| /* |
| * Copyright (C) 2016 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.collect.ImmutableSet; |
| import com.google.inject.Binder; |
| import com.google.inject.Key; |
| import com.google.inject.Provides; |
| import com.google.inject.TypeLiteral; |
| import com.google.inject.multibindings.MapKey; |
| import com.google.inject.multibindings.ProvidesIntoMap; |
| import com.google.inject.multibindings.ProvidesIntoOptional; |
| import com.google.inject.multibindings.ProvidesIntoSet; |
| import com.google.inject.spi.InjectionPoint; |
| import com.google.inject.spi.ModuleAnnotatedMethodScanner; |
| import java.lang.annotation.Annotation; |
| import java.lang.reflect.InvocationTargetException; |
| import java.lang.reflect.Method; |
| import java.util.Set; |
| |
| /** |
| * A {@link ModuleAnnotatedMethodScanner} that handles the {@Provides}, {@link ProvidesIntoSet}, |
| * {@link ProvidesIntoMap} and {@link ProvidesIntoOptional} annotations. |
| * |
| * <p>This is the default scanner used by ProviderMethodsModule and handles all the built in |
| * annotations. |
| */ |
| final class ProvidesMethodScanner extends ModuleAnnotatedMethodScanner { |
| static final ProvidesMethodScanner INSTANCE = new ProvidesMethodScanner(); |
| private static final ImmutableSet<Class<? extends Annotation>> ANNOTATIONS = |
| ImmutableSet.of( |
| Provides.class, ProvidesIntoSet.class, ProvidesIntoMap.class, ProvidesIntoOptional.class); |
| |
| private ProvidesMethodScanner() {} |
| |
| @Override |
| public Set<? extends Class<? extends Annotation>> annotationClasses() { |
| return ANNOTATIONS; |
| } |
| |
| @SuppressWarnings({"unchecked", "rawtypes"}) // mapKey doesn't know its key type |
| @Override |
| public <T> Key<T> prepareMethod( |
| Binder binder, Annotation annotation, Key<T> key, InjectionPoint injectionPoint) { |
| Method method = (Method) injectionPoint.getMember(); |
| AnnotationOrError mapKey = findMapKeyAnnotation(binder, method); |
| if (annotation instanceof Provides) { |
| if (mapKey.annotation != null) { |
| binder.addError("Found a MapKey annotation on non map binding at %s.", method); |
| } |
| // no key rewriting for plain old @Provides |
| return key; |
| } |
| if (annotation instanceof ProvidesIntoSet) { |
| if (mapKey.annotation != null) { |
| binder.addError("Found a MapKey annotation on non map binding at %s.", method); |
| } |
| return RealMultibinder.newRealSetBinder(binder, key).getKeyForNewItem(); |
| } else if (annotation instanceof ProvidesIntoMap) { |
| if (mapKey.error) { |
| // Already failed on the MapKey, don't bother doing more work. |
| return key; |
| } |
| if (mapKey.annotation == null) { |
| // If no MapKey, make an error and abort. |
| binder.addError("No MapKey found for map binding at %s.", method); |
| return key; |
| } |
| TypeAndValue typeAndValue = typeAndValueOfMapKey(mapKey.annotation); |
| return RealMapBinder.newRealMapBinder(binder, typeAndValue.type, key) |
| .getKeyForNewValue(typeAndValue.value); |
| } else if (annotation instanceof ProvidesIntoOptional) { |
| if (mapKey.annotation != null) { |
| binder.addError("Found a MapKey annotation on non map binding at %s.", method); |
| } |
| switch (((ProvidesIntoOptional) annotation).value()) { |
| case DEFAULT: |
| return RealOptionalBinder.newRealOptionalBinder(binder, key).getKeyForDefaultBinding(); |
| case ACTUAL: |
| return RealOptionalBinder.newRealOptionalBinder(binder, key).getKeyForActualBinding(); |
| } |
| } |
| throw new IllegalStateException("Invalid annotation: " + annotation); |
| } |
| |
| private static class AnnotationOrError { |
| final Annotation annotation; |
| final boolean error; |
| |
| AnnotationOrError(Annotation annotation, boolean error) { |
| this.annotation = annotation; |
| this.error = error; |
| } |
| |
| static AnnotationOrError forPossiblyNullAnnotation(Annotation annotation) { |
| return new AnnotationOrError(annotation, false); |
| } |
| |
| static AnnotationOrError forError() { |
| return new AnnotationOrError(null, true); |
| } |
| } |
| |
| private static AnnotationOrError findMapKeyAnnotation(Binder binder, Method method) { |
| Annotation foundAnnotation = null; |
| for (Annotation annotation : method.getAnnotations()) { |
| MapKey mapKey = annotation.annotationType().getAnnotation(MapKey.class); |
| if (mapKey != null) { |
| if (foundAnnotation != null) { |
| binder.addError("Found more than one MapKey annotations on %s.", method); |
| return AnnotationOrError.forError(); |
| } |
| if (mapKey.unwrapValue()) { |
| try { |
| // validate there's a declared method called "value" |
| Method valueMethod = annotation.annotationType().getDeclaredMethod("value"); |
| if (valueMethod.getReturnType().isArray()) { |
| binder.addError( |
| "Array types are not allowed in a MapKey with unwrapValue=true: %s", |
| annotation.annotationType()); |
| return AnnotationOrError.forError(); |
| } |
| } catch (NoSuchMethodException invalid) { |
| binder.addError( |
| "No 'value' method in MapKey with unwrapValue=true: %s", |
| annotation.annotationType()); |
| return AnnotationOrError.forError(); |
| } |
| } |
| foundAnnotation = annotation; |
| } |
| } |
| return AnnotationOrError.forPossiblyNullAnnotation(foundAnnotation); |
| } |
| |
| @SuppressWarnings({"unchecked", "rawtypes"}) |
| static TypeAndValue<?> typeAndValueOfMapKey(Annotation mapKeyAnnotation) { |
| if (!mapKeyAnnotation.annotationType().getAnnotation(MapKey.class).unwrapValue()) { |
| return new TypeAndValue(TypeLiteral.get(mapKeyAnnotation.annotationType()), mapKeyAnnotation); |
| } else { |
| try { |
| Method valueMethod = mapKeyAnnotation.annotationType().getDeclaredMethod("value"); |
| valueMethod.setAccessible(true); |
| TypeLiteral<?> returnType = |
| TypeLiteral.get(mapKeyAnnotation.annotationType()).getReturnType(valueMethod); |
| return new TypeAndValue(returnType, valueMethod.invoke(mapKeyAnnotation)); |
| } catch (NoSuchMethodException e) { |
| throw new IllegalStateException(e); |
| } catch (SecurityException e) { |
| throw new IllegalStateException(e); |
| } catch (IllegalAccessException e) { |
| throw new IllegalStateException(e); |
| } catch (InvocationTargetException e) { |
| throw new IllegalStateException(e); |
| } |
| } |
| } |
| |
| private static class TypeAndValue<T> { |
| final TypeLiteral<T> type; |
| final T value; |
| |
| TypeAndValue(TypeLiteral<T> type, T value) { |
| this.type = type; |
| this.value = value; |
| } |
| } |
| } |