java获取随机不重复的数得值

 

假如我有一个数组： 

 

ArrayList<Integer> mArrayList = new ArrayList<Integer>();
    	mArrayList.add(0);
    	mArrayList.add(1);
    	mArrayList.add(2);
    	mArrayList.add(3);

我需要从中随机抽取2个数  不能重复抽取，我就会用这个方法

 

 

 public void getValue(ArrayList<Integer> mArrayList){
    	Random mRandom = new Random();
    	int a = mRandom.nextInt(mArrayList.size());
    	
    	int value = mArrayList.get(a);
    	System.out.println(value + "");
    	mArrayList.remove(a);
    }

原理就是每抽取一次就删除已经抽取出来的值，这样获取到的值就不会重复了

 

完整代码：

 

package com.xiaoqiu.test;

import java.util.ArrayList;
import java.util.Random;

public class Test {
    public static void main(String[] args) {
    	ArrayList<Integer> mArrayList = new ArrayList<Integer>();
    	mArrayList.add(0);
    	mArrayList.add(1);
    	mArrayList.add(2);
    	mArrayList.add(3);
    	
    	Test mTest = new Test();
    	mTest.getValue(mArrayList);
    	mTest.getValue(mArrayList);
    }
    
    public void getValue(ArrayList<Integer> mArrayList){
    	Random mRandom = new Random();
    	int a = mRandom.nextInt(mArrayList.size());
    	
    	int value = mArrayList.get(a);
    	System.out.println(value + "");
    	mArrayList.remove(a);
    }
}

测试结果：

 

 

3

2

 

3

0

 

2

3