EJB+JPA演示实体类基本操作CRUD的实现

作者: Michael 日期: 2013 年 9 月 25 日发表评论 (2) 查看评论

本文详细介绍EJB+JPA实现Entity的CRUD基本操作。

创建POJO：BlogVo
创建Entity：Blog
配置persistence.xml
定义Remote接口
创建SessionBean实现类
配置datasource数据源
部署EJB工程
创建客户端测试类
运行测试类

[一]、创建POJO：BlogVo.java

package com.micmiu.ejb.vo;

import java.io.Serializable;

/**
 * Blog vo对象
 * 
 * @author <a href="http://www.micmiu.com">Michael</a>
 * @time Create on 2013-9-25 下午3:02:17
 * @version 1.0
 */
public class BlogVo implements Serializable {

	private static final long serialVersionUID = -6384496304647072095L;

	private Integer id;

	private String title;

	private String url;

	private String author;

	public Integer getId() {
		return id;
	}

	public String getTitle() {
		return title;
	}

	public String getUrl() {
		return url;
	}

	public String getAuthor() {
		return author;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	public void setTitle(String title) {
		this.title = title;
	}

	public void setUrl(String url) {
		this.url = url;
	}

	public void setAuthor(String author) {
		this.author = author;
	}

	@Override
	public String toString() {
		return "BlogVo [id=" + id + ", title=" + title + ", url=" + url
				+ ", author=" + author + "]";
	}
}

package com.micmiu.ejb.vo;

import java.io.Serializable;

/**

* Blog vo对象

* @author <a href="http://www.micmiu.com">Michael</a>

* @time Create on 2013-9-25 下午3:02:17

* @version 1.0

public class BlogVo implements Serializable {

private static final long serialVersionUID = -6384496304647072095L;

private Integer id;

private String title;

private String url;

private String author;

public Integer getId() {

return id;

}

public String getTitle() {

return title;

}

public String getUrl() {

return url;

}

public String getAuthor() {

return author;

}

public void setId(Integer id) {

this.id = id;

}

public void setTitle(String title) {

this.title = title;

}

public void setUrl(String url) {

this.url = url;

}

public void setAuthor(String author) {

this.author = author;

}

@Override

public String toString() {

return "BlogVo [id=" + id + ", title=" + title + ", url=" + url

+ ", author=" + author + "]";

}

[二]、创建Entity：Blog.java

package com.micmiu.ejb.entity;

import java.io.Serializable;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.Table;

/**
 * 实体类blog
 * 
 * @author <a href="http://www.micmiu.com">Michael</a>
 * @time Create on 2013-9-24 下午1:57:47
 * @version 1.0
 */
@Entity
@Table(name = "DEMO_T_BLOG")
@NamedQueries({ @NamedQuery(name = "queryAll", query = "select t from Blog t ") })
public class Blog implements Serializable {

	private static final long serialVersionUID = -1371929956020543775L;

	@Id
	@GeneratedValue
	@Column(name = "ID")
	private Integer id;

	@Column(name = "TITLE", length = 128)
	private String title;

	@Column(name = "URL", length = 1024)
	private String url;

	@Column(name = "AUTHOR", length = 20)
	private String author;

	public Integer getId() {
		return id;
	}

	public String getTitle() {
		return title;
	}

	public String getUrl() {
		return url;
	}

	public String getAuthor() {
		return author;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	public void setTitle(String title) {
		this.title = title;
	}

	public void setUrl(String url) {
		this.url = url;
	}

	public void setAuthor(String author) {
		this.author = author;
	}

	@Override
	public String toString() {
		return "Blog [id=" + id + ", title=" + title + ", url=" + url
				+ ", author=" + author + "]";
	}

}

package com.micmiu.ejb.entity;

import java.io.Serializable;

import javax.persistence.Column;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.Id;

import javax.persistence.NamedQueries;

import javax.persistence.NamedQuery;

import javax.persistence.Table;

/**

* 实体类blog

* @author <a href="http://www.micmiu.com">Michael</a>

* @time Create on 2013-9-24 下午1:57:47

* @version 1.0

@Entity

@Table(name = "DEMO_T_BLOG")

@NamedQueries({ @NamedQuery(name = "queryAll", query = "select t from Blog t ") })

public class Blog implements Serializable {

private static final long serialVersionUID = -1371929956020543775L;

