简单描述：需求说后端写一个XX数据的分页接口，给前端口调用，其实有一个PageHelper的工具类可以直接使用但是老大不让用，得用sql写，。小Kiss啦。直接上代码

代码：

//Controller代码 import com.github.pagehelper.PageInfo; import io.swagger.annotations.Api; import io.swagger.annotations.ApiOperation; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RestController; @Api(value = "CourseController",tags = "课程查询") @RestController @RequestMapping("/client/course") public class CourseController extends BaseController {
       @Autowired     private CourseService courseService;     @ApiOperation(value = "获取分页列表")     @RequestMapping(value = "/queryPage", method = RequestMethod.GET, produces = "application/json;charset=utf-8")     public ResultDto queryPage(Integer page,Integer rows,String categoryId){
           PageInfo
     
       pageInfo = new PageInfo
      
       ();         try {
               pageInfo = courseService.queryPage(page,rows);             if(pageInfo.getList().size()< 0){
                   return ResultDto.success("返回结果无内容");             }         } catch (Exception e) {
               e.printStackTrace();             return ResultDto.error();         }         return ResultDto.success(pageInfo);     } } 
      
     

 

//Service代码 import com.github.pagehelper.PageInfo; import org.springframework.stereotype.Service; import javax.annotation.Resource; import java.util.HashMap; import java.util.List; import java.util.Map; @Service public class CourseService {
       @Resource     private CourseMapper courseMapper;     public PageInfo
     
       queryPage(Integer page,Integer rows)throws Exception{
           Map
      
        param = new HashMap
       
        ();         Integer firstIndex = (page - 1) * rows;         Integer lastIndex = page * rows;         // 从第几条数据开始 int firstIndex = (currPage - 1) * pageSize;         // 到第几条数据结束 int lastIndex = currPage * pageSize;         param.put("page",firstIndex);         param.put("rows",lastIndex);         List
        
          reList = courseMapper.findByPage(param);         // 取分页信息         PageInfo
         
           pageInfo = new PageInfo
          
           (reList); return pageInfo; } } 
          
         
        
       
      
     

 

//Mapper接口 import com.xx.xxx.xxxx.util.MyMapper; import java.util.List; import java.util.Map; public interface CourseMapper extends MyMapper
     
       {
       List
      
        findByPage(Map
       
         param); }  //Mapper.xml中的sql 
            select * from table_course where is_del = '1' limit #{page},#{rows}   
            
             
          　　``````  
        
       
      
     

That's all !!!   下边来说一说PageHelper的方式

//仅仅是调用就OJBK啦 不过这种查询方式使用的是mybatis的example动态生成sql查询的，不需要你写mapper.xml中的sql了，只需要在对应的类上加上注解 public PageInfo
     
       queryPage(Integer page,Integer rows)throws Exception{
       Example example = new Example(CourseVo.class);     example.createCriteria().andEqualTo("isDel", 1);     PageHelper.startPage(page, rows);     List
      
        list = courseMapper.selectByExample(example);//查询     return pageInfo; }