/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.camel.guice.support;
import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.List;
import java.util.Map;
import java.util.Set;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.common.collect.Sets;
import com.google.inject.AbstractModule;
import com.google.inject.Key;
import com.google.inject.MembersInjector;
import com.google.inject.Provider;
import com.google.inject.ProvisionException;
import com.google.inject.TypeLiteral;
import com.google.inject.binder.LinkedBindingBuilder;
import com.google.inject.matcher.AbstractMatcher;
import com.google.inject.name.Names;
import com.google.inject.spi.InjectionListener;
import com.google.inject.spi.TypeEncounter;
import com.google.inject.spi.TypeListener;
import org.apache.camel.guice.inject.Configures;
import org.apache.camel.guice.support.internal.MethodKey;
import static com.google.inject.matcher.Matchers.any;
import static org.apache.camel.guice.support.EncounterProvider.encounterProvider;
/**
* Adds some new helper methods to the base Guice module
*
* @version
*/
@SuppressWarnings({ "rawtypes", "unchecked" })
public abstract class GuiceyFruitModule extends AbstractModule {
protected void configure() {
// lets find all of the configures methods
List<Method> configureMethods = getConfiguresMethods();
if (!configureMethods.isEmpty()) {
final GuiceyFruitModule moduleInstance = this;
final Class<? extends GuiceyFruitModule> moduleType = getClass();
TypeLiteral<? extends GuiceyFruitModule> type = TypeLiteral
.get(moduleType);
for (final Method method : configureMethods) {
int size = method.getParameterTypes().length;
if (size == 0) {
throw new ProvisionException(
"No arguments on @Configures method " + method);
} else if (size > 1) {
throw new ProvisionException("Too many arguments " + size
+ " on @Configures method " + method);
}
final Class<?> paramType = getParameterType(type, method, 0);
bindListener(new AbstractMatcher<TypeLiteral<?>>() {
public boolean matches(TypeLiteral<?> typeLiteral) {
return typeLiteral.getRawType().equals(paramType);
}
}, new TypeListener() {
public <I> void hear(TypeLiteral<I> injectableType,
TypeEncounter<I> encounter) {
encounter.register(new MembersInjector<I>() {
public void injectMembers(I injectee) {
// lets invoke the configures method
try {
method.setAccessible(true);
method.invoke(moduleInstance, injectee);
} catch (IllegalAccessException e) {
throw new ProvisionException(
"Failed to invoke @Configures method "
+ method + ". Reason: " + e,
e);
} catch (InvocationTargetException ie) {
Throwable e = ie.getTargetException();
throw new ProvisionException(
"Failed to invoke @Configures method "
+ method + ". Reason: " + e,
e);
}
}
});
}
});
}
}
}
private List<Method> getConfiguresMethods() {
List<Method> answer = Lists.newArrayList();
List<Method> list = Reflectors.getAllMethods(getClass());
for (Method method : list) {
if (method.getAnnotation(Configures.class) != null) {
answer.add(method);
}
}
return answer;
}
/**
* Binds a post injection hook method annotated with the given annotation to
* the given method handler.
*/
protected <A extends Annotation> void bindMethodHandler(
final Class<A> annotationType, final MethodHandler methodHandler) {
bindMethodHandler(annotationType, encounterProvider(methodHandler));
}
/**
* Binds a post injection hook method annotated with the given annotation to
* the given method handler.
*/
protected <A extends Annotation> void bindMethodHandler(
final Class<A> annotationType,
final Key<? extends MethodHandler> methodHandlerKey) {
bindMethodHandler(annotationType, encounterProvider(methodHandlerKey));
}
/**
* Binds a post injection hook method annotated with the given annotation to
* the given method handler.
*/
protected <A extends Annotation> void bindMethodHandler(
final Class<A> annotationType,
final Class<? extends MethodHandler> methodHandlerType) {
bindMethodHandler(annotationType, encounterProvider(methodHandlerType));
}
private <A extends Annotation> void bindMethodHandler(
final Class<A> annotationType,
final EncounterProvider<MethodHandler> encounterProvider) {
bindListener(any(), new TypeListener() {
public <I> void hear(TypeLiteral<I> injectableType,
TypeEncounter<I> encounter) {
Class<? super I> type = injectableType.getRawType();
Method[] methods = type.getDeclaredMethods();
for (final Method method : methods) {
final A annotation = method.getAnnotation(annotationType);
if (annotation != null) {
final Provider<? extends MethodHandler> provider = encounterProvider
.get(encounter);
encounter.register(new InjectionListener<I>() {
public void afterInjection(I injectee) {
MethodHandler methodHandler = provider.get();
try {
methodHandler.afterInjection(injectee,
annotation, method);
} catch (InvocationTargetException ie) {
Throwable e = ie.getTargetException();
throw new ProvisionException(
e.getMessage(), e);
} catch (IllegalAccessException e) {
throw new ProvisionException(
e.getMessage(), e);
}
}
});
}
}
}
});
}
/**
* Binds a custom injection point for a given injection annotation to the
* annotation member provider so that occurrences of the annotation on
* fields and methods with a single parameter will be injected by Guice
* after the constructor and @Inject have been processed.
