| /** |
| * Copyright (C) 2008 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.Binder; |
| import com.google.inject.Injector; |
| import com.google.inject.Key; |
| import com.google.inject.PrivateBinder; |
| import static com.google.inject.internal.Preconditions.checkArgument; |
| import static com.google.inject.internal.Preconditions.checkNotNull; |
| import static com.google.inject.internal.Preconditions.checkState; |
| import com.google.inject.spi.Element; |
| import com.google.inject.spi.ElementVisitor; |
| import com.google.inject.spi.PrivateElements; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| |
| /** |
| * @author jessewilson@google.com (Jesse Wilson) |
| */ |
| public final class PrivateElementsImpl implements PrivateElements { |
| |
| /* |
| * This class acts as both a value object and as a builder. When getElements() is called, an |
| * immutable collection of elements is constructed and the original mutable list is nulled out. |
| * Similarly, the exposed keys are made immutable on access. |
| */ |
| |
| private final Object source; |
| |
| private List<Element> elementsMutable = Lists.newArrayList(); |
| private List<ExposureBuilder<?>> exposureBuilders = Lists.newArrayList(); |
| |
| /** lazily instantiated */ |
| private ImmutableList<Element> elements; |
| |
| /** lazily instantiated */ |
| private ImmutableMap<Key<?>, Object> exposedKeysToSources; |
| private Injector injector; |
| |
| public PrivateElementsImpl(Object source) { |
| this.source = checkNotNull(source, "source"); |
| } |
| |
| public Object getSource() { |
| return source; |
| } |
| |
| public List<Element> getElements() { |
| if (elements == null) { |
| elements = ImmutableList.copyOf(elementsMutable); |
| elementsMutable = null; |
| } |
| |
| return elements; |
| } |
| |
| public Injector getInjector() { |
| return injector; |
| } |
| |
| public void initInjector(Injector injector) { |
| checkState(this.injector == null, "injector already initialized"); |
| this.injector = checkNotNull(injector, "injector"); |
| } |
| |
| public Set<Key<?>> getExposedKeys() { |
| if (exposedKeysToSources == null) { |
| Map<Key<?>, Object> exposedKeysToSourcesMutable = Maps.newLinkedHashMap(); |
| for (ExposureBuilder<?> exposureBuilder : exposureBuilders) { |
| exposedKeysToSourcesMutable.put(exposureBuilder.getKey(), exposureBuilder.getSource()); |
| } |
| exposedKeysToSources = ImmutableMap.copyOf(exposedKeysToSourcesMutable); |
| exposureBuilders = null; |
| } |
| |
| return exposedKeysToSources.keySet(); |
| } |
| |
| public <T> T acceptVisitor(ElementVisitor<T> visitor) { |
| return visitor.visit(this); |
| } |
| |
| public List<Element> getElementsMutable() { |
| return elementsMutable; |
| } |
| |
| public void addExposureBuilder(ExposureBuilder<?> exposureBuilder) { |
| exposureBuilders.add(exposureBuilder); |
| } |
| |
| public void applyTo(Binder binder) { |
| PrivateBinder privateBinder = binder.withSource(source).newPrivateBinder(); |
| |
| for (Element element : getElements()) { |
| element.applyTo(privateBinder); |
| } |
| |
| getExposedKeys(); // ensure exposedKeysToSources is populated |
| for (Map.Entry<Key<?>, Object> entry : exposedKeysToSources.entrySet()) { |
| privateBinder.withSource(entry.getValue()).expose(entry.getKey()); |
| } |
| } |
| |
| public Object getExposedSource(Key<?> key) { |
| getExposedKeys(); // ensure exposedKeysToSources is populated |
| Object source = exposedKeysToSources.get(key); |
| checkArgument(source != null, "%s not exposed by %s.", key, this); |
| return source; |
| } |
| |
| @Override public String toString() { |
| return new ToStringBuilder(PrivateElements.class) |
| .add("exposedKeys", getExposedKeys()) |
| .add("source", getSource()) |
| .toString(); |
| } |
| } |