//一个POJO例子class User {String name;String age;public User(String name,String age){this.name=name;this.age=age;}public String getAge() {return age;}public void setAge(String age) {this.age = age;}public String getName() {return name;}public void setName(String name) {this.name = name;}}
//具体的比较类，实现Comparator接口import java.util.Comparator;import java.util.List;import java.util.ArrayList;import java.util.Collections;public class ComparatorUser implements Comparator{
public int compare(Object arg0, Object arg1) {User user0=(User)arg0;User user1=(User)arg1; //首先比较年龄，如果年龄相同，则比较名字int flag=user0.getAge().compareTo(user1.getAge());if(flag==0){return user0.getName().compareTo(user1.getName());}else{return flag;}}}
//测试类public class SortTest {
public static void main(String[] args){List userlist=new ArrayList();userlist.add(new User("dd","4"));userlist.add(new User("aa","1"));userlist.add(new User("ee","5"));userlist.add(new User("bb","2"));userlist.add(new User("ff","5"));userlist.add(new User("cc","3"));userlist.add(new User("gg","6"));ComparatorUser comparator=new ComparatorUser();Collections.sort(userlist, comparator);for (int i=0;i<userlist.size();i++){User user_temp=(User)userlist.get(i); System.out.println(user_temp.getAge()+","+user_temp.getName());}}}//首先年龄排序，如果年龄相同，则按名字排序结果: 1, aa 2, bb 3, cc 4, dd 5, ee //注意:同样是5岁的人，则比较名字(ee,ff)，然后排序 5, ff 6, gg
这一次是一个告别，或者一个永远的告别，
