Hibernate的基本开发流程

一、Hibernate开发的基本流程

                                   

二、Hibernate开发的环境搭建

1、引入Hibernate核心包以及Hibernate依赖包即可。可以在Hibernate目录下的lib equired目录下找到所需jar包。

2、加入数据库驱动。这里主要是采用Mysql数据库来操作，所以在这里引入MysqL的JDBC驱动。

3、提供核心配置文件hibernate.cfg.xml文件（在src文件夹下即可）。

三、数据库方面的操作

在mysql中新建一个数据库Hibernate5，然后建立如下的一个表来进行测试。

create table T_register
(
    id    int primary key,
    userName varchar(30),
    userPwd varchar(30),
    sex varchar(10),
    age int
)

四、编写POJO类

根据数据表的字段情况，创建如下持久化类，实际上是一个javaBean类

package com.chen;

public class TRegister{


    //定义基本属性，与数据库中的字段对应。注意都是引用类型

     private Integer id;
     private String userName;
     private String userPwd;
     private String sex;
     private Integer age;


    // Constructors

    /** default constructor */
    public TRegister() {
    }

    /** minimal constructor */
    public TRegister(Integer id) {
        this.id = id;
    }
    
    /** full constructor */
    public TRegister(Integer id, String userName, String userPwd, String sex, Integer age) {
        this.id = id;
        this.userName = userName;
        this.userPwd = userPwd;
        this.sex = sex;
        this.age = age;
    }

   
    // 定义get set方法

    public Integer getId() {
        return this.id;
    }
    
    public void setId(Integer id) {
        this.id = id;
    }

    public String getUserName() {
        return this.userName;
    }
    
    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getUserPwd() {
        return this.userPwd;
    }
    
    public void setUserPwd(String userPwd) {
        this.userPwd = userPwd;
    }

    public String getSex() {
        return this.sex;
    }
    
    public void setSex(String sex) {
        this.sex = sex;
    }

    public Integer getAge() {
        return this.age;
    }
    
    public void setAge(Integer age) {
        this.age = age;
    }
}

五、配置相关的xml文件

1、配置hibernate.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
		"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
		"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
	<session-factory>
    
		<!-- 配置连接数据库的基本信息 -->
		<property name="connection.username">root</property>
		<property name="connection.password">root</property>
		<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
		<property name="connection.url">jdbc:mysql://192.168.1.148:3306/hibernate5</property>
		
		<!-- 配置 hibernate 的基本信息 -->
		<!-- hibernate 所使用的数据库方言 -->
		<property name="dialect">org.hibernate.dialect.MySQLInnoDBDialect</property>		
		
		<!-- 执行操作时是否在控制台打印 SQL -->
		<property name="show_sql">true</property>
		<!-- 是否对 SQL 进行格式化 -->
		<property name="format_sql">true</property>	
		<!-- 指定关联的 .hbm.xml 文件 -->
		<mapping resource="com/chen/TRegister.hbm.xml"/>
	
	</session-factory>

</hibernate-configuration>

注意：Hibernate4连接MySQL5.X数据库无法自动创建表，解决方法把数据库方言设为

<property name="dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>

2、配置映射文件TRegister.hbm.xml 

在持久化类所在的包中建立TRegister.hbm.xml ,可以通过eclipse Hibernate插件来完成

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 2017-3-7 22:14:28 by Hibernate Tools 3.4.0.CR1 -->
<hibernate-mapping>
    <class name="com.chen.TRegister" table="TREGISTER">
        <id name="id" type="java.lang.Integer">
            <column name="ID" />
            <!-- 我在MYSQL中并没有设置该字段递增，但在Hibernate中依然可以设置为递增 -->
            <generator class="increment" />
        </id>
        <property name="userName" type="java.lang.String">
            <column name="USERNAME" />
        </property>
        <property name="userPwd" type="java.lang.String">
            <column name="USERPWD" />
        </property>
        <property name="sex" type="java.lang.String">
            <column name="SEX" />
        </property>
        <property name="age" type="java.lang.Integer">
            <column name="AGE" />
        </property>
    </class>
</hibernate-mapping>

六、编写事务处理类HibernateUtil.java

package hibernate;

import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;

public class HibernateUtil {
    
    private static final SessionFactory sessionFactory;
    
    static
    {
        try
        {
            Configuration config = new Configuration().configure();
            ServiceRegistry serviceRegistry=
            		new ServiceRegistryBuilder().applySettings(config.getProperties())
            		.buildServiceRegistry();
            sessionFactory = config.buildSessionFactory(serviceRegistry);
        }
        catch(Throwable e)
        {
            throw new ExceptionInInitializerError(e);
        }
    }
    
    public static final ThreadLocal session = new ThreadLocal();
    
    public static Session currentSession() throws HibernateException
    {
        Session s = (Session)session.get();
        //Open a new Session,if this Thread has none yet
        if(s == null || !s.isOpen())
        {
            s = sessionFactory.openSession();
            session.set(s);
        }
        return s;
    }
    
    public static void closeSession() throws HibernateException
    {
        Session s = (Session)session.get();
        session.set(null);
        if(s != null)
            s.close();
    }

}

七、编写Servlet控制类RegisterServlet

package servlet;

import java.io.IOException;
import java.io.PrintWriter;

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 org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.Transaction;

import com.chen.TRegister;

import hibernate.HibernateUtil;

/**
 * Servlet implementation class RegisterServlet
 */
@WebServlet("/RegisterServlet")
public class RegisterServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
	private static final String CONTENT_TYPE = "text/html;charset=GBK";   
    /**
     * @see HttpServlet#HttpServlet()
     */
    public RegisterServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		response.setContentType(CONTENT_TYPE);
        request.setCharacterEncoding("GBK");
        
        PrintWriter out = response.getWriter();
        
        String userName = request.getParameter("userName");
        String userPwd = request.getParameter("userPwd");
        String sex = request.getParameter("sex");
        int age = Integer.parseInt(request.getParameter("age"));
        
        TRegister rg = new TRegister();
        rg.setAge(age);
        rg.setSex(sex);
        rg.setUserName(userName);
        rg.setUserPwd(userPwd);
        
        Session session = HibernateUtil.currentSession();//生成Session实例
        Transaction tx = session.beginTransaction();
        
        try
        {
            session.save(rg);    //保存持久类对象
            tx.commit();        //提交到数据库
            session.close();
            response.sendRedirect("registerOK.jsp");
        }
        catch(HibernateException e)
        {
            e.printStackTrace();
            tx.rollback();
        }
        
    }
	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}

八、编写jsp页面进行测试

1、register.jsp

<%@ page language="java" contentType="text/html; charset=GBK"
    pageEncoding="GBK"%>
<!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=GBK">
<title>Insert title here</title>
</head>
<body>

<form action="RegisterServlet" method="POST">
    用户名：<input type="text" name="userName" /><BR>
    密  码：<input type="text" name="userPwd" /><BR>
    性  别：<input type="text" name="sex" /><BR>
    年  龄：<input type="text" name="age" /><BR>
    <input type="submit" value="save" />
</form>
</body>
</html>

2、registerOK.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    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>Insert title here</title>
</head>
<body>
数据已保存到数据库，请查看.......
</body>
</html>

九、运行验证

运行register.jsp页面，填写信息，完成后点击save完成保存。查看数据库可以看到数据已保存。