<artifactId>jackson-databind</artifactId>
+    		<version>2.9.8</version>
+		</dependency>		
     </dependencies>
 
     <build>
diff --git a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/HandleOptionalTypeExample.java b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/HandleOptionalTypeExample.java
new file mode 100644
index 0000000000..a49909901b
--- /dev/null
+++ b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/HandleOptionalTypeExample.java
@@ -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;
+	}
+}
diff --git a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/OptionalToJsonExample.java b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/OptionalToJsonExample.java
new file mode 100644
index 0000000000..cec5ba5ce1
--- /dev/null
+++ b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/OptionalToJsonExample.java
@@ -0,0 +1,20 @@
+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) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		}
+	}
+}
diff --git a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistOptionalTypeExample.java b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistOptionalTypeExample.java
new file mode 100644
index 0000000000..afe46ca7eb
--- /dev/null
+++ b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistOptionalTypeExample.java
@@ -0,0 +1,24 @@
+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();
+	
+	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());
+	}
+}
diff --git a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistOptionalTypeExample2.java b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistOptionalTypeExample2.java
new file mode 100644
index 0000000000..0662b692a8
--- /dev/null
+++ b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistOptionalTypeExample2.java
@@ -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());
+	}
+}
diff --git a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistUserNoOptionalExample.java b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistUserNoOptionalExample.java
new file mode 100644
index 0000000000..dba67feecd
--- /dev/null
+++ b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistUserNoOptionalExample.java
@@ -0,0 +1,22 @@
+package com.baeldung.optionalReturnType;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.Persistence;
+
+public class PersistUserNoOptionalExample {
+	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());
+	}
+}
diff --git a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/SerializeOptionalTypeExample.java b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/SerializeOptionalTypeExample.java
new file mode 100644
index 0000000000..7ad4a5325e
--- /dev/null
+++ b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/SerializeOptionalTypeExample.java
@@ -0,0 +1,42 @@
+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();
+	     } 
+	}
+}
diff --git a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/User.java b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/User.java
new file mode 100644
index 0000000000..42bedb4817
--- /dev/null
+++ b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/User.java
@@ -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;
+	}
+	
+}
diff --git a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/UserOptional.java b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/UserOptional.java
new file mode 100644
index 0000000000..c48781ea80
--- /dev/null
+++ b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/UserOptional.java
@@ -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);
+	}
+	
+}
diff --git a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/UserOptionalField.java b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/UserOptionalField.java
new file mode 100644
index 0000000000..0778a8bb99
--- /dev/null
+++ b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/UserOptionalField.java
@@ -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;
+	}	
+}
diff --git a/core-java-modules/core-java-8-2/src/main/resources/META-INF/persistence.xml b/core-java-modules/core-java-8-2/src/main/resources/META-INF/persistence.xml
new file mode 100644
index 0000000000..3a05c733ee
--- /dev/null
+++ b/core-java-modules/core-java-8-2/src/main/resources/META-INF/persistence.xml
@@ -0,0 +1,32 @@
+<?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.UserNoOptional</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>
\ No newline at end of file

From 2c9c96a811f2cd1ebf90af4f2f042e795c598eb6 Mon Sep 17 00:00:00 2001
From: Liesheng Long <liesheng.long@gmail.com>
Date: Mon, 20 May 2019 21:59:47 -0400
Subject: [PATCH 2/5] fixed some code

---
 .../optionalReturnType/PersistOptionalTypeExample.java        | 2 ++
 ...sistUserNoOptionalExample.java => PersistUserExample.java} | 2 +-
 .../core-java-8-2/src/main/resources/META-INF/persistence.xml | 4 +++-
 3 files changed, 6 insertions(+), 2 deletions(-)
 rename core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/{PersistUserNoOptionalExample.java => PersistUserExample.java} (93%)

diff --git a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistOptionalTypeExample.java b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistOptionalTypeExample.java
index afe46ca7eb..681fae565b 100644
--- a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistOptionalTypeExample.java
+++ b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistOptionalTypeExample.java
@@ -12,6 +12,8 @@ public class PersistOptionalTypeExample {
 	
 	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);
diff --git a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistUserNoOptionalExample.java b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistUserExample.java
similarity index 93%
rename from core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistUserNoOptionalExample.java
rename to core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistUserExample.java
index dba67feecd..af17f83c6e 100644
--- a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistUserNoOptionalExample.java
+++ b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistUserExample.java
@@ -4,7 +4,7 @@ import javax.persistence.EntityManager;
 import javax.persistence.EntityManagerFactory;
 import javax.persistence.Persistence;
 
