llvm-gcc-4.2/libjava/classpath/gnu/java/rmi/server/RMIClassLoaderImpl.java - llvm-archive - Git at Google

 /* RMIClassLoaderImpl.java -- FIXME: briefly describe file purpose
    Copyright (C) 2005 Free Software Foundation, Inc.

 This file is part of GNU Classpath.

 GNU Classpath is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; either version 2, or (at your option)
 any later version.

 GNU Classpath 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 GNU
 General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with GNU Classpath; see the file COPYING.  If not, write to the
 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 02110-1301 USA.

 Linking this library statically or dynamically with other modules is
 making a combined work based on this library.  Thus, the terms and
 conditions of the GNU General Public License cover the whole
 combination.

 As a special exception, the copyright holders of this library give you
 permission to link this library with independent modules to produce an
 executable, regardless of the license terms of these independent
 modules, and to copy and distribute the resulting executable under
 terms of your choice, provided that you also meet, for each linked
 independent module, the terms and conditions of the license of that
 module.  An independent module is a module which is not derived from
 or based on this library.  If you modify this library, you may extend
 this exception to your version of the library, but you are not
 obligated to do so.  If you do not wish to do so, delete this
 exception statement from your version. */


 package gnu.java.rmi.server;

 import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.rmi.server.RMIClassLoaderSpi;
 import java.util.ArrayList;
 import java.util.Hashtable;
 import java.util.Map;
 import java.util.StringTokenizer;

 /**
  * The default implementation of {@link java.rmi.server.RMIClassLoaderSpi}.
  *
  * @author Roman Kennke (kennke@aicas.com)
  */
 public class RMIClassLoaderImpl extends RMIClassLoaderSpi
 {
   private static class MyClassLoader extends URLClassLoader
   {
     // Package-private to avoid a trampoline constructor.
     MyClassLoader (URL[] urls, ClassLoader parent, String annotation)
     {
       super (urls, parent);
       this.annotation = annotation;
     }

     private MyClassLoader (URL[] urls, ClassLoader parent)
     {
       super (urls, parent);
       this.annotation = urlToAnnotation (urls);
     }

     public static String urlToAnnotation (URL[] urls)
     {
       if (urls.length == 0)
         return null;

       StringBuffer annotation = new StringBuffer (64 * urls.length);

       for (int i = 0; i < urls.length; i++)
       {
         annotation.append (urls [i].toExternalForm());
         annotation.append (' ');
       }

       return annotation.toString();
     }

     public final String getClassAnnotation()
     {
       return annotation;
     }

     private final String annotation;
   }

   /**
    * This class is used to identify a cached classloader by its codebase and
    * the context classloader that is its parent.
    */
   private static class CacheKey
   {
      private String mCodeBase;
      private ClassLoader mContextClassLoader;

      public CacheKey (String theCodebase, ClassLoader theContextClassLoader)
      {
        mCodeBase = theCodebase;
        mContextClassLoader = theContextClassLoader;
      }

     /**
      * @return true if the codebase and the context classloader are equal
      */
     public boolean equals (Object theOther)
     {
       if (theOther instanceof CacheKey)
       {
         CacheKey key = (CacheKey) theOther;

         return (equals (this.mCodeBase,key.mCodeBase)
                 && equals (this.mContextClassLoader, key.mContextClassLoader));
         }
       return false;
     }

     /**
      * Test if the two objects are equal or both null.
      * @param theOne
      * @param theOther
      * @return
      */
     private boolean equals (Object theOne, Object theOther)
     {
       return theOne != null ? theOne.equals (theOther) : theOther == null;
     }

     /**
      * @return hashCode
      */
     public int hashCode()
     {
       return ((mCodeBase != null           ? mCodeBase.hashCode()           :  0)
               ^(mContextClassLoader != null ? mContextClassLoader.hashCode() : -1));
     }

     public String toString()
     {
       return "[" + mCodeBase + "," + mContextClassLoader + "]";
     }

   }

   private static RMIClassLoaderImpl instance = null;

   private static Map cacheLoaders; //map annotations to loaders
   private static Map cacheAnnotations; //map loaders to annotations
   //class loader for defaultAnnotation
   private static MyClassLoader defaultClassLoader;

   //defaultAnnotation is got from system property
   // "java.rmi.server.defaultAnnotation"
   private static String defaultAnnotation;

