关于compareTo()的重载 转

 

import java.util.SortedSet;
import java.util.TreeSet;

public class UserBean implements Comparable<UserBean>{
 private String username;
 private int age;
 
 public UserBean(String username,int age) {
  this.username = username;
  this.age = age;
 }
 public String getUsername() {
  return username;
 }
 public void setUsername(String username) {
  this.username = username;
 }
 public int getAge() {
  return age;
 }
 public void setAge(int age) {
  this.age = age;
 }
 
 
 
 
 
 @Override
 public int compareTo(UserBean user) {
  int i = 0;
  if(user!=null){
   i = this.age-user.age; 
   if(i==0){//如果年龄相同，则比较姓名，否则只能显示一个人
    i = this.username.hashCode()-user.username.hashCode();
   }
  }
  return i;
 }
 
 @Override
 public String toString() {
  // TODO Auto-generated method stub
  return this.username+":"+this.age;
 }
 
 public static void main(String[] args) {
  TreeSet sortedSet = new TreeSet();
  UserBean userBean1 = new UserBean("lj", 20);
  UserBean userBean2 = new UserBean("li", 20);
  sortedSet.add(userBean1);
  sortedSet.add(userBean2);
  System.out.println(sortedSet);
  
 }
 

}

原文链接： http://blog.csdn.net/weiyirong/article/details/6443710