com.cognifide.slice.commons.provider.KeyCache Maven / Gradle / Ivy
/*-
* #%L
* Slice - Core
* $Id:$
* $HeadURL:$
* %%
* Copyright (C) 2012 Cognifide Limited
* %%
* 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.
* #L%
*/
package com.cognifide.slice.commons.provider;
import java.util.HashMap;
import java.util.Map;
import com.cognifide.slice.api.qualifier.EmptyObject;
import com.google.inject.Key;
import com.google.inject.Singleton;
@Singleton
public class KeyCache {
private final Map, Key> cache;
public KeyCache() {
cache = new HashMap, Key>();
}
/**
* Create Guice Key object for given class and {@link EmptyObject} annotation. If such key has been
* already created, return cached value.
*
* @param clazz Class to be wrapped by Key object
* @return Key object created using {@code clazz} parameter
*/
@SuppressWarnings("unchecked")
public Key getKey(final Class clazz) {
Key key = (Key) cache.get(clazz);
if (key == null) {
key = Key.get(clazz, EmptyObject.class);
cache.put(clazz, key);
}
return key;
}
}