用Jersey构建RESTful服务5--Jersey+MySQL5.6+Hibernate4.3

#一、总体说明

本例运行演示了用Jersey构建RESTful服务中，如何同过Hibernate将数据持久化进MySQL的过程

#二、环境

1.上文的项目RestDemo

2.MySQL5.6下载http://dev.mysql.com/get/Downloads/MySQL-5.6/mysql-5.6.16-win32.zip

3.Hibernate4.3.4下载http://sourceforge.net/projects/hibernate/files/hibernate4/4.3.4.Final/hibernate-release-4.3.4.Final.zip

4.Java程序连接MySQL的驱动mysql-connector-java-5.1.29-bin.jar下载 http://dev.mysql.com/get/Downloads/Connector-J/mysql-connector-java-5.1.29.zip

#三、数据库准备

1.搭建MySQL数据库

2.创建数据库RestDemo ,及数据表t_user,结构如下

DROP TABLE IF EXISTS `t_user`;
CREATE TABLE `t_user` (
  `userId` varchar(50) NOT NULL,
  `userName` varchar(50) NOT NULL,
  `age` varchar(50) NOT NULL,
  PRIMARY KEY (`userId`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

PS: userId 非自增长类型，需要在业务添加

#四、引入Hibernate

1.解压Hibernate的包，在lib\required文件夹下所有jar引入进项目

2.解压mysql-connector-java-5.1.29.zip，将mysql-connector-java-5.1.29-bin.jar引入进项目

3.在项目的根目录创建hibernate的配置文件hibernate.cfg.xml，内容如下：

<?xml version='1.0' encoding='utf-8'?>  
<!DOCTYPE hibernate-configuration PUBLIC  
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"  
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">  
  
<hibernate-configuration>  
   <session-factory>  
   <!-- Database connection settings -->  
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>  
        <property name="connection.url">jdbc:mysql://127.0.0.1:3306/RestDemo</property>  
        <property name="connection.username">root</property>  
        <property name="connection.password"></property>  
  
        <!-- JDBC connection pool (use the built-in) -->  
        <property name="connection.pool_size">1</property>  
  
        <!-- SQL dialect -->  
        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>  
  
        <!-- Enable Hibernate's automatic session context management -->  
        <property name="current_session_context_class">thread</property>  
  
        <!-- Disable the second-level cache  -->  
        <property name="cache.provider_class">org.hibernate.cache.internal.NoCacheProvider</property>  
   
        <!-- Echo all executed SQL to stdout -->  
        <property name="show_sql">true</property>  
  
        <!-- Drop and re-create the database schema on startup -->  
        <property name="hbm2ddl.auto">update</property>  
  
  
        <mapping resource="com/waylau/rest/bean/User.hbm.xml"/>  
   
    </session-factory>  
</hibernate-configuration>  

4.在项目User.java 的同个目录下，创建该类的映射文件User.hbm.xml

<?xml version="1.0"?>  
<!DOCTYPE hibernate-mapping PUBLIC  
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"  
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">  
  
   
<hibernate-mapping package="com.waylau.rest.bean">  
  
    <class name="User" table="T_USER">  
        <id name="userId" column="USERID"  type="string" >  
            <generator class="assigned"/>  
        </id>  
        <property name="userName" type="string" />  
        <property name="age" type="string" />  
    </class>  
   
</hibernate-mapping>   

5.创建包com.waylau.rest.util，在该包下创建HibernateUtil.java

package com.waylau.rest.util;  
  
import org.hibernate.SessionFactory;  
import org.hibernate.boot.registry.StandardServiceRegistry;  
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;  
import org.hibernate.cfg.Configuration;  
/** 
 * Hibernate 初始化配置工具类 
 * @author waylau.com 
 * 2014-3-23 
 */  
public class HibernateUtil {  
     private static Configuration configuration;  
     private static SessionFactory sessionFactory;  
     private static StandardServiceRegistry standardServiceRegistry;  
        static {  
            try {  
             //第一步:读取Hibernate的配置文件  hibernamte.cfg.xml文件  
              configuration = new Configuration().configure("hibernate.cfg.xml");          
             //第二步:创建服务注册构建器对象，通过配置对象中加载所有的配置信息  
              StandardServiceRegistryBuilder sb = new StandardServiceRegistryBuilder();  
              sb.applySettings(configuration.getProperties());  
             //创建注册服务  
              standardServiceRegistry = sb.build();    
            //第三步:创建会话工厂  
              sessionFactory = configuration.buildSessionFactory(standardServiceRegistry);     
            } catch (Throwable ex) {  
                // Make sure you log the exception, as it might be swallowed  
                System.err.println("Initial SessionFactory creation failed." + ex);  
                throw new ExceptionInInitializerError(ex);  
            }  
        }  
  
        public static SessionFactory getSessionFactory() {  
            return sessionFactory;  
        }  
}  

6.在项目中建com.waylau.rest.dao包，在该包下建立User操作的接口UserDao.java

package com.waylau.rest.dao;  
  
import java.util.List;  
  
import com.waylau.rest.bean.User;  
   
  
/** 
 * User Dao 接口 
 * @author waylau.com 
 * 2014-3-18 
 */  
public interface UserDao {  
      
    public User getUserById(String id);  
  
    public boolean deleteUserById(String id);  
  
    public boolean createUser(User user);  
  
    public boolean updateUser(User user);  
  
    public List<User> getAllUsers();  
}  

7.在项目中建com.waylau.rest.dao.impl包，在该包下建立User操作接口的实现UserDaoImpl.java

package com.waylau.rest.dao.impl;  
  
import java.util.List;  
  
import org.hibernate.Query;  
import org.hibernate.Session;  
import org.hibernate.SessionFactory;  
import org.hibernate.Transaction;  
  
import com.waylau.rest.bean.User;  
import com.waylau.rest.dao.UserDao;  
import com.waylau.rest.util.HibernateUtil;  
/** 
 * 用户DAO实现 
 * @author waylau.com 
 * 2014-3-23 
 */  
public class UserDaoImpl implements UserDao {  
  
