如果对象具有特定方法，是否有办法检查Java运行时？

Question

I have a class and it has multiple subclasses which each implement their own methods. Some of these subclasses have common method which I need to call. Is there a way in java to know if the object has a method (without using instanceof )?

Answer 1

This probably points to a design flaw, but you could always use reflection to check if a method exists:

public static boolean hasMethod(Object obj, String methodName) {
    return Arrays.stream(obj.getClass().getMethods())
                 .anyMatch(m -> m.getName().equals(methodName));
}

This, of course, could be refined to include the method's signature too, but the basic idea remains the same.