1/** 2 * Copyright (C) 2008 Google Inc. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17package com.google.inject.internal; 18 19import com.google.inject.Key; 20import com.google.inject.spi.Dependency; 21import com.google.inject.spi.PrivateElements; 22 23/** 24 * This factory exists in a parent injector. When invoked, it retrieves its value from a child 25 * injector. 26 */ 27final class ExposedKeyFactory<T> implements InternalFactory<T>, CreationListener { 28 private final Key<T> key; 29 private final PrivateElements privateElements; 30 private BindingImpl<T> delegate; 31 32 ExposedKeyFactory(Key<T> key, PrivateElements privateElements) { 33 this.key = key; 34 this.privateElements = privateElements; 35 } 36 37 public void notify(Errors errors) { 38 InjectorImpl privateInjector = (InjectorImpl) privateElements.getInjector(); 39 BindingImpl<T> explicitBinding = privateInjector.state.getExplicitBinding(key); 40 41 // validate that the child injector has its own factory. If the getInternalFactory() returns 42 // this, then that child injector doesn't have a factory (and getExplicitBinding has returned 43 // its parent's binding instead 44 if (explicitBinding.getInternalFactory() == this) { 45 errors.withSource(explicitBinding.getSource()).exposedButNotBound(key); 46 return; 47 } 48 49 this.delegate = explicitBinding; 50 } 51 52 public T get(Errors errors, InternalContext context, Dependency<?> dependency, boolean linked) 53 throws ErrorsException { 54 return delegate.getInternalFactory().get(errors, context, dependency, linked); 55 } 56} 57