TestMapperProxy

package com.gzz.sys.user;

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

interface SerchDao {
    Object search(String msg);
}

interface SqlSession {
    List<Object> selectList(String statment);
}

class DefaultSqlSession implements SqlSession {
    @Override
    public List<Object> selectList(String statment) {
        System.out.println("DefaultSqlSession.selectList");
        return null;
    }
}

class MapperProxyHandler implements InvocationHandler {
    private SqlSession sqlSession;
    private Class<?> targetInterface;

    public MapperProxyHandler(SqlSession sqlSession, Class<?> targetInterface) {
        this.sqlSession = sqlSession;
        this.targetInterface = targetInterface;
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        System.out.println("MapperProxyHandler.invoke");
        String daoName = targetInterface.getName();
        String methodName = method.getName();
        String statement = daoName + "." + methodName;
        return sqlSession.selectList(statement);
    }
}

class MapperProxyFactory { 
    private Class<?> targetInterface; 

    public MapperProxyFactory(Class<?> targetInterface) {
        this.targetInterface = targetInterface;
    }

    public Object newInstance(MapperProxyHandler handler) {
        return Proxy.newProxyInstance(targetInterface.getClassLoader(), new Class[] { targetInterface }, handler);
    }
}

public class TestMapperProxy {
    public static void main(String[] args) {

        Class<?> targetInterface = SerchDao.class;
        SqlSession sqlSession = new DefaultSqlSession();
        MapperProxyHandler proxyHandler = new MapperProxyHandler(sqlSession, targetInterface);
        MapperProxyFactory proxyFactory = new MapperProxyFactory(SerchDao.class);
        SerchDao serchDao = (SerchDao) proxyFactory.newInstance(proxyHandler);
        System.out.println(serchDao.getClass().getName());
        serchDao.search("hello mybatis proxy");
    }
}