   //URL object for defaultAnnotation
   private static URL defaultCodebase;

   static
   {
     // 89 is a nice prime number for Hashtable initial capacity
     cacheLoaders = new Hashtable (89);
     cacheAnnotations = new Hashtable (89);

     defaultAnnotation = System.getProperty ("java.rmi.server.defaultAnnotation");

     try
       {
         if (defaultAnnotation != null)
           defaultCodebase = new URL (defaultAnnotation);
       }
     catch (Exception _)
       {
         defaultCodebase = null;
       }

     if (defaultCodebase != null)
       {
         defaultClassLoader = new MyClassLoader (new URL[] { defaultCodebase }, null,
                                                defaultAnnotation);
         cacheLoaders.put (new CacheKey (defaultAnnotation,
                                         Thread.currentThread().getContextClassLoader()),
                                         defaultClassLoader);
       }
     }

   /**
    * This is a singleton class and may only be instantiated once from within
    * the {@link #getInstance} method.
    */
   private RMIClassLoaderImpl()
   {
   }

   /**
    * Returns an instance of RMIClassLoaderImpl.
    *
    * @return an instance of RMIClassLoaderImpl
    */
   public static RMIClassLoaderSpi getInstance()
   {
     if (instance == null)
       instance = new RMIClassLoaderImpl();
     return instance;
   }

   public Class loadClass(String codeBase, String name,
                          ClassLoader defaultLoader)
     throws MalformedURLException, ClassNotFoundException
   {
     ClassLoader loader;
     if (defaultLoader == null)
       loader = Thread.currentThread().getContextClassLoader();
     else
       loader = defaultLoader;

     //try context class loader first
     try
       {
         return Class.forName(name, false, loader);
       }
     catch (ClassNotFoundException e)
       {
         // class not found in the local classpath
       }

     if (codeBase.length() == 0) //==""
       {
         loader = defaultClassLoader;
       }
     else
       {
         loader = getClassLoader(codeBase);
       }

     if (loader == null)
       {
         //do not throw NullPointerException
         throw new ClassNotFoundException ("Could not find class (" + name +
                                           ") at codebase (" + codeBase + ")");
       }

     return Class.forName(name, false, loader);
   }

   public Class loadProxyClass(String codeBase, String[] interfaces,
                               ClassLoader defaultLoader)
       throws MalformedURLException, ClassNotFoundException
   {
     // FIXME: Implement this.
     return null;
   }

   /**
    * Gets a classloader for the given codebase and with the current
    * context classloader as parent.
    *
    * @param codebase
    *
    * @return a classloader for the given codebase
    *
    * @throws MalformedURLException if the codebase contains a malformed URL
    */
   public ClassLoader getClassLoader(String codebase)
     throws MalformedURLException
   {
     ClassLoader loader;
     CacheKey loaderKey = new CacheKey
     (codebase, Thread.currentThread().getContextClassLoader());
     loader = (ClassLoader) cacheLoaders.get (loaderKey);

     if (loader == null)
       {
         //create an entry in cacheLoaders mapping a loader to codebases.
         // codebases are separated by " "
         StringTokenizer tok = new StringTokenizer (codebase, " ");
         ArrayList urls = new ArrayList();

         while (tok.hasMoreTokens())
           urls.add (new URL(tok.nextToken()));

         loader = new MyClassLoader((URL[]) urls.toArray(new URL [urls.size()]),
                                  Thread.currentThread().getContextClassLoader(),
                                  codebase);
         cacheLoaders.put (loaderKey, loader);
       }

     return loader;
   }

   /**
    * Returns a string representation of the network location where a remote
    * endpoint can get the class-definition of the given class.
    *
    * @param cl
    *
    * @return a space seperated list of URLs where the class-definition
    * of cl may be found
    */
   public String getClassAnnotation(Class cl)
   {
     ClassLoader loader = cl.getClassLoader();

     if (loader == null
         || loader == ClassLoader.getSystemClassLoader())
       {
         return System.getProperty ("java.rmi.server.codebase");
       }

     if (loader instanceof MyClassLoader)
       {
         return ((MyClassLoader) loader).getClassAnnotation();
       }

     String s = (String) cacheAnnotations.get (loader);

     if (s != null)
       return s;

     if (loader instanceof URLClassLoader)
       {
         URL[] urls = ((URLClassLoader) loader).getURLs();

         if (urls.length == 0)
           return null;

         StringBuffer annotation = new StringBuffer (64 * urls.length);

         for (int i = 0; i < urls.length; i++)
           {
             annotation.append (urls [i].toExternalForm());
             annotation.append (' ');
           }

         s = annotation.toString();
         cacheAnnotations.put (loader, s);
         return s;
       }

     return System.getProperty ("java.rmi.server.codebase");
   }
 }
	/* RMIClassLoaderImpl.java -- FIXME: briefly describe file purpose
	Copyright (C) 2005 Free Software Foundation, Inc.

