转载自 屌炸天，JDK8的排序大法！！

今天总结了下JDK中排序的方法，包括JDK8中强大的lambda表达式及函数式接口运用，不废话，请看下面示例。

public class Test {public static void main(String[] args) {List<User> list = initList();// jdk8之前的排序Collections.sort(list, new Comparator<User>() {@Overridepublic int compare(User o1, User o2) {return o1.getAge().compareTo(o2.getAge());}});// jdk8 lambda排序，带参数类型list = initList();list.sort((User u1, User u2) -> u1.getAge().compareTo(u2.getAge()));list.forEach(System.out::println);System.out.println();// jdk8 lambda排序，不带参数类型list = initList();list.sort((u1, u2) -> u1.getAge().compareTo(u2.getAge()));list.forEach(System.out::println);System.out.println();// jdk8 排序，User类静态方法引用list = initList();list.sort(User::compareAge);list.forEach(System.out::println);System.out.println();// jdk8 升序排序，Comparator提供的静态方法list = initList();Collections.sort(list, Comparator.comparing(User::getAge));list.forEach(System.out::println);System.out.println();// jdk8 降序排序，Comparator提供的静态方法list = initList();Collections.sort(list, Comparator.comparing(User::getAge).reversed());list.forEach(System.out::println);System.out.println();// jdk8 组合排序，Comparator提供的静态方法，先按年纪排序，年纪相同的按名称排序list = initList();Collections.sort(list, Comparator.comparing(User::getAge).thenComparing(User::getName));list.forEach(System.out::println);}private static List<User> initList() {List<User> list = new ArrayList<>();list.add(new User("lisa", 23));list.add(new User("tom", 11));list.add(new User("john", 16));list.add(new User("jennis", 26));list.add(new User("tin", 26));list.add(new User("army", 26));list.add(new User("mack", 19));list.add(new User("jobs", 65));return list;}
}