com.google.inject.internal.aop.AnonymousClassDefiner Maven / Gradle / Ivy
/*
* Copyright (C) 2021 Google Inc.
*
* 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.
*/
package com.google.inject.internal.aop;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
/**
* {@link ClassDefiner} that defines classes using {@code sun.misc.Unsafe#defineAnonymousClass}.
*
* @author [email protected] (Stuart McCulloch)
*/
final class AnonymousClassDefiner implements ClassDefiner {
private static final Object THE_UNSAFE;
private static final Method ANONYMOUS_DEFINE_METHOD;
static {
try {
Class unsafeType = Class.forName("sun.misc.Unsafe");
Field theUnsafeField = unsafeType.getDeclaredField("theUnsafe");
theUnsafeField.setAccessible(true);
THE_UNSAFE = theUnsafeField.get(null);
ANONYMOUS_DEFINE_METHOD =
unsafeType.getMethod("defineAnonymousClass", Class.class, byte[].class, Object[].class);
} catch (ReflectiveOperationException e) {
throw new ExceptionInInitializerError(e);
}
}
@Override
public Class define(Class hostClass, byte[] bytecode) throws Exception {
return (Class) ANONYMOUS_DEFINE_METHOD.invoke(THE_UNSAFE, hostClass, bytecode, null);
}
}