SecurityActions.java

/*
 * IronJacamar, a Java EE Connector Architecture implementation
 * Copyright 2014, Red Hat Inc, and individual contributors
 * as indicated by the @author tags. See the copyright.txt file in the
 * distribution for a full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the Eclipse Public License 1.0 as
 * published by the Free Software Foundation.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the Eclipse
 * Public License for more details.
 *
 * You should have received a copy of the Eclipse Public License
 * along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

package org.ironjacamar.core.workmanager;

import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.security.AccessController;
import java.security.PrivilegedAction;

/**
 * Privileged Blocks
 * @author <a href="mailto:jesper.pedersen@ironjacamar.org">Jesper Pedersen</a>
 */
class SecurityActions
{
   /**
    * Constructor
    */
   private SecurityActions()
   {
   }

   /**
    * Get the classloader.
    * @param c The class
    * @return The classloader
    */
   static ClassLoader getClassLoader(final Class<?> c)
   {
      if (System.getSecurityManager() == null)
         return c.getClassLoader();

      return AccessController.doPrivileged(new PrivilegedAction<ClassLoader>()
      {
         public ClassLoader run()
         {
            return c.getClassLoader();
         }
      });
   }

   /**
    * Get the thread context class loader
    * @return The class loader
    */
   static ClassLoader getThreadContextClassLoader()
   {
      return AccessController.doPrivileged(new PrivilegedAction<ClassLoader>()
      {
         @Override
         public ClassLoader run()
         {
            return Thread.currentThread().getContextClassLoader();
         }
      });
   }

   /**
    * Set the thread context class loader
    * @param cl The class loader
    */
   static void setThreadContextClassLoader(final ClassLoader cl)
   {
      AccessController.doPrivileged(new PrivilegedAction<Object>()
      {
         @Override
         public Object run()
         {
            Thread.currentThread().setContextClassLoader(cl);
            return null;
         }
      });
   }

   /**
    * Get the declared classes
    * @param c The class
    * @return The classes
    */
   static Class<?>[] getDeclaredClasses(final Class<?> c)
   {
      if (System.getSecurityManager() == null)
         return c.getDeclaredClasses();

      return AccessController.doPrivileged(new PrivilegedAction<Class<?>[]>()
      {
         public Class<?>[] run()
         {
            return c.getDeclaredClasses();
         }
      });
   }

   /**
    * Get the declared fields
    * @param c The class
    * @return The fields
    */
   static Field[] getDeclaredFields(final Class<?> c)
   {
      if (System.getSecurityManager() == null)
         return c.getDeclaredFields();

      return AccessController.doPrivileged(new PrivilegedAction<Field[]>()
      {
         public Field[] run()
         {
            return c.getDeclaredFields();
         }
      });
   }

   /**
    * Get the declared field
    * @param c The class
    * @param name The name
    * @return The field
    * @exception NoSuchFieldException If a matching field is not found.
    */
   static Field getDeclaredField(final Class<?> c, final String name)
      throws NoSuchFieldException
   {
      if (System.getSecurityManager() == null)
         return c.getDeclaredField(name);

      Field result = AccessController.doPrivileged(new PrivilegedAction<Field>()
      {
         public Field run()
         {
            try
            {
               return c.getDeclaredField(name);
            }
            catch (NoSuchFieldException e)
            {
               return null;
            }
         }
      });

      if (result != null)
         return result;

      throw new NoSuchFieldException();
   }

   /**
    * Set accessible
    * @param ao The object
    */
   static void setAccessible(final AccessibleObject ao)
   {
      if (System.getSecurityManager() == null)
         ao.setAccessible(true);

      AccessController.doPrivileged(new PrivilegedAction<Object>()
      {
         public Object run()
         {
            ao.setAccessible(true);
            return null;
         }
      });
   }

   /**
    * Get the method
    * @param c The class
    * @param name The name
    * @param params The parameters
    * @return The method
    * @exception NoSuchMethodException If a matching method is not found.
    */
   static Method getMethod(final Class<?> c, final String name, final Class<?>... params)
      throws NoSuchMethodException
   {
      if (System.getSecurityManager() == null)
         return c.getMethod(name, params);

      Method result = AccessController.doPrivileged(new PrivilegedAction<Method>()
      {
         public Method run()
         {
            try
            {
               return c.getMethod(name, params);
            }
            catch (NoSuchMethodException e)
            {
               return null;
            }
         }
      });

      if (result != null)
         return result;

      throw new NoSuchMethodException();
   }
}