/*

 * Copyright 2000-2004 Sun Microsystems, Inc.  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.  Sun designates this

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

 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package sun.awt.datatransfer;

import java.awt.datatransfer.DataFlavor;

import java.awt.datatransfer.Transferable;

import java.awt.datatransfer.UnsupportedFlavorException;

import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.InputStream;

import java.io.IOException;

import java.io.ObjectInputStream;

import java.io.ObjectOutputStream;

import java.io.ObjectStreamClass;

import java.io.OutputStream;

import java.lang.reflect.Modifier;

import java.lang.reflect.Proxy;

import java.security.AccessController;

import java.security.PrivilegedAction;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Map;

import java.util.Set;

/**

 * Proxies for another Transferable so that Serializable objects are never

 * returned directly by DnD or the Clipboard. Instead, a new instance of the

 * object is returned.

 *

 * @author Lawrence P.G. Cable

 * @author David Mendenhall

 *

 * @since 1.4

 */

public class TransferableProxy implements Transferable {

    public TransferableProxy(Transferable t, boolean local) {

        transferable = t;

        isLocal = local;

    }

    public DataFlavor[] getTransferDataFlavors() {

        return transferable.getTransferDataFlavors();

    }

    public boolean isDataFlavorSupported(DataFlavor flavor) {

        return transferable.isDataFlavorSupported(flavor);

    }

    public Object getTransferData(DataFlavor df)

        throws UnsupportedFlavorException, IOException

    {

        Object data = transferable.getTransferData(df);

        // If the data is a Serializable object, then create a new instance

        // before returning it. This insulates applications sharing DnD and

        // Clipboard data from each other.

        if (data != null && isLocal && df.isFlavorSerializedObjectType()) {

            ByteArrayOutputStream baos = new ByteArrayOutputStream();

            ClassLoaderObjectOutputStream oos =

                new ClassLoaderObjectOutputStream(baos);

            oos.writeObject(data);

            ByteArrayInputStream bais =

                new ByteArrayInputStream(baos.toByteArray());

            try {

                ClassLoaderObjectInputStream ois =

                    new ClassLoaderObjectInputStream(bais,

                                                     oos.getClassLoaderMap());

                data = ois.readObject();

            } catch (ClassNotFoundException cnfe) {

                throw (IOException)new IOException().initCause(cnfe);

            }

        }

        return data;

    }

    protected final Transferable transferable;

    protected final boolean isLocal;

}

class ClassLoaderObjectOutputStream extends ObjectOutputStream {

    private final Map<Set<String>, ClassLoader> map =

        new HashMap<Set<String>, ClassLoader>();

    public ClassLoaderObjectOutputStream(OutputStream os) throws IOException {

        super(os);

    }

    protected void annotateClass(final Class<?> cl) throws IOException {

        ClassLoader classLoader =

            (ClassLoader)AccessController.doPrivileged(new PrivilegedAction() {

                public Object run() {

                    return cl.getClassLoader();

                }

            });

        Set<String> s = new HashSet<String>(1);

        s.add(cl.getName());

        map.put(s, classLoader);

    }

    protected void annotateProxyClass(final Class<?> cl) throws IOException {

        ClassLoader classLoader =

            (ClassLoader)AccessController.doPrivileged(new PrivilegedAction() {

                public Object run() {

                    return cl.getClassLoader();

                }

            });

        Class[] interfaces = cl.getInterfaces();

        Set<String> s = new HashSet<String>(interfaces.length);

        for (int i = 0; i < interfaces.length; i++) {

            s.add(interfaces[i].getName());

        }

        map.put(s, classLoader);

    }

    public Map<Set<String>, ClassLoader> getClassLoaderMap() {

        return new HashMap(map);

    }

}

class ClassLoaderObjectInputStream extends ObjectInputStream {

    private final Map<Set<String>, ClassLoader> map;

    public ClassLoaderObjectInputStream(InputStream is,

                                        Map<Set<String>, ClassLoader> map)

      throws IOException {

        super(is);

        if (map == null) {

            throw new NullPointerException("Null map");

        }

        this.map = map;

    }

    protected Class<?> resolveClass(ObjectStreamClass classDesc)

      throws IOException, ClassNotFoundException {

        String className = classDesc.getName();

        Set<String> s = new HashSet<String>(1);

        s.add(className);

        ClassLoader classLoader = map.get(s);

        return Class.forName(className, false, classLoader);

    }

    protected Class<?> resolveProxyClass(String[] interfaces)

      throws IOException, ClassNotFoundException {

        Set<String> s = new HashSet<String>(interfaces.length);

        for (int i = 0; i < interfaces.length; i++) {

            s.add(interfaces[i]);

        }

        ClassLoader classLoader = map.get(s);

        // The code below is mostly copied from the superclass.

        ClassLoader nonPublicLoader = null;

        boolean hasNonPublicInterface = false;

        // define proxy in class loader of non-public interface(s), if any

        Class[] classObjs = new Class[interfaces.length];

        for (int i = 0; i < interfaces.length; i++) {

            Class cl = Class.forName(interfaces[i], false, classLoader);

            if ((cl.getModifiers() & Modifier.PUBLIC) == 0) {

                if (hasNonPublicInterface) {

                    if (nonPublicLoader != cl.getClassLoader()) {

                        throw new IllegalAccessError(

                            "conflicting non-public interface class loaders");

                    }

                } else {

                    nonPublicLoader = cl.getClassLoader();

                    hasNonPublicInterface = true;

                }

            }

            classObjs[i] = cl;

        }

        try {

            return Proxy.getProxyClass(hasNonPublicInterface ?

                                       nonPublicLoader : classLoader,

                                       classObjs);

        } catch (IllegalArgumentException e) {

            throw new ClassNotFoundException(null, e);

        }

    }

}