/**
* 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.ConfigurationException;
import com.google.inject.CreationException;
import com.google.inject.Key;
import com.google.inject.MembersInjector;
import com.google.inject.Provider;
import com.google.inject.ProvisionException;
import com.google.inject.Scope;
import com.google.inject.TypeLiteral;
import com.google.inject.Guice;
import com.google.inject.spi.Dependency;
import com.google.inject.spi.InjectionListener;
import com.google.inject.spi.InjectionPoint;
import com.google.inject.spi.Message;
import com.google.inject.spi.TypeListenerBinding;
import java.io.PrintWriter;
import java.io.Serializable;
import java.io.StringWriter;
import java.lang.annotation.Annotation;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Member;
import java.lang.reflect.Type;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.Formatter;
import java.util.List;
import java.util.logging.Logger;
import java.util.concurrent.atomic.AtomicInteger;
/**
* A collection of error messages. If this type is passed as a method parameter, the method is
* considered to have executed succesfully only if new errors were not added to this collection.
*
* <p>Errors can be chained to provide additional context. To add context, call {@link #withSource}
* to create a new Errors instance that contains additional context. All messages added to the
* returned instance will contain full context.
*
* <p>To avoid messages with redundant context, {@link #withSource} should be added sparingly. A
* good rule of thumb is to assume a ethod's caller has already specified enough context to
* identify that method. When calling a method that's defined in a different context, call that
* method with an errors object that includes its context.
*
* @author jessewilson@google.com (Jesse Wilson)
*/
public final class Errors implements Serializable {
private static final AtomicInteger warningsLogged = new AtomicInteger(0);
// TODO(kevinb): gee, ya think we might want to remove this?
private static boolean allowNullsBadBadBad(Dependency<?> dependency) {
boolean allowNulls = "I'm a bad hack"
.equals(System.getProperty("guice.allow.nulls.bad.bad.bad"));
if (allowNulls && warningsLogged.getAndIncrement() < 50) {
Logger.getLogger(Guice.class.getName()).warning(
"Guice injected null into " + dependency + "; please mark it @Nullable");
}
return allowNulls;
}
/**
* The root errors object. Used to access the list of error messages.
*/
private final Errors root;
/**
* The parent errors object. Used to obtain the chain of source objects.
*/
private final Errors parent;
/**
* The leaf source for errors added here.
*/
private final Object source;
/**
* null unless (root == this) and error messages exist. Never an empty list.
*/
private List<Message> errors; // lazy, use getErrorsForAdd()
public Errors() {
this.root = this;
this.parent = null;
this.source = SourceProvider.UNKNOWN_SOURCE;
}
public Errors(Object source) {
this.root = this;
this.parent = null;
this.source = source;
}
private Errors(Errors parent, Object source) {
this.root = parent.root;
this.parent = parent;
this.source = source;
}
/**
* Returns an instance that uses {@code source} as a reference point for newly added errors.
*/
public Errors withSource(Object source) {
return source == SourceProvider.UNKNOWN_SOURCE
? this
: new Errors(this, source);
}
/**
* We use a fairly generic error message here. The motivation is to share the
* same message for both bind time errors:
* <pre><code>Guice.createInjector(new AbstractModule() {
* public void configure() {
* bind(Runnable.class);
* }
* }</code></pre>
* ...and at provide-time errors:
* <pre><code>Guice.createInjector().getInstance(Runnable.class);</code></pre>
* Otherwise we need to know who's calling when resolving a just-in-time
* binding, which makes things unnecessarily complex.
