| /** |
| * 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 com.google.inject.util.ReferenceCache; |
| import com.google.inject.util.Strings; |
| |
| import net.sf.cglib.reflect.FastMethod; |
| import net.sf.cglib.reflect.FastClass; |
| import net.sf.cglib.reflect.FastConstructor; |
| |
| import java.lang.annotation.Annotation; |
| import java.lang.reflect.AccessibleObject; |
| import java.lang.reflect.AnnotatedElement; |
| import java.lang.reflect.Constructor; |
| import java.lang.reflect.Field; |
| import java.lang.reflect.InvocationTargetException; |
| import java.lang.reflect.Member; |
| import java.lang.reflect.Method; |
| import java.lang.reflect.Modifier; |
| import java.lang.reflect.Type; |
| import java.lang.reflect.ParameterizedType; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.HashMap; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Collections; |
| |
| /** |
| * Default {@link Container} implementation. |
| * |
| * @see ContainerBuilder |
| * @author crazybob@google.com (Bob Lee) |
| */ |
| class ContainerImpl implements Container { |
| |
| /** |
| * Maps between primitive types and their wrappers and vice versa. |
| */ |
| private static final Map<Class<?>, Class<?>> PRIMITIVE_COUNTERPARTS; |
| static { |
| Map<Class<?>, Class<?>> primitiveToWrapper = |
| new HashMap<Class<?>, Class<?>>() {{ |
| put(int.class, Integer.class); |
| put(long.class, Long.class); |
| put(boolean.class, Boolean.class); |
| put(byte.class, Byte.class); |
| put(short.class, Short.class); |
| put(float.class, Float.class); |
| put(double.class, Double.class); |
| put(char.class, Character.class); |
| }}; |
| |
| Map<Class<?>, Class<?>> counterparts = new HashMap<Class<?>, Class<?>>(); |
| for (Map.Entry<Class<?>, Class<?>> entry : primitiveToWrapper.entrySet()) { |
| Class<?> key = entry.getKey(); |
| Class<?> value = entry.getValue(); |
| counterparts.put(key, value); |
| counterparts.put(value, key); |
| } |
| |
| PRIMITIVE_COUNTERPARTS = Collections.unmodifiableMap(counterparts); |
| } |
| |
| private static final Map<Class<?>, Converter<?>> PRIMITIVE_CONVERTERS = |
| new PrimitiveConverters(); |
| |
| final Map<Key<?>, InternalFactory<?>> factories; |
| |
| ContainerImpl(Map<Key<?>, InternalFactory<?>> factories) { |
| this.factories = factories; |
| } |
| |
| @SuppressWarnings("unchecked") |
| <T> InternalFactory<? extends T> getFactory(Member member, Key<T> key) { |
| // Do we have a factory for the specified type and name? |
| InternalFactory<T> internalFactory = |
| (InternalFactory<T>) factories.get(key); |
| if (internalFactory != null) { |
| return internalFactory; |
| } |
| |
| // Handle cases where T is a Factory<?>. |
| if (key.getTypeToken().getRawType().equals(Factory.class)) { |
| Type factoryType = key.getTypeToken().getType(); |
| if (!(factoryType instanceof ParameterizedType)) { |
| return null; |
| } |
| Type entryType = |
| ((ParameterizedType) factoryType).getActualTypeArguments()[0]; |
| |
| // This can throw ConfigurationException. |
| final Factory<?> factory = getFactory(Key.get(entryType, key.getName())); |
| return new InternalFactory<T>() { |
| @SuppressWarnings({"unchecked"}) |
| public T get(InternalContext context) { |
| return (T) factory; |
| } |
| }; |
| } |
| |
| // Auto[un]box primitives. |
| Class<?> primitiveCounterpart = |
| PRIMITIVE_COUNTERPARTS.get(key.getTypeToken().getRawType()); |
| if (primitiveCounterpart != null) { |
| internalFactory = (InternalFactory<T>) factories.get( |
| Key.get(primitiveCounterpart, key.getName())); |
| if (internalFactory != null) { |
| return internalFactory; |
| } |
| } |
| |
| // Do we have a constant String factory of the same name? |
| InternalFactory<String> stringFactory = |
| (InternalFactory<String>) factories.get( |
| Key.get(String.class, key.getName())); |
