list<map<string, object>> 分组求和 文心快码BaiduComate 针对你提出的 list<map<string, object>> 分组求和的问题,我将按照你提供的提示进行解答,并附上相应的代码片段。 1. 解析 list<map<string, object>> 数据结构 我们有一个列表,列表中的每个元素都是一个字典(在Java中...
Map<String, Object> objectMap3 = new HashMap<>(); objectMap3.put("name","c"); objectMap3.put("num",22); list.add(objectMap3); int sum = list.stream().filter(x-> "a".equals(x.get("name").toString()) || "b".equals(x.get("name").toString())).mapToInt(a->((int) ...
Map<String, List<Map<String, Object>>> glist = list.stream().collect(Collectors.groupingBy(e -> e.get("projectCode").toString())); glist.forEach((k,slist)->{ Map<String,Object> nmap=new HashMap<>(); //这块是对某个key进行计算 可以求和 求平均值 求各种值 IntSummaryStatistics sumcc ...
Map<String,Object> stu4 =newHashMap<String, Object>(); stu4.put("name", "卫庄"); stu4.put("score",newBigDecimal(30)); list.add(stu4); list= list.stream().collect(Collectors.groupingBy(d -> d.get("name"))).values().stream().map(d ->{ Map<String, Object> sampleData = d....
Map<String, Object> map5 = new HashMap<>(); map5.put("userId", "159"); map5.put("value", 2022); list.add(map5); System.out.println("统计后的数据--->>>"+list); //根据userId key 合计value Map<String, Map<String, Object>> result = new HashMap<>(); ...
package test2;importjava.util.*;importjava.util.stream.Collectors;publicclassFenzu{publicstaticvoidmain(String[]args){Map<String,Object>map=newHashMap<String,Object>();map.put("name","a");map.put("price",500);Map<String,Object>map2=newHashMap<String,Object>();map2.put("name","a");...
Map<String,Object> nmap=new HashMap<>(); IntSummaryStatistics sumcc = slist.stream().collect(Collectors. summarizingInt(e->Integer.valueOf(e.get("countorder").toString())); nmap.put("name", slist.get(0).get(name)); nmap.put("value", sumcc.getSum());//求和 datas...
List<Map> 进行求和 简介:public class Main { public static void main(String[] args) { List lists = new ArrayList(10); Map m1 = new HashMap(16); m1. publicclassMain{ publicstaticvoidmain(String[] args) { List<Map> lists =newArrayList<>(10);Map<String,Object> m1 =newHashMap<>(16...
补充知识：Java8集合List排序、筛选、求和、求最⼤值、平均值、List转Map Java8集合List排序、筛选 1. List 元素有序 元素可重复 1.1 ArrayList 动态数组实现 查询快 增删慢(末尾处也快)1.2 LinkedList 链表实现 查询慢 增删快 1.3 ArrayList和LinkedList⽐较 实现查询增删线程安全?ArrayList动态数组快慢(末尾...