鍵盤解題

要改的應該是

item.getXX()

這個 function

如果可以改成傳參的話

然後在呼叫 getRandomAry 時

把參數帶進去

public List<String> getRandomAry(ArrayList<ExamItemsBean> items, int count, String target)
{
    List<String> resultAry = new ArrayList<String>();
    Random random = new Random();
    do
    {
        int next = random.nextInt(items.size());
        ExamItemsBean item = items.get(next);
        if (!resultAry.contains(item.getItem(target)))
        {
            resultAry.add(item.getItem(target));
        }
    } while (resultAry.size() < count);
    return resultAry;
}

僅供參考

沒測試過

public class MethodAsParams {
	//https://www.rgagnon.com/javadetails/java-0031.html
	public static void main(String s[]) throws Exception {
		// we assume that called methods have no argument
		Object paramsObj[];

		String[]hiStrings={"hi","，","hello"," ","World!!!"};

		paramsObj =new Object[]{hiStrings};
		
		Method thisMethod = Execute.class.getDeclaredMethod("go", paramsObj.getClass());//只有getClass(得到類型) 不是實例
		
		new UseMethodAsParaments(thisMethod, new Execute(), paramsObj);		
		
	}
	



}
class UseMethodAsParaments{
	Method method;
	Execute e;
	public UseMethodAsParaments(Method method,Object e,Object[]objs) throws IllegalAccessException, IllegalArgumentException, InvocationTargetException{
		this.method=method;
		method.invoke(e, objs);
	}
}
class Execute{
	public void go(Object[] args){
		System.out.print("work	");
		for (int i = 0; i < args.length; i++) {
			System.out.print(args[i]);
			
		}
	}
}

這是我平常拿來筆記的程式碼，這是委派,白話一點就是把方法當成參數傳遞
我之前使用此方法，把學校教授的程式碼縮短9倍(當然教授要教學生要用簡單一點的方式)
可以考慮看看

若是支援 JAVA8 可使用 Function 方式整合
https://docs.oracle.com/javase/8/docs/api/java/util/function/package-summary.html

//使用方式
getRandomAry(items, 0, bean -> bean.getAA());
getRandomAry(items, 0, bean -> bean.getBB());
getRandomAry(items, 0, bean -> bean.getCC());

//增加 function 參數
public static List<String> getRandomAry(ArrayList<ExamItemsBean> items, int count, Function<ExamItemsBean,String> function) {
    List<String> resultAry = new ArrayList<String>();
    Random random = new Random();
    do {
        int next = random.nextInt(items.size());
        ExamItemsBean item = items.get(next);
        if (!resultAry.contains(function.apply(item))) {
            resultAry.add(function.apply(item));
        }
    } while (resultAry.size() < count);
    return resultAry;
}

Java 函數（方法）整合問題
你應該只要把方法改為只要傳入要隨機取得的元素陣列就好了。

    public static <E> List<E> getRandomAry(List<E> list, int count) {
        if (list == null || list.size() < 1) {
            return new ArrayList<E>();
        }

        List<E> arr = new ArrayList<E>();
        Random random = new Random();
        do {
            int next = random.nextInt(list.size());
            E e = list.get(next);
            if (!arr.contains(e)) {
                arr.add(e);
            }
        } while (arr.size() < count);
        return arr;
    }