| if (stringFactory == null |
| || !(stringFactory instanceof ConstantFactory)) { |
| return null; |
| } |
| |
| Class<?> type = key.getRawType(); |
| |
| // We don't need do pass in an InternalContext because we know this is |
| // a ConstantFactory which will not use it. |
| String value = stringFactory.get(null); |
| |
| // TODO: Generalize everything below here and enable users to plug in |
| // their own converters. |
| |
| // Do we need a primitive? |
| Converter<T> converter = (Converter<T>) PRIMITIVE_CONVERTERS.get(type); |
| if (converter != null) { |
| return new ConstantFactory<T>(converter.convert(member, key, value)); |
| } |
| |
| // Do we need an enum? |
| if (Enum.class.isAssignableFrom(type)) { |
| T t = null; |
| try { |
| t = (T) Enum.valueOf((Class) type, value); |
| } catch (IllegalArgumentException e) { |
| throw new ConstantConversionException(member, key, value, e); |
| } |
| return new ConstantFactory<T>(t); |
| } |
| |
| // Do we need a class? |
| if (type == Class.class) { |
| try { |
| return new ConstantFactory<T>((T) Class.forName(value)); |
| } catch (ClassNotFoundException e) { |
| throw new ConstantConversionException(member, key, value, e); |
| } |
| } |
| |
| return null; |
| } |
| |
| boolean isConstantType(Class<?> type) { |
| return PRIMITIVE_CONVERTERS.containsKey(type) |
| || Enum.class.isAssignableFrom(type) |
| || type == Class.class; |
| } |
| |
| /** |
| * Field and method injectors. |
| */ |
| final Map<Class<?>, List<Injector>> injectors = |
| new ReferenceCache<Class<?>, List<Injector>>() { |
| protected List<Injector> create(Class<?> key) { |
| List<Injector> injectors = new ArrayList<Injector>(); |
| addInjectors(key, injectors); |
| return injectors; |
| } |
| }; |
| |
| /** |
| * Recursively adds injectors for fields and methods from the given class to |
| * the given list. Injects parent classes before sub classes. |
| */ |
| void addInjectors(Class clazz, List<Injector> injectors) { |
| if (clazz == Object.class) { |
| return; |
| } |
| |
| // Add injectors for superclass first. |
| addInjectors(clazz.getSuperclass(), injectors); |
| |
| // TODO (crazybob): Filter out overridden members. |
| addInjectorsForFields(clazz.getDeclaredFields(), false, injectors); |
| addInjectorsForMethods(clazz.getDeclaredMethods(), false, injectors); |
| } |
| |
| void injectStatics(List<Class<?>> staticInjections) { |
| final List<Injector> injectors = new ArrayList<Injector>(); |
| |
| for (Class<?> clazz : staticInjections) { |
| addInjectorsForFields(clazz.getDeclaredFields(), true, injectors); |
| addInjectorsForMethods(clazz.getDeclaredMethods(), true, injectors); |
| } |
| |
| callInContext(new ContextualCallable<Void>() { |
| public Void call(InternalContext context) { |
| for (Injector injector : injectors) { |
| injector.inject(context, null); |
| } |
| return null; |
| } |
| }); |
| } |
| |
| void addInjectorsForMethods(Method[] methods, boolean statics, |
| List<Injector> injectors) { |
| addInjectorsForMembers(Arrays.asList(methods), statics, injectors, |
| new InjectorFactory<Method>() { |
| public Injector create(ContainerImpl container, Method method, |
| String name) throws MissingDependencyException { |
| return new MethodInjector(container, method, name); |
| } |
| }); |
| } |
| |
| void addInjectorsForFields(Field[] fields, boolean statics, |
| List<Injector> injectors) { |
| addInjectorsForMembers(Arrays.asList(fields), statics, injectors, |
| new InjectorFactory<Field>() { |
| public Injector create(ContainerImpl container, Field field, |
| String name) throws MissingDependencyException { |
| return new FieldInjector(container, field, name); |
| } |
| }); |
| } |
| |
| <M extends Member & AnnotatedElement> void addInjectorsForMembers( |
| List<M> members, boolean statics, List<Injector> injectors, |
