/**
*
* Copyright 2004 The Apache Software Foundation
*
* Licensed 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 org.apache.geronimo.messaging.interceptors;
import java.io.IOException;
import java.io.InputStream;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.geronimo.messaging.Msg;
import org.apache.geronimo.messaging.io.PopSynchronization;
import org.apache.geronimo.messaging.io.PopSynchronizationAdaptor;
import org.apache.geronimo.messaging.io.ReplacerResolver;
import org.apache.geronimo.messaging.io.StreamInputStream;
import org.apache.geronimo.messaging.io.StreamManager;
/**
* Allows popping Msgs from an InputStream.
*
* @version $Rev: 46019 $ $Date: 2004-09-14 04:56:06 -0500 (Tue, 14 Sep 2004) $
*/
public class StreamInInterceptor
implements MsgInInterceptor
{
private static final Log log = LogFactory.getLog(StreamInInterceptor.class);
/**
* Null PopSynchronizarion;
*/
private static final PopSynchronization NULL_POP_SYNC =
new PopSynchronizationAdaptor();
/**
* Raw InputStream to pop Msgs from.
*/
private final InputStream rawIn;
/**
* Used to read in Msg mode from the raw InputStream.
*/
private final StreamInputStream streamInputStream;
/**
* Pop synchronization to be applied by this instance.
*/
private final PopSynchronization popSynchronization;
/**
* Pops Msgs from an InputStream. Msgs are read by a StreamInputStream
* using the provided StreamManager to resolve InputStreams encoded in the
* raw InputStream.
*
* @param anIn InputStream to read from.
* @param aManager Used to resolve encoded InputStreams.
* @param aSynchronization PopSynchronization applied by this instance.
* @param aResolver Used to resolve Objects read from anIn.
* @exception IOException Indicates an I/O error.
*/
public StreamInInterceptor(InputStream anIn, StreamManager aManager,
PopSynchronization aSynchronization, ReplacerResolver aResolver)
throws IOException {
if ( null == anIn ) {
throw new IllegalArgumentException("InputStream is required.");
} else if ( null == aManager ) {
throw new IllegalArgumentException("StreamManager is required.");
}
rawIn = anIn;
streamInputStream = new StreamInputStream(anIn, aManager, aResolver);
if ( null == aSynchronization ) {
popSynchronization = NULL_POP_SYNC;
} else {
popSynchronization = aSynchronization;
}
}
public Msg pop() {
Msg msg;
try {
synchronized (rawIn) {
Object opaque = popSynchronization.beforePop(streamInputStream);
msg = (Msg) streamInputStream.readObject();
popSynchronization.afterPop(streamInputStream, msg, opaque);
}
} catch (ClassNotFoundException e) {
log.error(e);
throw new RuntimeException(e);
} catch (IOException e) {
log.error(e);
throw new RuntimeException(e);
}
return msg;
}
}