@Id

@GeneratedValue

@Column(name = "ID")

private Integer id;

@Column(name = "TITLE", length = 128)

private String title;

@Column(name = "URL", length = 1024)

private String url;

@Column(name = "AUTHOR", length = 20)

private String author;

public Integer getId() {

return id;

}

public String getTitle() {

return title;

}

public String getUrl() {

return url;

}

public String getAuthor() {

return author;

}

public void setId(Integer id) {

this.id = id;

}

public void setTitle(String title) {

this.title = title;

}

public void setUrl(String url) {

this.url = url;

}

public void setAuthor(String author) {

this.author = author;

}

@Override

public String toString() {

return "Blog [id=" + id + ", title=" + title + ", url=" + url

+ ", author=" + author + "]";

}

[三]、配置persistence.xml

修改配置文件 src: META-INF/persistence.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0"
	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">
	<!-- 为持久化单元取名=micmiuJPA,transaction-type=JTA 利用容器的事务管理 -->
	<persistence-unit name="micmiuJPA" transaction-type="JTA">
		<provider>org.hibernate.ejb.HibernatePersistence</provider>

		<jta-data-source>java:/micmiuOracleDS</jta-data-source>
		<!-- <class>com.micmiu.ejb.entity.Blog</class> -->
		<!-- 声明是否扫描jar文件中标注了@Enity类.若不扫描,值为true 默认也是true -->
		<exclude-unlisted-classes>true</exclude-unlisted-classes>
		<properties>
			<property name="hibernate.archive.autodetection" value="class,hbm" />
			<!--配置Hibernate方言 -->
			<property name="hibernate.dialect" value="org.hibernate.dialect.Oracle10gDialect" />
			<!--自动输出schema创建DDL语句 -->
			<property name="hibernate.hbm2ddl.auto" value="update" />
			<!-- 输出SQL语句 -->
			<property name="hibernate.show_sql" value="true" />
			<!-- 格式化SQL语句 -->
			<property name="hibernate.format_sql" value="true" />
		</properties>
	</persistence-unit>
</persistence>

<?xml version="1.0" encoding="UTF-8"?>

<persistence version="2.0"

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">

<persistence-unit name="micmiuJPA" transaction-type="JTA">

<provider>org.hibernate.ejb.HibernatePersistence</provider>

<jta-data-source>java:/micmiuOracleDS</jta-data-source>

<exclude-unlisted-classes>true</exclude-unlisted-classes>

</properties>

</persistence-unit>

</persistence>

ps：<jta-data-source></jta-data-source>配置的值“java:/micmiuOracleDS”需要和JBOSS_HOME/server/default/conf/tandardjbosscmp-jdbc.xml 中配置的<datasource></datasource>一致，详见下面第[六]部分配置datasource数据源

[四]、定义Remote接口

BlogBeanRemote.java

package com.micmiu.ejb;

import java.util.List;

import javax.ejb.Remote;

import com.micmiu.ejb.vo.BlogVo;

/**
 * BlogBean remote
 * 
 * @author <a href="http://www.micmiu.com">Michael</a>
 * @time Create on 2013-9-25 下午3:05:42
 * @version 1.0
 */
@Remote
public interface BlogBeanRemote {

	BlogVo create(BlogVo blog);

	BlogVo read(Integer id);

	void update(BlogVo blog);

	void delete(Integer id);

	List<BlogVo> queryAll();

	List<BlogVo> queryByAuthor(String author);
}

package com.micmiu.ejb;

import java.util.List;

import javax.ejb.Remote;

import com.micmiu.ejb.vo.BlogVo;

/**

* BlogBean remote

* @author <a href="http://www.micmiu.com">Michael</a>

* @time Create on 2013-9-25 下午3:05:42

* @version 1.0

@Remote

public interface BlogBeanRemote {

BlogVo create(BlogVo blog);

BlogVo read(Integer id);

void update(BlogVo blog);

void delete(Integer id);

List<BlogVo> queryAll();

List<BlogVo> queryByAuthor(String author);

}

[五]、创建SessionBean实现类

BlogBean.java

package com.micmiu.ejb;

import java.util.ArrayList;
import java.util.List;