	This file is part of GNU Classpath.

	GNU Classpath is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 2, or (at your option)
	any later version.

	GNU Classpath 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 GNU
	General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with GNU Classpath; see the file COPYING. If not, write to the
	Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
	02110-1301 USA.

	Linking this library statically or dynamically with other modules is
	making a combined work based on this library. Thus, the terms and
	conditions of the GNU General Public License cover the whole
	combination.

	As a special exception, the copyright holders of this library give you
	permission to link this library with independent modules to produce an
	executable, regardless of the license terms of these independent
	modules, and to copy and distribute the resulting executable under
	terms of your choice, provided that you also meet, for each linked
	independent module, the terms and conditions of the license of that
	module. An independent module is a module which is not derived from
	or based on this library. If you modify this library, you may extend
	this exception to your version of the library, but you are not
	obligated to do so. If you do not wish to do so, delete this
	exception statement from your version. */


	package gnu.java.rmi.server;

	import java.net.MalformedURLException;
	import java.net.URL;
	import java.net.URLClassLoader;
	import java.rmi.server.RMIClassLoaderSpi;
	import java.util.ArrayList;
	import java.util.Hashtable;
	import java.util.Map;
	import java.util.StringTokenizer;

	/**
	* The default implementation of {@link java.rmi.server.RMIClassLoaderSpi}.
	*
	* @author Roman Kennke (kennke@aicas.com)
	*/
	public class RMIClassLoaderImpl extends RMIClassLoaderSpi
	{
	private static class MyClassLoader extends URLClassLoader
	{
	// Package-private to avoid a trampoline constructor.
	MyClassLoader (URL[] urls, ClassLoader parent, String annotation)
	{
	super (urls, parent);
	this.annotation = annotation;
	}

	private MyClassLoader (URL[] urls, ClassLoader parent)
	{
	super (urls, parent);
	this.annotation = urlToAnnotation (urls);
	}

	public static String urlToAnnotation (URL[] urls)
	{
	if (urls.length == 0)
	return null;

	StringBuffer annotation = new StringBuffer (64 * urls.length);

	for (int i = 0; i < urls.length; i++)
	{
	annotation.append (urls [i].toExternalForm());
	annotation.append (' ');
	}

	return annotation.toString();
	}

	public final String getClassAnnotation()
	{
	return annotation;
	}

	private final String annotation;
	}

	/**
	* This class is used to identify a cached classloader by its codebase and
	* the context classloader that is its parent.
	*/
	private static class CacheKey
	{
	private String mCodeBase;
	private ClassLoader mContextClassLoader;

	public CacheKey (String theCodebase, ClassLoader theContextClassLoader)
	{
	mCodeBase = theCodebase;
	mContextClassLoader = theContextClassLoader;
	}

	/**
	* @return true if the codebase and the context classloader are equal
	*/
	public boolean equals (Object theOther)
	{
	if (theOther instanceof CacheKey)
	{
	CacheKey key = (CacheKey) theOther;

	return (equals (this.mCodeBase,key.mCodeBase)
	&& equals (this.mContextClassLoader, key.mContextClassLoader));
	}
	return false;
	}

	/**
	* Test if the two objects are equal or both null.
	* @param theOne
	* @param theOther
	* @return
	*/
	private boolean equals (Object theOne, Object theOther)
	{
	return theOne != null ? theOne.equals (theOther) : theOther == null;
	}

	/**
	* @return hashCode
	*/
	public int hashCode()
	{
	return ((mCodeBase != null ? mCodeBase.hashCode() : 0)
	^(mContextClassLoader != null ? mContextClassLoader.hashCode() : -1));
	}

	public String toString()
	{
	return "[" + mCodeBase + "," + mContextClassLoader + "]";
	}

	}

	private static RMIClassLoaderImpl instance = null;

	private static Map cacheLoaders; //map annotations to loaders
	private static Map cacheAnnotations; //map loaders to annotations
	//class loader for defaultAnnotation
	private static MyClassLoader defaultClassLoader;

	//defaultAnnotation is got from system property
	// "java.rmi.server.defaultAnnotation"
	private static String defaultAnnotation;

