自定义分页查询入参与返回

在后端开发在编写接口向前端提供列表数据的时候，往往需要进行分页处理。下面以ssm框架整合为例。

1、编写接口分页请求基类

入参基类PageQuery ,定义当前页码pageNo、每页记录大小pageSize。请求对象继承基类即可

import java.io.Serializable;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.ToString;
@ApiModel(value = "分页查询参数")
@Data
@ToString
@AllArgsConstructor
@NoArgsConstructor
public class PageQuery implements Serializable{
   private static final long serialVersionUID = -7219221162786108170L;
   @ApiModelProperty(value="当前页面")
   private Integer pageNo = 1;
   @ApiModelProperty(value="每页几行")
   private Integer pageSize = 10;
   public static PageQuery def() {
      PageQuery query = new PageQuery();
      query.setPageNo(1);
      query.setPageSize(10);
      return query;
   }
}

2、定义返回结果集

返回对象结果集封装在PageResult中

public class PageResult<T> implements Serializable {
   private static final long serialVersionUID = 2626585127466370060L;
   /**当前页面 */
   private Integer pageNo = 1;
   /**每页几行*/
   private Integer pageSize = 10;
   /**数据总数*/
   private Integer totalCount;
   /**行总数*/
   private Integer totalPage;
   private List<T> list;
   public PageResult(){
   }
   public Integer getPageNo() {
      return pageNo != null && pageNo>0?pageNo:1;
   }
   public void setPageNo(Integer pageNo) {
      this.pageNo = pageNo;
   }
   public Integer getPageSize() {
      return pageSize == null ? 10 : pageSize;
   }
   public void setPageSize(Integer pageSize) {
      this.pageSize = pageSize;
   }
   public Integer getTotalCount() {
      return totalCount;
   }
   public void setTotalCount(Integer totalCount) {
      this.totalCount = totalCount;
   }
   public Integer getTotalPage() {
      if(pageSize ==0 ) return 0;
      return totalCount/pageSize+(totalCount%pageSize==0?0:1);
   }
   public void setTotalPage(Integer totalPage) {
      this.totalPage = totalPage;
   }
   public List<T> getList() {
      return list;
   }
   public void setList(List<T> list) {
      this.list = list;
   }
   public Integer startPageNo(PageQuery query){
      this.pageNo = query.getPageNo();
      this.pageSize = query.getPageSize();
      return (getPageNo()-1)*pageSize;
   }
}

3、mapper.xml文件中的sql语句。其中getDrawInfoCreditOrNon为根据条件获取数据，getCountDrawInfoCreditOrNon为获取总记录数

<select id="getDrawInfoCreditOrNon"
        parameterType="com.shitou.huishi.contract.datacontract.request.web.loan.QueryLoanApproveListRequest"
        resultType="com.shitou.huishi.contract.datacontract.response.web.loan.DrawInfoListResponse">
  select
  c.draw_id drawId,
  d.credit_id creditId,
  a.product_type productName,
  a.org_source orgSource,
  e.subject_no subjectNo,
  e.subject_no_type subjectNoType,
  CASE a.loan_type
  WHEN 1 THEN a.main_subject
  WHEN 2 THEN a.borrower_name
  END subjectName,
  c.draw_amount drawAmount,
  b.apply_period LoanLimit,
  c.draw_status drawStatus,
  c.loan_platform LoanPlatForm,
  c.approve_status approveStatus,
  c.create_user_id approveUserName,
  c.process_instance_id processInstanceId,
  DATE_FORMAT(c.create_time,'%Y-%m-%d %H:%i:%s') applyTime
  from hs_draw_info c
  INNER JOIN hs_loan_order a ON a.`loan_order_id` = c.`loan_order_id`
  INNER JOIN hs_loan_order_detail b ON a.`loan_order_id` = b.`loan_order_id`
  INNER JOIN hs_user_credit_info d ON d.`loan_order_id` = c.`loan_order_id`
  INNER JOIN hs_archive_info e ON e.archive_id =
  (CASE a.loan_type
  WHEN  1 THEN  a.main_subject_archive_id
  WHEN  2 THEN  a.borrower_archive_id
  END
  )
  WHERE 1=1
  <if test="null!=isCredit and isCredit!='' ">
    and b.is_credit = #{isCredit,jdbcType=VARCHAR}
  </if>
  <if test="null!=drawId">
    and c.draw_id=#{drawId,jdbcType=BIGINT}
  </if>
  <if test="null!=orgSource and orgSource!='' ">
    and a.org_source=#{orgSource,jdbcType=VARCHAR}
  </if>
  <if test="null!=productType">
    and a.product_type=#{productType,jdbcType=BIGINT}
  </if>
  <if test="null!=subjectName and ''!=subjectName">
    and e.subject_name=#{subjectName,jdbcType=VARCHAR}
  </if>
  <if test="null!=subjectNo and ''!=subjectNo">
    and e.subject_no=#{subjectNo,jdbcType=VARCHAR}
  </if>
  <if test="null!=creditId and creditId!='' ">
    and d.credit_id=#{creditId,jdbcType=VARCHAR}
  </if>
  <if test="null!=drawStatus and drawStatus!='' ">
    and c.draw_status=#{drawStatus,jdbcType=Integer}
  </if>
  ORDER by c.draw_id DESC
  limit #{pageNo}, #{pageSize}
</select>
<select id="getCountDrawInfoCreditOrNon"
        parameterType="com.shitou.huishi.contract.datacontract.request.web.loan.QueryLoanApproveListRequest"
        resultType="java.lang.Integer">
  select count(1)
  from hs_draw_info c
  INNER JOIN hs_loan_order a ON a.`loan_order_id` = c.`loan_order_id`
  INNER JOIN hs_loan_order_detail b ON a.`loan_order_id` = b.`loan_order_id`
  INNER JOIN hs_user_credit_info d ON d.`loan_order_id` = c.`loan_order_id`
  INNER JOIN hs_archive_info e ON e.archive_id =
  (CASE a.loan_type
  WHEN  1 THEN  a.main_subject_archive_id
  WHEN  2 THEN  a.borrower_archive_id
  END
  )
  WHERE 1=1
  <if test="null!=isCredit and isCredit!='' ">
    and b.is_credit = #{isCredit,jdbcType=VARCHAR}
  </if>
  <if test="null!=drawId">
    and c.draw_id=#{drawId,jdbcType=BIGINT}
  </if>
  <if test="null!=orgSource and orgSource!='' ">
    and a.org_source=#{orgSource,jdbcType=VARCHAR}
  </if>
  <if test="null!=productType">
    and a.product_type=#{productType,jdbcType=BIGINT}
  </if>
  <if test="null!=subjectName and ''!=subjectName">
    and e.subject_name=#{subjectName,jdbcType=VARCHAR}
  </if>
  <if test="null!=subjectNo and ''!=subjectNo">
    and e.subject_no=#{subjectNo,jdbcType=VARCHAR}
  </if>
  <if test="null!=creditId and creditId!='' ">
    and d.credit_id=#{creditId,jdbcType=VARCHAR}
  </if>
  <if test="null!=drawStatus and drawStatus!='' ">
    and c.draw_status=#{drawStatus,jdbcType=Integer}
  </if>
</select>

