技術標籤：javaspring bootmybatis

SpringBoot+MyBatisPlus實現分頁功能

前言

本片文章僅為了本人整理思路，總結經驗所寫。
（作為剛入行的新人，大佬看到勿噴。）

專案框架

基於SpringBoot + MyBatisPlus實現分頁功能。話不多說，下面直接上程式碼。（其餘的別問我，問就是不會。）

第一步

封裝一個實體類，包含分頁所需要的引數

import io.swagger.annotations.ApiModelProperty;
import lombok.AllArgsConstructor;
import lombok.Builder;
 

import lombok.Data;
import lombok.NoArgsConstructor;
import java.io.Serializable;
import java.util.List;

@Data
@Builder
@NoArgsConstructor
@AllArgsConstructor
public class AgentApplyResponse<T> implements Serializable {
    private static final long serialVersionUID = 1L;

    @ApiModelProperty
 
(name = "currentPage", value = "當前頁")
    private Long currentPage;

    @ApiModelProperty(name = "size", value = "獲取每頁顯示條數")
    private Long size;

    @ApiModelProperty(name = "total", value = "當前滿足條件總行數")
    private Long total;

    @ApiModelProperty
 
(name = "pages", value = "當前頁面總數")
    private Long pages;

    @ApiModelProperty(name = "list", value = "分頁記錄列表")
    private List<T> list;

}

第二步

一個轉換類，把分頁需要的引數，轉換成想要的資料形式返回。

import com.flashsal.dto.FlashSaleDto;
import com.flashsal.entity.FlashsaleActivity;
import org.mapstruct.Mapper;
import org.mapstruct.factory.Mappers;
import java.util.List;

@Mapper
public interface FlashConvert {
    FlashConvert CONVERT = Mappers.getMapper(FlashConvert.class);

    List<FlashSaleDto> proxy(List<FlashsaleActivity> flashsaleActivity);

    FlashSaleDto flashSaleDto(FlashsaleActivity flashsaleActivity);
}

還有分頁需要的service。

public interface FlashConfigService {

    AgentApplyResponse select(Integer currentPage, Integer size);
}

第三步

實現上步service

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.agent.response.AgentApplyResponse;
import com.flashsal.convert.FlashConvert;
import com.flashsal.dto.FlashSaleDto;
import com.flashsal.entity.FlashsaleActivity;
import com.flashsal.mapper.FlashConfigMapper;
import com.flashsal.mapper.ProductSpuMapper;
import com.flashsal.service.FlashConfigService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;
import java.util.List;

@Service
@Slf4j
public class FlashConfigServiceImpl implements FlashConfigService {
    @Resource
    private FlashConfigMapper flashConfigMapper;
    @Resource
    private ProductSpuMapper productSpuMapper;

    @Override
    public AgentApplyResponse select(Integer currentPage, Integer size) {
        log.info("current{}=" + currentPage + "size{}" + size);
        IPage<FlashsaleActivity> flashSaleDtoIPage = new Page<>(currentPage, size);
        LambdaQueryWrapper<FlashsaleActivity> flashWrapper = new LambdaQueryWrapper<>();
        IPage<FlashsaleActivity> selectPage = flashConfigMapper.selectPage(flashSaleDtoIPage, flashWrapper);

        //這是你查到資料  遍歷這個 list 能取到資料
        //1 查詢到資料  轉換成想要的返回型別 2 在new一個AgentApplyResponse 設定分頁  把資料裝進去
        List<FlashsaleActivity> records = selectPage.getRecords();

        AgentApplyResponse response = new AgentApplyResponse<>();

        response.setPages(selectPage.getPages());
        response.setSize(selectPage.getSize());
        response.setTotal(selectPage.getTotal());
        response.setCurrentPage(selectPage.getCurrent());
        List<FlashSaleDto> flashSaleDtos = FlashConvert.CONVERT.proxy(records);
        for (int i = 0; i < records.size(); i++) {
            FlashsaleActivity flashsaleActivity = records.get(i);
            String spuId = flashsaleActivity.getSpuId();
            LambdaQueryWrapper<FlashsaleActivity> activity = new LambdaQueryWrapper<FlashsaleActivity>()
                    .eq(FlashsaleActivity::getSpuId,spuId)
                    .eq(FlashsaleActivity::getIsDelete,0);
            FlashsaleActivity fs = flashConfigMapper.selectOne(activity);
            FlashSaleDto saleDto = flashSaleDtos.get(i);
            saleDto.setSpuId(fs.getSpuId());
            saleDto.setSpuName(productSpuMapper.selectSpuName(spuId));
            saleDto.setSpuLogo(productSpuMapper.selectSpuLogo(spuId));
            saleDto.setFakeTotal(fs.getRoundNumber());
            saleDto.setStartTime(fs.getStartTime());
            saleDto.setRoundNumber(fs.getRoundNumber());
            saleDto.setDuration(fs.getDuration());
            saleDto.setStartingPrice(fs.getStartingPrice());
            saleDto.setStride(fs.getStride());
            saleDto.setStatus(fs.getStatus());
        }
        response.setList(flashSaleDtos);
        log.info("{}" + response);

        return response;
    }
}

最後一步

寫Api介面

import com.admin.common.exception.BaseApiException;
import com.admin.common.result.ApiResult;
import com.agent.response.AgentApplyResponse;
import com.domain.sys.AdminEnumStatus;
import com.flashsal.service.FlashConfigService;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import javax.annotation.Resource;
@Api(tags = "商品管理")
@Slf4j
@RestController
@RequestMapping("/flashsale")
public class FlashConfigApi {

    @Resource
    private FlashConfigService flashConfigService;
    @GetMapping("/select")
    @ApiOperation(value = "分頁獲取商品資訊", notes = "")
    public ApiResult select(@RequestParam("currentPage") Integer currentPage, @RequestParam("size") Integer size) {
        try {
            AgentApplyResponse response = flashConfigService.select(currentPage, size);
            return ApiResult.ok(response);
        } catch (Exception e) {
            log.error("異常：分頁展示異常", e);
            if (e instanceof BaseApiException) {
                return ApiResult.error(((BaseApiException) e).getCode(), ((BaseApiException) e).getMsg());
            }
            return ApiResult.error(AdminEnumStatus.SYSTEM_ERROR.getResultCode(), AdminEnumStatus.SYSTEM_ERROR.getResultMsg());
        }
    }
}

以上就是分頁大致思路整理。作為新手確實還有很多不懂的地方，並且程式碼也可能寫的非常low，還請看到的大佬們勿噴，歡迎評論不吝賜教！