EJB 配置jboss 数据源 及 对数据库映射的实体Bean

一、在jboss\docs\examples\jca目录下有各种数据库的数据源配置模板文件，由于我用的是Mysql数据库，所以我找到 mysql-ds.xml ，对其进行修改。再把该文件复制到jboss\server\default\deploy目录下

<datasources>
  <local-tx-datasource>
    <jndi-name>testDS</jndi-name>
    <connection-url>jdbc:mysql://localhost:3306/test</connection-url>
    <driver-class>com.mysql.jdbc.Driver</driver-class>
    <user-name>root</user-name>
    <password>root</password>
    <exception-sorter-class-name>org.jboss.resource.adapter.jdbc.vendor.MySQLExceptionSorter</exception-sorter-class-name>
    <metadata>
       <type-mapping>mySQL</type-mapping>
    </metadata>
  </local-tx-datasource>
</datasources>

二、把mysql驱动包复制到jboss\server\default\lib目录下

三、根据JPA规范要求，在实体bean应用中，我们需要在应用的src类路径下新建名为META-INF的目录，在其目录下加入持久化配置文件persistence.xml

<?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_1_0.xsd"
	version="1.0">
	<!-- 持久化单元 ，就是一堆实体类的集合-->
	<persistence-unit name="testunit" transaction-type="JTA">
		<!-- 指定数据源  JNDI名称 -->
		<jta-data-source>java:/testDS</jta-data-source>
		<properties>
			 <!--自动输出schema创建DDL语句 -->
             <property name="hibernate.hbm2ddl.auto" value="update" />   
		</properties>
	</persistence-unit>
</persistence>

四、根据数据库中对应的表建立实体Bean，并通过注解对其进行映射

package com.test.bean;

import java.io.Serializable;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="person")
public class Person implements Serializable{
	private static final long serialVersionUID = -2428867574977899381L;
	private Integer id;
	private String name;
	
	public Person() {
	}
	
	public Person(String name) {
		this.name = name;
	}

	public Person(Integer id, String name) {
		this.id = id;
		this.name = name;
	}

	@Id
	@Column(name="id")
	@GeneratedValue(strategy=GenerationType.AUTO)
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	@Column(name="name",nullable=false)
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + ((id == null) ? 0 : id.hashCode());
		return result;
	}
	
	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		Person other = (Person) obj;
		if (id == null) {
			if (other.id != null)
				return false;
		} else if (!id.equals(other.id))
			return false;
		return true;
	}
	
}

五、创建方法接口并实现接口(这里不把接口代码写出来)，再通过实体管理器来对数据库表进行增删改查

package com.test.service.impl;

import java.util.List;

import javax.ejb.Remote;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

import com.test.bean.Person;
import com.test.service.PersonService;

@Stateless //无状态会话bean
@Remote(PersonService.class)//远程接口
public class PersonServiceImpl implements PersonService {
	//实体管理器
	@PersistenceContext(unitName="testunit") EntityManager em;
	
	@Override
	public void add(Person person) {
		em.persist(person);
	}

	@Override
	public void delete(Integer id) {
		em.remove(em.getReference(Person.class, id));
	}

	@Override
	public Person getPerson(Integer id) {
		return em.find(Person.class, id);
	}

	@SuppressWarnings("unchecked")
	@Override
	public List<Person> listPerson() {
		return em.createQuery("select p from Person p").getResultList();
	}

	@Override
	public void update(Person person) {
		em.merge(person);
	}

}

六、测试

static{
	try {
		//加载驱动
		Class.forName("com.mysql.jdbc.Driver");
	} catch (ClassNotFoundException e) {
		e.printStackTrace();
	}
}
private static PersonService ps;

public static void main(String[] args) {
	Properties props = new Properties();
	//jboss所用的JNDI
	props.setProperty("java.naming.factory.initial", "org.jnp.interfaces.NamingContextFactory");
	props.setProperty("java.naming.provider.url", "localhost:1099");
	
	try {
		InitialContext ctx = new InitialContext(props);
		ps = (PersonService)ctx.lookup("PersonServiceImpl/remote");
		ps.add(new Person("haha"));
	} catch (NamingException e) {
		e.printStackTrace();
	}
}