| InjectorFactory<M> injectorFactory) { |
| for (M member : members) { |
| if (isStatic(member) == statics) { |
| Inject inject = member.getAnnotation(Inject.class); |
| if (inject != null) { |
| try { |
| injectors.add(injectorFactory.create(this, member, inject.value())); |
| } catch (MissingDependencyException e) { |
| if (inject.required()) { |
| throw new ConfigurationException(e); |
| } |
| } |
| } |
| } |
| } |
| } |
| |
| interface InjectorFactory<M extends Member & AnnotatedElement> { |
| Injector create(ContainerImpl container, M member, String name) |
| throws MissingDependencyException; |
| } |
| |
| private boolean isStatic(Member member) { |
| return Modifier.isStatic(member.getModifiers()); |
| } |
| |
| static class FieldInjector implements Injector { |
| |
| final Field field; |
| final InternalFactory<?> factory; |
| final ExternalContext<?> externalContext; |
| |
| public FieldInjector(ContainerImpl container, Field field, String name) |
| throws MissingDependencyException { |
| this.field = field; |
| field.setAccessible(true); |
| |
| Key<?> key = Key.get(field.getGenericType(), name); |
| factory = container.getFactory(field, key); |
| if (factory == null) { |
| throw new MissingDependencyException( |
| "No mapping found for dependency " + key + " for field: " |
| + field); |
| } |
| |
| this.externalContext = ExternalContext.newInstance(field, key, container); |
| } |
| |
| public void inject(InternalContext context, Object o) { |
| ExternalContext<?> previous = context.getExternalContext(); |
| context.setExternalContext(externalContext); |
| try { |
| field.set(o, factory.get(context)); |
| } catch (IllegalAccessException e) { |
| throw new AssertionError(e); |
| } finally { |
| context.setExternalContext(previous); |
| } |
| } |
| } |
| |
| /** |
| * Gets parameter injectors. |
| * |
| * @param member to which the parameters belong |
| * @param annotations on the parameters |
| * @param parameterTypes parameter types |
| * @return injections |
| */ |
| <M extends AccessibleObject & Member> ParameterInjector<?>[] |
| getParametersInjectors(M member, |
| Annotation[][] annotations, Type[] parameterTypes, String defaultName) |
| throws MissingDependencyException { |
| List<ParameterInjector<?>> parameterInjectors = |
| new ArrayList<ParameterInjector<?>>(); |
| |
| Iterator<Annotation[]> annotationsIterator = |
| Arrays.asList(annotations).iterator(); |
| for (Type parameterType : parameterTypes) { |
| Inject annotation = findInject(annotationsIterator.next()); |
| String name = annotation == null ? defaultName : annotation.value(); |
| Key<?> key = Key.get(parameterType, name); |
| parameterInjectors.add(createParameterInjector(key, member)); |
| } |
| |
| return toArray(parameterInjectors); |
| } |
| |
| <T> ParameterInjector<T> createParameterInjector( |
| Key<T> key, Member member) throws MissingDependencyException { |
| InternalFactory<? extends T> factory = getFactory(member, key); |
| if (factory == null) { |
| throw new MissingDependencyException( |
| "No mapping found for dependency " + key + " for member: " |
| + member + ""); |
| } |
| |
| ExternalContext<T> externalContext = |
| ExternalContext.newInstance(member, key, this); |
| return new ParameterInjector<T>(externalContext, factory); |
| } |
| |
| @SuppressWarnings("unchecked") |
| private ParameterInjector<?>[] toArray( |
| List<ParameterInjector<?>> parameterInjections) { |
| return parameterInjections.toArray( |
| new ParameterInjector[parameterInjections.size()]); |
| } |
| |
| /** |
| * Finds the {@link Inject} annotation in an array of annotations. |
| */ |
| Inject findInject(Annotation[] annotations) { |
| for (Annotation annotation : annotations) { |
| if (annotation.annotationType() == Inject.class) { |
