博客

List<String> useList = new ArrayList<>();
        int use=3;
        for (int i=1;i<=use;i++){
            useList.add(String.valueOf(i));
        }
        List<TRoom> tRooms = new ArrayList<>();
        TRoom tRoom1 = new TRoom();
        tRoom1.setTrPurpose("1");
        tRooms.add(tRoom1);
        TRoom tRoom2 = new TRoom();
        tRoom2.setTrPurpose("2");
        tRooms.add(tRoom2);
        TRoom tRoom3 = new TRoom();
        tRoom3.setTrPurpose("5");
        tRooms.add(tRoom3);

        List<TRoom> collect = tRooms.stream()
                .filter(u -> useList.contains(u.getTrPurpose()))
                .collect(Collectors.toList());
        System.out.println(collect);

最后输出的list只有tRoom1和tRoom2两个对象，tRoom3所对应字段的值不在userList中所以过滤掉了。