org.apache.mina.filter.codec.statemachine.ConsumeToEndOfSessionDecodingState 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.codec.statemachine;
import org.apache.mina.core.buffer.IoBuffer;
import org.apache.mina.filter.codec.ProtocolDecoderException;
import org.apache.mina.filter.codec.ProtocolDecoderOutput;
/**
* {@link DecodingState} which consumes all received bytes until the session is
* closed.
*
* @author Apache MINA Project
*/
public abstract class ConsumeToEndOfSessionDecodingState implements DecodingState {
private IoBuffer buffer;
private final int maxLength;
/**
* Creates a new instance using the specified maximum length.
*
* @param maxLength the maximum number of bytes which will be consumed. If
* this max is reached a {@link ProtocolDecoderException} will be
* thrown by {@link #decode(IoBuffer, ProtocolDecoderOutput)}.
*/
public ConsumeToEndOfSessionDecodingState(int maxLength) {
this.maxLength = maxLength;
}
/**
* {@inheritDoc}
*/
@Override
public DecodingState decode(IoBuffer in, ProtocolDecoderOutput out) throws Exception {
if (buffer == null) {
buffer = IoBuffer.allocate(256).setAutoExpand(true);
}
if (buffer.position() + in.remaining() > maxLength) {
throw new ProtocolDecoderException("Received data exceeds " + maxLength + " byte(s).");
}
buffer.put(in);
return this;
}
/**
* {@inheritDoc}
*/
@Override
public DecodingState finishDecode(ProtocolDecoderOutput out) throws Exception {
try {
if (buffer == null) {
buffer = IoBuffer.allocate(0);
}
buffer.flip();
return finishDecode(buffer, out);
} finally {
buffer = null;
}
}
/**
* Invoked when this state has consumed all bytes until the session is
* closed.
*
* @param product the bytes read.
* @param out the current {@link ProtocolDecoderOutput} used to write
* decoded messages.
* @return the next state if a state transition was triggered (use
* this for loop transitions) or null if
* the state machine has reached its end.
* @throws Exception if the read data violated protocol specification.
*/
protected abstract DecodingState finishDecode(IoBuffer product, ProtocolDecoderOutput out) throws Exception;
}