業務程式碼寫多了，應該時不時研究下演算法，以保持思維的靈活性

import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Random;


/**打亂撲克牌*/
public class test1 {
    public static void main(String[] args) {
        String [] hua = new String[]{"黑桃","紅桃","梅花","方磚"};
        String [] num = {"1"
 
,"2","3","4","5","6","7","8","9","10","J","Q","K","A"};
        //抽象撲克牌集合
        List<String> puke = new LinkedList<>();
        for(int i=0;i<num.length;i++){
//          System.out.print("\n");
            for(int j=0;j<hua.length;j++){
//              System.out.print(hua[j]+num[i] +"\t");
 

                puke.add(hua[j]+num[i]);
            }
        }
        //例項化個隨機數
        Random random = new Random();
        String temp = null;
        //模仿洗牌100次
        for(int k=0;k<100;k++){
            int max = puke.size();
            int be = random.nextInt(max)%(max-0+1);
            int af = random.nextInt(max)%(max-0
 
+1);
            //兩次抽取的隨機數相等的話就不洗，以免會出現重複數值
            if(be==af)continue;
//          System.out.println(me);
            temp = puke.get(be);
            puke.set(be, puke.get(af));
            puke.set(af, temp);
        }

        int p = 0;
        for(Iterator<String> it = puke.iterator();it.hasNext();){
            if(p%4==0)System.out.print("\n");
            System.out.print(it.next());
            p++;
        }   
    }
}