/**
* 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.inject.Binder;
import com.google.inject.Binding;
import com.google.inject.ConfigurationException;
import com.google.inject.ImplementedBy;
import com.google.inject.Injector;
import com.google.inject.Key;
import com.google.inject.MembersInjector;
import com.google.inject.Module;
import com.google.inject.ProvidedBy;
import com.google.inject.Provider;
import com.google.inject.ProvisionException;
import com.google.inject.Scope;
import com.google.inject.Stage;
import com.google.inject.TypeLiteral;
import com.google.inject.internal.util.ImmutableList;
import com.google.inject.internal.util.ImmutableMap;
import com.google.inject.internal.util.ImmutableSet;
import com.google.inject.internal.util.Lists;
import com.google.inject.internal.util.Maps;
import com.google.inject.internal.util.Nullable;
import com.google.inject.internal.util.Objects;
import com.google.inject.internal.util.SourceProvider;
import com.google.inject.internal.util.ToStringBuilder;
import com.google.inject.spi.BindingTargetVisitor;
import com.google.inject.spi.ConvertedConstantBinding;
import com.google.inject.spi.Dependency;
import com.google.inject.spi.HasDependencies;
import com.google.inject.spi.InjectionPoint;
import com.google.inject.spi.ProviderBinding;
import com.google.inject.spi.TypeConverterBinding;
import com.google.inject.util.Providers;
import java.lang.annotation.Annotation;
import java.lang.reflect.GenericArrayType;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* Default {@link Injector} implementation.
*
* @author crazybob@google.com (Bob Lee)
*/
final class InjectorImpl implements Injector, Lookups {
public static final TypeLiteral<String> STRING_TYPE = TypeLiteral.get(String.class);
/** Options that control how the injector behaves. */
static class InjectorOptions {
final Stage stage;
final boolean jitDisabled;
final boolean disableCircularProxies;
InjectorOptions(Stage stage, boolean jitDisabled, boolean disableCircularProxies) {
this.stage = stage;
this.jitDisabled = jitDisabled;
this.disableCircularProxies = disableCircularProxies;
}
@Override
public String toString() {
return new ToStringBuilder(getClass())
.add("stage", stage)
.add("jitDisabled", jitDisabled)
.add("disableCircularProxies", disableCircularProxies)
.toString();
}
}
/** some limitations on what just in time bindings are allowed. */
enum JitLimitation {
/** does not allow just in time bindings */
NO_JIT,
/** allows existing just in time bindings, but does not allow new ones */
EXISTING_JIT,
/** allows existing just in time bindings & allows new ones to be created */
NEW_OR_EXISTING_JIT,
}
final State state;
final InjectorImpl parent;
final BindingsMultimap bindingsMultimap = new BindingsMultimap();
final InjectorOptions options;
/** Just-in-time binding cache. Guarded by state.lock() */
final Map<Key<?>, BindingImpl<?>> jitBindings = Maps.newHashMap();
Lookups lookups = new DeferredLookups(this);
InjectorImpl(@Nullable InjectorImpl parent, State state, InjectorOptions injectorOptions) {
this.parent = parent;
this.state = state;
this.options = injectorOptions;
if (parent != null) {
localContext = parent.localContext;
} else {
localContext = new ThreadLocal<Object[]>() {
protected Object[] initialValue() {
return new Object[1];
}
};
}
}
/** Indexes bindings by type. */
void index() {
for (Binding<?> binding : state.getExplicitBindingsThisLevel().values()) {
index(binding);
}
}
<T> void index(Binding<T> binding) {
bindingsMultimap.put(binding.getKey().getTypeLiteral(), binding);
}
public <T> List<Binding<T>> findBindingsByType(TypeLiteral<T> type) {
return bindingsMultimap.getAll(type);
}
/** Returns the binding for {@code key} */
public <T> BindingImpl<T> getBinding(Key<T> key) {
Errors errors = new Errors(key);
try {
BindingImpl<T> result = getBindingOrThrow(key, errors, JitLimitation.EXISTING_JIT);
errors.throwConfigurationExceptionIfErrorsExist();
return result;
} catch (ErrorsException e) {
throw new ConfigurationException(errors.merge(e.getErrors()).getMessages());
}
}
public <T> BindingImpl<T> getExistingBinding(Key<T> key) {
// Check explicit bindings, i.e. bindings created by modules.