| return Inject.class.cast(annotation); |
| } |
| } |
| return null; |
| } |
| |
| static class MethodInjector implements Injector { |
| |
| final FastMethod fastMethod; |
| final ParameterInjector<?>[] parameterInjectors; |
| |
| public MethodInjector(ContainerImpl container, Method method, String name) |
| throws MissingDependencyException { |
| this.fastMethod = |
| FastClass.create(method.getDeclaringClass()).getMethod(method); |
| |
| method.setAccessible(true); |
| |
| Type[] parameterTypes = method.getGenericParameterTypes(); |
| if (parameterTypes.length == 0) { |
| throw new ConfigurationException( |
| method + " has no parameters to inject."); |
| } |
| parameterInjectors = container.getParametersInjectors( |
| method, method.getParameterAnnotations(), parameterTypes, name); |
| } |
| |
| public void inject(InternalContext context, Object o) { |
| try { |
| fastMethod.invoke(o, getParameters(context, parameterInjectors)); |
| } catch (Exception e) { |
| throw new RuntimeException(e); |
| } |
| } |
| } |
| |
| Map<Class<?>, ConstructorInjector> constructors = |
| new ReferenceCache<Class<?>, ConstructorInjector>() { |
| @SuppressWarnings("unchecked") |
| protected ConstructorInjector<?> create(Class<?> implementation) { |
| return new ConstructorInjector(ContainerImpl.this, implementation); |
| } |
| }; |
| |
| class ConstructorInjector<T> implements Factory<T> { |
| |
| final Class<T> implementation; |
| final List<Injector> injectors; |
| final FastConstructor fastConstructor; |
| final ParameterInjector<?>[] parameterInjectors; |
| |
| ConstructorInjector(ContainerImpl container, Class<T> implementation) { |
| this.implementation = implementation; |
| |
| Constructor<T> constructor = findConstructorIn(implementation); |
| constructor.setAccessible(true); |
| |
| try { |
| Inject inject = constructor.getAnnotation(Inject.class); |
| parameterInjectors = inject == null |
| ? null // default constructor. |
| : container.getParametersInjectors( |
| constructor, |
| constructor.getParameterAnnotations(), |
| constructor.getGenericParameterTypes(), |
| inject.value() |
| ); |
| } catch (MissingDependencyException e) { |
| throw new ConfigurationException(e); |
| } |
| injectors = container.injectors.get(implementation); |
| |
| fastConstructor = FastClass.create(constructor.getDeclaringClass()) |
| .getConstructor(constructor); |
| } |
| |
| @SuppressWarnings({"unchecked"}) |
| private Constructor<T> findConstructorIn(Class<T> implementation) { |
| Constructor<T> found = null; |
| for (Constructor<T> constructor |
| : implementation.getDeclaredConstructors()) { |
| if (constructor.getAnnotation(Inject.class) != null) { |
| if (found != null) { |
| throw new ConfigurationException("More than one constructor annotated" |
| + " with @Inject found in " + implementation + "."); |
| } |
| found = constructor; |
| } |
| } |
| if (found != null) { |
| return found; |
| } |
| |
| // If no annotated constructor is found, look for a no-arg constructor |
| // instead. |
| try { |
| return implementation.getDeclaredConstructor(); |
| } catch (NoSuchMethodException e) { |
| throw new ConfigurationException("Could not find a suitable constructor" |
| + " in " + implementation.getName() + "."); |
| } |
| } |
| |
| /** |
| * Construct an instance. Returns {@code Object} instead of {@code T} |
| * because it may return a proxy. |
| */ |
| Object construct(InternalContext context, Class<? super T> expectedType) { |
| ConstructionContext<T> constructionContext = |
| context.getConstructionContext(this); |
| |
| // We have a circular reference between constructors. Return a proxy. |
| if (constructionContext.isConstructing()) { |
| // TODO (crazybob): if we can't proxy this object, can we proxy the |
| // other object? |
| return constructionContext.createProxy(expectedType); |