*/
public Errors missingImplementation(Key key) {
return addMessage("No implementation for %s was bound.", key);
}
public Errors converterReturnedNull(String stringValue, Object source,
TypeLiteral<?> type, MatcherAndConverter matchingConverter) {
return addMessage("Received null converting '%s' (bound at %s) to %s%n"
+ " using %s.",
stringValue, convert(source), type, matchingConverter);
}
public Errors conversionTypeError(String stringValue, Object source, TypeLiteral<?> type,
MatcherAndConverter matchingConverter, Object converted) {
return addMessage("Type mismatch converting '%s' (bound at %s) to %s%n"
+ " using %s.%n"
+ " Converter returned %s.",
stringValue, convert(source), type, matchingConverter, converted);
}
public Errors conversionError(String stringValue, Object source,
TypeLiteral<?> type, MatcherAndConverter matchingConverter, RuntimeException cause) {
return errorInUserCode(cause, "Error converting '%s' (bound at %s) to %s%n"
+ " using %s.%n"
+ " Reason: %s",
stringValue, convert(source), type, matchingConverter, cause);
}
public Errors ambiguousTypeConversion(String stringValue, Object source, TypeLiteral<?> type,
MatcherAndConverter a, MatcherAndConverter b) {
return addMessage("Multiple converters can convert '%s' (bound at %s) to %s:%n"
+ " %s and%n"
+ " %s.%n"
+ " Please adjust your type converter configuration to avoid overlapping matches.",
stringValue, convert(source), type, a, b);
}
public Errors bindingToProvider() {
return addMessage("Binding to Provider is not allowed.");
}
public Errors subtypeNotProvided(Class<? extends Provider<?>> providerType,
Class<?> type) {
return addMessage("%s doesn't provide instances of %s.", providerType, type);
}
public Errors notASubtype(Class<?> implementationType, Class<?> type) {
return addMessage("%s doesn't extend %s.", implementationType, type);
}
public Errors recursiveImplementationType() {
return addMessage("@ImplementedBy points to the same class it annotates.");
}
public Errors recursiveProviderType() {
return addMessage("@ProvidedBy points to the same class it annotates.");
}
public Errors missingRuntimeRetention(Object source) {
return addMessage("Please annotate with @Retention(RUNTIME).%n"
+ " Bound at %s.", convert(source));
}
public Errors missingScopeAnnotation() {
return addMessage("Please annotate with @ScopeAnnotation.");
}
public Errors optionalConstructor(Constructor constructor) {
return addMessage("%s is annotated @Inject(optional=true), "
+ "but constructors cannot be optional.", constructor);
}
public Errors cannotBindToGuiceType(String simpleName) {
return addMessage("Binding to core guice framework type is not allowed: %s.", simpleName);
}
public Errors scopeNotFound(Class<? extends Annotation> scopeAnnotation) {
return addMessage("No scope is bound to %s.", scopeAnnotation);
}
public Errors scopeAnnotationOnAbstractType(
Class<? extends Annotation> scopeAnnotation, Class<?> type, Object source) {
return addMessage("%s is annotated with %s, but scope annotations are not supported "
+ "for abstract types.%n Bound at %s.", type, scopeAnnotation, convert(source));
}
public Errors misplacedBindingAnnotation(Member member, Annotation bindingAnnotation) {
return addMessage("%s is annotated with %s, but binding annotations should be applied "
+ "to its parameters instead.", member, bindingAnnotation);
}
private static final String CONSTRUCTOR_RULES =
"Classes must have either one (and only one) constructor "
+ "annotated with @Inject or a zero-argument constructor that is not private.";
public Errors missingConstructor(Class<?> implementation) {
return addMessage("Could not find a suitable constructor in %s. " + CONSTRUCTOR_RULES,
implementation);
}
public Errors tooManyConstructors(Class<?> implementation) {
return addMessage("%s has more than one constructor annotated with @Inject. "
+ CONSTRUCTOR_RULES, implementation);
}