BindingImpl<T> explicitBinding = state.getExplicitBinding(key);
if (explicitBinding != null) {
return explicitBinding;
}
synchronized (state.lock()) {
// See if any jit bindings have been created for this key.
for (InjectorImpl injector = this; injector != null; injector = injector.parent) {
@SuppressWarnings("unchecked")
BindingImpl<T> jitBinding = (BindingImpl<T>) injector.jitBindings.get(key);
if(jitBinding != null) {
return jitBinding;
}
}
}
// If Key is a Provider, we have to see if the type it is providing exists,
// and, if so, we have to create the binding for the provider.
if(isProvider(key)) {
try {
// This is safe because isProvider above ensures that T is a Provider<?>
@SuppressWarnings("unchecked")
Key<?> providedKey = (Key<?>)getProvidedKey((Key)key, new Errors());
if(getExistingBinding(providedKey) != null) {
return getBinding(key);
}
} catch(ErrorsException e) {
throw new ConfigurationException(e.getErrors().getMessages());
}
}
// No existing binding exists.
return null;
}
/**
* Gets a binding implementation. First, it check to see if the parent has a binding. If the
* parent has a binding and the binding is scoped, it will use that binding. Otherwise, this
* checks for an explicit binding. If no explicit binding is found, it looks for a just-in-time
* binding.
*/
<T> BindingImpl<T> getBindingOrThrow(Key<T> key, Errors errors, JitLimitation jitType)
throws ErrorsException {
// Check explicit bindings, i.e. bindings created by modules.
BindingImpl<T> binding = state.getExplicitBinding(key);
if (binding != null) {
return binding;
}
// Look for an on-demand binding.
return getJustInTimeBinding(key, errors, jitType);
}
public <T> Binding<T> getBinding(Class<T> type) {
return getBinding(Key.get(type));
}
public Injector getParent() {
return parent;
}
public Injector createChildInjector(Iterable<? extends Module> modules) {
return new InternalInjectorCreator()
.parentInjector(this)
.addModules(modules)
.build();
}
public Injector createChildInjector(Module... modules) {
return createChildInjector(ImmutableList.of(modules));
}
/**
* Returns a just-in-time binding for {@code key}, creating it if necessary.
*
* @throws ErrorsException if the binding could not be created.
*/
private <T> BindingImpl<T> getJustInTimeBinding(Key<T> key, Errors errors, JitLimitation jitType)
throws ErrorsException {
boolean jitOverride = isProvider(key) || isTypeLiteral(key) || isMembersInjector(key);
if(options.jitDisabled && jitType == JitLimitation.NO_JIT && !jitOverride) {
throw errors.jitDisabled(key).toException();
}
synchronized (state.lock()) {
// first try to find a JIT binding that we've already created
for (InjectorImpl injector = this; injector != null; injector = injector.parent) {
@SuppressWarnings("unchecked") // we only store bindings that match their key
BindingImpl<T> binding = (BindingImpl<T>) injector.jitBindings.get(key);
if (binding != null) {
return binding;
}
}
if(options.jitDisabled && jitType != JitLimitation.NEW_OR_EXISTING_JIT && !jitOverride) {
throw errors.jitDisabled(key).toException();
} else {
return createJustInTimeBindingRecursive(key, errors);
}
}
}
/** Returns true if the key type is Provider (but not a subclass of Provider). */
private static boolean isProvider(Key<?> key) {
return key.getTypeLiteral().getRawType().equals(Provider.class);
}
private static boolean isTypeLiteral(Key<?> key) {
return key.getTypeLiteral().getRawType().equals(TypeLiteral.class);
}
private static <T> Key<T> getProvidedKey(Key<Provider<T>> key, Errors errors) throws ErrorsException {
Type providerType = key.getTypeLiteral().getType();
// If the Provider has no type parameter (raw Provider)...
