基于stream实现操作集合

1.生成map collect

Map<String, ActivityDto> map1= vinActivityList.stream().collect(Collectors.toMap(k->k.getCampaignId(), Function.identity(), (o, n) -> n));

Map<String, ActivityDto> map2= vinActivityList.stream().collect(Collectors.toMap(ActivityDto::getCampaignId, Function.identity(), (o, n) -> n));

2.过滤集合filter

//过滤后返回map
Map<String, ActivityDto> map3= vinActivityList.stream().filter(k -> k.getPackageType()== Constant.PackageType.DIFFPACKAGE.getValue()).collect(Collectors.toMap(DstPkgScriptDto :: getEcuSVer, Function.identity(), (o, n) -> n));

//过滤后返回对象
ActivityDto dto1= vinActivityList.stream().filter(k -> k.getPackageType() == Constant.PackageType.FULLPACKAGE.getValue()).findFirst().orElse(null);

//过滤后返回集合
List<ActivityDto > list2= vinActivityList.stream().filter(e -> DateUtils.isEffectiveDate(new Date(), e.getActivityStartTime(), e.getActivityEndTime())).collect(Collectors.toList());

3.返回集合map

//返回集合对象
List<ActivityDto> list1= vinActivityList.stream().map(dst -> {
          
   
           ActivityDto dto= new ActivityDto ();
          	//todo 
            return dto;
        }).collect(Collectors.toList());
 
//返回String 集合
List<String> campaignIdList = vinActivityList.stream().map(ActivityDto::getCampaignId).collect(Collectors.toList());

4.基于stream 删除集合对象

recordDtoList.stream().findFirst().map(vo -> {
          
   
         if (vo.getCampaignId().equals(entity.getCampaignId())){
          
   
              recordDtoList.remove(vo);
          }
          return vo;
      });

5.循环forEach

dependVinEntities.stream().forEach(e->{
          
   
	//查询redis数据
	String dependVinActivityList = redisTemplate.opsForValue().get(ENV+Constant.ACTIVITY_DEPEND+e.getVin());
   });