com.google.inject.internal.ConstructionContext Maven / Gradle / Ivy
/*
* 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.inject.internal.InjectorImpl.InjectorOptions;
import java.util.ArrayList;
import java.util.List;
/**
* Context of a dependency construction. Used to manage circular references.
*
* @author [email protected] (Bob Lee)
*/
final class ConstructionContext {
T currentReference;
boolean constructing;
List> invocationHandlers;
public T getCurrentReference() {
return currentReference;
}
public void removeCurrentReference() {
this.currentReference = null;
}
public void setCurrentReference(T currentReference) {
this.currentReference = currentReference;
}
public boolean isConstructing() {
return constructing;
}
public void startConstruction() {
this.constructing = true;
}
public void finishConstruction() {
this.constructing = false;
invocationHandlers = null;
}
public Object createProxy(InjectorOptions injectorOptions, Class expectedType)
throws InternalProvisionException {
if (injectorOptions.disableCircularProxies) {
throw InternalProvisionException.circularDependenciesDisabled(expectedType);
}
if (!expectedType.isInterface()) {
throw InternalProvisionException.cannotProxyClass(expectedType);
}
if (invocationHandlers == null) {
invocationHandlers = new ArrayList<>();
}
DelegatingInvocationHandler invocationHandler = new DelegatingInvocationHandler<>();
invocationHandlers.add(invocationHandler);
// TODO: if I create a proxy which implements all the interfaces of
// the implementation type, I'll be able to get away with one proxy
// instance (as opposed to one per caller).
return BytecodeGen.newCircularProxy(expectedType, invocationHandler);
}
public void setProxyDelegates(T delegate) {
if (invocationHandlers != null) {
for (DelegatingInvocationHandler handler : invocationHandlers) {
handler.setDelegate(delegate);
}
// initialization of each handler can happen no more than once
invocationHandlers = null;
}
}
}