if (!(providerType instanceof ParameterizedType)) {
throw errors.cannotInjectRawProvider().toException();
}
Type entryType = ((ParameterizedType) providerType).getActualTypeArguments()[0];
@SuppressWarnings("unchecked") // safe because T came from Key<Provider<T>>
Key<T> providedKey = (Key<T>) key.ofType(entryType);
return providedKey;
}
/** Returns true if the key type is MembersInjector (but not a subclass of MembersInjector). */
private static boolean isMembersInjector(Key<?> key) {
return key.getTypeLiteral().getRawType().equals(MembersInjector.class)
&& !(key.getAnnotationType() != null);
}
private <T> BindingImpl<MembersInjector<T>> createMembersInjectorBinding(
Key<MembersInjector<T>> key, Errors errors) throws ErrorsException {
Type membersInjectorType = key.getTypeLiteral().getType();
if (!(membersInjectorType instanceof ParameterizedType)) {
throw errors.cannotInjectRawMembersInjector().toException();
}
@SuppressWarnings("unchecked") // safe because T came from Key<MembersInjector<T>>
TypeLiteral<T> instanceType = (TypeLiteral<T>) TypeLiteral.get(
((ParameterizedType) membersInjectorType).getActualTypeArguments()[0]);
MembersInjector<T> membersInjector = membersInjectorStore.get(instanceType, errors);
InternalFactory<MembersInjector<T>> factory = new ConstantFactory<MembersInjector<T>>(
Initializables.of(membersInjector));
return new InstanceBindingImpl<MembersInjector<T>>(this, key, SourceProvider.UNKNOWN_SOURCE,
factory, ImmutableSet.<InjectionPoint>of(), membersInjector);
}
/**
* Creates a synthetic binding to {@code Provider<T>}, i.e. a binding to the provider from
* {@code Binding<T>}.
*/
private <T> BindingImpl<Provider<T>> createProviderBinding(Key<Provider<T>> key, Errors errors)
throws ErrorsException {
Key<T> providedKey = getProvidedKey(key, errors);
BindingImpl<T> delegate = getBindingOrThrow(providedKey, errors, JitLimitation.NO_JIT);
return new ProviderBindingImpl<T>(this, key, delegate);
}
private static class ProviderBindingImpl<T> extends BindingImpl<Provider<T>>
implements ProviderBinding<Provider<T>>, HasDependencies {
final BindingImpl<T> providedBinding;
ProviderBindingImpl(InjectorImpl injector, Key<Provider<T>> key, Binding<T> providedBinding) {
super(injector, key, providedBinding.getSource(), createInternalFactory(providedBinding),
Scoping.UNSCOPED);
this.providedBinding = (BindingImpl<T>) providedBinding;
}
static <T> InternalFactory<Provider<T>> createInternalFactory(Binding<T> providedBinding) {
final Provider<T> provider = providedBinding.getProvider();
return new InternalFactory<Provider<T>>() {
public Provider<T> get(Errors errors, InternalContext context, Dependency dependency, boolean linked) {
return provider;
}
};
}
public Key<? extends T> getProvidedKey() {
return providedBinding.getKey();
}
public <V> V acceptTargetVisitor(BindingTargetVisitor<? super Provider<T>, V> visitor) {
return visitor.visit(this);
}
public void applyTo(Binder binder) {
throw new UnsupportedOperationException("This element represents a synthetic binding.");
}
@Override public String toString() {
return new ToStringBuilder(ProviderBinding.class)
.add("key", getKey())
.add("providedKey", getProvidedKey())
.toString();
}
public Set<Dependency<?>> getDependencies() {
return ImmutableSet.<Dependency<?>>of(Dependency.get(getProvidedKey()));
}
@Override
public boolean equals(Object obj) {
if(obj instanceof ProviderBindingImpl) {
ProviderBindingImpl<?> o = (ProviderBindingImpl<?>)obj;
return getKey().equals(o.getKey())
&& getScoping().equals(o.getScoping())
&& Objects.equal(providedBinding, o.providedBinding);
} else {
return false;
}
}
@Override
public int hashCode() {
return Objects.hashCode(getKey(), getScoping(), providedBinding);
}
}
/**
* Converts a constant string binding to the required type.
*
* @return the binding if it could be resolved, or null if the binding doesn't exist
* @throws com.google.inject.internal.ErrorsException if there was an error resolving the binding
*/
private <T> BindingImpl<T> convertConstantStringBinding(Key<T> key, Errors errors)
throws ErrorsException {
// Find a constant string binding.
Key<String> stringKey = key.ofType(STRING_TYPE);
BindingImpl<String> stringBinding = state.getExplicitBinding(stringKey);
if (stringBinding == null || !stringBinding.isConstant()) {
return null;
}
String stringValue = stringBinding.getProvider().get();
Object source = stringBinding.getSource();
// Find a matching type converter.
