org.apache.mina.filter.util.WriteRequestFilter Maven / Gradle / Ivy
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* 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 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 {
/**
* {@inheritDoc}
*/
@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);
}
}
/**
* {@inheritDoc}
*/
@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 IllegalArgumentException("filteredMessage");
}
this.filteredMessage = filteredMessage;
}
public WriteRequestFilter getParent() {
return WriteRequestFilter.this;
}
@Override
public Object getMessage() {
return filteredMessage;
}
}
}