java ArrayList排序2009-01-06 13:37常常遇到數(shù)組排序的問題.比如我有一個Person類,它的實例對象存儲在ArrayList數(shù)組中,現(xiàn)在要把ArrayList數(shù)組中的Person對象按照年齡排序.
其實這種情況經(jīng)常遇到.
下面給出源代碼:

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-------------------------------
//實現(xiàn)Comparator接口,也就是定義排序規(guī)則,你幾乎可以定義任何規(guī)則
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());
        }

     }

}