TypeLiteral<T> type = key.getTypeLiteral();
TypeConverterBinding typeConverterBinding = state.getConverter(stringValue, type, errors, source);
if (typeConverterBinding == null) {
// No converter can handle the given type.
return null;
}
// Try to convert the string. A failed conversion results in an error.
try {
@SuppressWarnings("unchecked") // This cast is safe because we double check below.
T converted = (T) typeConverterBinding.getTypeConverter().convert(stringValue, type);
if (converted == null) {
throw errors.converterReturnedNull(stringValue, source, type, typeConverterBinding)
.toException();
}
if (!type.getRawType().isInstance(converted)) {
throw errors.conversionTypeError(stringValue, source, type, typeConverterBinding, converted)
.toException();
}
return new ConvertedConstantBindingImpl<T>(this, key, converted, stringBinding,
typeConverterBinding);
} catch (ErrorsException e) {
throw e;
} catch (RuntimeException e) {
throw errors.conversionError(stringValue, source, type, typeConverterBinding, e)
.toException();
}
}
private static class ConvertedConstantBindingImpl<T>
extends BindingImpl<T> implements ConvertedConstantBinding<T> {
final T value;
final Provider<T> provider;
final Binding<String> originalBinding;
final TypeConverterBinding typeConverterBinding;
ConvertedConstantBindingImpl(
InjectorImpl injector, Key<T> key, T value, Binding<String> originalBinding,
TypeConverterBinding typeConverterBinding) {
super(injector, key, originalBinding.getSource(),
new ConstantFactory<T>(Initializables.of(value)), Scoping.UNSCOPED);
this.value = value;
provider = Providers.of(value);
this.originalBinding = originalBinding;
this.typeConverterBinding = typeConverterBinding;
}
@Override public Provider<T> getProvider() {
return provider;
}
public <V> V acceptTargetVisitor(BindingTargetVisitor<? super T, V> visitor) {
return visitor.visit(this);
}
public T getValue() {
return value;
}
public TypeConverterBinding getTypeConverterBinding() {
return typeConverterBinding;
}
public Key<String> getSourceKey() {
return originalBinding.getKey();
}
public Set<Dependency<?>> getDependencies() {
return ImmutableSet.<Dependency<?>>of(Dependency.get(getSourceKey()));
}
public void applyTo(Binder binder) {
throw new UnsupportedOperationException("This element represents a synthetic binding.");
}
@Override public String toString() {
return new ToStringBuilder(ConvertedConstantBinding.class)
.add("key", getKey())
.add("sourceKey", getSourceKey())
.add("value", value)
.toString();
}
@Override
public boolean equals(Object obj) {
if(obj instanceof ConvertedConstantBindingImpl) {
ConvertedConstantBindingImpl<?> o = (ConvertedConstantBindingImpl<?>)obj;
return getKey().equals(o.getKey())
&& getScoping().equals(o.getScoping())
&& Objects.equal(value, o.value);
} else {
return false;
}
}
@Override
public int hashCode() {
return Objects.hashCode(getKey(), getScoping(), value);
}
}
<T> void initializeBinding(BindingImpl<T> binding, Errors errors) throws ErrorsException {
if (binding instanceof ConstructorBindingImpl<?>) {
((ConstructorBindingImpl) binding).initialize(this, errors);
}
}
<T> void initializeJitBinding(BindingImpl<T> binding, Errors errors) throws ErrorsException {
// Put the partially constructed binding in the map a little early. This enables us to handle
// circular dependencies. Example: FooImpl -> BarImpl -> FooImpl.
// Note: We don't need to synchronize on state.lock() during injector creation.
if (binding instanceof ConstructorBindingImpl<?>) {
Key<T> key = binding.getKey();
jitBindings.put(key, binding);
boolean successful = false;
ConstructorBindingImpl cb = (ConstructorBindingImpl)binding;
try {
cb.initialize(this, errors);
successful = true;
} finally {
if (!successful) {
// We do not pass cb.getInternalConstructor as the second parameter
// so that cached exceptions while constructing it get stored.
// See TypeListenerTest#testTypeListenerThrows
removeFailedJitBinding(key, null);
cleanup(binding, new HashSet<Key>());
}
}
}
}
/**
* Iterates through the binding's dependencies to clean up any stray bindings that were leftover
* from a failed JIT binding. This is required because the bindings are eagerly &
* optimistically added to allow circular dependency support, so dependencies may pass where they
* should have failed.
