This tutorial will use Hibernate Annotations to replace the Hibernate XML mapping files. The project infrastructure introduced in the previous section – Maven + Hibernate (XML mapping file) + MySQL Example will be reused.

Prerequisite requirement

- Create project infrastructure in Maven + Hibernate (XML mapping file) + MySQL Example
- Basic knowledge of Maven
- Installed and configure Maven
- Installed and configured MySQL – Preparing database and tables, reference here
- Installed and configured Eclipse IDE

P.S Make sure you have done all the prerequisite requirements before continue this tutorial

Tutorial …

1. Create project infrastructure

Create project infrastructure in Maven + Hibernate (XML mapping file) + MySQL Example

2. Add JBoss repository

JBoss repository in pom.xml is required to download the Hibernate annotation library.

 <repositories>
    <repository>
      <id>JBoss repository</id>
      <url>http://repository.jboss.com/maven2/</url>
    </repository>
  </repositories>

3. Add Hibernate annotation dependency

Add hibernate-annotations and hibernate-commons-annotations dependency in pom.xml.

	<dependency>
		<groupId>hibernate-annotations</groupId>
		<artifactId>hibernate-annotations</artifactId>
		<version>3.3.0.GA</version>
	</dependency>
 
	<dependency>
		<groupId>hibernate-commons-annotations</groupId>
		<artifactId>hibernate-commons-annotations</artifactId>
		<version>3.0.0.GA</version>
	</dependency>
pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" 
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 
  http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.mkyong.common</groupId>
  <artifactId>HibernateExample</artifactId>
  <packaging>jar</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>HibernateExample</name>
  <url>http://maven.apache.org</url>
 
  <repositories>
    <repository>
      <id>JBoss repository</id>
      <url>http://repository.jboss.com/maven2/</url>
    </repository>
  </repositories>
 
  <dependencies>
 
        <!-- MySQL database driver -->
	<dependency>
		<groupId>mysql</groupId>
		<artifactId>mysql-connector-java</artifactId>
		<version>5.1.9</version>
	</dependency>
 
	<!-- Hibernate core -->
	<dependency>
		<groupId>hibernate</groupId>
		<artifactId>hibernate3</artifactId>
		<version>3.2.3.GA</version>
	</dependency>
 
	<!-- Hibernate annotation -->
	<dependency>
		<groupId>hibernate-annotations</groupId>
		<artifactId>hibernate-annotations</artifactId>
		<version>3.3.0.GA</version>
	</dependency>
 
	<dependency>
		<groupId>hibernate-commons-annotations</groupId>
		<artifactId>hibernate-commons-annotations</artifactId>
		<version>3.0.0.GA</version>
	</dependency>
 
	<!-- Hibernate library dependecy start -->
	<dependency>
		<groupId>dom4j</groupId>
		<artifactId>dom4j</artifactId>
		<version>1.6.1</version>
	</dependency>
 
	<dependency>
		<groupId>commons-logging</groupId>
		<artifactId>commons-logging</artifactId>
		<version>1.1.1</version>
	</dependency>
 
	<dependency>
		<groupId>commons-collections</groupId>
		<artifactId>commons-collections</artifactId>
		<version>3.2.1</version>
	</dependency>
 
	<dependency>
		<groupId>cglib</groupId>
		<artifactId>cglib</artifactId>
		<version>2.2</version>
	</dependency>
	<!-- Hibernate library dependecy end -->
  </dependencies>
</project>

4. Update project classpath

Issue “mvn eclipse:eclipse” in command prompt to download the dependency library and update the Eclipse’s project classpath.

5. Update HibernateUtil.java

Update “HibernateUtil” to use “AnnotationConfiguration” instead of “Configuration” to build the Hibernate session factory.

Previously is using “Configuration” – For Hibernate XML mapping file

return new Configuration().configure().buildSessionFactory();

Change it to “AnnotationConfiguration” – For Hibernation annotation support

return new AnnotationConfiguration().configure().buildSessionFactory();
HibernateUtil.java
package com.mkyong.persistence;
 
import org.hibernate.SessionFactory;
import org.hibernate.cfg.AnnotationConfiguration;
 
public class HibernateUtil {
 
    private static final SessionFactory sessionFactory = buildSessionFactory();
 
    private static SessionFactory buildSessionFactory() {
        try {
            // Create the SessionFactory from hibernate.cfg.xml
            return new AnnotationConfiguration().configure().buildSessionFactory();
 
        }
        catch (Throwable ex) {
            // Make sure you log the exception, as it might be swallowed
            System.err.println("Initial SessionFactory creation failed." + ex);
            throw new ExceptionInInitializerError(ex);
        }
    }
 
    public static SessionFactory getSessionFactory() {
        return sessionFactory;
    }
 
    public static void shutdown() {
    	// Close caches and connection pools
    	getSessionFactory().close();
    }
 
}

6. Update Model class

Update “Stock.java” to use annotation as follow :

Stock.java
package com.mkyong.common;
 
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import static javax.persistence.GenerationType.IDENTITY;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.persistence.UniqueConstraint;
 
@Entity
@Table(name = "stock", catalog = "mkyong", uniqueConstraints = {
		@UniqueConstraint(columnNames = "STOCK_NAME"),
		@UniqueConstraint(columnNames = "STOCK_CODE") })
public class Stock implements java.io.Serializable {
 
	private Integer stockId;
	private String stockCode;
	private String stockName;
 
	public Stock() {
	}
 
	public Stock(String stockCode, String stockName) {
		this.stockCode = stockCode;
		this.stockName = stockName;
	}
 
	@Id
	@GeneratedValue(strategy = IDENTITY)
	@Column(name = "STOCK_ID", unique = true, nullable = false)
	public Integer getStockId() {
		return this.stockId;
	}
 
	public void setStockId(Integer stockId) {
		this.stockId = stockId;
	}
 
	@Column(name = "STOCK_CODE", unique = true, nullable = false, length = 10)
	public String getStockCode() {
		return this.stockCode;
	}
 
	public void setStockCode(String stockCode) {
		this.stockCode = stockCode;
	}
 
	@Column(name = "STOCK_NAME", unique = true, nullable = false, length = 20)
	public String getStockName() {
		return this.stockName;
	}
 
	public void setStockName(String stockName) {
		this.stockName = stockName;
	}
 
}

7. Delete existing Hibernate XML mapping file

Delete existing Hibernate XML mapping file – “Stock.hbm.xml”, this is no longer require.

8. Update Hibernate configuration file

Update the Hibernate configuration file – hibernate.cfg.xml.

Previously it had the Hibernate XML mapping file with “mapping resource” tag

<mapping resource="com/mkyong/common/Stock.hbm.xml"></mapping>

Change it to model class with “mapping class” tag

<mapping class="com.mkyong.common.Stock"></mapping>
hibernate.cfg.xml
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <property name="hibernate.bytecode.use_reflection_optimizer">false</property>
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.password">password</property>
        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/mkyong</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
        <property name="show_sql">true</property>
        <mapping class="com.mkyong.common.Stock"></mapping>
    </session-factory>
</hibernate-configuration>

9. Review project structure

Sound like few files were modified, review it and make sure the folder structure as follow :

maven_hibernate_annotation_mysql

10. Run it and see output

Run your App.java, it will insert a new record into “Stock” table. The result should be same with previous Hibernate XML mapping file example.

Maven + Hibernate + MySQL
...
Hibernate: insert into mkyong.stock (STOCK_CODE, STOCK_NAME) values (?, ?)

Done ~ enjoy Hibernate annotation :)

You can download the whole project in zip file – Maven-Hibernate-annotation-MySQL-Example.zip

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