public Errors constructorNotDefinedByType(Constructor<?> constructor, TypeLiteral<?> type) {
return addMessage("%s does not define %s", type, constructor);
}
public Errors duplicateScopes(Scope existing,
Class<? extends Annotation> annotationType, Scope scope) {
return addMessage("Scope %s is already bound to %s. Cannot bind %s.", existing,
annotationType, scope);
}
public Errors voidProviderMethod() {
return addMessage("Provider methods must return a value. Do not return void.");
}
public Errors missingConstantValues() {
return addMessage("Missing constant value. Please call to(...).");
}
public Errors cannotInjectInnerClass(Class<?> type) {
return addMessage("Injecting into inner classes is not supported. "
+ "Please use a 'static' class (top-level or nested) instead of %s.", type);
}
public Errors duplicateBindingAnnotations(Member member,
Class<? extends Annotation> a, Class<? extends Annotation> b) {
return addMessage("%s has more than one annotation annotated with @BindingAnnotation: "
+ "%s and %s", member, a, b);
}
public Errors duplicateScopeAnnotations(
Class<? extends Annotation> a, Class<? extends Annotation> b) {
return addMessage("More than one scope annotation was found: %s and %s.", a, b);
}
public Errors recursiveBinding() {
return addMessage("Binding points to itself.");
}
public Errors bindingAlreadySet(Key<?> key, Object source) {
return addMessage("A binding to %s was already configured at %s.", key, convert(source));
}
public Errors childBindingAlreadySet(Key<?> key) {
return addMessage("A binding to %s already exists on a child injector.", key);
}
public Errors errorInjectingMethod(Throwable cause) {
return errorInUserCode(cause, "Error injecting method, %s", cause);
}
public Errors errorNotifyingTypeListener(TypeListenerBinding listener,
TypeLiteral<?> type, Throwable cause) {
return errorInUserCode(cause,
"Error notifying TypeListener %s (bound at %s) of %s.%n"
+ " Reason: %s",
listener.getListener(), convert(listener.getSource()), type, cause);
}
public Errors errorInjectingConstructor(Throwable cause) {
return errorInUserCode(cause, "Error injecting constructor, %s", cause);
}
public Errors errorInProvider(RuntimeException runtimeException) {
return errorInUserCode(runtimeException, "Error in custom provider, %s", runtimeException);
}
public Errors errorInUserInjector(
MembersInjector<?> listener, TypeLiteral<?> type, RuntimeException cause) {
return errorInUserCode(cause, "Error injecting %s using %s.%n"
+ " Reason: %s", type, listener, cause);
}
public Errors errorNotifyingInjectionListener(
InjectionListener<?> listener, TypeLiteral<?> type, RuntimeException cause) {
return errorInUserCode(cause, "Error notifying InjectionListener %s of %s.%n"
+ " Reason: %s", listener, type, cause);
}
public void exposedButNotBound(Key<?> key) {
addMessage("Could not expose() %s, it must be explicitly bound.", key);
}
public static Collection<Message> getMessagesFromThrowable(Throwable throwable) {
if (throwable instanceof ProvisionException) {
return ((ProvisionException) throwable).getErrorMessages();
} else if (throwable instanceof ConfigurationException) {
return ((ConfigurationException) throwable).getErrorMessages();
} else if (throwable instanceof CreationException) {
return ((CreationException) throwable).getErrorMessages();
} else {
return ImmutableSet.of();
}
}
public Errors errorInUserCode(Throwable cause, String messageFormat, Object... arguments) {
Collection<Message> messages = getMessagesFromThrowable(cause);
if (!messages.isEmpty()) {
return merge(messages);
} else {
return addMessage(cause, messageFormat, arguments);
}
}
public Errors cannotInjectRawProvider() {
return addMessage("Cannot inject a Provider that has no type parameter");
}
public Errors cannotInjectRawMembersInjector() {
return addMessage("Cannot inject a MembersInjector that has no type parameter");
}
public Errors cannotInjectTypeLiteralOf(Type unsupportedType) {