| } |
| |
| // If we're re-entering this factory while injecting fields or methods, |
| // return the same instance. This prevents infinite loops. |
| T t = constructionContext.getCurrentReference(); |
| if (t != null) { |
| return t; |
| } |
| |
| try { |
| // First time through... |
| constructionContext.startConstruction(); |
| try { |
| Object[] parameters = getParameters(context, parameterInjectors); |
| t = newInstance(parameters); |
| constructionContext.setProxyDelegates(t); |
| } finally { |
| constructionContext.finishConstruction(); |
| } |
| |
| // Store reference. If an injector re-enters this factory, they'll |
| // get the same reference. |
| constructionContext.setCurrentReference(t); |
| |
| // Inject fields and methods. |
| if (!injectors.isEmpty()) { |
| for (Injector injector : injectors) { |
| injector.inject(context, t); |
| } |
| } |
| |
| return t; |
| } catch (InvocationTargetException e) { |
| throw new RuntimeException(e); |
| } finally { |
| constructionContext.removeCurrentReference(); |
| } |
| } |
| |
| @SuppressWarnings({"unchecked"}) |
| private T newInstance(Object[] parameters) throws InvocationTargetException { |
| return (T) fastConstructor.newInstance(parameters); |
| } |
| |
| public T get() { |
| try { |
| return callInContext(new ContextualCallable<T>() { |
| @SuppressWarnings({"unchecked"}) |
| public T call(InternalContext context) { |
| return (T) construct(context, implementation); |
| } |
| }); |
| } catch (RuntimeException e) { |
| throw e; |
| } catch (Exception e) { |
| throw new RuntimeException(e); |
| } |
| } |
| } |
| |
| static class ParameterInjector<T> { |
| |
| final ExternalContext<T> externalContext; |
| final InternalFactory<? extends T> factory; |
| |
| public ParameterInjector(ExternalContext<T> externalContext, |
| InternalFactory<? extends T> factory) { |
| this.externalContext = externalContext; |
| this.factory = factory; |
| } |
| |
| T inject(InternalContext context) { |
| ExternalContext<?> previous = context.getExternalContext(); |
| context.setExternalContext(externalContext); |
| try { |
| return factory.get(context); |
| } finally { |
| context.setExternalContext(previous); |
| } |
| } |
| } |
| |
| private static Object[] getParameters(InternalContext context, |
| ParameterInjector[] parameterInjectors) { |
| if (parameterInjectors == null) { |
| return null; |
| } |
| |
| Object[] parameters = new Object[parameterInjectors.length]; |
| for (int i = 0; i < parameters.length; i++) { |
| parameters[i] = parameterInjectors[i].inject(context); |
| } |
| return parameters; |
| } |
| |
| void injectMembers(Object o, InternalContext context) { |
| List<Injector> injectors = this.injectors.get(o.getClass()); |
| for (Injector injector : injectors) { |
| injector.inject(context, o); |
| } |
| } |
| |
| public <T> Factory<T> getCreator(final Class<T> implementation) { |
| return getConstructor(implementation); |
| } |
| |
| public boolean hasBindingFor(Key<?> key) { |
| try { |
| return getFactory(null, key) != null; |
| } catch (ConstantConversionException e) { |
| return false; |
| } |
| } |
| |
| public void injectMembers(final Object o) { |
| callInContext(new ContextualCallable<Void>() { |
| public Void call(InternalContext context) { |
| injectMembers(o, context); |
| return null; |
| } |
| }); |
| } |
| |
| public <T> Factory<T> getFactory(final Key<T> key) { |
| final InternalFactory<? extends T> factory = getFactory(null, key); |
| |
| if (factory == null) { |
| throw new ConfigurationException("Missing binding for " + key + "."); |
| } |
| |
| return new Factory<T>() { |
| public T get() { |
| return callInContext(new ContextualCallable<T>() { |
| public T call(InternalContext context) { |
| ExternalContext<?> previous = context.getExternalContext(); |
