Java层级List的排序怎么实现List<MyObject>

Question

MyObject: long id; long parentId; long index; List<MyObject> child;顶级parentId = 0.....如何根据index排序。。。。现在好像是 默认的字典排序

Answer 1

Java排序，Java8方法
外层排序直接

list.sort(Comparator.comparing(t -> ((MyObject) t).getIndex()));

外层排序好了过后再循环排序里面的

list.forEach(t->{
            ((MyObject)t).getChild().sort(Comparator.comparing(MyObject::getIndex));
        });

Answer 2

 private List<TextbookChapterTreeBO> children;

    public List<TextbookChapterTreeBO> getChildren() {
        children.forEach(t->{
            ((TextbookChapterTreeBO)t).getChildren().sort(Comparator.comparing(TextbookChapterTreeBO::getIndex));
        });
        return children;
    }

    public void setChildren(List<TextbookChapterTreeBO> children) {
        this.children = children;
    }

把这个排序加到bean里就行了