爱威尔-目前项目中常用的java stream用法，不断更新

// list集合转map key是list单属性，value是list对象，支持重复key 
Map<Integer, AdvVsitCountObj> map = advVsitCountObjList.stream().collect(Collectors.toMap(AdvVsitCountObj::getShopId, a -> a, (k1, k2) -> k1)); 
checkVinSuccess.stream().filter(m -> !StringUtils.isEmpty(m.getError())). 
 collect(Collectors.toMap(MaintainUserVinCheckVo::getId, a -> a, (k1, k2) -> k1)) 
 
// list集合去重 
List<String> phones 
phones.stream().distinct().collect(Collectors.toList()) 
 
// list集合转map key是list单属性, value是list对象集合 
List<CollisionImage> collisionImages 
Map<Integer, List<CollisionImage>> mapImage = collisionImages.stream().collect( 
 Collectors.groupingBy(CollisionImage::getMessageId)); 
 
// 去掉集合对象某属性为空的对象，生成新的集合 
List<InsuranceHistory> data 
List<InsuranceHistory> haveOperator = data.stream().filter( 
 insuranceHistory -> insuranceHistory.getOperatorId() != null) 
 .collect(Collectors.toList()); 
 
// 对象集合提取某属性为新集合，对新集合去重，set  to  List 
List<MaintainUserDto> dtoList 
List<Integer> vehicleIds = dtoList.stream().map(s -> s.getVehicleId()).collect(Collectors.toList()); 
 Set<Integer> vehicleIdsSet = vehicleIds.stream().collect(Collectors.toSet()); 
 vehicleIds = vehicleIdsSet.stream().collect(Collectors.toList()); 
 
 
List<String> vins 
// 差集 
List<String> reduce1 = vins.stream() 
        .filter(item -> !vins3.contains(item)) 
        .collect(Collectors.toList()); 
 
// 提取重复数据 
List<String> result = new ArrayList<>(); 
Map<String, Long> collect = vins.stream().collect(Collectors 
        .groupingBy(Function.identity(), Collectors.counting())); 
collect.forEach((k, v) -> { 
    if (v > 1) 
        result.add(k); 
}); 
 
// 对象集合转map，key value 都是某个属性，支持重复key 
List<VehicleBrandInfo> brand 
Map<Integer, String> brandMap = brand.stream().collect(Collectors.toMap( 
                        VehicleBrandInfo::getId, VehicleBrandInfo::getName, (k1, k2) -> k1)); 
map = mileageList.stream().collect(Collectors.toMap( 
 VehicleMileageItem::getVehicleId, s -> s.getMileage())); 
 
 
//两个不同对象集合转换 
List<MaintainUserImportVo> successList 
List<MaintainUserVinCheckVo> vinList = new ArrayList(); 
vinList.addAll(successList.stream().map(line -> initCheckVin(line)).collect(Collectors.toList())); 
private MaintainUserVinCheckVo initCheckVin(MaintainUserImportVo maintainUserImportVo) { 
 MaintainUserVinCheckVo maintainUserVinCheckVo = new MaintainUserVinCheckVo(); 
 maintainUserVinCheckVo.setId(maintainUserImportVo.getId()); 
 maintainUserVinCheckVo.setVin(maintainUserImportVo.getVin()); 
 return maintainUserVinCheckVo; 
 } 
 
// list集合 to 数组 
List<Integer> vehicleIds 
Integer[] mm = vehicleIds.stream().toArray(Integer[]::new) 
 
 
 
// 运用正则 
Pattern p = Pattern.compile("^1\\d{10}$"); //正则过滤手机号 
List<String> phoneLista = phoneList.stream().filter(line -> p.matcher(line).matches()).collect(Collectors.toList()); 
 
// 去重 
Set<Integer> couponSet = usedList.stream().map(s -> s.getCouponId()).collect(Collectors.toSet()); 
List<Integer> shopIds = selectShop.stream().map(s -> s.getId()).distinct().collect(Collectors.toList()); 
 
 
// 累加 
Double totalRepair = executiveForCmRepair.stream().collect( 
 Collectors.summingDouble(OrgCollisionVo::getTotalRepair)); 
 
// 求平均值 
double average = orderVos3.stream().mapToDouble(ResponseTimeResultVo::getGrade).average().getAsDouble(); 
 
 
// 正则 排序 
List<VehicleModelDTO> types 
List<VehicleModelDTO> numbers = types.stream() 
                .filter(it -> PATTERN.matcher(it.getName()).find()) 
                .sorted(Comparator.reverseOrder()) 
                .collect(Collectors.toList()); 
 
 
subFilter = ignoreList.stream().filter(ignore -> ignore.startsWith(prefix)).map(ignore -> ignore.substring(prefix.length())).toArray(String[]::new); 
 
 
 
list.stream().forEach(i -> { 
            ZeusPersonDTO customer = personMap.get(i.getVehicleOwnerId()); 
            if (!ValidateUtils.validPhone(customer.getPhone())) { 
                removeDTO.add(i); 
            } 
        });