| context.setExternalContext( |
| ExternalContext.newInstance(null, key, ContainerImpl.this)); |
| try { |
| return factory.get(context); |
| } finally { |
| context.setExternalContext(previous); |
| } |
| } |
| }); |
| } |
| }; |
| } |
| |
| ThreadLocal<InternalContext[]> localContext = |
| new ThreadLocal<InternalContext[]>() { |
| protected InternalContext[] initialValue() { |
| return new InternalContext[1]; |
| } |
| }; |
| |
| /** |
| * Looks up thread local context. Creates (and removes) a new context if |
| * necessary. |
| */ |
| <T> T callInContext(ContextualCallable<T> callable) { |
| InternalContext[] reference = localContext.get(); |
| if (reference[0] == null) { |
| reference[0] = new InternalContext(this); |
| try { |
| return callable.call(reference[0]); |
| } finally { |
| // Only remove the context if this call created it. |
| reference[0] = null; |
| } |
| } else { |
| // Someone else will clean up this context. |
| return callable.call(reference[0]); |
| } |
| } |
| |
| interface ContextualCallable<T> { |
| T call(InternalContext context); |
| } |
| |
| /** |
| * Gets a constructor function for a given implementation class. |
| */ |
| @SuppressWarnings("unchecked") |
| <T> ConstructorInjector<T> getConstructor(Class<T> implementation) { |
| return constructors.get(implementation); |
| } |
| |
| @SuppressWarnings("unchecked") |
| <T> ConstructorInjector<T> getConstructor(TypeToken<T> implementation) { |
| return constructors.get(implementation.getRawType()); |
| } |
| |
| /** |
| * Injects a field or method in a given object. |
| */ |
| interface Injector { |
| void inject(InternalContext context, Object o); |
| } |
| |
| static class MissingDependencyException extends Exception { |
| |
| MissingDependencyException(String message) { |
| super(message); |
| } |
| } |
| |
| /** |
| * Map of primitive type converters. |
| */ |
| static class PrimitiveConverters extends HashMap<Class<?>, Converter<?>> { |
| |
| PrimitiveConverters() { |
| putParser(int.class); |
| putParser(long.class); |
| putParser(boolean.class); |
| putParser(byte.class); |
| putParser(short.class); |
| putParser(float.class); |
| putParser(double.class); |
| |
| // Character doesn't follow the same pattern. |
| Converter<Character> characterConverter = new Converter<Character>() { |
| public Character convert(Member member, Key<Character> key, |
| String value) { |
| value = value.trim(); |
| if (value.length() != 1) { |
| throw new ConstantConversionException(member, key, value, |
| "Length != 1."); |
| } |
| return value.charAt(0); |
| } |
| }; |
| put(char.class, characterConverter); |
| put(Character.class, characterConverter); |
| } |
| |
| <T> void putParser(final Class<T> primitive) { |
| try { |
| Class<?> wrapper = PRIMITIVE_COUNTERPARTS.get(primitive); |
| final Method parser = wrapper.getMethod("parse" + |
| Strings.capitalize(primitive.getName()), String.class); |
| Converter<T> converter = new Converter<T>() { |
| @SuppressWarnings({"unchecked"}) |
| public T convert(Member member, Key<T> key, String value) { |
| try { |
| return (T) parser.invoke(null, value); |
| } catch (IllegalAccessException e) { |
| // This should never happen. |
| throw new RuntimeException(e); |
| } catch (InvocationTargetException e) { |
| throw new ConstantConversionException(member, key, value, |
| e.getTargetException()); |
| } |
| } |
| }; |
| put(wrapper, converter); |
| put(primitive, converter); |
| } catch (NoSuchMethodException e) { |
| // This should never happen. |
| throw new RuntimeException(e); |
| } |
| } |
| } |
| |
| /** |
| * Converts a {@code String} to another type. |
| */ |
| interface Converter<T> { |
| |
| /** |
| * Converts {@code String} value. |
| */ |
| T convert(Member member, Key<T> key, String value); |
| } |
| } |