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

import com.micmiu.ejb.entity.Blog;
import com.micmiu.ejb.vo.BlogVo;

/**
 * Session Bean implementation class BlogBean
 * 
 * @author <a href="http://www.micmiu.com">Michael</a>
 * @time Create on 2013-9-25 上午9:20:36
 * @version 1.0
 */
@Stateless
public class BlogBean implements BlogBeanRemote {

	@PersistenceContext(unitName = "micmiuJPA")
	private EntityManager em;

	/**
	 * Default constructor.
	 */
	public BlogBean() {
	}

	@Override
	public BlogVo create(BlogVo vo) {
		Blog po = this.parseVo2Po(vo);
		em.persist(po);
		em.flush();
		return this.parsePo2Vo(po);
	}

	@Override
	public BlogVo read(Integer id) {
		Blog po = em.find(Blog.class, id);
		return this.parsePo2Vo(po);

	}

	@Override
	public void update(BlogVo vo) {
		Blog po = this.parseVo2Po(vo);
		em.merge(po);
	}

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

	@SuppressWarnings("unchecked")
	@Override
	public List<BlogVo> queryAll() {
		List<Blog> list = em.createNamedQuery("queryAll").getResultList();
		List<BlogVo> volist = new ArrayList<BlogVo>();
		for (Blog po : list) {
			volist.add(this.parsePo2Vo(po));
		}
		return volist;
	}

	@SuppressWarnings("unchecked")
	@Override
	public List<BlogVo> queryByAuthor(String author) {
		Query query = em.createQuery(
				"select t from Blog t where t.author =:author").setParameter(
				"author", author);
		List<Blog> list = query.getResultList();
		List<BlogVo> volist = new ArrayList<BlogVo>();
		for (Blog po : list) {
			volist.add(this.parsePo2Vo(po));
		}
		return volist;
	}

	private Blog parseVo2Po(BlogVo vo) {
		Blog blog = new Blog();
		blog.setAuthor(vo.getAuthor());
		blog.setId(vo.getId());
		blog.setTitle(vo.getTitle());
		blog.setUrl(vo.getUrl());
		return blog;
	}

	private BlogVo parsePo2Vo(Blog po) {
		BlogVo vo = new BlogVo();
		vo.setAuthor(po.getAuthor());
		vo.setId(po.getId());
		vo.setTitle(po.getTitle());
		vo.setUrl(po.getUrl());
		return vo;
	}
}

100

101

package com.micmiu.ejb;

import java.util.ArrayList;

import java.util.List;

import javax.ejb.Stateless;

import javax.persistence.EntityManager;

import javax.persistence.PersistenceContext;

import javax.persistence.Query;

import com.micmiu.ejb.entity.Blog;

import com.micmiu.ejb.vo.BlogVo;

/**

* Session Bean implementation class BlogBean

* @author <a href="http://www.micmiu.com">Michael</a>

* @time Create on 2013-9-25 上午9:20:36

* @version 1.0

@Stateless

public class BlogBean implements BlogBeanRemote {

@PersistenceContext(unitName = "micmiuJPA")

private EntityManager em;

/**

* Default constructor.

public BlogBean() {

}

@Override

public BlogVo create(BlogVo vo) {

Blog po = this.parseVo2Po(vo);

em.persist(po);

em.flush();

return this.parsePo2Vo(po);

}

@Override

public BlogVo read(Integer id) {

Blog po = em.find(Blog.class, id);

return this.parsePo2Vo(po);

}

@Override

public void update(BlogVo vo) {

Blog po = this.parseVo2Po(vo);

em.merge(po);

}

@Override

public void delete(Integer id) {

em.remove(em.getReference(Blog.class, id));

}

@SuppressWarnings("unchecked")

@Override

public List<BlogVo> queryAll() {

List<Blog> list = em.createNamedQuery("queryAll").getResultList();

List<BlogVo> volist = new ArrayList<BlogVo>();

for (Blog po : list) {

volist.add(this.parsePo2Vo(po));

}

return volist;

}

@SuppressWarnings("unchecked")

@Override

public List<BlogVo> queryByAuthor(String author) {

Query query = em.createQuery(

"select t from Blog t where t.author =:author").setParameter(

"author", author);

List<Blog> list = query.getResultList();