*/
private boolean cleanup(BindingImpl<?> binding, Set<Key> encountered) {
boolean bindingFailed = false;
Set<Dependency<?>> deps = getInternalDependencies(binding);
for(Dependency dep : deps) {
Key<?> depKey = dep.getKey();
InjectionPoint ip = dep.getInjectionPoint();
if(encountered.add(depKey)) { // only check if we haven't looked at this key yet
BindingImpl depBinding = jitBindings.get(depKey);
if(depBinding != null) { // if the binding still exists, validate
boolean failed = cleanup(depBinding, encountered); // if children fail, we fail
if(depBinding instanceof ConstructorBindingImpl) {
ConstructorBindingImpl ctorBinding = (ConstructorBindingImpl)depBinding;
ip = ctorBinding.getInternalConstructor();
if(!ctorBinding.isInitialized()) {
failed = true;
}
}
if(failed) {
removeFailedJitBinding(depKey, ip);
bindingFailed = true;
}
} else if(state.getExplicitBinding(depKey) == null) {
// ignore keys if they were explicitly bound, but if neither JIT
// nor explicit, it's also invalid & should let parent know.
bindingFailed = true;
}
}
}
return bindingFailed;
}
/** Cleans up any state that may have been cached when constructing the JIT binding. */
private void removeFailedJitBinding(Key<?> key, InjectionPoint ip) {
jitBindings.remove(key);
membersInjectorStore.remove(key.getTypeLiteral());
if(ip != null) {
constructors.remove(ip);
}
}
/** Safely gets the dependencies of possibly not initialized bindings. */
@SuppressWarnings("unchecked")
private Set<Dependency<?>> getInternalDependencies(BindingImpl<?> binding) {
if(binding instanceof ConstructorBindingImpl) {
return ((ConstructorBindingImpl)binding).getInternalDependencies();
} else if(binding instanceof HasDependencies) {
return ((HasDependencies)binding).getDependencies();
} else {
return ImmutableSet.of();
}
}
/**
* Creates a binding for an injectable type with the given scope. Looks for a scope on the type if
* none is specified.
*/
<T> BindingImpl<T> createUninitializedBinding(Key<T> key, Scoping scoping, Object source,
Errors errors, boolean jitBinding) throws ErrorsException {
Class<?> rawType = key.getTypeLiteral().getRawType();
// Don't try to inject arrays, or enums.
if (rawType.isArray() || rawType.isEnum()) {
throw errors.missingImplementation(key).toException();
}
// Handle TypeLiteral<T> by binding the inner type
if (rawType == TypeLiteral.class) {
@SuppressWarnings("unchecked") // we have to fudge the inner type as Object
BindingImpl<T> binding = (BindingImpl<T>) createTypeLiteralBinding(
(Key<TypeLiteral<Object>>) key, errors);
return binding;
}
// Handle @ImplementedBy
ImplementedBy implementedBy = rawType.getAnnotation(ImplementedBy.class);
if (implementedBy != null) {
Annotations.checkForMisplacedScopeAnnotations(rawType, source, errors);
return createImplementedByBinding(key, scoping, implementedBy, errors);
}
// Handle @ProvidedBy.
ProvidedBy providedBy = rawType.getAnnotation(ProvidedBy.class);
if (providedBy != null) {
Annotations.checkForMisplacedScopeAnnotations(rawType, source, errors);
return createProvidedByBinding(key, scoping, providedBy, errors);
}
return ConstructorBindingImpl.create(this, key, null, source, scoping, errors, jitBinding && options.jitDisabled);
}
/**
* Converts a binding for a {@code Key<TypeLiteral<T>>} to the value {@code TypeLiteral<T>}. It's
* a bit awkward because we have to pull out the inner type in the type literal.
