/*
* Copyright 2008-2016 the original author or authors.
*
* 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.nominanuda.zen.stereotype;
import java.util.HashMap;
import java.util.Map;
public class ScopedSingletonFactory {
private static ScopedSingletonFactory INSTANCE;
public synchronized static ScopedSingletonFactory getInstance() {
if(INSTANCE == null) {
INSTANCE = new ScopedSingletonFactory();
}
return INSTANCE;
}
private static final Object JVM_SCOPE = new Object();
private Map<Object, Map<Class<?>, Object>> scopes = new HashMap<>();
public <V> V buildJvmSingleton(Class<V> clazz) throws IllegalArgumentException {
return buildScopedSingleton(JVM_SCOPE, clazz);
}
@SuppressWarnings("unchecked")
public <V> V buildScopedSingleton(Object appScope, Class<V> clazz) {
try {
Map<Class<?>, Object> scope = scopes.get(appScope);
if(scope == null) {
scope = new HashMap<>();
scopes.put(appScope, scope);
}
Object o = scope.get(clazz);
if(o != null) {
return (V)o;
} else {
V v = clazz.newInstance();
scope.put(clazz, v);
return v;
}
} catch (Exception e) {
throw new IllegalArgumentException(e);
}
}
}