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/*
* 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.shrinkwrap.api;
import java.lang.reflect.Constructor;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.util.Arrays;
/**
* 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>() {
@Override
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);
}
}
}
}
/**
* Creates a new instance of the specified {@link Class} using the specified construction arguments. Casts and
* returns as the specified expected type
*
* @param
* @param clazz
* @param argumentTypes
* @param arguments
* @param expectedType
* @return
*/
static T newInstance(final Class clazz, final Class[] argumentTypes, final Object[] arguments,
final Class expectedType) {
// Precondition checks
if (clazz == null) {
throw new IllegalArgumentException("Class 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");
}
if (expectedType == null) {
throw new IllegalArgumentException("Expected type must be specified");
}
// Get the ctor
final Constructor constructor;
try {
constructor = getConstructor(clazz, argumentTypes);
} catch (final NoSuchMethodException e) {
throw new RuntimeException("Could not create new instance of " + clazz + " using ctor argument types "
+ Arrays.asList(argumentTypes), e);
}
// Create the instance
final Object obj;
try {
obj = constructor.newInstance(arguments);
} catch (final Exception e) {
throw new RuntimeException("Could not create a new instance of " + clazz + " using arguments "
+ Arrays.asList(arguments), 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());
}
}
/**
* 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
* @param cl
* The ClassLoader to use in constructing the new instance
* @return a new instance
* @throws IllegalArgumentException
* if className, argumentTypes, ClassLoader, 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, final ClassLoader cl) {
// Precondition checks
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");
}
if (expectedType == null) {
throw new IllegalArgumentException("Expected type must be specified");
}
if (cl == null) {
throw new IllegalArgumentException("CL must be specified");
}
final Class implClass;
try {
implClass = Class.forName(className, false, cl);
} catch (ClassNotFoundException cnfe) {
throw new IllegalArgumentException("Could not find class named " + className + " in the specified CL: "
+ cl, cnfe);
}
// Delegate
return newInstance(implClass, argumentTypes, arguments, expectedType);
}
// -------------------------------------------------------------------------------||
// Inner Classes ----------------------------------------------------------------||
// -------------------------------------------------------------------------------||
/**
* Single instance to get the TCCL
*/
private enum GetTcclAction implements PrivilegedAction {
INSTANCE;
@Override
public ClassLoader run() {
return Thread.currentThread().getContextClassLoader();
}
}
}