TA的每日心情 | 开心 2021-3-12 23:18 |
---|
签到天数: 2 天 [LV.1]初来乍到
|
常常遇到数组排序的问题.比如我有一个Person类,它的实例对象存储在ArrayList数组中,现在要把ArrayList数组中的
Person对象按照年龄排序.其实这种情况经常遇到.
下面给出源代码:
1:Person.java文件:-------------------------------
public class Person{
String name;
int age;
public Person(String name,int age){
this.name = name;
this.age = age;
} public int getAge() {
return age;
} public void setAge(int age) {
this.age = age;
} public String getName() {
return name;
} public void setName(String name) {
this.name = name;
}
} 2:Mycomparator.java-------------------------------
//实现Comparator接口,也就是定义排序规则,你几乎可以定义任何规则
package com.infoearth;
import java.util.*;
public class Mycomparator implements Comparator{
public int compare(Object o1,Object o2) {
Person p1=(Person)o1;
Person p2=(Person)o2;
if(p1.age<p2.age)
return 1;
else
return 0;
} } 3:ListSort.java------------------------------------ package com.infoearth; import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator; public class ListSort {
public static void main(String[] args){
ArrayList list = new ArrayList();
list.add(new Person("lcl",28));
list.add(new Person("fx",23));
list.add(new Person("wqx",29));
Comparator comp = new Mycomparator();
Collections.sort(list,comp);
for(int i = 0;i<list.size();i++){
Person p = (Person)list.get(i);
System.out.println(p.getName());
}
}
}
运行结果: wqx
lcl
fx
源码下载:http://file.javaxxz.com/2014/10/30/235546671.zip |
|