    @Override  
    public User getUserById(String id) {  
        SessionFactory sessionFactory = HibernateUtil.getSessionFactory();   
        Session s = null;  
        Transaction t = null;  
        User user = null;  
        try{  
         s = sessionFactory.openSession();  
         t = s.beginTransaction();  
         String hql = "from User where userId="+id;    
         Query query = s.createQuery(hql);    
         user = (User) query.uniqueResult();   
         t.commit();  
        }catch(Exception err){  
        t.rollback();  
        err.printStackTrace();  
        }finally{  
        s.close();  
        }  
        return user;  
    }  
  
    @Override  
    public boolean deleteUserById(String id) {  
        SessionFactory sessionFactory = HibernateUtil.getSessionFactory();   
        Session s = null;  
        Transaction t = null;  
        boolean flag = false;  
        try{  
         s = sessionFactory.openSession();  
         t = s.beginTransaction();  
         User user = new User();    
         user.setUserId(id);  
         s.delete(user);  
         t.commit();  
         flag = true;  
        }catch(Exception err){  
        t.rollback();  
        err.printStackTrace();  
        }finally{  
        s.close();  
        }  
        return flag;  
    }  
  
    @Override  
    public boolean createUser(User user) {  
        SessionFactory sessionFactory = HibernateUtil.getSessionFactory();   
        Session s = null;  
        Transaction t = null;  
        boolean flag = false;  
        try{  
         s = sessionFactory.openSession();  
         t = s.beginTransaction();  
         s.save(user);  
         t.commit();  
         flag = true;  
        }catch(Exception err){  
        t.rollback();  
        err.printStackTrace();  
        }finally{  
        s.close();  
        }  
        return flag;  
    }  
  
    @Override  
    public boolean updateUser(User user) {  
        SessionFactory sessionFactory = HibernateUtil.getSessionFactory();   
        Session s = null;  
        Transaction t = null;  
        boolean flag = false;  
        try{  
         s = sessionFactory.openSession();  
         t = s.beginTransaction();  
         s.update(user);  
         t.commit();  
         flag = true;  
        }catch(Exception err){  
        t.rollback();  
        err.printStackTrace();  
        }finally{  
        s.close();  
        }  
        return flag;  
    }  
  
    @Override  
    public List<User> getAllUsers() {  
        SessionFactory sessionFactory = HibernateUtil.getSessionFactory();   
        Session s = null;  
        Transaction t = null;  
        List<User> uesrs = null;  
        try{  
         s = sessionFactory.openSession();  
         t = s.beginTransaction();  
         String hql = "select * from t_user";    
         Query query = s.createSQLQuery(hql).addEntity(User.class);    
         query.setCacheable(true); // 设置缓存    
         uesrs = query.list();    
         t.commit();  
        }catch(Exception err){  
        t.rollback();  
        err.printStackTrace();  
        }finally{  
        s.close();  
        }  
        return uesrs;  
    }  
  
}  

8.修改项目中 com.waylau.rest.resources包下的UserResource.java，使之前在内存中模拟CURD转为在数据库中实现

package com.waylau.rest.resources;  
  
import java.util.ArrayList;  
import java.util.List;  
  
import javax.ws.rs.Path;  
import javax.ws.rs.Produces;  
import javax.ws.rs.Consumes;  
import javax.ws.rs.PathParam;  
import javax.ws.rs.core.MediaType;  
import javax.ws.rs.DELETE;  
import javax.ws.rs.GET;  
import javax.ws.rs.POST;  
import javax.ws.rs.PUT;  
  
import com.waylau.rest.bean.User;  
import com.waylau.rest.dao.impl.UserDaoImpl;  
  
/** 
 * 用户资源 
 * @author waylau.com 
 * 2014-3-19 
 */  
@Path("/users")  
public class UserResource {  
    private UserDaoImpl userDaoImpl = new UserDaoImpl();  
    /** 
     * 增加 
     * @param user 
     */  
    @POST  
    @Consumes({MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON})  
    public void createUser(User user)  
    {  
        userDaoImpl.createUser(user);  
    }  
      
    /** 
     * 删除 
     * @param id 
     */  
    @DELETE  
    @Path("{id}")  
    public void deleteUser(@PathParam("id")String id){  
        userDaoImpl.deleteUserById(id);  
    }  
      
    /** 
     * 修改 
     * @param user 
     */  
    @PUT  
    @Consumes(MediaType.APPLICATION_XML)  
    public void updateUser(User user){  
        userDaoImpl.updateUser(user);  
    }  
   
    /** 
     * 根据id查询 
     * @param id 
     * @return 
     */  
    @GET  
    @Path("{id}")  
    @Produces({MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON})  
    public User getUserById(@PathParam("id") String id){  
        User u = userDaoImpl.getUserById(id);  
        return u;  
    }  
     
    /** 
     * 查询所有 
     * @return 
     */  
    @GET  
    @Produces({MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON})  
    public List<User> getAllUsers(){       
        List<User> users = new ArrayList<User>();     
        users = userDaoImpl.getAllUsers();  
        return users;  
    }  
      
      
}  

#五、运行 1.将服务端运行后

2.运行UserClient客户端，可以看到数据库已经实现增删改查

完整项目架构如下：

本章源码：https://github.com/waylau/RestDemo/tree/master/jersey-demo5-mysql-hibernate

Way Lau

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