JAVADOC clarification needed in Class.getMethod

Kyung Koo Yoon yoonforh at
Sat Aug 29 13:44:58 UTC 2015

> 2015. 8. 29., 오후 10:40, Kyung Koo Yoon <yoonforh at> 작성:
> Hi, Jochen.
> -- 
> --------------------
>  Software Innovation Driver yoonforh at gmail dot com
>  Analyze, Reason, Reshape the Question
>  PGP <>
>> 2015. 8. 29., 오후 10:01, Jochen Theodorou <blackdrag at <mailto:blackdrag at>> 작성:
>> Am 29.08.2015 10:56, schrieb Kyung Koo Yoon:
>>> Hi, all.
>>> The javadoc comment of java.lang.Class.getMethod API has following clause.
>>> @CallerSensitive
>>>     public Method getMethod(String name, Class<?>... parameterTypes)
>>>         throws NoSuchMethodException, SecurityException
>>> "The {@code parameterTypes} parameter is an array of {@code Class}
>>> objects that identify the method's formal parameter types, in declared
>>>  order. If {@code parameterTypes} is {@code null}, it is
>>>  treated as if it were an empty array."
>>> As you know the method signature changed to use varargs since JDK 1.5,
>>> if parameterTypes is given null, the compiler will interpret the parameter with “new Class[] { null }”.
>> you are making a wrong assumption here. If null is given there will be
>> no wrapping in an array.  varargs are defined that there is no wrapping
>> if the given argument type is compatible. For Class[] this is Class[]
>> and of course null. Even if you had been right, you could still give
>> produce a call with null by reflection or using the MethodHandles API
> You can check by simply decompiling the generated byte codes.
> vararg is not a JVM feature so the compiler pre-processes and the compiler handles the given null as array’s first element.
> Originally class.getMethod(“methodName”, null) should have meant a static method, but with vararg, it’s not.

Sorry, static is not correct. should have meant a void method.

>> bye blackdrag
>> -- 
>> Jochen "blackdrag" Theodorou
>> blog: <>

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