jboss+ejb entityManager操作数据库

1、创建EJB服务端项目，右键->EJB PROJECT : ejbserver_jboss

2、创建实体类User:

package ejbtest01.entity;

import java.io.Serializable;

import javax.persistence.*;

@Entity  //注明是实体类型
@Table(name="ejb_user") //设置要映射的表名
public class User implements Serializable{
    private int id;
    private String name;
    private int age;
    private String address;
    
    @Id  //将id设为该实体的主键
    //@GeneratedValue(strategy=GenerationType.AUTO) //生成数据表时才需要，表已存在，则不需要
//    @GeneratedValue()
    @Column(nullable=false,name="id")
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    @Column(nullable=false,name="name")
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    @Column(nullable=true,name="age")
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    @Column(nullable=true,name="address")
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    
    

}
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3、创建操作数据库接口类：UserDao

package ejbtest01.dao;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

import javax.ejb.EJBObject;
import javax.persistence.Query;


import ejbtest01.entity.User;

public interface UserDao extends Serializable{
     public void insertUser(User user);
     public void updateUser(String name,int id);
     public void mergeUser(User user);
     public void deleteUser(int id);
     public User findUserByID(int id);
     public List<User> findAll();
     public String hello();
}
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4、创建操作数据库的实现类：UserDaoBean

package ejbtest01.dao;

import java.io.Serializable;
import java.rmi.RemoteException;
import java.util.ArrayList;
import java.util.List;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.ejb.EJBHome;
import javax.ejb.EJBObject;
import javax.ejb.Handle;
import javax.ejb.Remote;
import javax.ejb.RemoveException;
import javax.ejb.Stateless;
import javax.ejb.TransactionAttribute;
import javax.ejb.TransactionAttributeType;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;


import ejbtest01.entity.User;

@Stateless(name="hello") //name :改变Jndi的名称的, lookup("hello/remote"),默认是UserDaoBean/remote
@Remote(UserDao.class) //指定远程调用的接口类
public class UserDaoBean implements UserDao{

    //unitName:EJB_PU :与persistence.xml中配置的持久化单元名称一致
    @PersistenceContext(unitName="ejbserver_jbossPU")public EntityManager em;
    
//    @TransactionAttribute(TransactionAttributeType.REQUIRES_NEW)
    public void insertUser(User user) {
        em.persist(user);
    }

    public void mergeUser(User user) {
        this.em.getTransaction().begin();
        em.merge(user);
    }

    public void updateUser(String name,int id) {
        User user = em.find(User.class, id);
        if(null!=user){
            user.setName(name);
        }
    }

     public String hello(){
         System.out.println("hello.........");
         return "hello, ";
     }
    public void deleteUser(int id) {
        // TODO Auto-generated method stub

    }

    public List<User> findAll() {
        Query query = em.createQuery("from User u");
        List<User> list = (ArrayList<User>)query.getResultList();
        return list;
    }

    public User findUserByID(int id) {
        return em.find(User.class, id);
    }


}
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5、配置数据源：
在JBOSS目录：E:installjboss-5.1.0.GAdocsexamplesjca 下找到mysql-ds.xml文件，（数据源的配置文件命名是：*-ds.xml）,将mysql-ds.xml文件拷贝到

E:installjboss-5.1.0.GAserverdefaultdeploy目录下，然后在服务端项目ejbserver_jboss/src/META-INF目录下创建persistence.xml文件：

<?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">
    
    <persistence-unit name="ejbserver_jbossPU" transaction-type="JTA">
          <jta-data-source>java:/MySqlDS</jta-data-source> <!-- MySqlDS与数据源配置文件mysql-ds.xml文件中的名称对应 -->
          <!-- 
          <provider>org.hibernate.ejb.HibernatePersistence</provider>
           -->
          <class>ejbtest01.entity.User</class>
          <properties>
              <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect"/>
              <property name="hibernate.show_sql" value="true"/>
              <property name="hibernate.format_sql" value="false"/>
              <property name="hibernate.hbm2ddl.auto" value="update"/>
          </properties>
    </persistence-unit>
  
</persistence>
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6、导入需要的jar包：mysql-connector-java-5.0.4-bin.jar，并将服务端项目打成jar包：ejbserver.jar，

7、新建一个客户端web项目：ejbclientdemo

8、将JBOSS目录下：E:installjboss-5.1.0.GAclient文件夹中的jar全部导入到客户端项目中+mysql-connector-java-5.0.4-bin.jar。+ 服务端项目jar包(ejbserver.jar)

9、在SRC下创建jndi.properties文件：

# DO NOT EDIT THIS FILE UNLESS YOU KNOW WHAT YOU ARE DOING

###new factory name远程实例化工厂的名字
java.naming.factory.initial=org.jnp.interfaces.NamingContextFactory

##remote package path远程调用类的包路径

java.naming.factory.url.pkgs=org.jboss.naming:org.jnp.interfaces

###remote class server path调用类的服务器路径

##localhost:8080 is not run  , must locahost
java.naming.provider.url=localhost
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10、配置客户端web.xml文件的数据源：

<resource-ref>
  <description>DB Connection</description>
  <res-ref-name>jdbc/test</res-ref-name><!-- test:是对应的数据库名称，不是连接名称 -->
  <res-type>javax.sql.DataSource</res-type>
  <res-auth>Container</res-auth>
 </resource-ref>
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11、在客户端的main方法中测试调用接口：

package ejb.client;

import java.io.Serializable;
import java.util.List;

import javax.naming.InitialContext;
import javax.rmi.PortableRemoteObject;
import ejbtest01.dao.UserDao;
import ejbtest01.dao.UserDaoBean;
import ejbtest01.entity.User;

public class Client implements Serializable{
    
    public static void main(String[] args) {
        try{    
    InitialContext ctx = new InitialContext();
            UserDao dao = (UserDao)ctx.lookup("hello/remote");
            
            //1、先新增数据
          User user = new User();
          user.setId(10);
          user.setName("10000");
          user.setAge(30);
          user.setAddress("呵呵111");
          dao.insertUser(user);
            
            //2、再查询数据
            List<User> users = dao.findAll();
           for(User u : users){
               System.out.println("===="+u.getName());
           }

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

}
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12、启动JBOSS，运行客户端Main方法，输出查询结果，即测试成功。

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原文地址：https://www.cnblogs.com/summer520/p/3184461.html