/*

 * Copyright (c) 1998, 2007, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/*

 * Licensed Materials - Property of IBM

 * RMI-IIOP v1.0

 * Copyright IBM Corp. 1998 1999  All Rights Reserved

 *

 */

package sun.rmi.rmic.iiop;

import java.util.Hashtable;

import java.io.File;

import java.io.FileInputStream;

/**

 * DirectoryLoader is a simple ClassLoader which loads from a specified

 * file system directory.

 * @author Bryan Atsatt

 */

public class DirectoryLoader extends ClassLoader {

    private Hashtable cache;

    private File root;

    /**

     * Constructor.

     */

    public DirectoryLoader (File rootDir) {

        cache = new Hashtable();

        if (rootDir == null || !rootDir.isDirectory()) {

            throw new IllegalArgumentException();

        }

        root = rootDir;

    }

    private DirectoryLoader () {}

    /**

     * Convenience version of loadClass which sets 'resolve' == true.

     */

    public Class loadClass(String className) throws ClassNotFoundException {

        return loadClass(className, true);

    }

    /**

     * This is the required version of loadClass which is called

     * both from loadClass above and from the internal function

     * FindClassFromClass.

     */

    public synchronized Class loadClass(String className, boolean resolve)

        throws ClassNotFoundException {

        Class result;

        byte  classData[];

        // Do we already have it in the cache?

        result = (Class) cache.get(className);

        if (result == null) {

            // Nope, can we get if from the system class loader?

            try {

                result = super.findSystemClass(className);

            } catch (ClassNotFoundException e) {

                // No, so try loading it...

                classData = getClassFileData(className);

                if (classData == null) {

                    throw new ClassNotFoundException();

                }

                // Parse the class file data...

                result = defineClass(classData, 0, classData.length);

                if (result == null) {

                    throw new ClassFormatError();

                }

                // Resolve it...

                if (resolve) resolveClass(result);

                // Add to cache...

                cache.put(className, result);

            }

        }

        return result;

    }

    /**

     * Reurn a byte array containing the contents of the class file.  Returns null

     * if an exception occurs.

     */

    private byte[] getClassFileData (String className) {

        byte result[] = null;

        FileInputStream stream = null;

        // Get the file...

        File classFile = new File(root,className.replace('.',File.separatorChar) + ".class");

        // Now get the bits...

        try {

            stream = new FileInputStream(classFile);

            result = new byte[stream.available()];

            stream.read(result);

        } catch(ThreadDeath death) {

            throw death;

        } catch (Throwable e) {

        }

        finally {

            if (stream != null) {

                try {

                    stream.close();

                } catch(ThreadDeath death) {

                    throw death;

                } catch (Throwable e) {

                }

            }

        }

        return result;

    }

}