[转]mybatis 的简单使用

 

需要用到的包：（这里只是其中一个版本，其他的百度）

mysql-connector-java-5.1.6-bin

mybatis-3.2.2

先看项目目录：

配置文件mybatisconfig.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>
    <!-- 用XML映射的时候必须配此项！指定mappers里面的返回值对应的实体类 -->
    <!-- <typeAliases>
        <typeAlias alias="User" type="com.miquan.mybatis.bean.User"/>
    </typeAliases> -->
    <!-- JDBC配置 -->
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">  <!--POOLED指的是：已经缓存的，即使用缓存-->
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/weixinface"/>
                <property name="username" value="root"/>
                <property name="password" value=""/>
            </dataSource>
        </environment>
    </environments>
    <!-- mappers，每个实体类对应着一个xml -->
    <mappers>
        <mapper resource="com/miquan/mybatis/bean/User.xml"/>
    </mappers>
</configuration>

实体类User.java:

package com.miquan.mybatis.bean;

public class User {
    private int id;
    private String userName;
    private String password;

    public User(int id, String userName, String password) {
        super();
        this.id = id;
        this.userName = userName;
        this.password = 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;
    }
}

User.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">
<!-- namespace对应着接口类 -->
<mapper namespace="com.miquan.mybatis.inter.IUserOperation">
    <!-- <select id="selectById" parameterType="int" resultType="User">
        select * from User where id = #{id}
    </select> -->
</mapper>

IUserOperation.java:

package com.miquan.mybatis.inter;

import java.util.List;

import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;

import com.miquan.mybatis.bean.User;

public interface IUserOperation {
    @Select("select * from User where id = #{id}")
    public User selectById(int id);

    @Select("select * from User where userName = #{userName}")
    public List<User> selectUsers(String userName);

    @Insert("insert into User values(null, #{userName}, #{password})")
    public boolean addUser(User user);

    @Delete("delete from User where id = #{id}")
    public boolean delUser(int id);

    @Update("update User "
            + "set userName = #{userName}, "
                + "password = #{password} "
            + "where id = #{id}")
    public boolean updateUser(User user);
}

注意：此处接口不支持多态。

（不知道为什么，用着就是不可以。。。方法名不能一样）

最后进行测试：Test.java:

package com.miquan.mybatis.test;

import java.io.InputStream;
import java.util.List;

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

import com.miquan.mybatis.bean.User;
import com.miquan.mybatis.inter.IUserOperation;

public class Test {
    static SqlSession session;

    public static void main(String[] args) {
        try {
            //获取session
            InputStream is = Resources.getResourceAsStream("mybatisconfig.xml");
            SqlSessionFactory sqlSessionFactory =
                    new SqlSessionFactoryBuilder().build(is);
            session = sqlSessionFactory.openSession();

            //XML配置对应用法
//          User user = session.selectOne("com.miquan.mybatis.bean.UserDB.selectById", 1);
//          System.out.println(user.toString());

            //接口调用法
            //////注意：insert、delete和update方法调用之后必须commit才能真正的改变数据
            IUserOperation userOperation = session.getMapper(IUserOperation.class);

            //查
//          User user = userOperation.selectById(1);
//          System.out.println(user.toString());

            //查找List
//          List<User> users = userOperation.selectUsers("miquan");
//          System.out.println(users.size());

            //增
//          User user = new User();
//          user.setUserName("zhiquan");
//          user.setPassword("999");
//          userOperation.addUser(user);
//          session.commit();

            //删
//          userOperation.delUser(7);
//          session.commit();

            //改
            User user = new User(8, "qiantu", "shaxppp");
            userOperation.updateUser(user);
            session.commit();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                session.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}

简单的增删查改可以实现了。