JPA2 on JBoss6

刚刚接触JPA2，写了个测试程序和大家分享。

环境：

server:JBoss6-M3

db:mysql

 

1.创建数据库 jpa ， 建表 user:

CREATE TABLE `user` (
  `userid` int(11) NOT NULL auto_increment,
  `usercode` varchar(255) default NULL,
  `username` varchar(255) default NULL,
  `password` varchar(255) default NULL,
  `email` varchar(255) default NULL,
  `remark` varchar(255) default NULL,
  PRIMARY KEY  (`userid`)
) TYPE=MyISAM;

2.配置资源文件 mysql-ds.xml 放到 jboss deploy 目录下(比如 D:\server\jboss6m3\server\default\deploy )

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

<datasources>
   <local-tx-datasource>
      <jndi-name>jpa2 </jndi-name>
      <connection-url>jdbc:mysql://localhost:3306/jpa </connection-url>
      <driver-class>com.mysql.jdbc.Driver</driver-class>
      <user-name>root</user-name>
      <password>123456WSad!</password>
      <min-pool-size>5</min-pool-size>
      <max-pool-size>100</max-pool-size>
      <idle-timeout-minutes>15</idle-timeout-minutes>
      <check-valid-connection-sql>select count(*) from user</check-valid-connection-sql>
      <track-statements/>
   </local-tx-datasource>
</datasources>

3.配置 jpa2 的persistence文件 persistence.xml，该文件应放到 src/META-INF下，否则请使用ant,maven等工具编译到classes/META-INF下。

<?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="JPA2 " transaction-type="JTA">

    <jta-data-source>java:jpa2 </jta-data-source>

    <properties/>

  </persistence-unit>

</persistence>

 

properties

<property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect"/>
<property name="hibernate.hbm2ddl.auto" value="create-drop"/> 正向工程时会用到：创建数据库和相关表

 

4.使用JPA2的工具，或者手动创建 User.java

package com.pojo;

import java.io.Serializable;

import javax.persistence.Basic;

import javax.persistence.Column;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.GenerationType;

import javax.persistence.Id;

import javax.persistence.NamedQueries;

import javax.persistence.NamedQuery;

import javax.persistence.Table;

@Entity

@Table(name = "user ")

@NamedQueries( {

@NamedQuery(name = "User.findAll", query = "SELECT u FROM User u"),

@NamedQuery(name = "User.findByUserid", query = "SELECT u FROM User u WHERE u.userid = :userid"),

@NamedQuery(name = "User.findByUsercode", query = "SELECT u FROM User u WHERE u.usercode = :usercode"),

@NamedQuery(name = "User.findByUsername", query = "SELECT u FROM User u WHERE u.username = :username"),

@NamedQuery(name = "User.findByPassword", query = "SELECT u FROM User u WHERE u.password = :password"),

@NamedQuery(name = "User.findByEmail", query = "SELECT u FROM User u WHERE u.email = :email"),

@NamedQuery(name = "User.findByRemark", query = "SELECT u FROM User u WHERE u.remark = :remark") })

public class User implements Serializable {

private static final long serialVersionUID = 1L;

@Id

@GeneratedValue(strategy = GenerationType.IDENTITY)

@Basic(optional = false)

@Column(name = "userid")

private Integer userid;

@Column(name = "usercode")

private String usercode;

@Column(name = "username")

private String username;

@Column(name = "password")

private String password;

@Column(name = "email")

private String email;

@Column(name = "remark")

private String remark;

public User() {

}

public User(Integer userid) {

this.userid = userid;

}

public Integer getUserid() {

return userid;

}

public void setUserid(Integer userid) {

this.userid = userid;

}

public String getUsercode() {

return usercode;

}

public void setUsercode(String usercode) {

this.usercode = usercode;

}

public String getUsername() {

return username;

}

public void setUsername(String username) {

this.username = username;

}

public String getPassword() {

return password;

}

public void setPassword(String password) {

this.password = password;

}

public String getEmail() {

return email;

}

public void setEmail(String email) {

this.email = email;

}

public String getRemark() {

return remark;

}

public void setRemark(String remark) {

this.remark = remark;

}

@Override

public int hashCode() {

int hash = 0;

hash += (userid != null ? userid.hashCode() : 0);

return hash;

}

@Override

public boolean equals(Object object) {

// TODO: Warning - this method won't work in the case the id fields are

// not set

if (!(object instanceof User)) {

return false;

}

User other = (User) object;

if ((this.userid == null && other.userid != null)

|| (this.userid != null && !this.userid.equals(other.userid))) {

return false;

}

return true;

}

@Override

public String toString() {

return "com.pojo.User[userid=" + userid + "]";

}

}

5.创建访问数据库的session bean

package com.ejb;

import com.pojo.User;

import java.util.List;

import javax.ejb.Stateless;

import javax.persistence.EntityManager;

import javax.persistence.PersistenceContext;

import javax.persistence.Query;

