java8 merge合并两个map,key相同value相加
Map<String,Integer> map1= new HashMap<String, Integer>(); map1.put("one",1); map1.put("two",2); map1.put("three",3); Map<String,Integer> map2= new HashMap<String,Integer>(); map2.put("one",1); map2.put("two",2); //map1合并到map2中 map1.forEach((key,value) -> map2.merge(key,value,Integer::sum)); System.out.println(JSON.toJSONString(map2)); 结果:{"one":2,"three":3,"two":4} 来源: CSDN 作者: df331009 链接: https://blog.csdn.net/df331009/article/details/104225770