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=zhangshan@gmail.com ">             insert test         </a>         <br/>         <a href="http://localhost:8080/eboss/TestServlet?method=update&usercode=zhangshan&username=lisi&password=4321&email=lisi@gmail.com">             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/