/* MarshalledObject.java --
Copyright (c) 1996, 1997, 1998, 1999, 2004, 2006
Free Software Foundation, Inc.
This file is part of GNU Classpath.
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it under the terms of the GNU General Public License as published by
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exception statement from your version. */
* A <code>MarshalledObject</code> consists of a serialized object which is
* marshalled according to the RMI specification.
* An object passed to the constructor is serialized and tagged with the needed
* URL to retrieve its class definition for remote usage. If the object is a
* remote reference its stub is serialized instead. The instance of this
* marshalled object can be later retrieved by its <code>get()</code> method.
* @author unknown
public final class MarshalledObject<T>
// The following fields are from Java API Documentation "Serialized form"
private static final long serialVersionUID = 8988374069173025854L;
* Constructs a <code>MarshalledObject</code> from the given object.
* @param obj the object to marshal
* @throws IOException if an I/O error during serialization occurs.
public MarshalledObject(T obj) throws IOException
ByteArrayOutputStream objStream = new ByteArrayOutputStream();
RMIMarshalledObjectOutputStream stream =
objBytes = objStream.toByteArray();
locBytes = stream.getLocBytes();
// The following algorithm of calculating hashCode is similar to String
hash = 0;
for (int i = 0; i < objBytes.length; i++)
hash = hash * 31 + objBytes[i];
if (locBytes != null)
for (int i = 0; i < locBytes.length; i++)
hash = hash * 31 + locBytes[i];
* Checks if the given object is equal to this marshalled object.
* <p>Marshalled objects are considered equal if they contain the
* same serialized object. Codebase annotations where the class
* definition can be downloaded are ignored in the equals test.</p>
* @param obj the object to compare.
* @return <code>true</code> if equal, <code>false</code> otherwise.
public boolean equals(Object obj)
if (! (obj instanceof MarshalledObject))
// hashCode even differs, don't do the time-consuming comparisons
if (obj.hashCode() != hash)
MarshalledObject aobj = (MarshalledObject) obj;
if (objBytes == null || aobj.objBytes == null)
return objBytes == aobj.objBytes;
if (objBytes.length != aobj.objBytes.length)
for (int i = 0; i < objBytes.length; i++)
if (objBytes[i] != aobj.objBytes[i])
// Ignore comparison of locBytes(annotation)
* Constructs and returns a copy of the internal serialized object.
* @return The deserialized object.
* @throws IOException if an I/O exception occurs during deserialization.
* @throws ClassNotFoundException if the class of the deserialized object
* cannot be found.
public T get() throws IOException, ClassNotFoundException
if (objBytes == null)
RMIMarshalledObjectInputStream stream =
new RMIMarshalledObjectInputStream(objBytes, locBytes);
return (T) stream.readObject();
public int hashCode()