package com.gxa.oop; import java.util.ArrayList; import java.util.Collections; import java.util.Comparator; import java.util.HashSet; import java.util.List; import java.util.Set; public class DemoTest3 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub //ctrl shirf o 導包 /*Set<User> strs = new HashSet<User>(); strs.add(new User("andy",11)); strs.add(new User("andy",11)); System.out.println(strs); Integer i = 3; int j = i;*/ List<User> users = new ArrayList<User>(); users.add(new User("andy",11)); users.add(new User("jack",9)); users.add(new User("belly",10)); Collections.sort(users,new MyComparator()); System.out.println(users); List<String> strs = new ArrayList<String>(); strs.add("dd"); strs.add("ac"); strs.add("ab"); Collections.sort(strs); System.out.println(strs); } } class MyComparator implements Comparator<User>{ @Override public int compare(User o1, User o2) { /*if (o1.getAge()>o2.getAge()) { return 1; }else if(o1.getAge()<o2.getAge()){ return -1; }else{ return 0 ; }*/ //return o1.getAge()>o2.getAge()?1:-1; return o1.getName().compareTo(o2.getName()); } }
其實就是實現Comparator接口!!!!
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