/** | |
* Copyright 2006-2016 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 org.objenesis.instantiator.sun; | |
import org.objenesis.ObjenesisException; | |
import org.objenesis.instantiator.ObjectInstantiator; | |
import java.lang.reflect.Field; | |
import java.lang.reflect.Method; | |
/** | |
* Instantiates an object, WITHOUT calling it's constructor, using | |
* sun.misc.Unsafe.allocateInstance(). Unsafe and its methods are implemented by most | |
* modern JVMs. | |
* | |
* @author Henri Tremblay | |
* @see ObjectInstantiator | |
*/ | |
@SuppressWarnings("restriction") | |
public class UnsafeFactoryInstantiator<T> implements ObjectInstantiator<T> { | |
private static Object unsafe; | |
private static Method allocateInstance; | |
private final Class<T> type; | |
public UnsafeFactoryInstantiator(Class<T> type) { | |
if (unsafe == null) { | |
Class<?> unsafeClass; | |
try { | |
unsafeClass = Class.forName("sun.misc.Unsafe"); | |
} catch (ClassNotFoundException e) { | |
throw new ObjenesisException(e); | |
} | |
Field f; | |
try { | |
f = unsafeClass.getDeclaredField("theUnsafe"); | |
} catch (NoSuchFieldException e) { | |
throw new ObjenesisException(e); | |
} | |
f.setAccessible(true); | |
try { | |
unsafe = f.get(null); | |
} catch (IllegalAccessException e) { | |
throw new ObjenesisException(e); | |
} | |
try { | |
allocateInstance = unsafeClass.getMethod("allocateInstance", Class.class); | |
} catch (NoSuchMethodException e) { | |
throw new ObjenesisException(e); | |
} | |
} | |
this.type = type; | |
} | |
public T newInstance() { | |
try { | |
return type.cast(allocateInstance.invoke(unsafe, type)); | |
} catch (Exception e) { | |
throw new ObjenesisException(e); | |
} | |
} | |
} |