List<BlogVo> volist = new ArrayList<BlogVo>();

for (Blog po : list) {

volist.add(this.parsePo2Vo(po));

}

return volist;

}

private Blog parseVo2Po(BlogVo vo) {

Blog blog = new Blog();

blog.setAuthor(vo.getAuthor());

blog.setId(vo.getId());

blog.setTitle(vo.getTitle());

blog.setUrl(vo.getUrl());

return blog;

}

private BlogVo parsePo2Vo(Blog po) {

BlogVo vo = new BlogVo();

vo.setAuthor(po.getAuthor());

vo.setId(po.getId());

vo.setTitle(po.getTitle());

vo.setUrl(po.getUrl());

return vo;

}

ps:

@PersistenceContext 用来注入 EntityManager
unitName 的值”micmiuJPA” 和配置文件persistence.xml 中定义的名称一致

[六]、配置datasource数据源

数据源配置详见：http://www.micmiu.com/j2ee/ejb/ejb-deploy-jboss-ds-config/

[七]、部署EJB工程

导出EJB工程打包，copy 到 JBOSS_HOME/server/default/deploy 默认发布配置下,启动JBOSS即可，能看的类似如下的日志信息：

09:39:43,291 INFO [SessionSpecContainer] Starting jboss.j2ee:jar=EJB-HelloWorld.jar,name=BlogBean,service=EJB3
09:39:43,298 INFO [EJBContainer] STARTED EJB: com.micmiu.ejb.BlogBean ejbName: BlogBean
09:39:43,306 INFO [JndiSessionRegistrarBase] Binding the following Entries in Global JNDI:

BlogBean/remote – EJB3.x Default Remote Business Interface
BlogBean/remote-com.micmiu.ejb.BlogBeanRemote – EJB3.x Remote Business Interface

[八]、创建客户端测试类

把EJB工程中的Remote接口以及引用到的Vo类导出JAR包，copy到客户端工程中，然后创建客户端调用类：BlogBeanClientTest.java

package com.micmiu.ejb.demo;

import java.util.List;
import java.util.Properties;

import javax.naming.InitialContext;
import javax.naming.NamingException;

import com.micmiu.ejb.BlogBeanRemote;
import com.micmiu.ejb.vo.BlogVo;

/**
 * 客户端调用测试类
 * 
 * @author <a href="http://www.micmiu.com">Michael</a>
 * @time Create on 2013-9-21 下午2:51:59
 * @version 1.0
 */
public class BlogBeanClientTest {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		try {
			Properties props = new Properties();
			props.setProperty("java.naming.factory.initial",
					"org.jnp.interfaces.NamingContextFactory");
			props.setProperty("java.naming.provider.url", "localhost:1099");
			props.setProperty("java.naming.factory.url.pkgs",
					"org.jboss.naming");

			System.out.println(">>>> InitialContext ");
			InitialContext ctx = new InitialContext(props);

			System.out.println(">>>> lookup  ");
			String serviceName = "BlogBean/remote";
			BlogBeanRemote remote = (BlogBeanRemote) ctx.lookup(serviceName);

			System.out.println(">>>>  操作之前 query michael's Blog");
			List<BlogVo> list = remote.queryByAuthor("michael");
			System.out.println("query result size = " + list.size());
			for (BlogVo blog : list) {
				System.out.println(blog);
			}

			System.out.println(">>>> create new blog");
			BlogVo blog = new BlogVo();
			blog.setAuthor("michael");
			blog.setTitle("图文演示Eclipse+JBoss创建第一个EJB项目");
			blog.setUrl("http://www.micmiu.com/j2ee/ejb/eclipse-jboss-ejb-demo/");
			BlogVo createVo = remote.create(blog);
			System.out.println(createVo);

			System.out.println(">>>> read exit blog");
			BlogVo readVo = remote.read(1);
			System.out.println(readVo);

			System.out.println(">>>> update blog");
			System.out.println("update title " + readVo.getTitle()
					+ " to 大大&&小小 ");
			readVo.setTitle("大大&&小小");
			remote.update(readVo);

			System.out.println(">>>>  操作之后 query michael's Blog");
			list = remote.queryByAuthor("michael");
			System.out.println(">>>> 结果 = " + list.size());
			for (BlogVo vo : list) {
				System.out.println(vo);
			}