*/
private <T> BindingImpl<TypeLiteral<T>> createTypeLiteralBinding(
Key<TypeLiteral<T>> key, Errors errors) throws ErrorsException {
Type typeLiteralType = key.getTypeLiteral().getType();
if (!(typeLiteralType instanceof ParameterizedType)) {
throw errors.cannotInjectRawTypeLiteral().toException();
}
ParameterizedType parameterizedType = (ParameterizedType) typeLiteralType;
Type innerType = parameterizedType.getActualTypeArguments()[0];
// this is unforunate. We don't support building TypeLiterals for type variable like 'T'. If
// this proves problematic, we can probably fix TypeLiteral to support type variables
if (!(innerType instanceof Class)
&& !(innerType instanceof GenericArrayType)
&& !(innerType instanceof ParameterizedType)) {
throw errors.cannotInjectTypeLiteralOf(innerType).toException();
}
@SuppressWarnings("unchecked") // by definition, innerType == T, so this is safe
TypeLiteral<T> value = (TypeLiteral<T>) TypeLiteral.get(innerType);
InternalFactory<TypeLiteral<T>> factory = new ConstantFactory<TypeLiteral<T>>(
Initializables.of(value));
return new InstanceBindingImpl<TypeLiteral<T>>(this, key, SourceProvider.UNKNOWN_SOURCE,
factory, ImmutableSet.<InjectionPoint>of(), value);
}
/** Creates a binding for a type annotated with @ProvidedBy. */
<T> BindingImpl<T> createProvidedByBinding(Key<T> key, Scoping scoping,
ProvidedBy providedBy, Errors errors) throws ErrorsException {
final Class<?> rawType = key.getTypeLiteral().getRawType();
final Class<? extends Provider<?>> providerType = providedBy.value();
// Make sure it's not the same type. TODO: Can we check for deeper loops?
if (providerType == rawType) {
throw errors.recursiveProviderType().toException();
}
// Assume the provider provides an appropriate type. We double check at runtime.
@SuppressWarnings("unchecked")
final Key<? extends Provider<T>> providerKey
= (Key<? extends Provider<T>>) Key.get(providerType);
final BindingImpl<? extends Provider<?>> providerBinding
= getBindingOrThrow(providerKey, errors, JitLimitation.NEW_OR_EXISTING_JIT);
InternalFactory<T> internalFactory = new InternalFactory<T>() {
public T get(Errors errors, InternalContext context, Dependency dependency, boolean linked)
throws ErrorsException {
errors = errors.withSource(providerKey);
Provider<?> provider = providerBinding.getInternalFactory().get(
errors, context, dependency, true);
try {
Object o = provider.get();
if (o != null && !rawType.isInstance(o)) {
throw errors.subtypeNotProvided(providerType, rawType).toException();
}
@SuppressWarnings("unchecked") // protected by isInstance() check above
T t = (T) o;
return t;
} catch (RuntimeException e) {
throw errors.errorInProvider(e).toException();
}
}
};
Object source = rawType;
return new LinkedProviderBindingImpl<T>(
this,
key,
source,
Scoping.<T>scope(key, this, internalFactory, source, scoping),
scoping,
providerKey);
}
/** Creates a binding for a type annotated with @ImplementedBy. */
private <T> BindingImpl<T> createImplementedByBinding(Key<T> key, Scoping scoping,
ImplementedBy implementedBy, Errors errors)
throws ErrorsException {
Class<?> rawType = key.getTypeLiteral().getRawType();
Class<?> implementationType = implementedBy.value();
// Make sure it's not the same type. TODO: Can we check for deeper cycles?
if (implementationType == rawType) {
throw errors.recursiveImplementationType().toException();
}
// Make sure implementationType extends type.
if (!rawType.isAssignableFrom(implementationType)) {
throw errors.notASubtype(implementationType, rawType).toException();
}
@SuppressWarnings("unchecked") // After the preceding check, this cast is safe.
Class<? extends T> subclass = (Class<? extends T>) implementationType;
// Look up the target binding.
final Key<? extends T> targetKey = Key.get(subclass);
final BindingImpl<? extends T> targetBinding = getBindingOrThrow(targetKey, errors, JitLimitation.NEW_OR_EXISTING_JIT);
InternalFactory<T> internalFactory = new InternalFactory<T>() {
public T get(Errors errors, InternalContext context, Dependency<?> dependency, boolean linked)
throws ErrorsException {
return targetBinding.getInternalFactory().get(
errors.withSource(targetKey), context, dependency, true);
}
};
Object source = rawType;
return new LinkedBindingImpl<T>(
this,
key,
source,
Scoping.<T>scope(key, this, internalFactory, source, scoping),
scoping,
targetKey);
}
/**
* Attempts to create a just-in-time binding for {@code key} in the root injector, falling back to
* other ancestor injectors until this injector is tried.