return addMessage("Cannot inject a TypeLiteral of %s", unsupportedType);
}
public Errors cannotInjectRawTypeLiteral() {
return addMessage("Cannot inject a TypeLiteral that has no type parameter");
}
public Errors cannotSatisfyCircularDependency(Class<?> expectedType) {
return addMessage(
"Tried proxying %s to support a circular dependency, but it is not an interface.",
expectedType);
}
public void throwCreationExceptionIfErrorsExist() {
if (!hasErrors()) {
return;
}
throw new CreationException(getMessages());
}
public void throwConfigurationExceptionIfErrorsExist() {
if (!hasErrors()) {
return;
}
throw new ConfigurationException(getMessages());
}
public void throwProvisionExceptionIfErrorsExist() {
if (!hasErrors()) {
return;
}
throw new ProvisionException(getMessages());
}
private Message merge(Message message) {
List<Object> sources = Lists.newArrayList();
sources.addAll(getSources());
sources.addAll(message.getSources());
return new Message(sources, message.getMessage(), message.getCause());
}
public Errors merge(Collection<Message> messages) {
for (Message message : messages) {
addMessage(merge(message));
}
return this;
}
public Errors merge(Errors moreErrors) {
if (moreErrors.root == root || moreErrors.root.errors == null) {
return this;
}
merge(moreErrors.root.errors);
return this;
}
public List<Object> getSources() {
List<Object> sources = Lists.newArrayList();
for (Errors e = this; e != null; e = e.parent) {
if (e.source != SourceProvider.UNKNOWN_SOURCE) {
sources.add(0, e.source);
}
}
return sources;
}
public void throwIfNewErrors(int expectedSize) throws ErrorsException {
if (size() == expectedSize) {
return;
}
throw toException();
}
public ErrorsException toException() {
return new ErrorsException(this);
}
public boolean hasErrors() {
return root.errors != null;
}
public Errors addMessage(String messageFormat, Object... arguments) {
return addMessage(null, messageFormat, arguments);
}
private Errors addMessage(Throwable cause, String messageFormat, Object... arguments) {
String message = format(messageFormat, arguments);
addMessage(new Message(getSources(), message, cause));
return this;
}
public Errors addMessage(Message message) {
if (root.errors == null) {
root.errors = Lists.newArrayList();
}
root.errors.add(message);
return this;
}
public static String format(String messageFormat, Object... arguments) {
for (int i = 0; i < arguments.length; i++) {
arguments[i] = Errors.convert(arguments[i]);
}
return String.format(messageFormat, arguments);
}
public List<Message> getMessages() {
if (root.errors == null) {
return ImmutableList.of();
}
List<Message> result = Lists.newArrayList(root.errors);
Collections.sort(result, new Comparator<Message>() {
public int compare(Message a, Message b) {
return a.getSource().compareTo(b.getSource());
}
});
return result;
}
/** Returns the formatted message for an exception with the specified messages. */
public static String format(String heading, Collection<Message> errorMessages) {
Formatter fmt = new Formatter().format(heading).format(":%n%n");
int index = 1;
boolean displayCauses = getOnlyCause(errorMessages) == null;
for (Message errorMessage : errorMessages) {
fmt.format("%s) %s%n", index++, errorMessage.getMessage());
List<Object> dependencies = errorMessage.getSources();
for (int i = dependencies.size() - 1; i >= 0; i--) {
Object source = dependencies.get(i);
formatSource(fmt, source);
}
Throwable cause = errorMessage.getCause();
if (displayCauses && cause != null) {
StringWriter writer = new StringWriter();
cause.printStackTrace(new PrintWriter(writer));
fmt.format("Caused by: %s", writer.getBuffer());
}
fmt.format("%n");
}
if (errorMessages.size() == 1) {
fmt.format("1 error");
} else {
fmt.format("%s errors", errorMessages.size());
}
return fmt.toString();
}
/**
* Returns {@code value} if it is non-null allowed to be null. Otherwise a message is added and
* an {@code ErrorsException} is thrown.
