1, 公共Dao 

package com.gy.spring.mvc.common.dao;import org.apache.ibatis.session.SqlSessionFactory;import org.mybatis.spring.support.SqlSessionDaoSupport;import org.springframework.beans.factory.annotation.Autowired;import java.util.List;@Repositorypublic class CommonDao
    
      extends SqlSessionDaoSupport {    @Autowired    public CommonDao(SqlSessionFactory sqlSessionFactory) {        super.setSqlSessionFactory(sqlSessionFactory);    }    /**     * 查询 List 数据, 参数 Object     * */    public List
     
       list(String sqlId, Object params) {        return getSqlSession().selectList(sqlId, params);    }    /**     * 查询一条数据, 参数 Object     * */    public T get(String sqlId, Object params) {        return getSqlSession().selectOne(sqlId, params);    }    /**     * 新增, 参数 Object     * */    public void insert(String sqlId, Object params) {        getSqlSession().insert(sqlId, params);    }    /**     * 编辑, 参数 Object     * */    public void update(String sqlId, Object params) {        getSqlSession().update(sqlId, params);    }    /**     * 删除, 参数 Object     * */    public void delete(String sqlId, Object params) {        getSqlSession().delete(sqlId, params);    }}
     
    

2, 注意该类是否声明到spring容器中,若未声明:

3, service 中使用

@Servicepublic class UserServiceImpl implements UserService {	@Autowired	private CommonDao
    
      userMapper;	@Override	public List listUser() {		return userMapper.list("UserMapper.listUser", null);	}}
    

4, SQL

    
    	
     		SELECT user_id, username, password, birthday, create_time FROM `user`	
    

5, 作用, 减少Mapper接口开发..