*/
private <T> BindingImpl<T> createJustInTimeBindingRecursive(Key<T> key, Errors errors)
throws ErrorsException {
// ask the parent to create the JIT binding
if (parent != null && !parent.options.jitDisabled) {
try {
return parent.createJustInTimeBindingRecursive(key, new Errors());
} catch (ErrorsException ignored) {
}
}
if (state.isBlacklisted(key)) {
throw errors.childBindingAlreadySet(key).toException();
}
BindingImpl<T> binding = createJustInTimeBinding(key, errors);
state.parent().blacklist(key);
jitBindings.put(key, binding);
return binding;
}
/**
* Returns a new just-in-time binding created by resolving {@code key}. The strategies used to
* create just-in-time bindings are:
* <ol>
* <li>Internalizing Providers. If the requested binding is for {@code Provider<T>}, we delegate
* to the binding for {@code T}.
* <li>Converting constants.
* <li>ImplementedBy and ProvidedBy annotations. Only for unannotated keys.
* <li>The constructor of the raw type. Only for unannotated keys.
* </ol>
*
* @throws com.google.inject.internal.ErrorsException if the binding cannot be created.
*/
private <T> BindingImpl<T> createJustInTimeBinding(Key<T> key, Errors errors)
throws ErrorsException {
int numErrorsBefore = errors.size();
if (state.isBlacklisted(key)) {
throw errors.childBindingAlreadySet(key).toException();
}
// Handle cases where T is a Provider<?>.
if (isProvider(key)) {
// These casts are safe. We know T extends Provider<X> and that given Key<Provider<X>>,
// createProviderBinding() will return BindingImpl<Provider<X>>.
@SuppressWarnings("unchecked")
BindingImpl<T> binding = (BindingImpl<T>) createProviderBinding((Key) key, errors);
return binding;
}
// Handle cases where T is a MembersInjector<?>
if (isMembersInjector(key)) {
// These casts are safe. T extends MembersInjector<X> and that given Key<MembersInjector<X>>,
// createMembersInjectorBinding() will return BindingImpl<MembersInjector<X>>.
@SuppressWarnings("unchecked")
BindingImpl<T> binding = (BindingImpl<T>) createMembersInjectorBinding((Key) key, errors);
return binding;
}
// Try to convert a constant string binding to the requested type.
BindingImpl<T> convertedBinding = convertConstantStringBinding(key, errors);
if (convertedBinding != null) {
return convertedBinding;
}
// If the key has an annotation...
if (key.getAnnotationType() != null) {
// Look for a binding without annotation attributes or return null.
if (key.hasAttributes()) {
try {
Errors ignored = new Errors();
return getBindingOrThrow(key.withoutAttributes(), ignored, JitLimitation.NO_JIT);
} catch (ErrorsException ignored) {
// throw with a more appropriate message below
}
}
throw errors.missingImplementation(key).toException();
}
Object source = key.getTypeLiteral().getRawType();
BindingImpl<T> binding = createUninitializedBinding(key, Scoping.UNSCOPED, source, errors, true);
errors.throwIfNewErrors(numErrorsBefore);
initializeJitBinding(binding, errors);
return binding;
}
<T> InternalFactory<? extends T> getInternalFactory(Key<T> key, Errors errors, JitLimitation jitType)
throws ErrorsException {
return getBindingOrThrow(key, errors, jitType).getInternalFactory();
}
public Map<Key<?>, Binding<?>> getBindings() {
return state.getExplicitBindingsThisLevel();
}
public Map<Key<?>, Binding<?>> getAllBindings() {
synchronized (state.lock()) {
return new ImmutableMap.Builder<Key<?>, Binding<?>>()
.putAll(state.getExplicitBindingsThisLevel())
.putAll(jitBindings)
.build();
}
}
public Map<Class<? extends Annotation>, Scope> getScopeBindings() {
return ImmutableMap.copyOf(state.getScopes());
}
public Set<TypeConverterBinding> getTypeConverterBindings() {
return ImmutableSet.copyOf(state.getConvertersThisLevel());
}
private static class BindingsMultimap {
final Map<TypeLiteral<?>, List<Binding<?>>> multimap = Maps.newHashMap();
<T> void put(TypeLiteral<T> type, Binding<T> binding) {
List<Binding<?>> bindingsForType = multimap.get(type);
if (bindingsForType == null) {
bindingsForType = Lists.newArrayList();
multimap.put(type, bindingsForType);
}
bindingsForType.add(binding);
}
@SuppressWarnings("unchecked") // safe because we only put matching entries into the map
<T> List<Binding<T>> getAll(TypeLiteral<T> type) {
List<Binding<?>> bindings = multimap.get(type);
return bindings != null
? Collections.<Binding<T>>unmodifiableList((List) multimap.get(type))
: ImmutableList.<Binding<T>>of();
}
}
/**
* Returns parameter injectors, or {@code null} if there are no parameters.
