MethodHandle lookup&invocation performance

[Rémi Forax]

On 07/09/2011 12:21 PM, Rémi Forax wrote:
> You should avoid to create constants more than once.
> Also, bindTo() will create a method handle for-each call.
>
> You can transform your code like that:
>
>       private static final MethodHandles.Lookup lookup = MethodHandles.lookup();
>       private static final MethodType mt = MethodType.methodType(String.class, String.class);
>
>       private static MethodHandle methodhandleLookup(Object receiver, String methodName) throws Throwable {
>           return lookup.findVirtual(receiver.getClass(), methodName, mt);
>       }
>
>       private static String methodhandleInvoke(Object receiver, MethodHandle method) throws Throwable {
>           return (String) method.invoke(receiver, "methodhandle");
>       }
>
> or like that:
>
>       private static final MethodHandles.Lookup lookup = MethodHandles.lookup();
>       private static final MethodType mt = MethodType.methodType(String.class, String.class);
>       private static final MethodType mt2 = MethodType.methodType(String.class, Object.class, String.class);
>
>       private static MethodHandle methodhandleLookup(Object receiver, String methodName) throws Throwable {
>           MethodHandle mh = lookup.findVirtual(receiver.getClass(), methodName, mt);
>           return mh.asType(mt2);
>       }
>
>       private static String methodhandleInvoke(Object receiver, MethodHandle method) throws Throwable {
>           return (String) method.bindTo(receiver).invokeExact(receiver, "methodhandle");
>       }

oups, typo:

      private static String methodhandleInvoke(Object receiver, MethodHandle method) throws Throwable {
          return (String) method.invokeExact(receiver, "methodhandle");
      }


>
> Rémi

Rémi