*
* @param annotationType
* the annotation class used to define the injection point
* @param annotationMemberProviderKey
* the key of the annotation member provider which can be
* instantiated and injected by guice
* @param <A>
* the annotation type used as the injection point
*/
protected <A extends Annotation> void bindAnnotationInjector(
Class<A> annotationType,
Key<? extends AnnotationMemberProvider> annotationMemberProviderKey) {
bindAnnotationInjector(annotationType,
encounterProvider(annotationMemberProviderKey));
}
/**
* Binds a custom injection point for a given injection annotation to the
* annotation member provider so that occurrences of the annotation on
* fields and methods with a single parameter will be injected by Guice
* after the constructor and @Inject have been processed.
*
* @param annotationType
* the annotation class used to define the injection point
* @param annotationMemberProvider
* the annotation member provider which can be instantiated and
* injected by guice
* @param <A>
* the annotation type used as the injection point
*/
protected <A extends Annotation> void bindAnnotationInjector(
Class<A> annotationType,
AnnotationMemberProvider annotationMemberProvider) {
bindAnnotationInjector(annotationType,
encounterProvider(annotationMemberProvider));
}
/**
* Binds a custom injection point for a given injection annotation to the
* annotation member provider so that occurrences of the annotation on
* fields and methods with a single parameter will be injected by Guice
* after the constructor and @Inject have been processed.
*
* @param annotationType
* the annotation class used to define the injection point
* @param annotationMemberProviderType
* the type of the annotation member provider which can be
* instantiated and injected by guice
* @param <A>
* the annotation type used as the injection point
*/
protected <A extends Annotation> void bindAnnotationInjector(
Class<A> annotationType,
Class<? extends AnnotationMemberProvider> annotationMemberProviderType) {
bindAnnotationInjector(annotationType,
encounterProvider(annotationMemberProviderType));
}
private <A extends Annotation> void bindAnnotationInjector(
final Class<A> annotationType,
final EncounterProvider<AnnotationMemberProvider> memberProviderProvider) {
bindListener(any(), new TypeListener() {
Provider<? extends AnnotationMemberProvider> providerProvider;
public <I> void hear(TypeLiteral<I> injectableType,
TypeEncounter<I> encounter) {
Set<Field> boundFields = Sets.newHashSet();
Map<MethodKey, Method> boundMethods = Maps.newHashMap();
TypeLiteral<?> startType = injectableType;
while (true) {
Class<?> type = startType.getRawType();
if (type == Object.class) {
break;
}
Field[] fields = type.getDeclaredFields();
for (Field field : fields) {
if (boundFields.add(field)) {
bindAnnotationInjectorToField(encounter, startType,
field);
}
}
Method[] methods = type.getDeclaredMethods();
for (final Method method : methods) {
MethodKey key = new MethodKey(method);
if (boundMethods.get(key) == null) {
boundMethods.put(key, method);
bindAnnotationInjectionToMember(encounter,
startType, method);
}
}
Class<?> supertype = type.getSuperclass();
if (supertype == Object.class) {
break;
}
startType = startType.getSupertype(supertype);
}
}
protected <I> void bindAnnotationInjectionToMember(
final TypeEncounter<I> encounter,
final TypeLiteral<?> type, final Method method) {
// TODO lets exclude methods with @Inject?