4、domain类

@MyBatisMapper
public interface DrawInfoMapper extends BaseMapper<DrawInfo, Long> {
   List<DrawInfoListResponse> getDrawInfoCreditOrNon(QueryLoanApproveListRequest request);
   int getCountDrawInfoCreditOrNon(QueryLoanApproveListRequest request);
}

5、Impl类

@Service
public class DrawInfoBizFacadeImpl implements DrawInfoBizFacade {
    @Resource
    private DrawInfoMapper mapper;
    public int insert(DrawInfo drawinfo) {
        return mapper.insert(drawinfo);
    }
    public int insertSelective(DrawInfo drawinfo) {
        return mapper.insertSelective(drawinfo);
    }
    public DrawInfo selectByPrimaryKey(Long drawId) {
        return mapper.selectByPrimaryKey(drawId);
    }
    public int updateByPrimaryKeySelective(DrawInfo drawinfo) {
        return mapper.updateByPrimaryKeySelective(drawinfo);
    }
    public int updateByPrimaryKey(DrawInfo drawinfo) {
        return mapper.updateByPrimaryKey(drawinfo);
    }
    @Override
    public PageResult<DrawInfoListResponse> getDrawInfoCreditOrNon(QueryLoanApproveListRequest request) {
        PageResult<DrawInfoListResponse> page = new PageResult<>();
        request.setPageNo(page.startPageNo(new PageQuery(request.getPageNo(),request.getPageSize())));
        List<DrawInfoListResponse> data = mapper.getDrawInfoCreditOrNon(request);
        page.setList(data);
        page.setTotalCount(mapper.getCountDrawInfoCreditOrNon(request));
        return page;
    }
}

6、BizzFacade接口类

public interface DrawInfoBizFacade {
    int insert(DrawInfo drawinfo);
    int insertSelective(DrawInfo drawinfo);
    DrawInfo selectByPrimaryKey(Long drawId);
    int updateByPrimaryKeySelective(DrawInfo drawinfo);
    int updateByPrimaryKey(DrawInfo drawinfo);
    PageResult<DrawInfoListResponse> getDrawInfoCreditOrNon(QueryLoanApproveListRequest request);
}

7、业务调用，红色部分

/**
 * 授信/非授信项下订单提款列表
 * @param query
 * @return
 */
public PageResult<DrawInfoListResponse> queryCreditOrNonDrawInfoList(QueryLoanApproveListRequest query){
   PageResult<DrawInfoListResponse> result=new PageResult<>();
   PageResult<DrawInfoListResponse> drawInfoList = drawInfoBizFacade.getDrawInfoCreditOrNon(query);
   if(null==drawInfoList || null==drawInfoList.getList() || drawInfoList.getList().size()<1){
      return result;
   }
   List<DataDict> dataDictList=dataDictManage.getDataDictByParentKey(DataDictConstant.productType);
   drawInfoList.getList().forEach(x->{
      x.setProductName(dataDictList.stream().filter(y->y.getDictId().equals(x.getProductName())).map(y->y.getDictValue()).findFirst().orElse(null));
      x.setDrawStatus(DrawStatusEnum.getEnum(Integer.parseInt(x.getDrawStatus())).getDesc());
      TaskEntity currentTaskEntity=getCurrentTaskEntity(x.getProcessInstanceId());
      x.setApproveStatus(currentTaskEntity==null?null:currentTaskEntity.getTaskName());
      x.setApproveUserName(currentTaskEntity==null?null:currentTaskEntity.getUserName());   x.setLoanPlatform(LoanPlatformEnum.getEnum(Integer.parseInt(x.getLoanPlatform())).getDesc());
   });
   return drawInfoList;
}

本文地址：https://blog.csdn.net/u013252149/article/details/52788805