MyBatis Mapper动态代理规则及动态代理的调用

1.对应的书写SQL语句的xml文件中的nameapsce必须为接口的全路径

2.接口中的方法名称必须和xml中对应的ID相同

3.xml中的parameterType必须和接口中的参数类型一致当传递多个参数时parameterType可以省略不写

4.xml中的ResultType必须和接口中的返回值类型一致

例如：对于一个客户表实现其CRUD

其Customer.xml 如下：

<?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="com.bullet.mapper.CustomerMapper">
    <!--根据cust_id查询客户-->
    <select id="queryCustomerById" parameterType="Int" resultType="com.bullet.domain.Customer">
	  SELECT * FROM `customer` WHERE cust_id  = #{cust_id}
	</select>
    <!--查询所有用户-->
    <select id="queryAll"  resultType="com.bullet.domain.Customer">
	  SELECT * FROM `customer`
	</select>

    <!--根据用户名模糊查询用户-->
    <select id="queryCustomerByName"  parameterType="String" resultType="com.bullet.domain.Customer">
	  SELECT * FROM `customer` where cust_name like  #{value};
	</select>

    <!--添加客户-->
    <insert id="insertCustomer" parameterType="com.bullet.domain.Customer">
    <!--获取插入的最后一条id-->
        <!--keyColumn 哪一列是ID
            keyProperty  要把id给哪个属性
            resultType   id是什么类型
            order   是插入之前获得id还是插入之后获得id
        -->
        <selectKey keyColumn="cust_id" keyProperty="cust_id" resultType="Integer" order="AFTER">
            select last_insert_id()
        </selectKey>
	  insert into `customer` (cust_name,cust_profession,cust_phone,email)
	  values (#{cust_name},#{cust_profession},#{cust_phone},#{email})
	</insert>

    <!--更新-->
    <update id="updateCustomer" keyProperty="com.bullet.domain.Customer">
        update `customer` set cust_name=#{cust_name} where cust_id=#{cust_id}
    </update>

    <!--删除-->
    <delete id="deleteCustomer" parameterType="com.bullet.domain.Customer">
        delete from `customer` where cust_id=#{cust_id}
    </delete>
</mapper>

则其对应的接口为：

public interface CustomerMapper {
    //根据id查询客户
    public Customer queryCustomerById(Integer id);
    //查询所有
    public List<Customer> queryAll();
    //根据用户名模糊查询
    public List<Customer> queryCustomerByName(String name);
    //添加
    public void insertCustomer(Customer customer);
    //更新
    public void updateCustomer(Customer customer);
    //删除操作
    public void deleteCustomer(Customer customer);
}

这样便可以实现其动态代理

动态代理的调用：

 public void test2(){
        SqlSession sqlSession = MyBatisUtils.openSession();
        CustomerMapper mapper = sqlSession.getMapper(CustomerMapper.class);
        Customer customer = mapper.queryCustomerById(1);
        System.out.println(customer);

        List<Customer> customers = mapper.queryAll();
        for (Customer customer1 : customers) {
            System.out.println(customer1);
        }

        List<Customer> customers1 = mapper.queryCustomerByName("%李%");
        for (Customer customer1 : customers1) {
            System.out.println(customer1);
        }
        sqlSession.close();
    }

MyBatis Mapper动态代理规则及动态代理的调用

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