| /** |
| * 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 org.apache.aurora.common.inject; |
| |
| import java.lang.annotation.Annotation; |
| |
| import javax.inject.Qualifier; |
| |
| import com.google.common.base.Preconditions; |
| import com.google.common.collect.ImmutableList; |
| import com.google.inject.AbstractModule; |
| import com.google.inject.Binder; |
| import com.google.inject.BindingAnnotation; |
| import com.google.inject.Key; |
| import com.google.inject.Module; |
| import com.google.inject.PrivateModule; |
| import com.google.inject.TypeLiteral; |
| |
| /** |
| * A utility that helps with guice bindings. |
| * |
| * @author John Sirois |
| */ |
| public final class Bindings { |
| |
| |
| private Bindings() { |
| // utility |
| } |
| |
| /** |
| * Equivalent to calling {@code requireBinding(binder, Key.get(required))}. |
| */ |
| public static void requireBinding(Binder binder, Class<?> required) { |
| requireBinding(binder, Key.get(Preconditions.checkNotNull(required))); |
| } |
| |
| /** |
| * Registers {@code required} as non-optional dependency in the {@link com.google.inject.Injector} |
| * associated with {@code binder}. |
| * |
| * @param binder A binder to require bindings against. |
| * @param required The dependency that is required. |
| */ |
| public static void requireBinding(Binder binder, final Key<?> required) { |
| Preconditions.checkNotNull(binder); |
| Preconditions.checkNotNull(required); |
| |
| binder.install(new AbstractModule() { |
| @Override protected void configure() { |
| requireBinding(required); |
| } |
| }); |
| } |
| |
| /** |
| * A convenient version of {@link #exposing(Iterable, com.google.inject.Module)} when you just |
| * want to expose a single binding. |
| */ |
| public static Module exposing(Key<?> key, Module module) { |
| return exposing(ImmutableList.of(key), module); |
| } |
| |
| /** |
| * Creates a module that hides all the given module's bindings and only exposes bindings for |
| * the given key. |
| * |
| * @param keys The keys of the bindings to expose. |
| * @param module The module to hide most bindings for. |
| * @return A limited visibility module. |
| */ |
| public static Module exposing(final Iterable<? extends Key<?>> keys, final Module module) { |
| Preconditions.checkNotNull(keys); |
| Preconditions.checkNotNull(module); |
| |
| return new PrivateModule() { |
| @Override protected void configure() { |
| install(module); |
| for (Key<?> key : keys) { |
| expose(key); |
| } |
| } |
| }; |
| } |
| |
| /** |
| * Checks that the given annotation type is a {@link BindingAnnotation @BindingAnnotation}. |
| * |
| * @param annotationType The annotation type to check. |
| * @param <T> The type of the binding annotation. |
| * @return The checked binding annotation type. |
| * @throws NullPointerException If the given {@code annotationType} is null. |
| * @throws IllegalArgumentException If the given {@code annotationType} is not a |
| * {@literal @BindingAnnotation}. |
| */ |
| public static <T extends Annotation> Class<T> checkBindingAnnotation(Class<T> annotationType) { |
| Preconditions.checkNotNull(annotationType); |
| boolean bindingAnnotation = annotationType.isAnnotationPresent(BindingAnnotation.class); |
| boolean qualifier = annotationType.isAnnotationPresent(Qualifier.class); |
| Preconditions.checkArgument(bindingAnnotation || qualifier, |
| "%s is not a @BindingAnnotation or @Qualifier", annotationType); |
| return annotationType; |
| } |
| |
| /** |
| * A factory for binding {@link Key keys}. |
| */ |
| public interface KeyFactory { |
| |
| /** |
| * Creates plain un-annotated keys. |
| */ |
| KeyFactory PLAIN = new KeyFactory() { |
| @Override public <T> Key<T> create(Class<T> type) { |
| return Key.get(type); |
| } |
| @Override public <T> Key<T> create(TypeLiteral<T> type) { |
| return Key.get(type); |
| } |
| }; |
| |
| /** |
| * Creates a key for the given type. |
| * |
| * @param type The type to create a key for. |
| * @param <T> The keyed type. |
| * @return A key. |
| */ |
| <T> Key<T> create(Class<T> type); |
| |
| /** |
| * Creates a key for the given type. |
| * |
| * @param type The type to create a key for. |
| * @param <T> The keyed type. |
| * @return A key. |
| */ |
| <T> Key<T> create(TypeLiteral<T> type); |
| } |
| |
| /** |
| * Creates a key factory that produces keys for a given annotation type. |
| * |
| * @param annotationType The annotation type to apply to all keys. |
| * @return A key factory that creates annotated keys. |
| */ |
| public static KeyFactory annotatedKeyFactory(final Class<? extends Annotation> annotationType) { |
| checkBindingAnnotation(annotationType); |
| return new KeyFactory() { |
| @Override public <T> Key<T> create(Class<T> type) { |
| return Key.get(type, annotationType); |
| } |
| @Override public <T> Key<T> create(TypeLiteral<T> type) { |
| return Key.get(type, annotationType); |
| } |
| }; |
| } |
| } |