Java Mybatis框架增删查改与核心配置详解流程与用法

    <dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.32</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.6</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
    </dependencies>

public class User {
 
    private int id;
    private String username;
    private String password;
    //省略get和set方法
}

<?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">
<mapper namespace="userMapper">
    <!--查询操作-->
    <select id="findAll" resultType="user">
        select * from user
    </select>
</mapper>

 <?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>
    <!--数据源环境-->
    <environments default="developement">
        <environment id="developement">
            <transactionManager type="JDBC"></transactionManager>
            <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>
    <!--加载映射文件-->
    <mappers>
        <mapper resource="com/longdi/mapper/UserMapper.xml"></mapper>
    </mappers>
</configuration>

    @Test
    //查询操作
    public void test1() throws IOException {
        //获得核心配置文件
        InputStream resourceAsStream = Resources.getResourceAsStream("sqlMapConfig.xml");
        //获得session工厂对象
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream);
        //获得session回话对象
        SqlSession sqlSession = sqlSessionFactory.openSession();
        //执行操作  参数：namespace+id
        List<User> userList = sqlSession.selectList("userMapper.findAll");
        //打印数据
        System.out.println(userList);
        //释放资源
        sqlSession.close();
    }

<mapper namespace="userMapper">  
  <!--插入操作-->
    <insert id="save" parameterType="com.longdi.domain.User">
        insert into user values(#{id},#{username},#{password})
    </insert>
</mapper>

    @Test
    //插入操作
    public void test2() throws IOException {
 
        //模拟user对象
        User user = new User();
        user.setUsername("xxx");
        user.setPassword("abc");
 
        //获得核心配置文件
        InputStream resourceAsStream = Resources.getResourceAsStream("sqlMapConfig.xml");
        //获得session工厂对象
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream);
        //获得session回话对象
        SqlSession sqlSession = sqlSessionFactory.openSession(true);
        //执行操作  参数：namespace+id
        sqlSession.insert("userMapper.save",user);
 
        //释放资源
        sqlSession.close();
    }

<mapper namespace="userMapper">  
    <!--修改操作-->
    <update id="update" parameterType="com.longdi.domain.User">
        update user set username=#{username},password=#{password} where id=#{id}
    </update>
</mapper>

    @Test
    //修改操作
    public void test3() throws IOException {
 
        //模拟user对象
        User user = new User();
        user.setId(7);
        user.setUsername("lucy");
        user.setPassword("123");
 
        //获得核心配置文件
        InputStream resourceAsStream = Resources.getResourceAsStream("sqlMapConfig.xml");
        //获得session工厂对象
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream);
        //获得session回话对象
        SqlSession sqlSession = sqlSessionFactory.openSession();
        //执行操作  参数：namespace+id
        sqlSession.update("userMapper.update",user);
 
        //mybatis执行更新操作  提交事务   因为mybatis默认不提交事物
        sqlSession.commit();
 
        //释放资源
        sqlSession.close();
    }

<mapper namespace="userMapper">  
    <!--删除操作-->
    <delete id="delete" parameterType="int">
        delete from user where id=#{abc}
    </delete>
</mapper>

    @Test
    //删除操作
    public void test4() throws IOException {
 
        //获得核心配置文件
        InputStream resourceAsStream = Resources.getResourceAsStream("sqlMapConfig.xml");
        //获得session工厂对象
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream);
        //获得session回话对象
        SqlSession sqlSession = sqlSessionFactory.openSession();
        //执行操作  参数：namespace+id
        sqlSession.delete("userMapper.delete",8);
 
        //mybatis执行更新操作  提交事务
        sqlSession.commit();
 
        //释放资源
        sqlSession.close();
    }