java8 stream代替for循环 sort多字段排序 group by多级排序

List list = new ArrayList();

Category ctg= new Category();

ctg.setType(1);//0商品，1销售规格

ctg.setSort(2);

ctg.setInheritFlag(0);//0继承属性1非继承属性

ctg.setValueSort(1)

Category ctg1= new Category();

ctg1.setType(0);//0商品，1销售规格

ctg1.setSort(1);

ctg1.setInheritFlag(1);//0继承属性1非继承属性

ctg1.setValueSort(2)

list.add(ctg);

list.add(ctg1);

                lista.stream().sorted(Comparator.comparing(Category::getSort()).thenComparing(Category::getValueSort())).collect(Collectors.groupingBy(fetchGroupInheritKey(mtg)),Collectors.groupingBy(fetchGroupTypeKey(mtg)));

private String fetchGroupInheritKey(Category ctg){
                if(inheritFlag==0){
                    return "inheritList";
                }else if(inheritFlag==1){
                    return "ownList";
                }else{
                    return "";
                }
                
            }

使用Comparator实现多字段排序和多级分组，前面的sort排序会影响后面的groupBy分组后的list中的排序

mcvo中有有多个property List ，按商品属性和销售属性区分将多个小list聚合为一个list

mc V o list.stream(). flat Map(mc vo→mcvo.getPropertyList(). stream ())