Ejb3.0--4

1,创建jboss数据源，mysql-ds.xml

<?xml version="1.0" encoding="utf-8"?>
   
  <!--   $Id:   mysql-ds.xml,v   1.3.2.3   2006/02/07   14:23:00   acoliver   Exp   $   -->  
  <!--     Datasource   config   for   MySQL   using   3.0.9   available   from:  
  http://www.mysql.com/downloads/api-jdbc-stable.html  
  -->  
   
  <datasources>  
      <local-tx-datasource>  
          <jndi-name>chenzhq_mysql</jndi-name>  
          <connection-url>jdbc:mysql://192.168.40.10:3306/school</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>  
          <!--   should   only   be   used   on   drivers   after   3.22.1   with   "ping"   support  
          <valid-connection-checker-class-name>org.jboss.resource.adapter.jdbc.vendor.MySQLValidConnectionChecker</valid-connection-checker-class-name>  
          -->  
          <!--   sql   to   call   when   connection   is   created  
          <new-connection-sql>some   arbitrary   sql</new-connection-sql>  
              -->  
          <!--   sql   to   call   on   an   existing   pooled   connection   when   it   is   obtained   from   pool   -   MySQLValidConnectionChecker   is   preferred   for   newer   drivers  
          <check-valid-connection-sql>some   arbitrary   sql</check-valid-connection-sql>  
              -->  
   
          <!--   corresponding   type-mapping   in   the   standardjbosscmp-jdbc.xml   (optional)   -->  
          <metadata>  
                <type-mapping>mySQL</type-mapping>  
          </metadata>  
      </local-tx-datasource>  
</datasources>

2.编写persistence.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistences>
  <persistence-unit name="student">
  <!-- 
   <jta-data-source>java:chenzhq_oracle_datasource</jta-data-source>
    <class>com.chenzhq.ejb.entity.Student</class>
   -->
    <jta-data-source>java:/chenzhq_mysql</jta-data-source>
    <class>com.chenzhq.ejb.entity.Student</class>
  </persistence-unit>
</persistences>

3.写个Entity-bean

package com.chenzhq.ejb.entity;

import java.io.Serializable;

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


@Entity//Entity标记声明student是个实体bean
@Table (name="student")//for mysql 注册映射表为student
//@Table (name="test.student")//for oracle
public class Student implements Serializable {//注意必须实现可序列化，否则在你调用Remote接口的时候就会报错。

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private int id;
	private String name;
	private String sex;
	private String classes;
	private int points;
	
	@Column (name="classes")//映射到classes列
	public String getClasses() {
		return classes;
	}
	public void setClasses(String classes) {
		this.classes = classes;
	}
	@Id//声明student的主键
	//@GeneratedValue
	@Column (name="id")
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	@Column (name="name")
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	@Column (name="points")
	public int getPoints() {
		return points;
	}
	public void setPoints(int points) {
		this.points = points;
	}
	@Column (name="sex")
	public String getSex() {
		return sex;
	}
	public void setSex(String sex) {
		this.sex = sex;
	}
	
}

4，在写个sessionbean调用处理实体bean，ejb3.0中entitybean就像个pojo

package com.chenzhq.ejb.session;

import javax.ejb.Init;
import javax.ejb.Local;
import javax.ejb.Remote;
import javax.ejb.Stateful;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.FlushModeType;
import javax.persistence.PersistenceContext;
import javax.persistence.PersistenceContextType;

import com.chenzhq.ejb.entity.Student;

@Stateful
@Remote ({ProcessStudentRemote.class})
@Local  ({ProcessStudentLocal.class})


public class ProcessStudent implements ProcessStudentLocal,ProcessStudentRemote {


	
	//@PersistenceUnit (unitName="student") private static EntityManagerFactory emf;
	/*  这里面的大多数方法是我简化写的，只是提及一下，深入了解的化买本书吧！
	 * //获得对实体bean的上下文引用,unitName对应这Persistence.xml中的uintName
	 * type可以是EXTEND，或是TRANSACTION，EXTEND的相对与TRANSACTION的生存的时间长
	 * 
	 * 
	 */
	@PersistenceContext (unitName="student",type=PersistenceContextType.EXTENDED)
	    private static EntityManagerFactory emf;
	private static EntityManager em;
	
	@Init
	public void init(){
		System.out.println(emf);
	}
	

	
	public boolean createStudent(Student s){
		System.out.println(s);
		em = emf.createEntityManager();
		/*
		 * 如果你的EntityManager是使用EntityManagerFactoty生成的，那么joinTransaction是必须的
		 *
		 */
		em.joinTransaction();
		em.setFlushMode(FlushModeType.COMMIT);
		System.out.println(em.toString().toUpperCase());
		if(em.isOpen()){
			//em.merge(s);
			em.persist(s);//持久化一个student
			em.flush();
			
		}else{
			throw new RuntimeException("the entity manager is closed");
		}
		
		return true;
	}
	
	public boolean queryStudent(Object o){
		em = emf.createEntityManager();
		em.joinTransaction();
		em.setFlushMode(FlushModeType.COMMIT);
		System.out.println(em.toString().toUpperCase());
		System.out.println(em.find(Student.class, o).getId());
		try{
			/*
			 * find和reference的区别再用，如果没有发现find返回null，而reference出现异常。
			 */
			Student s = em.getReference(Student.class, o);
			System.out.print(s.getName());
		}catch(Exception e){
			e.printStackTrace();
		}
		return true;
	}
	
	public boolean removeStudent(Object o){
		em = emf.createEntityManager();
		em.joinTransaction();
		em.setFlushMode(FlushModeType.COMMIT);
		System.out.println(em.toString().toUpperCase());
		Student s = em.find(Student.class, o);
		em.remove(s);
		em.flush();
		em.clear();
		return true;
	}
	
	public boolean updateStudent(String name,Object o){
		em = emf.createEntityManager();
		em.joinTransaction();
		em.setFlushMode(FlushModeType.COMMIT);
		System.out.println(em.toString().toUpperCase());
		Student s =  em.find(Student.class, o);
		/*
		 * 因为是managed的Bean所以容器会将改变的bean同步到database的。
		 */
		s.setName(name);
		return true;
		
	}
}