Java实现多字段分组，多字段求和（下）

2023-11-29 03:54| 来源: 网络整理| 查看: 265

一需求

分组的多个字段有：员工ID、员工编码、员工名称、考勤配置ID、考勤配置名称。

统计的多个字段有：总条数、总的工作小时数、实际的小时数。

通过分组字段求算统计字段。

二代码 import lombok.Data; import org.springframework.beans.BeanUtils; import java.util.ArrayList; import java.util.List; import java.util.Map; import java.util.stream.Collectors; /** * @className: AttendanceStatisticByDayDTO * @description: 包含分组字段和统计字段 * @date: 2021/3/14 * @author: cakin */ @Data class AttendanceStatisticByDayDTO { // 分组字段开始 /** * 员工ID */ private String userId; /** * 员工编码 */ private String userCode; /** * 员工名称 */ private String userName; /** * 考勤配置ID */ private String attendanceTypeId; /** * 考勤配置名称 */ private String attendanceTypeName; // 分组字段结束 // 统计字段开始 /** * 应上时长 */ private Double workDueHour; /** * 实上时长 */ private Double workRealHour; /** * 统计次数 */ private Long statisticTimes; // 统计字段结束 } /** * @className: ComputeGroupByDTO * @description: 统计字段 * @date: 2021/3/14 * @author: cakin */ @Data class ComputeGroupByDTO { /** * 总条数 */ private Long totalCount; /** * 总的工作小时数 */ private Double dueHourSum; /** * 真实的小时数 */ private Double realHourSum; } /** * @ClassName: GroupSumManyToMany * @Description: 多字段分组，多字段求和参考：https://blog.csdn.net/qq_38428623/article/details/103754446 * @Date: 2021/3/14 * @Author: cakin */ public class GroupSumManyToMany { /** * 功能描述：得到分组字段 * * @param attendanceStatisticByDayDTO 考勤统计 * @return 返回分组的KEY */ private static AttendanceStatisticByDayDTO fetchGroupKey(final AttendanceStatisticByDayDTO attendanceStatisticByDayDTO) { final AttendanceStatisticByDayDTO statisticByDay = new AttendanceStatisticByDayDTO(); statisticByDay.setUserId(attendanceStatisticByDayDTO.getUserId()); // 员工ID statisticByDay.setUserCode(attendanceStatisticByDayDTO.getUserCode()); // 员工编码 statisticByDay.setUserName(attendanceStatisticByDayDTO.getUserName()); // 员工名称 statisticByDay.setAttendanceTypeId(attendanceStatisticByDayDTO.getAttendanceTypeId()); // 考勤配置ID statisticByDay.setAttendanceTypeName(attendanceStatisticByDayDTO.getAttendanceTypeName()); // 考勤配置名称 return statisticByDay; } /** * 功能描述：测试多字段分组，多字段求和 * * @param args 命令行 * @author cakin * @date 2021/3/14 */ public static void main(final String[] args) { final List attendanceStatisticByDayDTOS = new ArrayList(); // 初始化数据 for (long i = 0; i < 100; i++) { final AttendanceStatisticByDayDTO attendanceStatisticByDayDTO = new AttendanceStatisticByDayDTO(); attendanceStatisticByDayDTO.setUserId("" + (i % 5)); attendanceStatisticByDayDTO.setUserCode("" + (i % 5)); attendanceStatisticByDayDTO.setUserName("" + (i % 5)); attendanceStatisticByDayDTO.setWorkDueHour((double) (i % 5)); attendanceStatisticByDayDTO.setWorkRealHour((double) (i % 5)); attendanceStatisticByDayDTO.setStatisticTimes(i); attendanceStatisticByDayDTO.setAttendanceTypeId("" + (i % 5)); attendanceStatisticByDayDTO.setAttendanceTypeName("" + (i % 5)); attendanceStatisticByDayDTOS.add(attendanceStatisticByDayDTO); } /** * 获取分组结果 * 分组字段:员工ID、员工编码、员工名称、考勤配置ID、考勤配置名称,通过 fetchGroupKey 获取 * 统计字段：通过 collectingAndThen 的第2个参数定义统计方式 */ final Map groupByMap = attendanceStatisticByDayDTOS .stream() .collect(Collectors.groupingBy(n -> fetchGroupKey(n), Collectors.collectingAndThen(Collectors.toList(), m -> { // totalCount 采用计数方式 final long totalCount = m.stream().count(); // dueHourSum 采用求和方式 final Double dueHourSum = m.stream().mapToDouble(AttendanceStatisticByDayDTO::getWorkDueHour).sum(); // realHourSum 