*/
SingleParameterInjector<?>[] getParametersInjectors(
List<Dependency<?>> parameters, Errors errors) throws ErrorsException {
if (parameters.isEmpty()) {
return null;
}
int numErrorsBefore = errors.size();
SingleParameterInjector<?>[] result = new SingleParameterInjector<?>[parameters.size()];
int i = 0;
for (Dependency<?> parameter : parameters) {
try {
result[i++] = createParameterInjector(parameter, errors.withSource(parameter));
} catch (ErrorsException rethrownBelow) {
// rethrown below
}
}
errors.throwIfNewErrors(numErrorsBefore);
return result;
}
<T> SingleParameterInjector<T> createParameterInjector(final Dependency<T> dependency,
final Errors errors) throws ErrorsException {
InternalFactory<? extends T> factory = getInternalFactory(dependency.getKey(), errors, JitLimitation.NO_JIT);
return new SingleParameterInjector<T>(dependency, factory);
}
/** Invokes a method. */
interface MethodInvoker {
Object invoke(Object target, Object... parameters)
throws IllegalAccessException, InvocationTargetException;
}
/** Cached constructor injectors for each type */
final ConstructorInjectorStore constructors = new ConstructorInjectorStore(this);
/** Cached field and method injectors for each type. */
MembersInjectorStore membersInjectorStore;
@SuppressWarnings("unchecked") // the members injector type is consistent with instance's type
public void injectMembers(Object instance) {
MembersInjector membersInjector = getMembersInjector(instance.getClass());
membersInjector.injectMembers(instance);
}
public <T> MembersInjector<T> getMembersInjector(TypeLiteral<T> typeLiteral) {
Errors errors = new Errors(typeLiteral);
try {
return membersInjectorStore.get(typeLiteral, errors);
} catch (ErrorsException e) {
throw new ConfigurationException(errors.merge(e.getErrors()).getMessages());
}
}
public <T> MembersInjector<T> getMembersInjector(Class<T> type) {
return getMembersInjector(TypeLiteral.get(type));
}
public <T> Provider<T> getProvider(Class<T> type) {
return getProvider(Key.get(type));
}
<T> Provider<T> getProviderOrThrow(final Key<T> key, Errors errors) throws ErrorsException {
final InternalFactory<? extends T> factory = getInternalFactory(key, errors, JitLimitation.NO_JIT);
final Dependency<T> dependency = Dependency.get(key);
return new Provider<T>() {
public T get() {
final Errors errors = new Errors(dependency);
try {
T t = callInContext(new ContextualCallable<T>() {
public T call(InternalContext context) throws ErrorsException {
Dependency previous = context.setDependency(dependency);
try {
return factory.get(errors, context, dependency, false);
} finally {
context.setDependency(previous);
}
}
});
errors.throwIfNewErrors(0);
return t;
} catch (ErrorsException e) {
throw new ProvisionException(errors.merge(e.getErrors()).getMessages());
}
}
@Override public String toString() {
return factory.toString();
}
};
}
public <T> Provider<T> getProvider(final Key<T> key) {
Errors errors = new Errors(key);
try {
Provider<T> result = getProviderOrThrow(key, errors);
errors.throwIfNewErrors(0);
return result;
} catch (ErrorsException e) {
throw new ConfigurationException(errors.merge(e.getErrors()).getMessages());
}
}
public <T> T getInstance(Key<T> key) {
return getProvider(key).get();
}
public <T> T getInstance(Class<T> type) {
return getProvider(type).get();
}
final ThreadLocal<Object[]> localContext;
/** Looks up thread local context. Creates (and removes) a new context if necessary. */
<T> T callInContext(ContextualCallable<T> callable) throws ErrorsException {
Object[] reference = localContext.get();
if (reference[0] == null) {
reference[0] = new InternalContext();
try {
return callable.call((InternalContext)reference[0]);
} finally {
// Only clear the context if this call created it.
reference[0] = null;
}
} else {
// Someone else will clean up this context.
return callable.call((InternalContext)reference[0]);
}
}
public String toString() {
return new ToStringBuilder(Injector.class)
.add("bindings", state.getExplicitBindingsThisLevel().values())
.toString();
}
}