@Stateless

public class Userdao {

@PersistenceContext(unitName = " JPA2 ")

private EntityManager em;

public void save(User entity) {

this.em.persist(entity);

}

public void delete(User entity) {

try {

em.remove(em.merge(entity));

} catch (Exception e) {

String s = e.getMessage();

System.out.print(s);

}

}

public void update(User entity) {

em.merge(entity);

}

public List<User> getAll() {

Query query = em.createNamedQuery("User.findAll");

return query.getResultList();

}

public User getById(int id) {

return (User) em.createNamedQuery("User.findByUserid").getSingleResult();

}

public User getByUserCode(String usercode) {

Query query = em.createNamedQuery("User.findByUsercode");

query.setParameter("usercode", usercode);

try {

Object o = query.getSingleResult();

return (User) o;

} catch (Exception e) {// if result more than one, it will throw

// exception.

String s = e.getMessage();

System.out.print(s);

}

return null;

}

public User getByUserName(String username) {

Query query = em.createNamedQuery("User.findByUsername");

query.setParameter("username", username);

return (User) query.getSingleResult();

}

}

6.创建测试使用的servlet

package com.servlet;

import java.io.IOException;

import java.io.PrintWriter;

import java.util.List;

import javax.ejb.EJB;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import com.ejb.Userdao;

import com.pojo.User;

@WebServlet(name = " TestServlet ", urlPatterns = { "/TestServlet" })

public class TestServlet extends HttpServlet {

    @EJB

    private Userdao userDao;

    protected void processRequest(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {

        String msg = "";

        String para = request.getParameter("method");

        msg = "method=" + para + " :\n";

        if (para.equals("insert")) {

            String username = request.getParameter("username");

            String usercode = request.getParameter("usercode");

            String password = request.getParameter("password");

            String email = request.getParameter("email");

            User user = new User();

            user.setUsercode(usercode);

            user.setUsername(username);

            user.setPassword(password);

            user.setEmail(email);

            this.userDao.save(user);

            msg += "successful insert :" + username;

        } else if (para.equals("update")) {

            String username = request.getParameter("username");

            String usercode = request.getParameter("usercode");

            String password = request.getParameter("password");

            String email = request.getParameter("email");

            User user = this.userDao.getByUserCode(usercode);

            user.setUsercode(usercode);

            user.setUsername(username);

            user.setPassword(password);

            user.setEmail(email);

            this.userDao.update(user);

            msg += "successful update :" + username;

        } else if (para.equals("delete")) {

            String usercode = request.getParameter("usercode");

            User user = this.userDao.getByUserCode(usercode);

            if (user != null) {

                this.userDao.delete(user);

            }

            msg += "successful remove :" + user.getUsername();

        } else if (para.equals("findall")) {

            List<User> list = this.userDao.getAll();

            for (User user : list) {

                msg += "—>" + user.getUsername();

            }

        }

        response.setContentType("text/html;charset=UTF-8");

        PrintWriter out = response.getWriter();

        try {

            out.println("<html>");

            out.println("<head>");

            out.println("<title>Servlet TestServlet</title>");

            out.println("</head>");

            out.println("<body>");

            out.println(msg);

            out.println("</body>");

            out.println("</html>");

        } finally {

            out.close();

        }

    }

    @Override

    protected void doGet(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {

        processRequest(request, response);

    }

    @Override

    protected void doPost(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {

        String mothed = request.getParameter("method");

        if (mothed.equals("insert")) {

            processRequest(request, response);

        }

    }

    @Override

    public String getServletInfo() {

        return "Short description";

    }

}

7最后写一个测试用的 jsp

<%@page contentType="text/html" pageEncoding="UTF-8"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"

    "http://www.w3.org/TR/html4/loose.dtd">

<html>

    <head>

        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">

        <title>JSP Page</title>

    </head>

    <body>

        <a href="http://localhost:8080/eboss/TestServlet ?method=insert &usercode=zhangshan &username=zhangsan &password=1234 &email=[e-mail] ">

            insert test

        </a>

        <br/>

        <a href="http://localhost:8080/eboss/TestServlet?method=update&usercode=zhangshan&username=lisi&password=4321&email=[e-mail]">

            update test

        </a>

        <br/>

        <a href="http://localhost:8080/eboss/TestServlet?method=findall">

            list test

        </a>

        <br/>

        <a href="http://localhost:8080/eboss/TestServlet?method=delete&usercode=zhangshan">

            delete test

        </a>

    </body>

</html>

8. 别忘了把 db driver jar 放入 jboss lib 目录(比如 D:\server\jboss6m3\server\default\lib ，driver jar：mysql-connector-java-5.1.6-bin.jar )

 

9. 运行JBoss 访问 http://localhost:8080/eboss/