ArrayList中的数据排序--java对象排序
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对象按照年龄和职位排序.
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;
int position;
public Person(String name,int age,int position){
this.name = name;
this.age = age;
this.position = position;
}
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;
}
public int getPosition() {
return position;
}
public void setPosition(int position) {
this.position= position;
}
}
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
//规则:首先根据年龄排序,如果年龄相同,则根据职位排序
package com.infoearth;
import java.util.*;
public class Mycomparator implements Comparator{
// 实现Comparator接口中的compare方法
public int compare(Object o1,Object o2) {
Person p1=(Person)o1;
Person p2=(Person)o2;
if(p1.age return 1;
else if(p1.age == p2.age&&p1.position return 1;
else
return 0
}
}
3:ListSort.java------------------------------------
// 实现List排序
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",28,1));
list.add(new Person("fx",23,1));
list.add(new Person("fx22",23,2));
list.add(new Person("wqx",29,3));
Comparator comp = new Mycomparator();
Collections.sort(list,comp);
for(int i = 0;i Person p = (Person)list.get(i);
System.out.println(p.getName());
}
}
}
阅读(427) | 评论(0) | 转发(0) |