我有一个Java集合:
Collection<CustomObject> list = new ArrayList<CustomObject>();
CustomObject id现在在显示列表之前有一个字段,我想按此排序此集合id。
CustomObject id
id
有什么办法可以做到吗?
使用比较器:
List<CustomObject> list = new ArrayList<CustomObject>(); Comparator<CustomObject> comparator = new Comparator<CustomObject>() { @Override public int compare(CustomObject left, CustomObject right) { return left.getId() - right.getId(); // use your logic } }; Collections.sort(list, comparator); // use the comparator as much as u want System.out.println(list);
此外,如果CustomObject实现Comparable,则只需使用Collections.sort(list)
CustomObject
Comparable
Collections.sort(list)
使用JDK 8,语法要简单得多。
List<CustomObject> list = getCustomObjectList(); Collections.sort(list, (left, right) -> left.getId() - right.getId()); System.out.println(list);
更简单
List<CustomObject> list = getCustomObjectList(); list.sort((left, right) -> left.getId() - right.getId()); System.out.println(list);
最简单的
List<CustomObject> list = getCustomObjectList(); list.sort(Comparator.comparing(CustomObject::getId)); System.out.println(list);
显然,初始代码也可以用于JDK 8。