Java 数组的排序(包括原始数据类型数组及引用数据类型数组)

java.util.Arrays类有个sort方法可以实现数组的排序,都有现成的车轮了,就不用再写冒泡啥的重新发明一次了.直接上例子代码:

package com.pocketdigi;

import java.util.ArrayList;
import java.util.Arrays;

public class Main {
    static ArrayList list;

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        //原始类型数组的排序
        int[] a = new int[] { 1, 5, 3 };
        for (int value : a) {
            System.out.println(value);
        }
        Arrays.sort(a);
        for (int value : a) {
            System.out.println(value);
        }
        //引用类型数组的排序
        People[] peoples=new People[]{new People("zhang",20),new People("li",25),new People("wang",15),new People("qian",15)};
        for(People p:peoples){
            System.out.println(p);
        }
        Arrays.sort(peoples);
        for(People p:peoples){
            System.out.println(p);
        }		
    }

}

class People implements Comparable {
    //必须实现Comparable接口
    String name;
    int age;

    People(String name, int age) {
        this.name = name;
        this.age = age;
    }

    @Override
    public int compareTo(Object o) {
        //重写Comparable接口的compareTo方法 
        //先根据age排序,如果age相同,再根据name排序
        People p = (People) o;
        int result;
        if (age > p.age) {
            result = 1;
        } else if (age == p.age) {
            result=0;
        } else {
            result = -1;
        }
        if(result==0){
            result=name.compareTo(p.name);
        }
        return result;
    }

    @Override
    public String toString() {
        // TODO Auto-generated method stub
        return "Name:"+name+" Age:"+age;
    }

}