SpringBoot中使用PageHelper分页

前言

PageHelper分页插件，最方便使用的分页插件。分页插件支持任何复杂的单表、多表分页官方文档：https://pagehelper.github.io/ 添加依赖


    com.github.pagehelper
    pagehelper-spring-boot-starter

配置文件

这里有两种方式：

在mybatis的全局配置文件中配置

在application.yml文件中配置

# pageHelper分页配置
pagehelper:
  helper-dialect: mysql
  reasonable: true
  support-methods-arguments: true

简单使用

举个例子，前台用户列表数据展示

通用类准备

public class AjaxResponse{

    private String code;

    private String errMsg;

    private Object data;

    public AjaxResponse(String code, String errMsg, Object data) {
        this.code = code;
        this.errMsg = errMsg;
        this.data = data;
    }

    public AjaxResponse(String code, String errMsg) {
        this.code = code;
        this.errMsg = errMsg;
    }

    public static AjaxResponse suc(Object data){
        return new AjaxResponse("200", "操作成功", data);
    }

    public static AjaxResponse err(String errMsg){
        return new AjaxResponse("400", errMsg);
    }
    //省略get set
}


public class PageParam implements IPage {

    //页码
    private Integer pageNum = 1;

    //页数，我这里设置默认设置2，一般是10，20
    private Integer pageSize = 2;

    //排序
    private String orderBy;

    @Override
    public Integer getPageNum() {
        return pageNum;
    }

    @Override
    public Integer getPageSize() {
        return pageSize;
    }

    @Override
    public String getOrderBy() {
        return orderBy;
    }
}

流程类准备

参数实体，主要用于接收前台查询条件，以及pageNum和pageSize等参数

public class UserListParam extends PageParam {

    //用户名
    private String username;

    //....其他参数

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

}

controller

@Controller
@RequestMapping("/user")
public class UserController {

    @Resource
    UserService userService;

    @GetMapping(value = "/getList")
    @ResponseBody
    public AjaxResponse getList(UserListParam listParam){
        //这里接收一个PageInfo，包含了返回的list，总页数，总数等前台所需数据
        PageInfo pageInfo = userService.getPageList(listParam);
        return AjaxResponse.suc(pageInfo);
    }
}

service

public interface UserService {

    
    public PageInfo getPageList(UserListParam listParam);
}

serviceImpl

@Service
public class UserServiceImpl implements UserService {

    @Resource
    private UserMapper userMapper;
	
    //这里写了两种方式，我是比较常用第二种
    @Override
    public PageInfo getPageList(UserListParam listParam) {
        
        return PageHelper.startPage(listParam.getPageNum(), listParam.getPageSize())
                .doSelectPageInfo(() -> userMapper.getPageList(listParam));
    }
}

UserMapper

public interface UserMapper extends baseMapper {

    
    List getPageList(UserListParam param);
}

UserMapper.xml




  
    
    
  
  
    user_id, username