Collectors.groupingBy根据一个或多个属性对集合中的项目进行分组
代码如下。
publicclasslisttomaptest { publicstaticvoidmain (string [ ] args ) throwsparseexception (listuser users=arrays.as list ) nns MapInteger,listuser map=users.stream (.collect ) collectors.grouping by (user : get age ); MapString,listuser map1=users.stream (.collect ) collectors.grouping by (I-I.get age ) ) ' _ '年龄'); MapString,listuser map2=users.stream (.collect ) collectors.groupingby(I-{if ) I.getage ) ) 10 ) return ' } eler () ); system.out.println (映射; system.out.println(map1; system.out.println(map2; }输出如下。
参考文献: https://blog.csdn.net/u 014231523/article/details/10253590