private static MethodHandle unbox(Wrapper wrap, boolean cast) {
EnumMap<Wrapper, MethodHandle> cache = UNBOX_CONVERSIONS[(cast ? 1 : 0)];
MethodHandle mh = cache.get(wrap);
if (mh != null) {
return mh;
}
// slow path
switch (wrap) {
case OBJECT:
mh = IDENTITY;
break;
case VOID:
mh = IGNORE;
break;
}
if (mh != null) {
cache.put(wrap, mh);
return mh;
}
// look up the method
String name = "unbox" + wrap.wrapperSimpleName();
MethodType type = unboxType(wrap);
try {
mh = IMPL_LOOKUP.findStatic(THIS_CLASS, name, type);
} catch (ReflectiveOperationException ex) {
mh = null;
}
if (mh != null) {
mh = MethodHandles.insertArguments(mh, 1, cast);
cache.put(wrap, mh);
return mh;
}
throw new IllegalArgumentException(
"cannot find unbox adapter for " + wrap + (cast ? " (cast)" : ""));
}
/**
* Return a method that casts its sole argument (an Object) to the given type and returns it as
* the given type.
*/
public static MethodHandle cast(Class<?> type) {
if (type.isPrimitive())
throw new IllegalArgumentException("cannot cast primitive type " + type);
MethodHandle mh;
Wrapper wrap = null;
EnumMap<Wrapper, MethodHandle> cache = null;
if (Wrapper.isWrapperType(type)) {
wrap = Wrapper.forWrapperType(type);
cache = WRAPPER_CASTS[0];
mh = cache.get(wrap);
if (mh != null) return mh;
}
mh = MethodHandles.insertArguments(CAST_REFERENCE, 0, type);
if (cache != null) cache.put(wrap, mh);
return mh;
}