/*
*
* Copyright 2010-2014 Orient Technologies LTD (info(at)orientechnologies.com)
*
* 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.orientechnologies.common.factory;
import com.orientechnologies.common.exception.OException;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Set;
/**
* Configurable stateful factory. New instances are created when newInstance() is called, invoking its default empty constructor.
*
* @param <K>
* Factory key
* @param <V>
* Instance type
*/
public class OConfigurableStatefulFactory<K, V> {
protected final Map<K, Class<? extends V>> registry = new LinkedHashMap<K, Class<? extends V>>();
protected Class<? extends V> defaultClass;
public Class<? extends V> get(final K iKey) {
return registry.get(iKey);
}
public V newInstance(final K iKey) {
if (iKey == null && defaultClass == null)
throw new IllegalArgumentException("Cannot create implementation for type null");
final Class<? extends V> cls = registry.get(iKey);
if (cls != null) {
try {
return cls.newInstance();
} catch (Exception e) {
throw new OException(String.format("Error on creating new instance of class '%s' registered in factory with key '%s'", cls,
iKey), e);
}
}
return newInstanceOfDefaultClass();
}
public V newInstanceOfDefaultClass() {
if (defaultClass != null) {
try {
return defaultClass.newInstance();
} catch (Exception e) {
throw new OException(String.format("Error on creating new instance of default class '%s'", defaultClass), e);
}
}
return null;
}
public Set<K> getKeys()
{
return registry.keySet();
}
public OConfigurableStatefulFactory<K, V> register(final K iKey, final Class<? extends V> iValue) {
registry.put(iKey, iValue);
return this;
}
public OConfigurableStatefulFactory<K, V> unregister(final K iKey) {
registry.remove(iKey);
return this;
}
public OConfigurableStatefulFactory<K, V> unregisterAll() {
registry.clear();
return this;
}
public Class<? extends V> getDefaultClass() {
return defaultClass;
}
public <C extends Class<? extends V>> OConfigurableStatefulFactory<K, V> setDefaultClass(final C defaultClass) {
this.defaultClass = defaultClass;
return this;
}
}