		} catch (NamingException e) {
			e.printStackTrace();
		}
	}
}

package com.micmiu.ejb.demo;

import java.util.List;

import java.util.Properties;

import javax.naming.InitialContext;

import javax.naming.NamingException;

import com.micmiu.ejb.BlogBeanRemote;

import com.micmiu.ejb.vo.BlogVo;

/**

* 客户端调用测试类

* @author <a href="http://www.micmiu.com">Michael</a>

* @time Create on 2013-9-21 下午2:51:59

* @version 1.0

public class BlogBeanClientTest {

/**

* @param args

public static void main(String[] args) {

try {

Properties props = new Properties();

props.setProperty("java.naming.factory.initial",

"org.jnp.interfaces.NamingContextFactory");

props.setProperty("java.naming.provider.url", "localhost:1099");

props.setProperty("java.naming.factory.url.pkgs",

"org.jboss.naming");

System.out.println(">>>> InitialContext ");

InitialContext ctx = new InitialContext(props);

System.out.println(">>>> lookup ");

String serviceName = "BlogBean/remote";

BlogBeanRemote remote = (BlogBeanRemote) ctx.lookup(serviceName);

System.out.println(">>>> 操作之前 query michael's Blog");

List<BlogVo> list = remote.queryByAuthor("michael");

System.out.println("query result size = " + list.size());

for (BlogVo blog : list) {

System.out.println(blog);

}

System.out.println(">>>> create new blog");

BlogVo blog = new BlogVo();

blog.setAuthor("michael");

blog.setTitle("图文演示Eclipse+JBoss创建第一个EJB项目");

blog.setUrl("http://www.micmiu.com/j2ee/ejb/eclipse-jboss-ejb-demo/");

BlogVo createVo = remote.create(blog);

System.out.println(createVo);

System.out.println(">>>> read exit blog");

BlogVo readVo = remote.read(1);

System.out.println(readVo);

System.out.println(">>>> update blog");

System.out.println("update title " + readVo.getTitle()

+ " to 大大&&小小 ");

readVo.setTitle("大大&&小小");

remote.update(readVo);

System.out.println(">>>> 操作之后 query michael's Blog");

list = remote.queryByAuthor("michael");

System.out.println(">>>> 结果 = " + list.size());

for (BlogVo vo : list) {

System.out.println(vo);

}

} catch (NamingException e) {

e.printStackTrace();

}

[九]、运行测试类

运行后日志信息如下：

>>>> InitialContext
>>>> lookup
>>>> 操作之前 query michael’s Blog
query result size = 1
BlogVo [id=1, title=Michael的博客, url=http://www.micmiu.com, author=michael]
>>>> create new blog
BlogVo [id=114, title=图文演示Eclipse+JBoss创建第一个EJB项目, url=http://www.micmiu.com/j2ee/ejb/eclipse-jboss-ejb-demo/, author=michael]
>>>> read exit blog
BlogVo [id=1, title=Michael的博客, url=http://www.micmiu.com, author=michael]
>>>> update blog
update title Michael的博客 to 大大&&小小
>>>> 操作之后 query michael’s Blog
>>>> 结果 = 2
BlogVo [id=1, title=大大&&小小, url=http://www.micmiu.com, author=michael]
BlogVo [id=114, title=图文演示Eclipse+JBoss创建第一个EJB项目, url=http://www.micmiu.com/j2ee/ejb/eclipse-jboss-ejb-demo/, author=michael]

本文介绍到此结束@Michael Sun.

原创文章，转载请注明： 转载自micmiu – 软件开发+生活点滴[ http://www.micmiu.com/ ]

本文链接地址: http://www.micmiu.com/j2ee/ejb/ejb-jpa-entity-crud-demo/

EJB

← EJB部署在JBoss下的datasource配置

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发表评论？

2 条评论。

汪大海 2018 年 9 月 10 日在上午 10:30

你好，孙大哥，想问一下，已经平稳运行好多年的EJB2.0项目，可以保证既往不咎的原则，怼上JPA，让后面开发更便捷么

回复
我我我我我问问 2015 年 7 月 20 日在下午 3:55

😕 😕 😕 😕 😕 😕 😕

回复

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