| /** |
| * 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; |
| |
| import static com.google.inject.util.Objects.nonNull; |
| import com.google.inject.util.Objects; |
| |
| import java.util.*; |
| |
| /** |
| * Builds a binding. |
| * |
| * @author crazybob@google.com (Bob Lee) |
| */ |
| public class BindingBuilder<T> { |
| |
| final SourceProvider sourceProvider; |
| Key<T> key; |
| Object source; |
| InternalFactory<? extends T> factory; |
| boolean eagerlyLoad = false; |
| |
| /** |
| * Keeps error messages in order and prevents duplicates. |
| */ |
| Set<ErrorMessage> errorMessages = new LinkedHashSet<ErrorMessage>(); |
| |
| /** |
| * Creates a new binding for the given key. |
| */ |
| BindingBuilder(Key<T> key, SourceProvider sourceProvider) { |
| this.key = nonNull(key, "key"); |
| this.sourceProvider = nonNull(sourceProvider, "sourceProvider"); |
| } |
| |
| /** |
| * Specifies that this binding should load as soon as its scope loads. For |
| * example, a singleton will load at startup. |
| */ |
| public BindingBuilder<T> eagerlyLoad() { |
| this.eagerlyLoad = true; |
| return this; |
| } |
| |
| /** |
| * Sets the name of this dependency. |
| */ |
| public BindingBuilder<T> named(String name) { |
| if (!this.key.hasDefaultName()) { |
| errorMessages.add( |
| new ErrorMessage(source, "Name set more than once.")); |
| } |
| |
| this.key = this.key.rename(name); |
| return this; |
| } |
| |
| /** |
| * Sets the implementation to the given class. |
| */ |
| public <I extends T> BindingBuilder<T> to(Class<I> implementation) { |
| ensureImplementationIsNotSet(); |
| this.factory = new DefaultFactory<I>(implementation); |
| return this; |
| } |
| |
| /** |
| * Uses the given factory to create instances of the implementation. |
| */ |
| public BindingBuilder<T> to(final Factory<? extends T> factory) { |
| ensureImplementationIsNotSet(); |
| |
| this.factory = new InternalFactory<T>() { |
| public T create(InternalContext context) { |
| try { |
| Context externalContext = context.getExternalContext(); |
| return factory.create(externalContext); |
| } catch (Exception e) { |
| throw new RuntimeException(e); |
| } |
| } |
| |
| public String toString() { |
| return factory.toString(); |
| } |
| }; |
| |
| return this; |
| } |
| |
| /** |
| * Sets the implementation to the given class. |
| */ |
| public BindingBuilder<T> to(Key<? extends T> implementation) { |
| ensureImplementationIsNotSet(); |
| // this.factory = new DefaultFactory<I>(implementation); |
| return this; |
| } |
| |
| private void ensureImplementationIsNotSet() { |
| if (factory != null) { |
| errorMessages.add( |
| new ErrorMessage(source, "Implementation set more than once.")); |
| } |
| } |
| |
| /** |
| * Specifies the scope. |
| */ |
| public BindingBuilder<T> in(Scope scope) { |
| if (scope != null) { |
| errorMessages.add( |
| new ErrorMessage(source, "Scope set more than once.")); |
| } |
| |
| return this; |
| } |
| |
| /** |
| * Sets the source object. Useful for debugging. Contents may include the |
| * name of the file and the line number this binding came from, a code |
| * snippet, etc. |
| */ |
| public BindingBuilder<T> from(Object source) { |
| this.source = source; |
| return this; |
| } |
| |
| /** |
| * Injects new instances of the specified implementation class. |
| */ |
| private class DefaultFactory<I extends T> implements InternalFactory<I> { |
| |
| volatile ContainerImpl.ConstructorInjector<I> constructor; |
| |
| private final Class<I> implementation; |
| |
| public DefaultFactory(Class<I> implementation) { |
| this.implementation = implementation; |
| } |
| |
| @SuppressWarnings("unchecked") |
| public I create(InternalContext context) { |
| if (constructor == null) { |
| this.constructor = |
| context.getContainerImpl().getConstructor(implementation); |
| } |
| return (I) constructor.construct(context, key.getRawType()); |
| } |
| |
| public String toString() { |
| return implementation.toString(); |
| } |
| } |
| } |