Mapper代理类实现

Posted 2020-12-19 葵儿啊ε≡٩(๑>₃<)۶ 一心向学

package org.simple.proxy;

import org.apache.ibatis.session.SqlSession;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.util.List;

//Java 动态代理方式一个代理类
public class MyMapperProxy<T> implements InvocationHandler {
    private Class<T> mapperInterface;
    private SqlSession sqlSession;

    public MyMapperProxy(Class<T> mapperInterface,SqlSession sqlSession)
    {
        this.mapperInterface=mapperInterface;
        this.sqlSession=sqlSession;
    }
    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        //针对不同的sql类型，需要调用sqlSession不同的方法
        //接口方法中的参数也有很多情况,这里只考虑有没有参数的情况
        List<T> list = sqlSession.selectList(mapperInterface.getCanonicalName() + "." + method.getName());
        //返回值也有很多情况, 这里不做处理直接返回
        return list;
    }
}







//测试类

package org.simple.test;

import org.apache.ibatis.session.SqlSession;
import org.junit.Assert;
import org.junit.Test;
import org.simple.mapper.SysUserMapper;
import org.simple.model.SysUser;
import org.simple.proxy.MyMapperProxy;
import org.simple.utils.BaseMapper;

import java.lang.reflect.Proxy;
import java.util.List;

public class ProxyTest extends BaseMapper
{

    @Test
    public void testProxy(){
        //获取sqlSession
        SqlSession sqlSession=getSqlSession();
        try {
            //获取UserMapper接口
            MyMapperProxy userMapperProxy=new MyMapperProxy(SysUserMapper.class,sqlSession);
            SysUserMapper userMapper = (SysUserMapper) Proxy.newProxyInstance(
                    Thread.currentThread().getContextClassLoader(),
                    new Class[]{SysUserMapper.class},
                    userMapperProxy
            );
            //调用selectAll方法
            List<SysUser> sysUsers = userMapper.selectAll();
           Assert.assertNotNull(sysUsers);
        }finally {

　　　　　　　　sqlSession.close();

        }
    }

}