1、利用lambda表达式过滤集合

过滤集合获取想要的属性集合

defectList，获取所有WoMold这个属性为1的集合。

defects = defectList.stream().filter(s -> s.getWoMold() != null && s.getWoMold().equals(1)).collect(Collectors.toList());

过滤集合获取交集

获取equipmentList集合中ptid和ptIds的交集。也就是equipmentList中ptid在ptIds这个范围里面的

//查找线路所属设备列表
            List<PoleTower> poleTowerList1 = poleTowerList.stream().filter(s -> s.getBranchId().equals(branchId)).collect(Collectors.toList());
            List<Long> ptIds = CollectionUtils.extractToList(poleTowerList1, "id");
            List<Equipment> equipmentList1 = equipmentList.stream()
                    .filter((Equipment s) -> ptIds.contains(s.getPtId()))
                    .collect(Collectors.toList());

如

ptIds = ['1','2','3']
equipmentList = {[ptid:'1',name:'hh'],[ptid:'2',name:'h'h],[ptid:'3',name:'hh'],[ptid:'4',name:'hh']}

返回结果应为

equipmentList = {[ptid:'1',name:'hh'],[ptid:'2',name:'hh'],[ptid:'3',name:'hh']}

2、利用lambda表达式去重

altermList根据TerminalNo去重

//告警涉及的设备数（根据设备no去重得到）
        altermList = altermList.stream().collect(Collectors.collectingAndThen(
                Collectors.toCollection(() -> new TreeSet<>
                        (Comparator.comparing(Alterm::getTerminalNo))), ArrayList::new));