| /** |
| * 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.common.base.Function; |
| import com.google.common.base.Joiner; |
| import com.google.common.base.Joiner.MapJoiner; |
| import com.google.common.base.Preconditions; |
| import com.google.common.collect.ImmutableMap; |
| import com.google.common.collect.MapMaker; |
| import com.google.common.collect.Maps; |
| import com.google.inject.BindingAnnotation; |
| import com.google.inject.Key; |
| import com.google.inject.ScopeAnnotation; |
| import com.google.inject.TypeLiteral; |
| import com.google.inject.internal.util.Classes; |
| import com.google.inject.name.Named; |
| import com.google.inject.name.Names; |
| |
| import java.lang.annotation.Annotation; |
| import java.lang.annotation.Retention; |
| import java.lang.annotation.RetentionPolicy; |
| import java.lang.reflect.InvocationHandler; |
| import java.lang.reflect.Member; |
| import java.lang.reflect.Method; |
| import java.lang.reflect.Proxy; |
| import java.util.Arrays; |
| import java.util.Collection; |
| import java.util.Map; |
| |
| import javax.inject.Qualifier; |
| |
| /** |
| * Annotation utilities. |
| * |
| * @author crazybob@google.com (Bob Lee) |
| */ |
| public class Annotations { |
| |
| /** |
| * Returns {@code true} if the given annotation type has no attributes. |
| */ |
| public static boolean isMarker(Class<? extends Annotation> annotationType) { |
| return annotationType.getDeclaredMethods().length == 0; |
| } |
| |
| public static boolean isAllDefaultMethods(Class<? extends Annotation> annotationType) { |
| boolean hasMethods = false; |
| for (Method m : annotationType.getDeclaredMethods()) { |
| hasMethods = true; |
| if (m.getDefaultValue() == null) { |
| return false; |
| } |
| } |
| return hasMethods; |
| } |
| |
| private static final Map<Class<? extends Annotation>, Annotation> cache = |
| new MapMaker().weakKeys().makeComputingMap( |
| new Function<Class<? extends Annotation>, Annotation>() { |
| @Override |
| public Annotation apply(Class<? extends Annotation> input) { |
| return generateAnnotationImpl(input); |
| } |
| }); |
| |
| /** |
| * Generates an Annotation for the annotation class. Requires that the annotation is all |
| * optionals. |
| */ |
| public static <T extends Annotation> T generateAnnotation(Class<T> annotationType) { |
| Preconditions.checkState( |
| isAllDefaultMethods(annotationType), "%s is not all default methods", annotationType); |
| return (T)cache.get(annotationType); |
| } |
| |
| private static <T extends Annotation> T generateAnnotationImpl(final Class<T> annotationType) { |
| final Map<String, Object> members = resolveMembers(annotationType); |
| return annotationType.cast(Proxy.newProxyInstance( |
| annotationType.getClassLoader(), |
| new Class<?>[] { annotationType }, |
| new InvocationHandler() { |
| @Override |
| public Object invoke(Object proxy, Method method, Object[] args) throws Exception { |
| String name = method.getName(); |
| if (name.equals("annotationType")) { |
| return annotationType; |
| } else if (name.equals("toString")) { |
| return annotationToString(annotationType, members); |
| } else if (name.equals("hashCode")) { |
| return annotationHashCode(annotationType, members); |
| } else if (name.equals("equals")) { |
| return annotationEquals(annotationType, members, args[0]); |
| } else { |
| return members.get(name); |
| } |
| } |
| })); |
| } |
| |
| private static ImmutableMap<String, Object> resolveMembers( |
| Class<? extends Annotation> annotationType) { |
| ImmutableMap.Builder<String, Object> result = ImmutableMap.builder(); |
| for (Method method : annotationType.getDeclaredMethods()) { |
| result.put(method.getName(), method.getDefaultValue()); |