采用求和方式 final Double realHourSum = m.stream().mapToDouble(AttendanceStatisticByDayDTO::getWorkDueHour).sum(); final ComputeGroupByDTO computeGroupBy = new ComputeGroupByDTO(); computeGroupBy.setTotalCount(totalCount); // 计数 computeGroupBy.setDueHourSum(dueHourSum); // 求和 computeGroupBy.setRealHourSum(realHourSum); // 求和 return computeGroupBy; }))); System.out.println("===============结果大小==============================="); System.out.println("groupByMap=" + groupByMap.size()); List list = new ArrayList(); System.out.println("===============中间结果==============================="); groupByMap.forEach((k, v) -> { System.out.println(k); System.out.println(v); AttendanceStatisticByDayDTO attendanceStatisticByDayDTO = new AttendanceStatisticByDayDTO(); BeanUtils.copyProperties(k, attendanceStatisticByDayDTO); attendanceStatisticByDayDTO.setStatisticTimes(v.getTotalCount()); attendanceStatisticByDayDTO.setWorkDueHour(v.getDueHourSum()); attendanceStatisticByDayDTO.setWorkRealHour(v.getRealHourSum()); list.add(attendanceStatisticByDayDTO); }); System.out.println("===============最终结果==============================="); for (AttendanceStatisticByDayDTO attendanceStatisticByDayDTO : list) { System.out.println(attendanceStatisticByDayDTO); } } } 三测试 ===============结果大小=============================== groupByMap=5 ===============中间结果=============================== AttendanceStatisticByDayDTO(userId=2, userCode=2, userName=2, attendanceTypeId=2, attendanceTypeName=2, workDueHour=null, workRealHour=null, statisticTimes=null) ComputeGroupByDTO(totalCount=20, dueHourSum=40.0, realHourSum=40.0) AttendanceStatisticByDayDTO(userId=4, userCode=4, userName=4, attendanceTypeId=4, attendanceTypeName=4, workDueHour=null, workRealHour=null, statisticTimes=null) ComputeGroupByDTO(totalCount=20, dueHourSum=80.0, realHourSum=80.0) AttendanceStatisticByDayDTO(userId=0, userCode=0, userName=0, attendanceTypeId=0, attendanceTypeName=0, workDueHour=null, workRealHour=null, statisticTimes=null) ComputeGroupByDTO(totalCount=20, dueHourSum=0.0, realHourSum=0.0) AttendanceStatisticByDayDTO(userId=3, userCode=3, userName=3, attendanceTypeId=3, attendanceTypeName=3, workDueHour=null, workRealHour=null, statisticTimes=null) ComputeGroupByDTO(totalCount=20, dueHourSum=60.0, realHourSum=60.0) AttendanceStatisticByDayDTO(userId=1, userCode=1, userName=1, attendanceTypeId=1, attendanceTypeName=1, workDueHour=null, workRealHour=null, statisticTimes=null) ComputeGroupByDTO(totalCount=20, dueHourSum=20.0, realHourSum=20.0) ===============最终结果=============================== AttendanceStatisticByDayDTO(userId=2, userCode=2, userName=2, attendanceTypeId=2, attendanceTypeName=2, workDueHour=40.0, workRealHour=40.0, statisticTimes=20) AttendanceStatisticByDayDTO(userId=4, userCode=4, userName=4, attendanceTypeId=4, attendanceTypeName=4, workDueHour=80.0, workRealHour=80.0, statisticTimes=20) AttendanceStatisticByDayDTO(userId=0, userCode=0, userName=0, attendanceTypeId=0, attendanceTypeName=0, workDueHour=0.0, workRealHour=0.0, statisticTimes=20) AttendanceStatisticByDayDTO(userId=3, userCode=3, userName=3, attendanceTypeId=3, attendanceTypeName=3, workDueHour=60.0, workRealHour=60.0, statisticTimes=20) AttendanceStatisticByDayDTO(userId=1, userCode=1, userName=1, attendanceTypeId=1, attendanceTypeName=1, workDueHour=20.0, workRealHour=20.0, statisticTimes=20)

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