map1.put("num1",1); Map<String,Object> map2=new HashMap<>(); map2.put("date","2021-11-25"); map2.put("num1",2); Map<String,Object> map3=new HashMap<>(); map3.put("date","2021-11-26"); map3.put("num1",3); Map<String,Object> map4=new HashMap<>(); map4.pu...
val countMap = groupMaps.map(kv => (kv._1,kv._2.length)) println(countMap) // 将map转化为list并且排序取前三 val sortList:List[(String,Int)] = countMap.toList.sortWith(_._2 > _._2).take(3) println(sortList) } } 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13....
map<String,Object> map1 = new HashMap<>(); map1.put("a_id",1); map1.put("in_num",10); map<String,Object> map2 = new HashMap<>(); map1.put("a_id",3); map1.put("in_num",10); map<String,Object> map3 = new HashMap<>(); map1.put("a_id",4); map1.put("in...
publicclassMapUtil{publicstaticvoidmain(String[]args){List<Map<String,String>>osvList=newArrayList<>();Map<String,String>map1=newHashMap<>();map1.put("osV","5.1");map1.put("gaidNum","100");Map<String,String>map2=newHashMap<>();map2.put("osV","4.4.2");map2.put("gaidNum",...
Map<String,Object>> list1 = new ArrayList<>(); list1.add(map1); list1.add(map2); list1.add(map3); map<String,Object> map4 = new HashMap<>(); map1.put("a_id",1); map1.put("out_num",20); map<String,Object> map5 = new HashMap<>(); map1.put("a_id",2); map1...
1 2 3 4 5 6 publicstaticvoidmain(String[] args) {<br> List<String> idList =newArrayList<>(Arrays.asList("姓名","性别")); List<String> nameList =newArrayList<>(Arrays.asList("杰克","男"));<br> Map<String,String> listMap = idList.stream().collect(Collectors.toMap(key->key, key...
{//合并Map<String,Object> map =o.getValue().stream().flatMap(m ->{returnm.entrySet().stream();}).collect(Collectors.toMap(Map.Entry::getKey,Map.Entry::getValue,(a,b)->b));//为没有key的赋值0set.stream().forEach(k->{if(!map.containsKey(k))map.put(k,0);});returnmap;})...
Map<String,Stu> stus = new HashMap<String,Stu>();for (Stu stu : list1) { if (stus.containsKey(stu.getName())) { Stu temp = stus.get(stu.getName());temp.setDesc(temp.getDesc()+stu.getDesc());stus.put(stu.getName(),temp);} else { stus.put(stu.getName(), ...
// 将list转换成Map类型 Map<String, String> map = list.stream().collect(Collectors.toMap(Person::getId, Person::getName)); // 如果报 map里的value空指针异常,则需要在value,也就是toMap()的第二个参数进行空(null)值的判断逻辑;例如:也就是 Person::getName 改成 p -> p.getName()==null?
("orange"); List<String> list2 = new ArrayList<>(); list2.add("banana"); list2.add("grape"); list2.add("orange"); List<String> distinctList = Stream.of(list1, list2) .flatMap(Collection::stream) .distinct() .collect(Collectors.toList()); System.out....