SSH上一个随笔的基础上添加上hibernate支持

配置文件

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.lgp</groupId>
    <artifactId>maven_ssh</artifactId>
    <packaging>war</packaging>
    <version>0.0.1-SNAPSHOT</version>
    <name>maven_ssh Maven Webapp</name>
    <url>http://maven.apache.org</url>
    <properties>
        <project.build.sourceEncoding>
            UTF-8
        </project.build.sourceEncoding>
    </properties>
    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>
        <!-- struts2的驱动包 -->
        <dependency>
            <groupId>org.apache.struts</groupId>
            <artifactId>struts2-core</artifactId>
            <version>2.3.31</version>
        </dependency>
        <!-- 添加Hibernate依赖 -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>3.6.10.Final</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.16</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-nop</artifactId>
            <version>1.6.4</version>
        </dependency>
        <!-- mysql数据库的驱动包 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.6</version>
        </dependency>
    </dependencies>
    <build>
        <finalName>maven_ssh</finalName>
    </build>
</project>

熟悉的pom.xml其中lo4g和slf4j这两个包第一眼看上去有点莫名奇妙，我也是这么觉得的，实际作用是在后台输出sql语句，不导入hibernate就会报错。

web.xml和struts2一致即可

 剩下的配置文件就放在resource文件夹以下即可

    ### direct log messages to stdout ###  
    log4j.appender.stdout=org.apache.log4j.ConsoleAppender  
    log4j.appender.stdout.Target=System.out  
    log4j.appender.stdout.layout=org.apache.log4j.PatternLayout  
    log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n  
      
    ### direct messages to file hibernate.log ###  
    #log4j.appender.file=org.apache.log4j.FileAppender  
    #log4j.appender.file.File=hibernate.log  
    #log4j.appender.file.layout=org.apache.log4j.PatternLayout  
    #log4j.appender.file.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n  
      
    ### set log levels - for more verbose logging change 'info' to 'debug' ###  
      
    log4j.rootLogger=warn, stdout  
      
    #log4j.logger.org.hibernate=info  
    log4j.logger.org.hibernate=debug  
      
    ### log HQL query parser activity  
    #log4j.logger.org.hibernate.hql.ast.AST=debug  
      
    ### log just the SQL  
    #log4j.logger.org.hibernate.SQL=debug  
      
    ### log JDBC bind parameters ###  
    log4j.logger.org.hibernate.type=info  
    #log4j.logger.org.hibernate.type=debug  
      
    ### log schema export/update ###  
    log4j.logger.org.hibernate.tool.hbm2ddl=debug  
      
    ### log HQL parse trees  
    #log4j.logger.org.hibernate.hql=debug  
      
    ### log cache activity ###  
    #log4j.logger.org.hibernate.cache=debug  
      
    ### log transaction activity  
    #log4j.logger.org.hibernate.transaction=debug  
      
    ### log JDBC resource acquisition  
    #log4j.logger.org.hibernate.jdbc=debug  
      
    ### enable the following line if you want to track down connection ###  
    ### leakages when using DriverManagerConnectionProvider ###  
    #log4j.logger.org.hibernate.connection.DriverManagerConnectionProvider=trace  

 log4j.properties全是复制粘贴就好，硬要深究每一个的作用你可以一个一个的改，认真看都能看懂的。

<?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>
<!-- 根据 <session-factory>创建与mysql的连接-->
	<session-factory>
		<!-- Database connection settings -->
		<property name="connection.driver_class">org.gjt.mm.mysql.Driver</property>
		<property name="connection.url">jdbc:mysql://localhost:3306/test</property>
		<property name="connection.username">root</property>
		<property name="connection.password">123456789</property>
		<!-- JDBC connection pool (use the built-in) -->
		<property name="connection.pool_size">10</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.NoCacheProvider</property>

		<!-- Echo all executed SQL to stdout -->
		<property name="show_sql">true</property>
		<property name="format_sql">true</property>
		<!-- Drop and re-create the database schema on startup -->
		<property name="hbm2ddl.auto">update</property>
		<mapping resource="Table.hbm.xml" />
	</session-factory>
</hibernate-configuration>

 hibernate.cfg.xml 注意<mapping resource="Table.hbm.xml" />里面是你的数据库表格设置

<?xml version="1.0" encoding="UTF-8"?>
<!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.entiy">
	<class name="com.entity.User" table="USER">
		<id name="id" column="ID">
			<generator class="increment" />
		</id>
		<property name="name" column="NAME" />
		<property name="pwd" column="PWD" />
	</class>
</hibernate-mapping> 

 Table.hbm.xml一个</class>就是一个表格，所有表格都写在里面即可。hibernate在加载时，如果你没有表格，就会自行创建。

java代码

package com.util;

import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

public class HibernateUtil {
	// 定义静态的SessionFactory，产生单例，只生成一个SessionFactory
	private static final SessionFactory sessionFactory = buildSessionFactory();

	// 用来初始化SessionFactory
	private static SessionFactory buildSessionFactory() {
		try {
			// Create the SessionFactory from hibernate.cfg.xml
			return new Configuration().configure().buildSessionFactory();
		} 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);
		}
	}

