Mybatis的基本应用

src下的配置文件：config.xml

<?xml version="1.0" encoding="UTF-8" ?> 
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" 
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
	<!-- 读取jdbc.properties 文件 -->
	<properties resource="jdbc.properties" />

	<!-- 取别名 -->
	<typeAliases>
		<typeAlias type="com.aowin.model.Demo" alias="Demo" />
	</typeAliases>

	<!-- 配置数据库连接信息 -->
	
	<!-- 告诉mybatis用development环境-->
	<environments default="development">
		<!-- 开发环境 -->
		<environment id="development">
			<transactionManager type="JDBC" />
			<dataSource type="POOLED">
				<property name="driver" value="${jdbc.driver}" />
				<property name="url" value="${jdbc.url}" />
				<property name="username" value="${jdbc.username}" />
				<property name="password" value="${jdbc.password}" />
			</dataSource>
		</environment>
	</environments>
	
	<!-- 加入映射文件 -->
	<mappers>
		<mapper resource="com/aowin/model/demo.xml"/>
	</mappers>
</configuration>

 model 下的 类的配置文件：

demo.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" 
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">

	<!-- 对model类进行映射 
		namespace:命名空间
	-->
<mapper namespace="name_space">
	<resultMap type="Demo" id="userResultMap">
		<!-- 数据表和model类属性一一对应 -->
		<result column="id" property="id" javaType="int" />
		<result column="content" property="content" javaType="string" />
		<result column="title" property="title" javaType="string" />
	</resultMap>
	
	<sql id="AllColumn">
		id,content,title
	</sql>
	
	<!-- 声明sql片段 -->
	<sql id="allColumnsWithoutId">
		content,title
	</sql>
	
	<select id="selectAllDemos" resultMap="userResultMap">
		select <include refid="AllColumn"/>  from demo 
	</select>
	
	<!-- 参数ID 可以任意取名 -->
	<select id="selectDemoById" resultMap="userResultMap" parameterType="int">
		select <include refid="AllColumn"/> from demo where id = #{id}
	</select>
	
	
	<!-- 传递多个参数-->
	<select id="selectDemoBytilteAndContent" resultMap="userResultMap" parameterType="Demo">
		select <include refid="AllColumn"/> from demo 
		where content = #{content} and title = #{title}
	</select>

	<insert id="insertOneDemo" parameterType="Demo">
		insert into  demo (<include refid="allColumnsWithoutId"/>)  values (#{content},#{title})
	</insert>
	
	
	<!-- 更新demo -->
	<update id="updateDemo" parameterType="Demo">
		update demo set content=#{content}
		where id= #{id}
	</update>
	
	<!-- 删除一条demo记录 -->
	<delete id="deleteDemoById" parameterType="int">
		delete from demo where id = #{id}
	</delete>
	
</mapper>

 Demo.java 类

 

package com.aowin.model;

public class Demo {
	private int id;
	private String content;
	private String title;

	public int getId() {
		return id;
	}

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

	public String getContent() {
		return content;
	}

	public void setContent(String content) {
		this.content = content;
	}

	public String getTitle() {
		return title;
	}

	public void setTitle(String title) {
		this.title = title;
	}

}

 创建SessionFactroy

 

package com.aowin.util;

import java.io.IOException;
import java.io.Reader;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

public class DBUtil {

	private static SqlSessionFactory sessionFactory = null;
	
	static {
		String resource = "config.xml";
		Reader reader = null;
		try {
			reader = Resources.getResourceAsReader(resource);
			sessionFactory = new SqlSessionFactoryBuilder().build(reader);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
	/**
	 * 拿到SqlSessoin. MyBatis操作数据库是通过SqlSession来完成的
	 * @return
	 */
	public static SqlSession getSqlSession(){
		return sessionFactory.openSession();
	}
	
}

 运行类：

 

package com.aowin.dao;

import java.util.List;

import org.apache.ibatis.session.SqlSession;

import com.aowin.model.Demo;
import com.aowin.util.DBUtil;

/**
 * MyBatis:把SQL单独写到配置文件中
 *         简化JDBC操作
 * @author jie.guo(mozzz.iteye.com)
 */
public class DemoDAO {
	
	public List<Demo> getDemos(){
		SqlSession session = DBUtil.getSqlSession();
		//命名空间+sql的ID  命名空间与包名没有关系 一般取模块的名字
		List<Demo> demoList = (List<Demo>)session.selectList("name_space.selectAllDemos");
		return demoList;
	}
	
	public static void main(String[] args) {
//		List<Demo> demos = new DemoDAO().getDemos();
//		for(Demo demo :demos){
//			System.out.println(demo.getContent());
//		}
		
		
//		SqlSession session = DBUtil.getSqlSession();
//		Demo demo = (Demo)session.selectOne("name_space.selectDemoById", 1);
//		System.out.println(demo.getContent());
		
//		
//		SqlSession session = DBUtil.getSqlSession();
//		Demo demo = new Demo();
//		demo.setTitle("hh2");
//		demo.setContent("hh2");
//		Demo demo2 = (Demo)session.selectOne("name_space.selectDemoBytilteAndContent",demo);
//		System.out.println(demo2.getId());
		
		
		//对于增加  修改 删除 要手动commit
//		SqlSession session = DBUtil.getSqlSession();
//		Demo demo = new Demo();
//		demo.setContent("新闻内容");
//		demo.setTitle("新闻标题");
//		int result = session.insert("name_space.insertOneDemo", demo);
//		System.out.println(result);
//		session.commit();
		
		
//		SqlSession session = DBUtil.getSqlSession();
//		Demo demo = new Demo();
//		demo.setId(9);
//		demo.setContent("新的content");
//		int result = session.update("name_space.updateDemo",demo);
//		System.out.println(result);
//		session.commit();
		
		
//		SqlSession session = DBUtil.getSqlSession();
//		session.delete("name_space.deleteDemoById",1);
//		session.commit();
	}

}