/** | |
* Copyright (C) 2011 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 static com.google.inject.internal.util.Preconditions.checkNotNull; | |
import javax.inject.Provider; | |
import com.google.inject.spi.Dependency; | |
/** | |
* Base class for InternalFactories that are used by Providers, to handle | |
* circular dependencies. | |
* | |
* @author sameb@google.com (Sam Berlin) | |
*/ | |
abstract class ProviderInternalFactory<T> implements InternalFactory<T> { | |
protected final Object source; | |
private final boolean allowProxy; | |
ProviderInternalFactory(Object source, boolean allowProxy) { | |
this.source = checkNotNull(source, "source"); | |
this.allowProxy = allowProxy; | |
} | |
protected T circularGet(Provider<? extends T> provider, Errors errors, | |
InternalContext context, Dependency<?> dependency, boolean linked) | |
throws ErrorsException { | |
Class<?> expectedType = dependency.getKey().getTypeLiteral().getRawType(); | |
// we do not use 'this' as the key because for JIT provider bindings, | |
// 'this' is recreated on failures... the key suffices. | |
ConstructionContext<T> constructionContext = context.getConstructionContext(dependency.getKey()); | |
// We have a circular reference between constructors. Return a proxy. | |
if (constructionContext.isConstructing()) { | |
if (!allowProxy) { | |
throw errors.circularProxiesDisabled(expectedType).toException(); | |
} else { | |
// TODO: if we can't proxy this object, can we proxy the other object? | |
@SuppressWarnings("unchecked") | |
T proxyType = (T) constructionContext.createProxy(errors, expectedType); | |
return proxyType; | |
} | |
} | |
// First time through... | |
constructionContext.startConstruction(); | |
try { | |
T t = errors.checkForNull(provider.get(), source, dependency); | |
constructionContext.setProxyDelegates(t); | |
return t; | |
} finally { | |
constructionContext.finishConstruction(); | |
} | |
} | |
} |