-public class PersistUserNoOptionalExample {
+public class PersistUserExample {
 	static String persistenceUnit = "com.baeldung.optionalReturnType";
 	static EntityManagerFactory emf = Persistence.createEntityManagerFactory(persistenceUnit);
 	
diff --git a/core-java-modules/core-java-8-2/src/main/resources/META-INF/persistence.xml b/core-java-modules/core-java-8-2/src/main/resources/META-INF/persistence.xml
index 3a05c733ee..e8cd723ec2 100644
--- a/core-java-modules/core-java-8-2/src/main/resources/META-INF/persistence.xml
+++ b/core-java-modules/core-java-8-2/src/main/resources/META-INF/persistence.xml
@@ -9,9 +9,11 @@
 		transaction-type="RESOURCE_LOCAL">
 		<description>Persist Optional Return Type Demo</description>
 		<provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
-		<class>com.baeldung.optionalReturnType.UserNoOptional</class>
+		<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>

From a5a99c28b1e5c3229cb6d2765a85c64bb35fdef6 Mon Sep 17 00:00:00 2001
From: Liesheng Long <liesheng.long@gmail.com>
Date: Thu, 23 May 2019 20:09:03 -0400
Subject: [PATCH 3/5] formatting the source code

---
 .../HandleOptionalTypeExample.java            | 64 +++++++++----------
 .../OptionalToJsonExample.java                | 25 ++++----
 .../PersistOptionalTypeExample.java           | 32 +++++-----
 .../PersistOptionalTypeExample2.java          | 28 ++++----
 .../PersistUserExample.java                   | 28 ++++----
 .../SerializeOptionalTypeExample.java         | 61 +++++++++---------
 .../com/baeldung/optionalReturnType/User.java | 36 +++++------
 .../optionalReturnType/UserOptional.java      | 40 ++++++------
 .../optionalReturnType/UserOptionalField.java | 34 +++++-----
 9 files changed, 173 insertions(+), 175 deletions(-)

diff --git a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/HandleOptionalTypeExample.java b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/HandleOptionalTypeExample.java
index a49909901b..c472bab077 100644
--- a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/HandleOptionalTypeExample.java
+++ b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/HandleOptionalTypeExample.java
@@ -5,37 +5,37 @@ 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);
+    static Map<String, User> usersByName = new HashMap();
+    static {
+        User user1 = new User();
+        user1.setUserId(1l);
+        user1.setFirstName("baeldung");
+        usersByName.put("baeldung", user1);
+    }
 
-	    return opt;
-	}
+    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;
+    }
 }
diff --git a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/OptionalToJsonExample.java b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/OptionalToJsonExample.java
index cec5ba5ce1..b44a35fae1 100644
--- a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/OptionalToJsonExample.java
+++ b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/OptionalToJsonExample.java
@@ -4,17 +4,16 @@ 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) {
-			// TODO Auto-generated catch block
-			e.printStackTrace();
-		}
-	}
+    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();
+        }
+    }
 }
diff --git a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistOptionalTypeExample.java b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistOptionalTypeExample.java
index 681fae565b..85c96b9bc3 100644
--- a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistOptionalTypeExample.java
+++ b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistOptionalTypeExample.java
@@ -7,20 +7,20 @@ 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());
-	}
+    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());
+    }
 }
diff --git a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistOptionalTypeExample2.java b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistOptionalTypeExample2.java
index 0662b692a8..3114e7cefb 100644
--- a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistOptionalTypeExample2.java
+++ b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistOptionalTypeExample2.java
@@ -5,18 +5,18 @@ 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());
-	}
+    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());
+    }
 }
diff --git a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistUserExample.java b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistUserExample.java
index af17f83c6e..f1284958e7 100644
--- a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistUserExample.java
+++ b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/PersistUserExample.java
@@ -5,18 +5,18 @@ 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());
-	}
+    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());
+    }
 }
diff --git a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/SerializeOptionalTypeExample.java b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/SerializeOptionalTypeExample.java
index 7ad4a5325e..d67337ad98 100644
--- a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/SerializeOptionalTypeExample.java
+++ b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/SerializeOptionalTypeExample.java
@@ -6,37 +6,36 @@ 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");
-	    
+    public static void main(String[] args) {
+        User user1 = new User();
+        user1.setUserId(1l);
+        user1.setFirstName("baeldung");
 
