动态实现类（对数据库的增删改查）

package mybatis.dao;



import mybatis.entity.Users;

import java.util.List;
import java.util.Map;

/**
 * @Author lance
 * */
public interface UserDaoInf {
    /**
     * 添加用户
     */
     void saveUser(Users users);

    /**
     * 修改用户
     */
     void updateUser(Users users);

    /**
     * 删除用户
     */
    void deleteUser(String uid);

    /**
     * 根据ID查询某条用户数据
     */
    Users findUsersById(String uid);

    /**
     * 查询所有的用户信息，保存在一个集合中
     */
    List<Users> findAll();
    /**
     * 统计查询
     */
    int userCount();
    /**
     * 模糊查询
     */
    List<Users> likeUsers(String name);
    /**
     * 查询所有的用户信息
     */
    List<Users> findAll2();
    /**
     * 查询单条的用户信息
     */
    Map<String ,Object> findUserMap(String uid);
    /**
     * 查询多条的用户信息
     */
    List<Map<String,Object>> findUserListMap();
}

package mybatis.dao.proxy;


import mybatis.tools.MyBatisUtil;
import org.apache.ibatis.session.SqlSession;

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

/**
 * 描述:
 * 动态代理实现类
 *
 * @author lance
 * @create 2018-10-15 9:33
 */
public class MethodProxy implements InvocationHandler{

    private Class<?> infClass;

    public MethodProxy(Class<?> infClass){
        this.infClass = infClass;
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        SqlSession session = MyBatisUtil.getSqlSession();
            try{
               Object mapper = session.getMapper(infClass);
               Object returnValue = method.invoke(mapper,args);
               session.commit();
               return returnValue;
            }catch (Exception e){
                session.rollback();
                throw new RuntimeException(e.getMessage());
            }finally {
                session.close();
            }
    }
}

package mybatis.dao.proxy;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Proxy;

/**
 * 描述:
 * 代理对象工厂
 * @author lance
 * @create 2018-10-15 11:42
 */
public class MethodProxyFactory {

    public static <T> T createProxy(Class<T> infClass){
        //调用回调处理器
        InvocationHandler handler = new MethodProxy(infClass);
        return (T)Proxy.newProxyInstance(infClass.getClassLoader(),new Class[]{infClass},handler);
    }

}

import mybatis.dao.UserDaoInf;
import mybatis.dao.proxy.MethodProxyFactory;
import mybatis.entity.Users;
import org.junit.Test;

import java.util.List;


/**
 * 描述:
 *
 * @author lance
 * @create 2018-09-10 15:15
 */
public class UserDaoImplTest {

    @Test
    public void testFindUserById2(){
        //动态生成代理对象
        UserDaoInf dao = MethodProxyFactory.createProxy(UserDaoInf.class);
        Users user = dao.findUsersById("1001");
        System.out.println(user.getUid());
        System.out.println(user.getUserName());

        List<Users> list = dao.findAll();
        for (Users users : list) {
            System.out.println(users.getUid());
        }
    }

}