	//URL object for defaultAnnotation
	private static URL defaultCodebase;

	static
	{
	// 89 is a nice prime number for Hashtable initial capacity
	cacheLoaders = new Hashtable (89);
	cacheAnnotations = new Hashtable (89);

	defaultAnnotation = System.getProperty ("java.rmi.server.defaultAnnotation");

	try
	{
	if (defaultAnnotation != null)
	defaultCodebase = new URL (defaultAnnotation);
	}
	catch (Exception _)
	{
	defaultCodebase = null;
	}

	if (defaultCodebase != null)
	{
	defaultClassLoader = new MyClassLoader (new URL[] { defaultCodebase }, null,
	defaultAnnotation);
	cacheLoaders.put (new CacheKey (defaultAnnotation,
	Thread.currentThread().getContextClassLoader()),
	defaultClassLoader);
	}
	}

	/**
	* This is a singleton class and may only be instantiated once from within
	* the {@link #getInstance} method.
	*/
	private RMIClassLoaderImpl()
	{
	}

	/**
	* Returns an instance of RMIClassLoaderImpl.
	*
	* @return an instance of RMIClassLoaderImpl
	*/
	public static RMIClassLoaderSpi getInstance()
	{
	if (instance == null)
	instance = new RMIClassLoaderImpl();
	return instance;
	}

	public Class loadClass(String codeBase, String name,
	ClassLoader defaultLoader)
	throws MalformedURLException, ClassNotFoundException
	{
	ClassLoader loader;
	if (defaultLoader == null)
	loader = Thread.currentThread().getContextClassLoader();
	else
	loader = defaultLoader;

	//try context class loader first
	try
	{
	return Class.forName(name, false, loader);
	}
	catch (ClassNotFoundException e)
	{
	// class not found in the local classpath
	}

	if (codeBase.length() == 0) //==""
	{
	loader = defaultClassLoader;
	}
	else
	{
	loader = getClassLoader(codeBase);
	}

	if (loader == null)
	{
	//do not throw NullPointerException
	throw new ClassNotFoundException ("Could not find class (" + name +
	") at codebase (" + codeBase + ")");
	}

	return Class.forName(name, false, loader);
	}

	public Class loadProxyClass(String codeBase, String[] interfaces,
	ClassLoader defaultLoader)
	throws MalformedURLException, ClassNotFoundException
	{
	// FIXME: Implement this.
	return null;
	}

	/**
	* Gets a classloader for the given codebase and with the current
	* context classloader as parent.
	*
	* @param codebase
	*
	* @return a classloader for the given codebase
	*
	* @throws MalformedURLException if the codebase contains a malformed URL
	*/
	public ClassLoader getClassLoader(String codebase)
	throws MalformedURLException
	{
	ClassLoader loader;
	CacheKey loaderKey = new CacheKey
	(codebase, Thread.currentThread().getContextClassLoader());
	loader = (ClassLoader) cacheLoaders.get (loaderKey);

	if (loader == null)
	{
	//create an entry in cacheLoaders mapping a loader to codebases.
	// codebases are separated by " "
	StringTokenizer tok = new StringTokenizer (codebase, " ");
	ArrayList urls = new ArrayList();

	while (tok.hasMoreTokens())
	urls.add (new URL(tok.nextToken()));

	loader = new MyClassLoader((URL[]) urls.toArray(new URL [urls.size()]),
	Thread.currentThread().getContextClassLoader(),
	codebase);
	cacheLoaders.put (loaderKey, loader);
	}

	return loader;
	}

	/**
	* Returns a string representation of the network location where a remote
	* endpoint can get the class-definition of the given class.
	*
	* @param cl
	*
	* @return a space seperated list of URLs where the class-definition
	* of cl may be found
	*/
	public String getClassAnnotation(Class cl)
	{
	ClassLoader loader = cl.getClassLoader();

	if (loader == null
	\|\| loader == ClassLoader.getSystemClassLoader())
	{
	return System.getProperty ("java.rmi.server.codebase");
	}

	if (loader instanceof MyClassLoader)
	{
	return ((MyClassLoader) loader).getClassAnnotation();
	}

	String s = (String) cacheAnnotations.get (loader);

	if (s != null)
	return s;

	if (loader instanceof URLClassLoader)
	{
	URL[] urls = ((URLClassLoader) loader).getURLs();

	if (urls.length == 0)
	return null;

	StringBuffer annotation = new StringBuffer (64 * urls.length);

	for (int i = 0; i < urls.length; i++)
	{
	annotation.append (urls [i].toExternalForm());
	annotation.append (' ');
	}

	s = annotation.toString();
	cacheAnnotations.put (loader, s);
	return s;
	}

	return System.getProperty ("java.rmi.server.codebase");
	}
	}