-	    UserOptionalField user2 = new UserOptionalField(); 
-	    user2.setUserId(1l);
-	    user2.setFirstName(Optional.of("baeldung"));				
-		 
-	    serializeObject(user2, "user2.ser");
+        serializeObject(user1, "user1.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();
-	     } 
-	}
+        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();
+        }
+    }
 }
diff --git a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/User.java b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/User.java
index 42bedb4817..7aa11d78cb 100644
--- a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/User.java
+++ b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/User.java
@@ -7,25 +7,25 @@ import javax.persistence.Id;
 
 @Entity
 public class User implements Serializable {
-	@Id
-	private long userId;
-	
-	private String firstName;
-	
-	public long getUserId() {
-		return userId;
-	}
+    @Id
+    private long userId;
 
-	public void setUserId(long userId) {
-		this.userId = userId;
-	}
+    private String firstName;
 
-	public String getFirstName() {
-		return 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;
+    }
 
-	public void setFirstName(String firstName) {
-		this.firstName = firstName;
-	}
-	
 }
diff --git a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/UserOptional.java b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/UserOptional.java
index c48781ea80..0138a84ab9 100644
--- a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/UserOptional.java
+++ b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/UserOptional.java
@@ -9,27 +9,27 @@ 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;
-	}
+    @Id
+    private long userId;
 
-	public void setUserId(long userId) {
-		this.userId = userId;
-	}
+    @Column(nullable = true)
+    private String firstName;
 
-	public Optional<String> getFirstName() {
-	    return Optional.ofNullable(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);
+    }
 
-	public void setFirstName(String firstName) {
-		this.firstName = firstName;
-	    Optional.ofNullable(firstName);
-	}
-	
 }
diff --git a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/UserOptionalField.java b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/UserOptionalField.java
index 0778a8bb99..c02430b1ba 100644
--- a/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/UserOptionalField.java
+++ b/core-java-modules/core-java-8-2/src/main/java/com/baeldung/optionalReturnType/UserOptionalField.java
@@ -8,24 +8,24 @@ import javax.persistence.Id;
 
 @Entity
 public class UserOptionalField implements Serializable {
-	@Id
-	private long userId;
-	
-	private Optional<String> firstName;
-	
-	public long getUserId() {
-		return userId;
-	}
+    @Id
+    private long userId;
 
-	public void setUserId(long userId) {
-		this.userId = userId;
-	}
+    private Optional<String> firstName;
 
-	public Optional<String> getFirstName() {
-		return firstName;
-	}
+    public long getUserId() {
+        return userId;
+    }
 
-	public void setFirstName(Optional<String> firstName) {
-		this.firstName = firstName;
-	}	
+    public void setUserId(long userId) {
+        this.userId = userId;
+    }
+
+    public Optional<String> getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(Optional<String> firstName) {
+        this.firstName = firstName;
+    }
 }

From a8cdcc610083fd4a3d51fea91c2b8664f18c05ef Mon Sep 17 00:00:00 2001
From: Liesheng Long <liesheng.long@gmail.com>
Date: Thu, 23 May 2019 20:18:30 -0400
Subject: [PATCH 4/5] formatting and use properties for versions

---
 core-java-modules/core-java-8-2/pom.xml | 103 ++++++++++++------------
 1 file changed, 53 insertions(+), 50 deletions(-)

diff --git a/core-java-modules/core-java-8-2/pom.xml b/core-java-modules/core-java-8-2/pom.xml
index 862b739530..150f36be59 100644
--- a/core-java-modules/core-java-8-2/pom.xml
+++ b/core-java-modules/core-java-8-2/pom.xml
@@ -1,64 +1,67 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-    <modelVersion>4.0.0</modelVersion>
-    <groupId>com.baeldung</groupId>
-    <artifactId>core-java-8-2</artifactId>
-    <version>0.1.0-SNAPSHOT</version>
-    <name>core-java-8-2</name>
-    <packaging>jar</packaging>
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>com.baeldung</groupId>
+	<artifactId>core-java-8-2</artifactId>
+	<version>0.1.0-SNAPSHOT</version>
+	<name>core-java-8-2</name>
+	<packaging>jar</packaging>
 
 
-    <parent>
-        <groupId>com.baeldung</groupId>
-        <artifactId>parent-java</artifactId>
-        <version>0.0.1-SNAPSHOT</version>
-        <relativePath>../../parent-java</relativePath>
-    </parent>
+	<parent>
+		<groupId>com.baeldung</groupId>
+		<artifactId>parent-java</artifactId>
+		<version>0.0.1-SNAPSHOT</version>
+		<relativePath>../../parent-java</relativePath>
+	</parent>
 
