五、分页

目录：使用Limit分页、RowBounds分页、分页插件

1.使用Limit分页

语法：

select * from user limit startIndex,pageSize;

使用MyBatis实现分页，核心是使用SQL语句。
1）实现接口

package com.ping.dao;
import …
public interface UserMapper {
  //分页
  List<User> getUserByLimit(Map<String,Integer> map);
}

2）UserMapper.xml中的sql语句

<!--//分页-->
<select id="getUserByLimit" parameterType="map" resultMap="UserMap">
  select * from  mybatis.user limit #{startIndex},#{pageSize}
</select>

3）测试

@Test
public void getUserByLimit(){
  SqlSession sqlSession = MybatisUtils.getSqlSession();
  UserMapper mapper = sqlSession.getMapper(UserMapper.class);
  HashMap<String, Integer> map = new HashMap<String, Integer>();
  map.put("startIndex",1);
  map.put("pageSize",2);
  List<User> userList =  mapper.getUserByLimit(map);
  for (User user : userList) {
    System.out.println(user);
  }
  sqlSession.close();
}

2.RowBounds分页

不再使用SQL实现分页。
1）实现接口

package com.ping.dao;
import …
public interface UserMapper {
  //分页
  List<User> getUserByRowBounds();
}

2）UserMapper.xml中的sql语句

<!--//分页-->
<select id="getUserByRowBounds" resultMap="UserMap">
  select * from  mybatis.user
</select>

3）测试

@Test
public void getUserByRowBounds(){
  SqlSession sqlSession = MybatisUtils.getSqlSession();
  //RowBounds实现
  RowBounds rowBounds = new RowBounds(1, 2);
  //通过Java代码层面实现分页
  List<User> userList = sqlSession.selectList("com.kuang.dao.UserMapper.getUserByRowBounds",null,rowBounds);
  for (User user : userList) {
    System.out.println(user);
  }
  sqlSession.close();
}