	// 得到SessionFactory
	public static SessionFactory getSessionFactory() {
		return sessionFactory;// 返回SessionFactory的对象
	}
}

 HibernateUtil的工具类

package com.entity;

public class User {
	private int id;// id
	private String name;// 名字
	private String pwd;// 密码

	public User() {

	}

	public User(int id, String name, String pwd) {
		this.id = id;
		this.name = name;
		this.pwd = pwd;
	}

	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getPwd() {
		return pwd;
	}

	public void setPwd(String pwd) {
		this.pwd = pwd;
	}

}

 user 就是表格的实体类，根据这个来创建表格

package com.action;

import java.util.List;
import java.util.Map;

import org.apache.struts2.interceptor.RequestAware;

import com.entity.User;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.ModelDriven;
import com.opensymphony.xwork2.util.ValueStack;
import com.service.UserService;

public class UserAction extends ActionSupport implements ModelDriven<User>, RequestAware {
	private static final long serialVersionUID = -1417237614181805435L;
	private User user;
	List<User> list;

	public List<User> getList() {
		return list;
	}

	public void setList(List<User> list) {
		this.list = list;
	}

	@SuppressWarnings("unused")
	private Map<String, Object> request;

	public String selectAll() {
		String sql = "from User";
		UserService userService = new UserService();// model
		list = userService.findAll(sql);
		ValueStack vs = ActionContext.getContext().getValueStack();
		vs.push(list);
		return "success";
	}

	public String add() {
		UserService userService = new UserService();// model
		userService.add(user);
		return "success";
	}

	public String delete() {
		UserService userService = new UserService();// model
		userService.delete(user);
		return "success";
	}

	public String update() {
		UserService userService = new UserService();// model
		userService.update(user);
		return "success";
	}

	public User getUser() {
		return user;
	}

	public void setUser(User user) {
		this.user = user;
	}

	public User getModel() {
		if (user == null) {
			user = new User();
		}
		return user;
	}

	public void setRequest(Map<String, Object> arg0) {
		request = arg0;
	}
}

 action类

package com.dao;

import java.util.List;

import com.entity.User;

public interface DBDao<T> {

    public List<T> selectAll(String sql);

    public int insert(User user);

    public void update(User user);

    public void delete(User user);
}

dao接口

package com.dao.impl;

import java.util.List;

import org.hibernate.Session;

import com.util.HibernateUtil;
import com.dao.DBDao;
import com.entity.User;

public class DBDaoImpl<T> implements DBDao<T> {
	@SuppressWarnings("unchecked")
	public List<T> selectAll(String sql) {
		Session session = HibernateUtil.getSessionFactory().getCurrentSession();// 得到目前运行的session
		session.beginTransaction();// 开始事务 没有终结事务的方法
		List<T> listUsers = session.createQuery(sql).list();
		HibernateUtil.getSessionFactory().close();
		return listUsers;
	}

	public int insert(User user) {
		Session session = HibernateUtil.getSessionFactory().getCurrentSession();// 得到目前运行的session
		session.beginTransaction();// 开始事务 没有终结事务的方法
		int result = (Integer) session.save(user);// 保存对象
		session.getTransaction().commit();// 提交事务
		HibernateUtil.getSessionFactory().close();
		return result;
	}

	public void delete(User user) {
		Session session = HibernateUtil.getSessionFactory().getCurrentSession();// 得到目前运行的session
		session.beginTransaction();// 开始事务 没有终结事务的方法
		session.delete(user);
		session.getTransaction().commit();// 提交事务
		HibernateUtil.getSessionFactory().close();
	}

	public void update(User user) {
		Session session = HibernateUtil.getSessionFactory().getCurrentSession();// 得到目前运行的session
		session.beginTransaction();// 开始事务 没有终结事务的方法
		session.update(user);
		session.getTransaction().commit();// 提交事务
		HibernateUtil.getSessionFactory().close();
	}
}

 DBDaoImpl接口的实现类，这里值得一提的是，有没有close，有没有beginTransaction，有没有commit，会有不会报错的逻辑bug，建议要么自己一个一个试试，要么像我这样贪方便（懒）全写。

package com.service;

import java.util.List;

import com.dao.impl.DBDaoImpl;
import com.entity.User;

public class UserService {

	@SuppressWarnings({ "unchecked", "rawtypes" })
	public List<User> findAll(String sql) {
		DBDaoImpl Impl = new DBDaoImpl();
		return Impl.selectAll(sql);
	}

	@SuppressWarnings("rawtypes")
	public int add(User user) {
		DBDaoImpl Impl = new DBDaoImpl();
		return Impl.insert(user);
	}

	@SuppressWarnings("rawtypes")
	public void delete(User user) {
		DBDaoImpl Impl = new DBDaoImpl();
		Impl.delete(user);
	}

	@SuppressWarnings("rawtypes")
	public void update(User user) {
		DBDaoImpl Impl = new DBDaoImpl();
		Impl.update(user);
	}
}

 service类model控制事务