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/*
* Fabric3
* Copyright (c) 2009-2011 Metaform Systems
*
* Fabric3 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 3 of
* the License, or (at your option) any later version, with the
* following exception:
*
* Linking this software statically or dynamically with other
* modules is making a combined work based on this software.
* Thus, the terms and conditions of the GNU General Public
* License cover the whole combination.
*
* As a special exception, the copyright holders of this software
* give you permission to link this software 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 software. If you modify this software, you may
* extend this exception to your version of the software, but
* you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version.
*
* Fabric3 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 Fabric3.
* If not, see .
*/
package org.fabric3.spi.classloader;

import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectStreamClass;
import java.net.URI;

/**
 * A specialized ObjectInputStream that can deserialize objects loaded in different runtime classloaders. When ObjectInputStream.resolveClass() is
 * called, a classloader id is read if present in the byte stream. The id is used to resolve the classloader to load the class in.
 *
 * @version $Rev: 9763 $ $Date: 2011-01-03 00:48:06 +0000 (Mon, 03 Jan 2011) $
 */
public class MultiClassLoaderObjectInputStream extends ObjectInputStream {
    private ClassLoaderRegistry registry;

    public MultiClassLoaderObjectInputStream(InputStream in, ClassLoaderRegistry registry) throws IOException {
        super(in);
        this.registry = registry;
    }

    protected Class resolveClass(ObjectStreamClass desc) throws IOException, ClassNotFoundException {
        int val = readByte();
        if (val == -1) {
            return super.resolveClass(desc);
        } else {
            byte[] bytes = new byte[val];
            int result = read(bytes);
            if (result == -1) {
                throw new IOException("Invalid classloader URL");
            }
            String id = new String(bytes);
            URI uri = URI.create(id);
            ClassLoader cl = registry.getClassLoader(uri);
            if (cl == null) {
                throw new IOException("Classloader not found: " + id);
            }
            return Class.forName(desc.getName(), false, cl);
        }
    }

}