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methodhandle invoke with arguments cast error

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  methodhandle invoke with arguments cast error Philipp Kraus <philipp.kraus@flashpixx.de> - 2015-02-05 20:57 +0100
    Re: methodhandle invoke with arguments cast error Arne Vajhøj <arne@vajhoej.dk> - 2015-02-05 15:18 -0500
      Re: methodhandle invoke with arguments cast error Philipp Kraus <philipp.kraus@flashpixx.de> - 2015-02-06 06:41 +0100
        Re: methodhandle invoke with arguments cast error Steven Simpson <ss@domain.invalid> - 2015-02-07 18:25 +0000
    Re: methodhandle invoke with arguments cast error Steven Simpson <ss@domain.invalid> - 2015-02-05 21:55 +0000
      Re: methodhandle invoke with arguments cast error Philipp Kraus <philipp.kraus@flashpixx.de> - 2015-02-06 06:43 +0100
        Re: methodhandle invoke with arguments cast error Steven Simpson <ss@domain.invalid> - 2015-02-06 11:32 +0000
          Re: methodhandle invoke with arguments cast error Philipp Kraus <philipp.kraus@flashpixx.de> - 2015-02-06 14:31 +0100

#31051 — methodhandle invoke with arguments cast error

Hello,

I use a method handle with this code:

List<Object> args = new LinkedList();
args.add( my object );
args.add( new Double(5) );

MethodHandle h = getMethodHandle_with_unreflect
h.invokedWithArguments( args );

The method, which is called shows

public void doit( Integer x )

so I get a cast error: Cannot cast java.lang.Double to java.lang.Integer
How can I do an explicit cast on the invokeMethodWithArguments?

Thanks

Phil

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#31052

On 2/5/2015 2:57 PM, Philipp Kraus wrote:
> I use a method handle with this code:
>
> List<Object> args = new LinkedList();
> args.add( my object );
> args.add( new Double(5) );
>
> MethodHandle h = getMethodHandle_with_unreflect
> h.invokedWithArguments( args );
>
> The method, which is called shows
>
> public void doit( Integer x )
>
> so I get a cast error: Cannot cast java.lang.Double to java.lang.Integer
> How can I do an explicit cast on the invokeMethodWithArguments?

Stuff an Integer into the args List??

Arne

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#31056

On 2015-02-05 20:18:37 +0000, Arne Vajhøj said:

> On 2/5/2015 2:57 PM, Philipp Kraus wrote:
>> I use a method handle with this code:
>> 
>> List<Object> args = new LinkedList();
>> args.add( my object );
>> args.add( new Double(5) );
>> 
>> MethodHandle h = getMethodHandle_with_unreflect
>> h.invokedWithArguments( args );
>> 
>> The method, which is called shows
>> 
>> public void doit( Integer x )
>> 
>> so I get a cast error: Cannot cast java.lang.Double to java.lang.Integer
>> How can I do an explicit cast on the invokeMethodWithArguments?
> 
> Stuff an Integer into the args List??

Sorry, I forgot the information, that the list will be build 
dynamically, so into the list can be pushed any numeric typ.
In a hardcoded source I would do (int), but I must use a method handle 
because of other dependencies

Phil

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#31073

On 06/02/15 05:41, Philipp Kraus wrote:
> On 2015-02-05 20:18:37 +0000, Arne Vajhøj said:
>
>> On 2/5/2015 2:57 PM, Philipp Kraus wrote:
>>> I use a method handle with this code:
>>>
>>> List<Object> args = new LinkedList();
>>> args.add( my object );
>>> args.add( new Double(5) );
>>>
>>> MethodHandle h = getMethodHandle_with_unreflect
>>> h.invokedWithArguments( args );
>>>
>>> The method, which is called shows
>>>
>>> public void doit( Integer x )
>>>
>>> so I get a cast error: Cannot cast java.lang.Double to 
>>> java.lang.Integer
>>> How can I do an explicit cast on the invokeMethodWithArguments?
>>
>> Stuff an Integer into the args List??
>
> Sorry, I forgot the information, that the list will be build 
> dynamically, so into the list can be pushed any numeric typ.

Is the method handle available when building the list?  You could get 
its MethodType, and scan over the parameter types for boxed primitives.  
If the corresponding argument is of type Number, call the appropriate 
XXXValue() method and push the result into the list.

-- 
ss at comp dot lancs dot ac dot uk

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#31054

On 05/02/15 19:57, Philipp Kraus wrote:
> MethodHandle h = getMethodHandle_with_unreflect

What is getMethodHandle_with_unreflect, and where is the rest of the line?


-- 
ss at comp dot lancs dot ac dot uk

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#31057

On 2015-02-05 21:55:21 +0000, Steven Simpson said:

> On 05/02/15 19:57, Philipp Kraus wrote:
>> MethodHandle h = getMethodHandle_with_unreflect
> 
> What is getMethodHandle_with_unreflect, and where is the rest of the line?

I don't write the full code, I get the method handle from a method, 
that uses reflection API
to get the method and returns with MethodHandles.lookup.unreflect the 
handle of the method.

Phil

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#31059

On 06/02/15 05:43, Philipp Kraus wrote:
> On 2015-02-05 21:55:21 +0000, Steven Simpson said:
>
>> On 05/02/15 19:57, Philipp Kraus wrote:
>>> MethodHandle h = getMethodHandle_with_unreflect
>>
>> What is getMethodHandle_with_unreflect, and where is the rest of the 
>> line?
>
> I don't write the full code, [...]

Ah, I didn't perceive it as pseudo-code.

-- 
ss at comp dot lancs dot ac dot uk

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#31061

On 2015-02-06 11:32:28 +0000, Steven Simpson said:

> On 06/02/15 05:43, Philipp Kraus wrote:
>> On 2015-02-05 21:55:21 +0000, Steven Simpson said:
>> 
>>> On 05/02/15 19:57, Philipp Kraus wrote:
>>>> MethodHandle h = getMethodHandle_with_unreflect
>>> 
>>> What is getMethodHandle_with_unreflect, and where is the rest of the line?
>> 
>> I don't write the full code, [...]
> 
> Ah, I didn't perceive it as pseudo-code.

yes, hope it is okay

Thx

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