如何把 activity 实例放到一个泛型为 string 的 arraylist 中去

private List<String> strList;
private void () {
	strList = new ArrayList<>();
	strList.add("你好");
	try {
		//获取所有不包括基类的成员变量
		Field strField = getClass().getDeclaredField("strList");
		strField.setAccessible(true);
		List list = (List) strField.get(this);//通过反射拿到 strList
		list.add(this);
		Log.d(TAG, "onCreate: " + list.size());
	} catch (NoSuchFieldException e) {
		e.printStackTrace();
	} catch (IllegalAccessException e) {
		e.printStackTrace();
	}
	Log.d(TAG, "onCreate: strList.size = " + strList.size());
}

List<String> strList = new ArrayList<>();
List<Activity> acList = strList;
acList.add(activity);