org.jboss.arquillian.spi.util.SecurityActions Maven / Gradle / Ivy
/*
* JBoss, Home of Professional Open Source
* Copyright 2009, Red Hat Middleware LLC, and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* 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.jboss.arquillian.spi.util;
import java.lang.reflect.Constructor;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
/**
* SecurityActions
*
* A set of privileged actions that are not to leak out
* of this package
*
* @author ALR
* @version $Revision: $
*/
final class SecurityActions
{
//-------------------------------------------------------------------------------||
// Constructor ------------------------------------------------------------------||
//-------------------------------------------------------------------------------||
/**
* No instantiation
*/
private SecurityActions()
{
throw new UnsupportedOperationException("No instantiation");
}
//-------------------------------------------------------------------------------||
// Utility Methods --------------------------------------------------------------||
//-------------------------------------------------------------------------------||
/**
* Obtains the Thread Context ClassLoader
*/
static ClassLoader getThreadContextClassLoader()
{
return AccessController.doPrivileged(GetTcclAction.INSTANCE);
}
/**
* Obtains the Constructor specified from the given Class and argument types
* @param clazz
* @param argumentTypes
* @return
* @throws NoSuchMethodException
*/
static Constructor getConstructor(final Class clazz, final Class... argumentTypes)
throws NoSuchMethodException
{
try
{
return AccessController.doPrivileged(new PrivilegedExceptionAction>()
{
public Constructor run() throws NoSuchMethodException
{
return clazz.getConstructor(argumentTypes);
}
});
}
// Unwrap
catch (final PrivilegedActionException pae)
{
final Throwable t = pae.getCause();
// Rethrow
if (t instanceof NoSuchMethodException)
{
throw (NoSuchMethodException) t;
}
else
{
// No other checked Exception thrown by Class.getConstructor
try
{
throw (RuntimeException) t;
}
// Just in case we've really messed up
catch (final ClassCastException cce)
{
throw new RuntimeException("Obtained unchecked Exception; this code should never be reached", t);
}
}
}
}
/**
* Create a new instance by finding a constructor that matches the argumentTypes signature
* using the arguments for instantiation.
*
* @param className Full classname of class to create
* @param argumentTypes The constructor argument types
* @param arguments The constructor arguments
* @return a new instance
* @throws IllegalArgumentException if className, argumentTypes, or arguments are null
* @throws RuntimeException if any exceptions during creation
* @author Aslak Knutsen
* @author ALR
*/
static T newInstance(final String className, final Class[] argumentTypes, final Object[] arguments,
final Class expectedType)
{
if (className == null)
{
throw new IllegalArgumentException("ClassName must be specified");
}
if (argumentTypes == null)
{
throw new IllegalArgumentException("ArgumentTypes must be specified. Use empty array if no arguments");
}
if (arguments == null)
{
throw new IllegalArgumentException("Arguments must be specified. Use empty array if no arguments");
}
final Object obj;
try
{
final ClassLoader tccl = getThreadContextClassLoader();
final Class implClass = Class.forName(className, false, tccl);
Constructor constructor = getConstructor(implClass, argumentTypes);
obj = constructor.newInstance(arguments);
}
catch (Exception e)
{
throw new RuntimeException("Could not create new instance of " + className
+ ", missing package from classpath?", e);
}
// Cast
try
{
return expectedType.cast(obj);
}
catch (final ClassCastException cce)
{
// Reconstruct so we get some useful information
throw new ClassCastException("Incorrect expected type, " + expectedType.getName() + ", defined for "
+ obj.getClass().getName());
}
}
//-------------------------------------------------------------------------------||
// Inner Classes ----------------------------------------------------------------||
//-------------------------------------------------------------------------------||
/**
* Single instance to get the TCCL
*/
private enum GetTcclAction implements PrivilegedAction {
INSTANCE;
public ClassLoader run()
{
return Thread.currentThread().getContextClassLoader();
}
}
}