/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.lang.reflect.*;
import java.util.Arrays;
class NarrowingTest {
interface I1 {
public Object foo();
}
interface I2 extends I1 {
// Note that this method declaration narrows the return type.
@Override
public String foo();
}
public static void main(String[] args) {
I2 proxy = (I2) Proxy.newProxyInstance(NarrowingTest.class.getClassLoader(),
new Class<?>[] { I2.class },
new InvocationHandler() {
int count = 0;
@Override
public Object invoke(Object proxy, Method method,
Object[] args) throws Throwable {
System.out.println("Invocation of " + method);
if (count == 0) {
count++;
return "hello";
} else {
return Integer.valueOf(1);
}
}
});
Main.registerProxyClassName(proxy.getClass().getCanonicalName());
Method[] methods = proxy.getClass().getDeclaredMethods();
System.out.println("Proxy methods: " +
Main.replaceProxyClassNamesForOutput(Arrays.deepToString(methods)));
System.out.println("Invoking foo using I2 type: " + proxy.foo());
I1 proxyAsParent = proxy;
System.out.println("Invoking foo using I1 type: " + proxyAsParent.foo());
try {
proxy.foo();
System.out.println("Didn't get expected exception");
} catch (ClassCastException e) {
// With an I2 invocation returning an integer is an exception.
System.out.println("Got expected exception");
}
System.out.println("Proxy narrowed invocation return type passed");
}
}