最新eclipse整合Struts2.3.29+Hibernate5.2.1+Spring4.3.1（二）Struts+Hibernate篇

继续上一篇，struts已经搭好了，接下来要往shDemo工程里面加入持久层框架Hibernate。

1.导入Hibernate所需要的包

把hibernate-release-5.2.1.Final\hibernate-release-5.2.1.Final\lib下required文件夹中的所有jar包导入工程，还有mysql-connector-java-5.1.39-bin.jar包，bulid path。

注：本次搭建不使用数据源，加入数据源会在下一篇整合spring时再加上。

2.创建对应数据库表的用户对象

com.tzy.bean.User.java

package com.tzy.bean;

public class User {

	private int id;
	private String username;
	private String password;
	
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	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;
	}
	
}

3.创建User.hbm.xml映射文件

com.tzy.dao.User.hbm.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
	"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >

<hibernate-mapping package="com.tzy.bean">
    <class name="User" table="user">
        <id name="id" column="id">
            <generator class="native"></generator>
        </id>
        <property name="username" column="username" type="java.lang.String"
            not-null="true" length="20"></property>
        <property name="password" column="password" type="java.lang.String"
            not-null="true" length="20" />
    </class>
</hibernate-mapping>

4.创建Hibernate配置文件

在src目录下创建Hibernate.cfg.xml文件

<?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://localhost:3306/tzy?characterEncoding=utf8&useSSL=true</property>
    <property name="connection.username">tzy</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/tzy/bean/User.hbm.xml"/>
  </session-factory>
</hibernate-configuration>

5.实现LoginDao接口（数据访问对象）

com.tzy.daoImpl.LoginDaoImpl.java

package com.tzy.daoImpl;

import java.util.List;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import com.tzy.bean.User;
import com.tzy.dao.LoginDao;


public class LoginDaoImpl implements LoginDao {

	User user;
	
	//hibernate读取对象所定义的对象
	private static final String CFG_FILE_LOCATION = "/Hibernate.cfg.xml";
	Configuration cfg;
	StandardServiceRegistryBuilder serviceRegistry;
	SessionFactory sessionFactory;
	Session session;
	Transaction ts;
	
	@SuppressWarnings("unchecked")
	@Override
	public User getUser(String username) {
		user = new User();
		
		//用hibernate从数据库获取user
		cfg = new Configuration().configure(CFG_FILE_LOCATION).addClass(com.tzy.bean.User.class);
		//5.*以前用ServiceRegistryBuilder
		//5.*以后用StandardServiceRegistryBuilder
		serviceRegistry = new StandardServiceRegistryBuilder().applySettings(cfg.getProperties());
		sessionFactory = cfg.buildSessionFactory(serviceRegistry.build());
		session = sessionFactory.openSession();
		ts = session.beginTransaction();

		//hql查询
		String hql = "from User";  
		@SuppressWarnings({"rawtypes"})
		List result = session.createQuery(hql).getResultList();  
		for(User user2 : (List<User>)result){
			if(username.equals(user2.getUsername())){
				user.setUsername(user2.getUsername());
				user.setPassword(user2.getPassword());
			}
		}
		
		//测试用		
		System.out.println("可以连接数据库");
		ts.commit();
		session.close();		
		
		if(user.getUsername()!=null){
			return user;
		}else{
			return new User();
		}		
	}
}

注：

1.这里的代码可以通过，但并不是最佳，理想状态是在session.createQuery(hql)这里最好用条件查询，只返回一个对象，但是我写的时候报错，这里不多纠结，就先用获取对象列表再逐一比对的笨方法代替，毕竟我的主要工作不是研究Hibernate的API，这里我试过生成一对象，用session.save(user)、session.delete(user)、session.update(user)方法操作数据库都成功。

2.搭建的时候遇到一点小麻烦，随着版本提升，有些API发生变化，最重要的有两点，一是new Configuration().configure(CFG_FILE_LOCATION).addClass(com.tzy.bean.User.class); 5.*以上版本这里一定要引入对象，在后面一定要加上.addClass(com.tzy.bean.User.class)，不然调bug够你喝一壶的；二是ServiceRegistryBuilder被StandardServiceRegistryBuilder替代。

6.实现LoginService接口（业务逻辑对象）

package com.tzy.serviceImpl;

import com.tzy.bean.User;
import com.tzy.daoImpl.LoginDaoImpl;
import com.tzy.service.LoginService;

public class LoginServiceImpl implements LoginService {

	LoginDaoImpl loginDao;
	User user;
	@Override
	public String checkUser(String username, String password) {
		loginDao = new LoginDaoImpl();
		user = loginDao.getUser(username);
		if(user.getUsername()!=null){
			if(password.equals(user.getPassword())){
				return "success";
			}else{
				return "error";
			}
		}else{
			return "register";
		}
	}
}

这样Struts+Hibernate框架就搭建成功了，最终的代码结构如下：

运行项目，可以正确的操作数据库。