分页的实现

1、分析mysql的分页语句:limit startIndex,pageNum

mapper映射文件

1. <!-- 查询所有用户 -->
2. <select id="selectAll" parameterType="Map" resultType="User">
3. select * from user limit #{startIndex},#{pageSize}
4. </select>

DAO中的写法

1. //分页查询
2. public List<User> getAll(int currentPage,int pageSize) throws IOException{
3. SqlSession session=MyBatisUtil.getSession();
4. Map<String,Integer> map = new HashMap<String,Integer>();
5. map.put("startIndex", (currentPage-1)*pageSize);
6. map.put("pageSize", pageSize);
7. List<User> list = session.selectList("cn.sxt.entity.UserMapper.selectAll",map);
8. session.close();
9. return list;
10. }

注意：不用为参数设置类，可以采用map结构来解决这个问题。

2、通过RowBounds来实现分页

Mapper文件不用做任何改变

1. <select id="getAll" resultType="User">
2. select * from user
3. </select>

Dao中需要新建RowBounds对象

RowBounds rowBounds=new RowBounds(index,size);index是下标，size数据

1. //分页查询
2. public List<User> getAll(int currentPage,int pageSize) throws IOException{
3. SqlSession session=MyBatisUtil.getSession();
4. RowBounds rowBounds = new RowBounds((currentPage-1)*pageSize,pageSize);
5. List<User> list = session.selectList("cn.sxt.entity.UserMapper.getAll",null,rowBounds);
6. session.close();
7. return list;
8. }