InjectorHolder.java revision 5dc171fcee4f9e3e144b120a10a51dadbde01f69
/*
* The contents of this file are subject to the terms of the Common Development and
* Distribution License (the License). You may not use this file except in compliance with the
* License.
*
* You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
* specific language governing permission and limitations under the License.
*
* When distributing Covered Software, include this CDDL Header Notice in each file and include
* the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
* Header, with the fields enclosed by brackets [] replaced by your own identifying
* information: "Portions copyright [year] [name of copyright owner]".
*
* Copyright 2013 ForgeRock Inc.
*/
package org.forgerock.openam.forgerockrest.authn;
import com.google.inject.Guice;
import com.google.inject.Injector;
/**
* A singleton holding the Guice Injector instance that other classes can call to get to use dependency injection.
*/
public class InjectorHolder {
private final Injector injector;
/**
* Uses Guice to create an instance of the class given as a parameter.
*
* @param clazz The class to get an instance of.
* @param <T> The type of class to get.
* @return An instance of the class.
*/
public static <T> T getInstance(Class<T> clazz) {
return SingletonHolder.INSTANCE.injector.getInstance(clazz);
}
/**
* Constructs an instance of the InjectorHolder and initialises the Guice Injector.
*/
private InjectorHolder() {
injector = Guice.createInjector(new IdentityRestServiceGuiceModule());
}
/**
* Holder class for the InjectorHolder singleton.
*/
private static final class SingletonHolder {
private static final InjectorHolder INSTANCE = new InjectorHolder();
}
}