private TestCase(Class<T> rtype, Function<Object, T> cast, ThrowMode throwMode, Throwable thrown)
throws NoSuchMethodException, IllegalAccessException {
this.cast = cast;
filter =
MethodHandles.lookup()
.findVirtual(Function.class, "apply", MethodType.methodType(Object.class, Object.class))
.bindTo(cast);
this.rtype = rtype;
this.throwMode = throwMode;
this.throwableClass = thrown.getClass();
switch (throwMode) {
case NOTHING:
this.thrown = null;
break;
case ADAPTER:
case UNCAUGHT:
this.thrown = new Error("do not catch this");
break;
default:
this.thrown = thrown;
}
MethodHandle throwOrReturn = THROW_OR_RETURN;
if (throwMode == ThrowMode.ADAPTER) {
MethodHandle fakeIdentity = FAKE_IDENTITY.bindTo(this);
for (int i = 0; i < 10; ++i) {
throwOrReturn = MethodHandles.filterReturnValue(throwOrReturn, fakeIdentity);
}
}
thrower = throwOrReturn.asType(MethodType.genericMethodType(2));
}
public static void main(String[] args) throws Throwable {
Object x, y;
String s;
int i;
MethodType mt;
MethodHandle mh;
MethodHandles.Lookup lookup = MethodHandles.lookup();
// mt is (char,char)String
mt = MethodType.methodType(String.class, char.class, char.class);
mh = lookup.findVirtual(String.class, "replace", mt);
s = (String) mh.invokeExact("daddy", 'd', 'n');
System.out.println("Result: " + s);
// invokeExact(Ljava/lang/String;CC)Ljava/lang/String;
// weakly typed invocation (using MHs.invoke)
s = (String) mh.invokeWithArguments("sappy", 'p', 'v');
System.out.println("Result: " + s);
// mt is (Object[])List
mt = MethodType.methodType(java.util.List.class, Object[].class);
mh = lookup.findStatic(java.util.Arrays.class, "asList", mt);
assert (mh.isVarargsCollector());
x = mh.invoke("one", "two");
// ArrayList
System.out.println("x: " + x + " type: " + x.getClass().getCanonicalName());
// invoke(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/Object;
// assertEquals(x, java.util.Arrays.asList("one","two"));
// mt is (Object,Object,Object)Object
mt = MethodType.genericMethodType(3);
mh = mh.asType(mt);
x = mh.invokeExact((Object) 1, (Object) 2, (Object) 3);
// invokeExact(Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
// 1,2,3
System.out.println("x: " + x + " type: " + x.getClass().getCanonicalName());
// assertEquals(x, java.util.Arrays.asList(1,2,3));
// mt is ()int
mt = MethodType.methodType(int.class);
mh = lookup.findVirtual(java.util.List.class, "size", mt);
i = (int) mh.invokeExact(java.util.Arrays.asList(1, 2, 3));
// invokeExact(Ljava/util/List;)I
assert (i == 3);
mt = MethodType.methodType(void.class, String.class);
mh = lookup.findVirtual(java.io.PrintStream.class, "println", mt);
mh.invokeExact(System.out, "Hello, world.");
// invokeExact(Ljava/io/PrintStream;Ljava/lang/String;)V
}