final A annotation = method.getAnnotation(annotationType);
if (annotation != null) {
if (providerProvider == null) {
providerProvider = memberProviderProvider
.get(encounter);
}
encounter.register(new MembersInjector<I>() {
public void injectMembers(I injectee) {
AnnotationMemberProvider provider = providerProvider
.get();
int size = method.getParameterTypes().length;
Object[] values = new Object[size];
for (int i = 0; i < size; i++) {
Class<?> paramType = getParameterType(type,
method, i);
Object value = provider.provide(annotation,
type, method, paramType, i);
checkInjectedValueType(value, paramType,
encounter);
// if we have a null value then assume the
// injection point cannot be satisfied
// which is the spring @Autowired way of doing
// things
if (value == null
&& !provider.isNullParameterAllowed(
annotation, method, paramType,
i)) {
return;
}
values[i] = value;
}
try {
method.setAccessible(true);
method.invoke(injectee, values);
} catch (IllegalAccessException e) {
throw new ProvisionException(
"Failed to inject method " + method
+ ". Reason: " + e, e);
} catch (InvocationTargetException ie) {
Throwable e = ie.getTargetException();
throw new ProvisionException(
"Failed to inject method " + method
+ ". Reason: " + e, e);
}
}
});
}
}
protected <I> void bindAnnotationInjectorToField(
final TypeEncounter<I> encounter,
final TypeLiteral<?> type, final Field field) {
// TODO lets exclude fields with @Inject?
final A annotation = field.getAnnotation(annotationType);
if (annotation != null) {
if (providerProvider == null) {
providerProvider = memberProviderProvider
.get(encounter);
}
encounter.register(new InjectionListener<I>() {
public void afterInjection(I injectee) {
AnnotationMemberProvider provider = providerProvider
.get();
Object value = provider.provide(annotation, type,
field);
checkInjectedValueType(value, field.getType(),
encounter);
try {
field.setAccessible(true);
field.set(injectee, value);
} catch (IllegalAccessException e) {
throw new ProvisionException(
"Failed to inject field " + field
+ ". Reason: " + e, e);
}
}
});
}
}
});
}
protected Class<?> getParameterType(TypeLiteral<?> type, Method method,
int i) {
Class<?>[] parameterTypes = method.getParameterTypes();
List<TypeLiteral<?>> list = type.getParameterTypes(method);
TypeLiteral<?> typeLiteral = list.get(i);
Class<?> paramType = typeLiteral.getRawType();
if (paramType == Object.class || paramType.isArray()
&& paramType.getComponentType() == Object.class) {
// if the TypeLiteral ninja doesn't work, lets fall back to the
// actual type
paramType = parameterTypes[i];
}
return paramType;
}
/*
* protected void bindCloseHook() { bindListener(any(), new Listener() {
* public <I> void hear(InjectableType<I> injectableType, Encounter<I>
* encounter) { encounter.registerPostInjectListener(new
* InjectionListener<I>() { public void afterInjection(I injectee) {
*
* } }); } }); }
*/
/**
* Returns true if the value to be injected is of the correct type otherwise
* an error is raised on the encounter and false is returned
*/
protected <I> void checkInjectedValueType(Object value, Class<?> type,
TypeEncounter<I> encounter) {
// TODO check the type
}
/**
* A helper method to bind the given type with the binding annotation.
*
* This allows you to replace this code
* <code> bind(Key.get(MyType.class, SomeAnnotation.class))
* </code>
*
* with this <code> bind(KMyType.class, SomeAnnotation.class) </code>
*/
protected <T> LinkedBindingBuilder<T> bind(Class<T> type,
Class<? extends Annotation> annotationType) {
return bind(Key.get(type, annotationType));
}
/**
* A helper method to bind the given type with the binding annotation.
*
* This allows you to replace this code
* <code> bind(Key.get(MyType.class, someAnnotation))
* </code>
*
* with this <code> bind(KMyType.class, someAnnotation) </code>
*/
protected <T> LinkedBindingBuilder<T> bind(Class<T> type,
Annotation annotation) {
return bind(Key.get(type, annotation));
}
/**
* A helper method to bind the given type with the
* {@link com.google.inject.name.Named} annotation of the given text value.
*
* This allows you to replace this code
* <code> bind(Key.get(MyType.class, Names.named("myName")))
* </code>
*
* with this <code> bind(KMyType.class, "myName") </code>
*/
protected <T> LinkedBindingBuilder<T> bind(Class<T> type, String namedText) {
return bind(type, Names.named(namedText));
}
/**
* A helper method which binds a named instance to a key defined by the
* given name and the instances type. So this method is short hand for
*
* <code> bind(instance.getClass(), name).toInstance(instance); </code>
*/
protected <T> void bindInstance(String name, T instance) {
// TODO not sure the generics ninja to avoid this cast
Class<T> aClass = (Class<T>) instance.getClass();
bind(aClass, name).toInstance(instance);
}
}