| } |
| return result.build(); |
| } |
| |
| /** Implements {@link Annotation#equals}. */ |
| private static boolean annotationEquals(Class<? extends Annotation> type, |
| Map<String, Object> members, Object other) throws Exception { |
| if (!type.isInstance(other)) { |
| return false; |
| } |
| for (Method method : type.getDeclaredMethods()) { |
| String name = method.getName(); |
| if (!Arrays.deepEquals( |
| new Object[] {method.invoke(other)}, new Object[] {members.get(name)})) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** Implements {@link Annotation#hashCode}. */ |
| private static int annotationHashCode(Class<? extends Annotation> type, |
| Map<String, Object> members) throws Exception { |
| int result = 0; |
| for (Method method : type.getDeclaredMethods()) { |
| String name = method.getName(); |
| Object value = members.get(name); |
| result += (127 * name.hashCode()) ^ (Arrays.deepHashCode(new Object[] {value}) - 31); |
| } |
| return result; |
| } |
| |
| private static final MapJoiner JOINER = Joiner.on(", ").withKeyValueSeparator("="); |
| |
| private static final Function<Object, String> DEEP_TO_STRING_FN = new Function<Object, String>() { |
| @Override |
| public String apply(Object arg) { |
| String s = Arrays.deepToString(new Object[] {arg}); |
| return s.substring(1, s.length() - 1); // cut off brackets |
| } |
| }; |
| |
| /** Implements {@link Annotation#toString}. */ |
| private static String annotationToString(Class<? extends Annotation> type, |
| Map<String, Object> members) throws Exception { |
| StringBuilder sb = new StringBuilder().append("@").append(type.getName()).append("("); |
| JOINER.appendTo(sb, Maps.transformValues(members, DEEP_TO_STRING_FN)); |
| return sb.append(")").toString(); |
| } |
| |
| /** |
| * Returns true if the given annotation is retained at runtime. |
| */ |
| public static boolean isRetainedAtRuntime(Class<? extends Annotation> annotationType) { |
| Retention retention = annotationType.getAnnotation(Retention.class); |
| return retention != null && retention.value() == RetentionPolicy.RUNTIME; |
| } |
| |
| /** Returns the scope annotation on {@code type}, or null if none is specified. */ |
| public static Class<? extends Annotation> findScopeAnnotation( |
| Errors errors, Class<?> implementation) { |
| return findScopeAnnotation(errors, implementation.getAnnotations()); |
| } |
| |
| /** Returns the scoping annotation, or null if there isn't one. */ |
| public static Class<? extends Annotation> findScopeAnnotation(Errors errors, Annotation[] annotations) { |
| Class<? extends Annotation> found = null; |
| |
| for (Annotation annotation : annotations) { |
| Class<? extends Annotation> annotationType = annotation.annotationType(); |
| if (isScopeAnnotation(annotationType)) { |
| if (found != null) { |
| errors.duplicateScopeAnnotations(found, annotationType); |
| } else { |
| found = annotationType; |
| } |
| } |
| } |
| |
| return found; |
| } |
| |
| /** |
| * Checks for the presence of annotations. Caches results because Android doesn't. |
| */ |
| static class AnnotationChecker { |
| private final Collection<Class<? extends Annotation>> annotationTypes; |
| |
| /** Returns true if the given class has one of the desired annotations. */ |
| private Function<Class<? extends Annotation>, Boolean> hasAnnotations = |
| new Function<Class<? extends Annotation>, Boolean>() { |
| public Boolean apply(Class<? extends Annotation> annotationType) { |
| for (Annotation annotation : annotationType.getAnnotations()) { |
| if (annotationTypes.contains(annotation.annotationType())) { |
| return true; |
| } |
| } |
| return false; |
| } |
| }; |
| |
| final Map<Class<? extends Annotation>, Boolean> cache = new MapMaker().weakKeys() |
