org.apache.mina.filter.util.WriteRequestFilter Maven / Gradle / Ivy
/**
* Copyright 2007-2015, Kaazing Corporation. All rights reserved.
*
* 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.mina.filter.util;
import org.apache.mina.core.filterchain.IoFilter;
import org.apache.mina.core.filterchain.IoFilterAdapter;
import org.apache.mina.core.session.IoEventType;
import org.apache.mina.core.session.IoSession;
import org.apache.mina.core.write.WriteRequest;
import org.apache.mina.core.write.WriteRequestWrapper;
/**
* An abstract {@link IoFilter} that simplifies the implementation of
* an {@link IoFilter} that filters an {@link IoEventType#WRITE} event.
*
* @author Apache MINA Project
*
*/
public abstract class WriteRequestFilter extends IoFilterAdapter {
@Override
public void filterWrite(NextFilter nextFilter, IoSession session,
WriteRequest writeRequest) throws Exception {
Object filteredMessage = doFilterWrite(nextFilter, session, writeRequest);
if (filteredMessage != null && filteredMessage != writeRequest.getMessage()) {
nextFilter.filterWrite(
session, new FilteredWriteRequest(
filteredMessage, writeRequest));
} else {
nextFilter.filterWrite(session, writeRequest);
}
}
@Override
public void messageSent(NextFilter nextFilter, IoSession session,
WriteRequest writeRequest) throws Exception {
if (writeRequest instanceof FilteredWriteRequest) {
FilteredWriteRequest req = (FilteredWriteRequest) writeRequest;
if (req.getParent() == this) {
nextFilter.messageSent(session, req.getParentRequest());
return;
}
}
nextFilter.messageSent(session, writeRequest);
}
protected abstract Object doFilterWrite(
NextFilter nextFilter, IoSession session, WriteRequest writeRequest) throws Exception;
private class FilteredWriteRequest extends WriteRequestWrapper {
private final Object filteredMessage;
public FilteredWriteRequest(Object filteredMessage, WriteRequest writeRequest) {
super(writeRequest);
if (filteredMessage == null) {
throw new NullPointerException("filteredMessage");
}
this.filteredMessage = filteredMessage;
}
public WriteRequestFilter getParent() {
return WriteRequestFilter.this;
}
@Override
public Object getMessage() {
return filteredMessage;
}
}
}