/*
 * 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.base.Preconditions;
import com.google.common.collect.ImmutableMap;
import com.google.inject.spi.InjectionPoint;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.List;

Produces construction proxies that invoke the class constructor.
Author:crazybob@google.com (Bob Lee)
/** * Produces construction proxies that invoke the class constructor. * * @author crazybob@google.com (Bob Lee) */
final class DefaultConstructionProxyFactory<T> implements ConstructionProxyFactory<T> { private final InjectionPoint injectionPoint;
Params:
  • injectionPoint – an injection point whose member is a constructor of T.
/** @param injectionPoint an injection point whose member is a constructor of {@code T}. */
DefaultConstructionProxyFactory(InjectionPoint injectionPoint) { this.injectionPoint = injectionPoint; } @Override public ConstructionProxy<T> create() { @SuppressWarnings("unchecked") // the injection point is for a constructor of T final Constructor<T> constructor = (Constructor<T>) injectionPoint.getMember(); /*if[AOP]*/ try { net.sf.cglib.reflect.FastClass fc = BytecodeGen.newFastClassForMember(constructor); if (fc != null) { int index = fc.getIndex(constructor.getParameterTypes()); // We could just fall back to reflection in this case but I believe this should actually // be impossible. Preconditions.checkArgument( index >= 0, "Could not find constructor %s in fast class", constructor); return new FastClassProxy<T>(injectionPoint, constructor, fc, index); } } catch (net.sf.cglib.core.CodeGenerationException e) { /* fall-through */ } /*end[AOP]*/ return new ReflectiveProxy<T>(injectionPoint, constructor); } /*if[AOP]*/
A ConstructionProxy that uses FastClass to invoke the constructor.
/** A {@link ConstructionProxy} that uses FastClass to invoke the constructor. */
private static final class FastClassProxy<T> implements ConstructionProxy<T> { final InjectionPoint injectionPoint; final Constructor<T> constructor; final net.sf.cglib.reflect.FastClass fc; final int index; private FastClassProxy( InjectionPoint injectionPoint, Constructor<T> constructor, net.sf.cglib.reflect.FastClass fc, int index) { this.injectionPoint = injectionPoint; this.constructor = constructor; this.fc = fc; this.index = index; } @Override @SuppressWarnings("unchecked") public T newInstance(Object... arguments) throws InvocationTargetException { // Use this method instead of FastConstructor to save a stack frame return (T) fc.newInstance(index, arguments); } @Override public InjectionPoint getInjectionPoint() { return injectionPoint; } @Override public Constructor<T> getConstructor() { return constructor; } @Override public ImmutableMap<Method, List<org.aopalliance.intercept.MethodInterceptor>> getMethodInterceptors() { return ImmutableMap.of(); } } /*end[AOP]*/ private static final class ReflectiveProxy<T> implements ConstructionProxy<T> { final Constructor<T> constructor; final InjectionPoint injectionPoint; ReflectiveProxy(InjectionPoint injectionPoint, Constructor<T> constructor) { if (!Modifier.isPublic(constructor.getDeclaringClass().getModifiers()) || !Modifier.isPublic(constructor.getModifiers())) { constructor.setAccessible(true); } this.injectionPoint = injectionPoint; this.constructor = constructor; } @Override public T newInstance(Object... arguments) throws InvocationTargetException { try { return constructor.newInstance(arguments); } catch (InstantiationException e) { throw new AssertionError(e); // shouldn't happen, we know this is a concrete type } catch (IllegalAccessException e) { throw new AssertionError(e); // a security manager is blocking us, we're hosed } } @Override public InjectionPoint getInjectionPoint() { return injectionPoint; } @Override public Constructor<T> getConstructor() { return constructor; } /*if[AOP]*/ @Override public ImmutableMap<Method, List<org.aopalliance.intercept.MethodInterceptor>> getMethodInterceptors() { return ImmutableMap.of(); } /*end[AOP]*/ } }