/**
* Copyright 2006-2017 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 org.objenesis;
import org.objenesis.instantiator.
ObjectInstantiator;
import org.objenesis.strategy.
InstantiatorStrategy;
import java.util.concurrent.
ConcurrentHashMap;
/**
* Base class to extend if you want to have a class providing your own default strategy. Can also be
* instantiated directly.
*
* @author Henri Tremblay
*/
public class
ObjenesisBase implements
Objenesis {
/** Strategy used by this Objenesi implementation to create classes */
protected final
InstantiatorStrategy strategy;
/** Strategy cache. Key = Class, Value = InstantiatorStrategy */
protected
ConcurrentHashMap<
String,
ObjectInstantiator<?>>
cache;
/**
* Constructor allowing to pick a strategy and using cache
*
* @param strategy Strategy to use
*/
public
ObjenesisBase(
InstantiatorStrategy strategy) {
this(
strategy, true);
}
/**
* Flexible constructor allowing to pick the strategy and if caching should be used
*
* @param strategy Strategy to use
* @param useCache If {@link ObjectInstantiator}s should be cached
*/
public
ObjenesisBase(
InstantiatorStrategy strategy, boolean
useCache) {
if(
strategy == null) {
throw new
IllegalArgumentException("A strategy can't be null");
}
this.
strategy =
strategy;
this.
cache =
useCache ? new
ConcurrentHashMap<
String,
ObjectInstantiator<?>>() : null;
}
@
Override
public
String toString() {
return
getClass().
getName() + " using " +
strategy.
getClass().
getName()
+ (
cache == null ? " without" : " with") + " caching";
}
/**
* Will create a new object without any constructor being called
*
* @param clazz Class to instantiate
* @return New instance of clazz
*/
public <T> T
newInstance(
Class<T>
clazz) {
return
getInstantiatorOf(
clazz).
newInstance();
}
/**
* Will pick the best instantiator for the provided class. If you need to create a lot of
* instances from the same class, it is way more efficient to create them from the same
* ObjectInstantiator than calling {@link #newInstance(Class)}.
*
* @param clazz Class to instantiate
* @return Instantiator dedicated to the class
*/
@
SuppressWarnings("unchecked")
public <T>
ObjectInstantiator<T>
getInstantiatorOf(
Class<T>
clazz) {
if(
clazz.
isPrimitive()) {
throw new
IllegalArgumentException("Primitive types can't be instantiated in Java");
}
if(
cache == null) {
return
strategy.
newInstantiatorOf(
clazz);
}
ObjectInstantiator<?>
instantiator =
cache.
get(
clazz.
getName());
if(
instantiator == null) {
ObjectInstantiator<?>
newInstantiator =
strategy.
newInstantiatorOf(
clazz);
instantiator =
cache.
putIfAbsent(
clazz.
getName(),
newInstantiator);
if(
instantiator == null) {
instantiator =
newInstantiator;
}
}
return (
ObjectInstantiator<T>)
instantiator;
}
}