| /** |
| * Copyright (C) 2009 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.spi; |
| |
| import com.google.inject.Binder; |
| import com.google.inject.MembersInjector; |
| import com.google.inject.TypeLiteral; |
| import static com.google.inject.internal.util.Preconditions.checkNotNull; |
| import static com.google.inject.internal.util.Preconditions.checkState; |
| |
| /** |
| * A lookup of the members injector for a type. Lookups are created explicitly in a module using |
| * {@link com.google.inject.Binder#getMembersInjector(Class) getMembersInjector()} statements: |
| * <pre> |
| * MembersInjector<PaymentService> membersInjector |
| * = getMembersInjector(PaymentService.class);</pre> |
| * |
| * @author crazybob@google.com (Bob Lee) |
| * @since 2.0 |
| */ |
| public final class MembersInjectorLookup<T> implements Element { |
| |
| private final Object source; |
| private final TypeLiteral<T> type; |
| private MembersInjector<T> delegate; |
| |
| public MembersInjectorLookup(Object source, TypeLiteral<T> type) { |
| this.source = checkNotNull(source, "source"); |
| this.type = checkNotNull(type, "type"); |
| } |
| |
| public Object getSource() { |
| return source; |
| } |
| |
| /** |
| * Gets the type containing the members to be injected. |
| */ |
| public TypeLiteral<T> getType() { |
| return type; |
| } |
| |
| public <T> T acceptVisitor(ElementVisitor<T> visitor) { |
| return visitor.visit(this); |
| } |
| |
| /** |
| * Sets the actual members injector. |
| * |
| * @throws IllegalStateException if the delegate is already set |
| */ |
| public void initializeDelegate(MembersInjector<T> delegate) { |
| checkState(this.delegate == null, "delegate already initialized"); |
| this.delegate = checkNotNull(delegate, "delegate"); |
| } |
| |
| public void applyTo(Binder binder) { |
| initializeDelegate(binder.withSource(getSource()).getMembersInjector(type)); |
| } |
| |
| /** |
| * Returns the delegate members injector, or {@code null} if it has not yet been initialized. |
| * The delegate will be initialized when this element is processed, or otherwise used to create |
| * an injector. |
| */ |
| public MembersInjector<T> getDelegate() { |
| return delegate; |
| } |
| |
| /** |
| * Returns the looked up members injector. The result is not valid until this lookup has been |
| * initialized, which usually happens when the injector is created. The members injector will |
| * throw an {@code IllegalStateException} if you try to use it beforehand. |
| */ |
| public MembersInjector<T> getMembersInjector() { |
| return new MembersInjector<T>() { |
| public void injectMembers(T instance) { |
| checkState(delegate != null, |
| "This MembersInjector cannot be used until the Injector has been created."); |
| delegate.injectMembers(instance); |
| } |
| |
| @Override public String toString() { |
| return "MembersInjector<" + type + ">"; |
| } |
| }; |
| } |
| } |