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/*
* Copyright (C) 2007 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 org.elasticsearch.common.inject.assistedinject;
import org.elasticsearch.common.inject.BindingAnnotation;
import org.elasticsearch.common.inject.ConfigurationException;
import org.elasticsearch.common.inject.Injector;
import org.elasticsearch.common.inject.Key;
import org.elasticsearch.common.inject.Provider;
import java.lang.annotation.Annotation;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
/**
* Models a method or constructor parameter.
*
* @author [email protected] (Jerome Mourits)
* @author [email protected] (Jesse Wilson)
*/
class Parameter {
private final Type type;
private final boolean isAssisted;
private final Annotation bindingAnnotation;
private final boolean isProvider;
public Parameter(Type type, Annotation[] annotations) {
this.type = type;
this.bindingAnnotation = getBindingAnnotation(annotations);
this.isAssisted = hasAssistedAnnotation(annotations);
this.isProvider = isProvider(type);
}
public boolean isProvidedByFactory() {
return isAssisted;
}
public Type getType() {
return type;
}
@Override
public String toString() {
StringBuilder result = new StringBuilder();
if (isAssisted) {
result.append("@Assisted");
result.append(" ");
}
if (bindingAnnotation != null) {
result.append(bindingAnnotation.toString());
result.append(" ");
}
result.append(type.toString());
return result.toString();
}
private boolean hasAssistedAnnotation(Annotation[] annotations) {
for (Annotation annotation : annotations) {
if (annotation.annotationType().equals(Assisted.class)) {
return true;
}
}
return false;
}
/**
* Returns the Guice {@link Key} for this parameter.
*/
public Object getValue(Injector injector) {
return isProvider
? injector.getProvider(getBindingForType(getProvidedType(type)))
: injector.getInstance(getPrimaryBindingKey());
}
Key getPrimaryBindingKey() {
return isProvider
? getBindingForType(getProvidedType(type))
: getBindingForType(type);
}
private Type getProvidedType(Type type) {
return ((ParameterizedType) type).getActualTypeArguments()[0];
}
private boolean isProvider(Type type) {
return type instanceof ParameterizedType
&& ((ParameterizedType) type).getRawType() == Provider.class;
}
private Key getBindingForType(Type type) {
return bindingAnnotation != null
? Key.get(type, bindingAnnotation)
: Key.get(type);
}
/**
* Returns the unique binding annotation from the specified list, or
* {@code null} if there are none.
*
* @throws IllegalStateException if multiple binding annotations exist.
*/
private Annotation getBindingAnnotation(Annotation[] annotations) {
Annotation bindingAnnotation = null;
for (Annotation a : annotations) {
if (a.annotationType().getAnnotation(BindingAnnotation.class) != null) {
if (bindingAnnotation != null) {
throw new IllegalArgumentException("Parameter has multiple binding annotations: " + bindingAnnotation + " and " + a);
}
bindingAnnotation = a;
}
}
return bindingAnnotation;
}
}