-    <properties>
-        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <maven.compiler.source>1.8</maven.compiler.source>
-        <maven.compiler.target>1.8</maven.compiler.target>
-        <icu.version>64.2</icu.version>
-    </properties>
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+		<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>
-        <dependency>
-            <groupId>com.ibm.icu</groupId>
-            <artifactId>icu4j</artifactId>
-            <version>${icu.version}</version>
-        </dependency>
+	<dependencies>
 		<dependency>
-    		<groupId>org.hibernate</groupId>
-    		<artifactId>hibernate-core</artifactId>
-    		<version>5.4.0.Final</version>
+			<groupId>com.ibm.icu</groupId>
+			<artifactId>icu4j</artifactId>
+			<version>${icu.version}</version>
 		</dependency>
 		<dependency>
-    		<groupId>com.h2database</groupId>
-    		<artifactId>h2</artifactId>
-    		<version>1.4.197</version>
+			<groupId>org.hibernate</groupId>
+			<artifactId>hibernate-core</artifactId>
+			<version>${hibernate.core.version}</version>
 		</dependency>
 		<dependency>
-    		<groupId>com.fasterxml.jackson.core</groupId>
-    		<artifactId>jackson-databind</artifactId>
-    		<version>2.9.8</version>
-		</dependency>		
-    </dependencies>
+			<groupId>com.h2database</groupId>
+			<artifactId>h2</artifactId>
+			<version>${h2database.version}</version>
+		</dependency>
+		<dependency>
+			<groupId>com.fasterxml.jackson.core</groupId>
+			<artifactId>jackson-databind</artifactId>
+			<version>${jackson.databind.version}</version>
+		</dependency>
+	</dependencies>
 
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-compiler-plugin</artifactId>
-                <version>${maven-compiler-plugin.version}</version>
-                <configuration>
-                    <source>${maven.compiler.source}</source>
-                    <target>${maven.compiler.target}</target>
-                </configuration>
-            </plugin>
-        </plugins>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-compiler-plugin</artifactId>
+				<version>${maven-compiler-plugin.version}</version>
+				<configuration>
+					<source>${maven.compiler.source}</source>
+					<target>${maven.compiler.target}</target>
+				</configuration>
+			</plugin>
+		</plugins>
 
-    </build>
+	</build>
 </project>

From 1050337dabfb4c84512bbe4a4bf7087a35f55ee3 Mon Sep 17 00:00:00 2001
From: Liesheng Long <liesheng.long@gmail.com>
Date: Fri, 24 May 2019 11:28:49 -0400
Subject: [PATCH 5/5] replace tabs with 4-spaces

---
 core-java-modules/core-java-8-2/pom.xml | 116 ++++++++++++------------
 1 file changed, 58 insertions(+), 58 deletions(-)

diff --git a/core-java-modules/core-java-8-2/pom.xml b/core-java-modules/core-java-8-2/pom.xml
index 150f36be59..ff2e290086 100644
--- a/core-java-modules/core-java-8-2/pom.xml
+++ b/core-java-modules/core-java-8-2/pom.xml
@@ -1,67 +1,67 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0"
-	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-	<modelVersion>4.0.0</modelVersion>
-	<groupId>com.baeldung</groupId>
-	<artifactId>core-java-8-2</artifactId>
-	<version>0.1.0-SNAPSHOT</version>
-	<name>core-java-8-2</name>
-	<packaging>jar</packaging>
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>com.baeldung</groupId>
+    <artifactId>core-java-8-2</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>core-java-8-2</name>
+    <packaging>jar</packaging>
 
 
-	<parent>
-		<groupId>com.baeldung</groupId>
-		<artifactId>parent-java</artifactId>
-		<version>0.0.1-SNAPSHOT</version>
-		<relativePath>../../parent-java</relativePath>
-	</parent>
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-java</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../../parent-java</relativePath>
+    </parent>
 
-	<properties>
-		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-		<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>
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <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>
-		<dependency>
-			<groupId>com.ibm.icu</groupId>
-			<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>
+    <dependencies>
+        <dependency>
+            <groupId>com.ibm.icu</groupId>
+            <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>
-		<plugins>
-			<plugin>
-				<groupId>org.apache.maven.plugins</groupId>
-				<artifactId>maven-compiler-plugin</artifactId>
-				<version>${maven-compiler-plugin.version}</version>
-				<configuration>
-					<source>${maven.compiler.source}</source>
-					<target>${maven.compiler.target}</target>
-				</configuration>
-			</plugin>
-		</plugins>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>${maven-compiler-plugin.version}</version>
+                <configuration>
+                    <source>${maven.compiler.source}</source>
+                    <target>${maven.compiler.target}</target>
+                </configuration>
+            </plugin>
+        </plugins>
 
-	</build>
+    </build>
 </project>