第五讲 分页的实现

一、分析mysql的分页语句：limit startIndex, pageSize

     mapper映射文件：

     <!-- 查询所有用户 -->

     <select id="selectAll" parameterType="Map" resultType="User">

           select * from user limit #{startIndex}, #{pageSize}

     </select>

     dao中的写法：

     //分页查询

     public List<User> getAll(int currentPage, int pageSize) throws IOException {

           SqlSession session = MyBatisUtil.getSqlSession();

           

           Map<String, Integer> map = new HashMap<String, Integer>();

           map.put("startIndex", (currentPage - 1) * pageSize);

           map.put("pageSize", pageSize);

           

           List<User> list = session.selectList("com.liujie.model.UserMapper.selectAll", map);

           

           session.close();

           return list;

     }

注意：不用为参数设置类，可以采用Map结构来解决这个问题

二、通过RowBounds来实现分页

     mapper映射文件不需要做任何改变：

     <!-- 查询所有用户 -->

     <select id="selectAll" resultType="User">

           select * from user

     </select>

     dao中需要新建RowBounds对象：

RowBounds rowBounds = new RowBounds(pageIndex, pageSize);

public RowBounds(int offset, int limit)

     //分页查询

     public List<User> getAll(int currentPage, int pageSize) throws IOException {

           SqlSession session = MyBatisUtil.getSqlSession();

           

           RowBounds rowBounds = new RowBounds((currentPage-1)*pageSize, pageSize);  

           List<User> list = session.selectList("com.liujie.model.UserMapper.selectAll", null, rowBounds);

           

           session.close();

           return list;

     }