/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.sun.jini.proxy;
import java.io.IOException;
import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.io.ObjectStreamException;
import java.io.Serializable;
import java.util.Collection;
import java.util.Iterator;
import net.jini.io.MarshalledInstance;
import net.jini.io.ObjectStreamContext;
import net.jini.io.context.IntegrityEnforcement;
/**
* Wrapper around {@link MarshalledInstance} that samples the integrity setting
* (if any) of the stream it is unmarshalled from, and uses that setting to
* determine whether or not to verify codebase integrity when calling the
* {@link MarshalledInstance#get(boolean) get} method of the contained
* <code>MarshalledInstance</code>.
*
* @author Sun Microsystems, Inc.
*
* @since 2.0
*/
public class MarshalledWrapper implements Serializable {
private static final long serialVersionUID = 2L;
/**
* The wrapped MarshalledInstance.
*
* @serial
*/
private final MarshalledInstance instance;
/**
* Flag set to true if this instance was unmarshalled from an
* integrity-protected stream, or false otherwise
*/
private transient boolean integrity = false;
/**
* Returns the integrity protection setting of the given stream, determined
* as follows: if the stream implements {@link ObjectStreamContext} and has
* in its context collection an object of type
* {@link IntegrityEnforcement}, the
* {@link IntegrityEnforcement#integrityEnforced integrityEnforced} method
* of that object is called and the resulting value returned; otherwise,
* <code>false</code> is returned.
*
* @return integrity protection setting of the given stream
*/
public static boolean integrityEnforced(ObjectInputStream stream) {
if (stream instanceof ObjectStreamContext) {
Collection ctx =
((ObjectStreamContext) stream).getObjectStreamContext();
for (Iterator i = ctx.iterator(); i.hasNext(); ) {
Object obj = i.next();
if (obj instanceof IntegrityEnforcement) {
return ((IntegrityEnforcement) obj).integrityEnforced();
}
}
}
return false;
}
/**
* Creates a new <code>MarshalledWrapper</code> wrapping a
* <code>MarshalledInstance</code> containing the given object.
*
* @param obj object to create <code>MarshalledInstance</code> with
* @throws IOException if <code>MarshalledInstance</code> creation fails
*/
public MarshalledWrapper(Object obj) throws IOException {
instance = new MarshalledInstance(obj);
}
/**
* Creates a new <code>MarshalledWrapper</code> wrapping the given
* <code>MarshalledInstance</code>.
*
* @param instance <code>MarshalledInstance</code> to wrap
* @throws NullPointerException if <code>instance</code> is
* <code>null</code>
*/
public MarshalledWrapper(MarshalledInstance instance) {
if (instance == null) {
throw new NullPointerException();
}
this.instance = instance;
}
/**
* Returns the result of calling the {@link MarshalledInstance#get(boolean)
* get} method of the wrapped <code>MarshalledInstance</code>, passing the
* integrity value sampled during deserialization as the
* <code>verifyCodebaseIntegrity</code> argument. If this
* <code>MarshalledWrapper</code> instance was not produced by
* deserialization or was deserialized from a stream with no integrity
* protection setting, then a <code>verifyCodebaseIntegrity</code> value of
* <code>false</code> is used.
*
* @return the object unmarshalled by the wrapped
* <code>MarshalledInstance</code>
* @throws IOException if an <code>IOException</code> occurs during
* unmarshalling
* @throws ClassNotFoundException if any classes necessary for
* reconstructing the object being unmarshalled cannot be found
*/
public Object get() throws IOException, ClassNotFoundException {
return instance.get(integrity);
}
/**
* Returns the <code>MarshalledInstance</code> wrapped by this
* <code>MarshalledWrapper</code>.
*
* @return wrapped <code>MarshalledInstance</code>
*/
public MarshalledInstance getMarshalledInstance() {
return instance;
}
/**
* Returns the integrity value sampled during deserialization of this
* <code>MarshalledWrapper</code> instance, or <code>false</code> if this
* instance was not produced by deserialization or was deserialized from a
* stream with no integrity protection setting.
*
* @return sampled integrity value
*/
public boolean getIntegrity() {
return integrity;
}
/**
* Returns the hash code value for this <code>MarshalledWrapper</code>.
*
* @return the hash code value for this <code>MarshalledWrapper</code>.
*/
public int hashCode() {
return MarshalledWrapper.class.hashCode() ^ instance.hashCode();
}
/**
* Compares the specified object with this <code>MarshalledWrapper</code>
* for equality. This method returns <code>true</code> if and only if the
* specified object is of the same class as this object and its wrapped
* <code>MarshalledInstance</code> is equal to the one in this object.
*
* @param obj object to compare with
* @return <code>true</code> if <code>obj</code> is equivalent to
* this object; <code>false</code> otherwise
*/
public boolean equals(Object obj) {
return obj == this ||
(obj != null &&
obj.getClass() == getClass() &&
instance.equals(((MarshalledWrapper) obj).instance));
}
/**
* Samples integrity protection setting (if any) of the stream from which
* this instance is being deserialized.
*/
private void readObject(ObjectInputStream in)
throws IOException, ClassNotFoundException
{
in.defaultReadObject();
if (instance == null) {
throw new InvalidObjectException("null instance");
}
integrity = integrityEnforced(in);
}
/**
* Throws InvalidObjectException, since data for this class is required.
*/
private void readObjectNoData() throws ObjectStreamException {
throw new InvalidObjectException("no data");
}
}