*/
public <T> T checkForNull(T value, Object source, Dependency<?> dependency)
throws ErrorsException {
if (value != null || dependency.isNullable() || allowNullsBadBadBad(dependency)) {
return value;
}
int parameterIndex = dependency.getParameterIndex();
String parameterName = (parameterIndex != -1)
? "parameter " + parameterIndex + " of "
: "";
addMessage("null returned by binding at %s%n but %s%s is not @Nullable",
source, parameterName, dependency.getInjectionPoint().getMember());
throw toException();
}
/**
* Returns the cause throwable if there is exactly one cause in {@code messages}. If there are
* zero or multiple messages with causes, null is returned.
*/
public static Throwable getOnlyCause(Collection<Message> messages) {
Throwable onlyCause = null;
for (Message message : messages) {
Throwable messageCause = message.getCause();
if (messageCause == null) {
continue;
}
if (onlyCause != null) {
return null;
}
onlyCause = messageCause;
}
return onlyCause;
}
public int size() {
return root.errors == null ? 0 : root.errors.size();
}
private static abstract class Converter<T> {
final Class<T> type;
Converter(Class<T> type) {
this.type = type;
}
boolean appliesTo(Object o) {
return type.isAssignableFrom(o.getClass());
}
String convert(Object o) {
return toString(type.cast(o));
}
abstract String toString(T t);
}
private static final Collection<Converter<?>> converters = ImmutableList.of(
new Converter<Class>(Class.class) {
public String toString(Class c) {
return c.getName();
}
},
new Converter<Member>(Member.class) {
public String toString(Member member) {
return MoreTypes.toString(member);
}
},
new Converter<Key>(Key.class) {
public String toString(Key key) {
if (key.getAnnotationType() != null) {
return key.getTypeLiteral() + " annotated with "
+ (key.getAnnotation() != null ? key.getAnnotation() : key.getAnnotationType());
} else {
return key.getTypeLiteral().toString();
}
}
});
public static Object convert(Object o) {
for (Converter<?> converter : converters) {
if (converter.appliesTo(o)) {
return converter.convert(o);
}
}
return o;
}
public static void formatSource(Formatter formatter, Object source) {
if (source instanceof Dependency) {
Dependency<?> dependency = (Dependency<?>) source;
InjectionPoint injectionPoint = dependency.getInjectionPoint();
if (injectionPoint != null) {
formatInjectionPoint(formatter, dependency, injectionPoint);
} else {
formatSource(formatter, dependency.getKey());
}
} else if (source instanceof InjectionPoint) {
formatInjectionPoint(formatter, null, (InjectionPoint) source);
} else if (source instanceof Class) {
formatter.format(" at %s%n", StackTraceElements.forType((Class<?>) source));
} else if (source instanceof Member) {
formatter.format(" at %s%n", StackTraceElements.forMember((Member) source));
} else if (source instanceof TypeLiteral) {
formatter.format(" while locating %s%n", source);
} else if (source instanceof Key) {
Key<?> key = (Key<?>) source;
formatter.format(" while locating %s%n", convert(key));
} else {
formatter.format(" at %s%n", source);
}
}
public static void formatInjectionPoint(Formatter formatter, Dependency<?> dependency,
InjectionPoint injectionPoint) {
Member member = injectionPoint.getMember();
Class<? extends Member> memberType = MoreTypes.memberType(member);
if (memberType == Field.class) {
dependency = injectionPoint.getDependencies().get(0);
formatter.format(" while locating %s%n", convert(dependency.getKey()));
formatter.format(" for field at %s%n", StackTraceElements.forMember(member));
} else if (dependency != null) {
formatter.format(" while locating %s%n", convert(dependency.getKey()));
formatter.format(" for parameter %s at %s%n",
dependency.getParameterIndex(), StackTraceElements.forMember(member));
} else {
formatSource(formatter, injectionPoint.getMember());
}
}
}