MyBatis

MyBatis的CRUD
1.select：

public User queryOne(int id) {
		SqlSession session = Util.getSqlSessionFactory().openSession();
		User user = null;
		try {
			//com.xlaohe1.example.model.UserMapper.selectOne
			/**
			 * 此处的com.xlaohe1.example.model.UserMapper是实体的映射文件mapper
			 * 的命名空间
			 * selectOne就是里面的一个查询语句
			 */
			user  = (User)session.selectOne("com.xlaohe1.example.model.UserMapper.selectOne", id);
		} catch (Exception e) {
			e.printStackTrace();
		}finally {
			session.close();
		}
		return user;
	}

2.insert：

public void insert(User user) {
		SqlSession session = Util.getSqlSessionFactory().openSession();
		try {
			session.insert("com.xlaohe1.example.model.UserMapper.insertOne", user);
			//session must commit
			session.commit();
		} catch (Exception e) {
			e.printStackTrace();
		}finally {
			session.close();
		}
	}

3.delete：

public void delete(int id) {
		SqlSession session = Util.getSqlSessionFactory().openSession();
		try {
			session.delete("com.xlaohe1.example.model.UserMapper.del", id);
			//session must commit
			session.commit();
		} catch (Exception e) {
			e.printStackTrace();
		}finally {
			session.close();
		}
	}

user.xml：

<?xml version="1.0" encoding="UTF-8" ?>    
<!DOCTYPE mapper PUBLIC "-//ibatis.apache.org//DTD Mapper 3.0//EN"    
"http://ibatis.apache.org/dtd/ibatis-3-mapper.dtd">    
    
<mapper namespace="com.xlaohe1.example.model.UserMapper">
    
    <select id="selectOne" parameterType="Integer" resultType="com.xlaohe1.example.model.User">    
        select * from users where id = #{id}
    </select>   


    <insert id="insertOne" keyProperty="id" parameterType="com.xlaohe1.example.model.User">
    	insert into users(username, password, age) values(#{username},#{password},#{age});
    </insert> 


    <delete id="del" parameterType="Integer">
    	delete from users where id = #{id};
    </delete>

</mapper> 

configuration.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>  
    <environments default="development">   
        <environment id="development">   
            <transactionManager type="JDBC"/>   
            <dataSource type="POOLED">   
                <property name="driver" value="com.mysql.jdbc.Driver"/>   
                <property name="url" value="jdbc:mysql://localhost:3306/test"/>   
                <property name="username" value="root"/>   
                <property name="password" value="root"/>   
            </dataSource>   
        </environment>   
    </environments>   
    <mappers>   
        <mapper resource="com/xlaohe1/example/model/User.xml"/> 
    </mappers>  
</configuration>  

util：

package com.xlaohe1.example.util;

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

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

public class Util {
	private static SqlSessionFactory sqlSessionFactory = null;
	
	static {
		String resource = "configuration.xml";
		Reader reader = null;
		try {
			reader = Resources.getResourceAsReader(resource);
		} catch (IOException e) {
			e.printStackTrace();
		}
		sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
	}
	
	public static SqlSessionFactory getSqlSessionFactory() {
		return sqlSessionFactory;
	}

}

修改很简单就没写