[SSH] Eclipse+Struts+Hibernate的简单应用

在上一次Struts的基础上，整合Hibernate，依然参考网上大神的案例代码，由于版本问题的地方做了修改。

Eclipse+Struts地址->点这里

在此基础上，需要用到的相关的版本信息（有需要的可以留言^.^）：

Hibernate ：hibernate-release-4.3.10.Final

MySQL ： MySQL Server 5.5

JDBC： mysql-connector-java-5.1.26-bin.jar

建议：大家在用的时候包名最好改成自己的这样在修改的过程中，可以更好的将映射的流程弄明白！

这里的步骤借鉴了原文的讲述，十分详细，感性探路的大神。

1.将Hibernate内的lib/required下的jar包和lib/jpa下的jar包复制到SSHProject项目的lib目录下。

2.在上面Struts项目的基础上添加com.tiny.ssh.dao和com.tiny.ssh.daoImpl包。分别创建BaseDao接口和UserDao类。

整理结构图（注意相应文件的位置和名字）：

3.在数据库中创建对应的表user来写入要注册的用户。

create table user(
userId int auto_increment,
userName varchar(16) not null,
password varchar(16) not null,
gender int not null,
primary key(userId)
);

4.创建user表的Hibernate映射文件。因为这里要创建user表对应的POJO类，所以我这里把之前com.tiny.ssh.beans包改成com.tiny.ssh.forms包，用来存放页面传过来的表单数据，新创建com.tiny.ssh.beans包，用来创建POJO对象来对应数据库中的表。路径：POJO类同目录。

User.java:

package com.tiny.ssh.beans;

public class User {
    
    private int userId;
    private String username;
    private String password;
    private int gender;
    
    public int getUserId() {
        return userId;
    }
    
    public void setUserId(int userId) {
        this.userId = userId;
    }
    
    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 int getGender() {
        return gender;
    }

    public void setGender(int gender) {
        this.gender = gender;
    }

}

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.tiny.ssh.beans">
    <class name="User" table="user">
        <id name="userId" column="userId">
            <generator class="native"></generator>
        </id>
        <property name="username" column="userName" type="java.lang.String"
            not-null="true" length="16"></property>
        <property name="password" column="password" type="java.lang.String"
            not-null="true" length="16" />
        <property name="gender" column="gender" type="java.lang.Integer" length="1" />
    </class>
</hibernate-mapping>

5.建立Hibernate配置文件。路径：src目录下。

Hibernate.cfg.xml（需要更改自己的数据库连接和最下面的映射）：

<?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/ssh</property>
    <property name="connection.username">root</property>
    <property name="connection.password">root</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/tiny/ssh/beans/User.hbm.xml"/>
  </session-factory>
</hibernate-configuration>

6.编写Session工厂类。整合Spring后，数据源的创建和SessionFactory的创建都交给Spring去管理，就无需这个工厂类了，所以这里我临时创建在daoImpl包里面。

HibernateSessionFactory.java（有几个方法已经不再使用了，这里作为演示，不再去修改）:

package com.tiny.ssh.daoImpl;

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 HibernateSessionFactory {

    private static final String CFG_FILE_LOCATION = "/Hibernate.cfg.xml";

    private static final ThreadLocal<Session> threadLocal = new ThreadLocal<Session>();

    private static final Configuration cfg = new Configuration()
            .configure(CFG_FILE_LOCATION);

    private static ServiceRegistryBuilder builder = new ServiceRegistryBuilder()
            .applySettings(cfg.getProperties());

    private static ServiceRegistry registry;

    private static SessionFactory sessionFactory;

    public static Session currentSession() throws HibernateException {
        Session session = threadLocal.get();

        if (session == null || session.isOpen() == false) {

            if (sessionFactory == null) {
                try {
                    registry = builder.buildServiceRegistry();
                    sessionFactory = cfg.buildSessionFactory(registry);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }

            session = sessionFactory.openSession();
            threadLocal.set(session);

        }

        return session;
    }

    public static void closeSession() throws HibernateException {
        Session session = threadLocal.get();
        threadLocal.set(null);
        if (session != null) {
            session.close();
        }
    }

}

7.修改业务逻辑实现类。

UserManagerImpl.java:

package com.tiny.ssh.serviceImp;

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

import com.tiny.ssh.beans.User;
import com.tiny.ssh.dao.BaseDao;
import com.tiny.ssh.daoImpl.HibernateSessionFactory;
import com.tiny.ssh.daoImpl.UserDao;
import com.tiny.ssh.forms.UserForm;
import com.tiny.ssh.service.UserManager;

public class UserManagerImpl implements UserManager {

    private BaseDao dao;

    private Session session;

    public UserManagerImpl() {
        dao = new UserDao();
    }

    @Override
    public void regUser(UserForm userForm) throws HibernateException {
        session = HibernateSessionFactory.currentSession();
        dao.setSession(session);
        // 获取事务
        Transaction ts = session.beginTransaction();
        // 构造User对象
        User user = new User();
        user.setUsername(userForm.getUsername());
        user.setPassword(userForm.getPassword());
        user.setGender(userForm.getGender());
        // 保存User对象
        dao.saveObject(user);
        // 提交事务
        ts.commit();
        // 关闭Session
        HibernateSessionFactory.closeSession();
    }

}