| .makeComputingMap(hasAnnotations); |
| |
| /** |
| * Constructs a new checker that looks for annotations of the given types. |
| */ |
| AnnotationChecker(Collection<Class<? extends Annotation>> annotationTypes) { |
| this.annotationTypes = annotationTypes; |
| } |
| |
| /** |
| * Returns true if the given type has one of the desired annotations. |
| */ |
| boolean hasAnnotations(Class<? extends Annotation> annotated) { |
| return cache.get(annotated); |
| } |
| } |
| |
| private static final AnnotationChecker scopeChecker = new AnnotationChecker( |
| Arrays.asList(ScopeAnnotation.class, javax.inject.Scope.class)); |
| |
| public static boolean isScopeAnnotation(Class<? extends Annotation> annotationType) { |
| return scopeChecker.hasAnnotations(annotationType); |
| } |
| |
| /** |
| * Adds an error if there is a misplaced annotations on {@code type}. Scoping |
| * annotations are not allowed on abstract classes or interfaces. |
| */ |
| public static void checkForMisplacedScopeAnnotations( |
| Class<?> type, Object source, Errors errors) { |
| if (Classes.isConcrete(type)) { |
| return; |
| } |
| |
| Class<? extends Annotation> scopeAnnotation = findScopeAnnotation(errors, type); |
| if (scopeAnnotation != null) { |
| errors.withSource(type).scopeAnnotationOnAbstractType(scopeAnnotation, type, source); |
| } |
| } |
| |
| /** Gets a key for the given type, member and annotations. */ |
| public static Key<?> getKey(TypeLiteral<?> type, Member member, Annotation[] annotations, |
| Errors errors) throws ErrorsException { |
| int numErrorsBefore = errors.size(); |
| Annotation found = findBindingAnnotation(errors, member, annotations); |
| errors.throwIfNewErrors(numErrorsBefore); |
| return found == null ? Key.get(type) : Key.get(type, found); |
| } |
| |
| /** |
| * Returns the binding annotation on {@code member}, or null if there isn't one. |
| */ |
| public static Annotation findBindingAnnotation( |
| Errors errors, Member member, Annotation[] annotations) { |
| Annotation found = null; |
| |
| for (Annotation annotation : annotations) { |
| Class<? extends Annotation> annotationType = annotation.annotationType(); |
| if (isBindingAnnotation(annotationType)) { |
| if (found != null) { |
| errors.duplicateBindingAnnotations(member, found.annotationType(), annotationType); |
| } else { |
| found = annotation; |
| } |
| } |
| } |
| |
| return found; |
| } |
| |
| private static final AnnotationChecker bindingAnnotationChecker = new AnnotationChecker( |
| Arrays.asList(BindingAnnotation.class, Qualifier.class)); |
| |
| /** |
| * Returns true if annotations of the specified type are binding annotations. |
| */ |
| public static boolean isBindingAnnotation(Class<? extends Annotation> annotationType) { |
| return bindingAnnotationChecker.hasAnnotations(annotationType); |
| } |
| |
| /** |
| * If the annotation is an instance of {@code javax.inject.Named}, canonicalizes to |
| * com.google.guice.name.Named. Returns the given annotation otherwise. |
| */ |
| public static Annotation canonicalizeIfNamed(Annotation annotation) { |
| if(annotation instanceof javax.inject.Named) { |
| return Names.named(((javax.inject.Named)annotation).value()); |
| } else { |
| return annotation; |
| } |
| } |
| |
| /** |
| * If the annotation is the class {@code javax.inject.Named}, canonicalizes to |
| * com.google.guice.name.Named. Returns the given annotation class otherwise. |
| */ |
| public static Class<? extends Annotation> canonicalizeIfNamed( |
| Class<? extends Annotation> annotationType) { |
| if (annotationType == javax.inject.Named.class) { |
| return Named.class; |
| } else { |
| return annotationType; |
| } |
| } |
| } |