/*
 * Copyright (C) 2006 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;

import com.google.common.collect.Lists;
import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import net.sf.cglib.proxy.MethodProxy;
import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;

Intercepts a method with a stack of interceptors.
Author:crazybob@google.com (Bob Lee)
/** * Intercepts a method with a stack of interceptors. * * @author crazybob@google.com (Bob Lee) */
final class InterceptorStackCallback implements net.sf.cglib.proxy.MethodInterceptor { private static final Set<String> AOP_INTERNAL_CLASSES = new HashSet<String>( Arrays.asList( InterceptorStackCallback.class.getName(), InterceptedMethodInvocation.class.getName(), MethodProxy.class.getName())); final MethodInterceptor[] interceptors; final Method method; public InterceptorStackCallback(Method method, List<MethodInterceptor> interceptors) { this.method = method; this.interceptors = interceptors.toArray(new MethodInterceptor[interceptors.size()]); } @Override public Object intercept(Object proxy, Method method, Object[] arguments, MethodProxy methodProxy) throws Throwable { return new InterceptedMethodInvocation(proxy, methodProxy, arguments, 0).proceed(); } private class InterceptedMethodInvocation implements MethodInvocation { final Object proxy; final Object[] arguments; final MethodProxy methodProxy; final int index; public InterceptedMethodInvocation( Object proxy, MethodProxy methodProxy, Object[] arguments, int index) { this.proxy = proxy; this.methodProxy = methodProxy; this.arguments = arguments; this.index = index; } @Override public Object proceed() throws Throwable { try { return index == interceptors.length ? methodProxy.invokeSuper(proxy, arguments) : interceptors[index] .invoke(new InterceptedMethodInvocation(proxy, methodProxy, arguments, index + 1)); } catch (Throwable t) { pruneStacktrace(t); throw t; } } @Override public Method getMethod() { return method; } @Override public Object[] getArguments() { return arguments; } @Override public Object getThis() { return proxy; } @Override public AccessibleObject getStaticPart() { return getMethod(); } }
Removes stacktrace elements related to AOP internal mechanics from the throwable's stack trace and any causes it may have.
/** * Removes stacktrace elements related to AOP internal mechanics from the throwable's stack trace * and any causes it may have. */
private void pruneStacktrace(Throwable throwable) { for (Throwable t = throwable; t != null; t = t.getCause()) { StackTraceElement[] stackTrace = t.getStackTrace(); List<StackTraceElement> pruned = Lists.newArrayList(); for (StackTraceElement element : stackTrace) { String className = element.getClassName(); if (!AOP_INTERNAL_CLASSES.contains(className) && !className.contains("$EnhancerByGuice$")) { pruned.add(element); } } t.setStackTrace(pruned.toArray(new StackTraceElement[pruned.size()])); } } }