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import java.util.ArrayList; import java.util.Collections; import java.util.Comparator; import java.util.List; import java.util.Random; /** * * @author www.zuidaima.com * */ public class ListSort { public static void main(String[] args) { List<User> users = new ArrayList<User>(); int id = 0; User user = null; Random random = new Random(); id = random.nextInt(100000); user = new User(id); user.setId(id); users.add(user); id = random.nextInt(100000); user = new User(id); user.setId(id); users.add(user); id = random.nextInt(100000); user = new User(id); user.setId(id); users.add(user); id = random.nextInt(100000); user = new User(id); user.setId(id); users.add(user); id = random.nextInt(100000); user = new User(id); user.setId(id); users.add(user); id = random.nextInt(100000); user = new User(id); user.setId(id); users.add(user); id = random.nextInt(100000); user = new User(id); user.setId(id); users.add(user); id = random.nextInt(100000); user = new User(id); user.setId(id); users.add(user); id = random.nextInt(100000); user = new User(id); user.setId(id); users.add(user); System.out.println("Before sort:"); for (User _user : users) { System.out.print(_user + " "); } Collections.sort(users, new Comparator<User>() { @Override public int compare(User user1, User user2) { Integer id1 = user1.getId(); Integer id2 = user2.getId(); //可以按User对象的其他属性排序，只要属性支持compareTo方法 return id2.compareTo(id1); } }); System.out.println("\nAfter sort 从大到小倒序:"); for (User _user : users) { System.out.print(_user + " "); } Collections.sort(users, new Comparator<User>() { @Override public int compare(User user1, User user2) { Integer id1 = user1.getId(); Integer id2 = user2.getId(); //可以按User对象的其他属性排序，只要属性支持compareTo方法 return id1.compareTo(id2); } }); System.out.println("\nAfter sort 从小到大正序:"); for (User _user : users) { System.out.print(_user + " "); } } } class User { private int id; public User(int id) { this.id = id; } public int getId() { return id; } public void setId(int id) { this.id = id; } @Override public String toString() { return id + ""; } } 程序运行输出结果： Before sort: 49459 73363 18294 65350 36522 77535 38273 58512 34980 After sort 倒序: 77535 73363 65350 58512 49459 38273 36522 34980 18294 After sort 正序: 18294 34980 36522 38273 49459 58512 65350 73363 77535