1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, 13 * software distributed under the License is distributed on an 14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 15 * KIND, either express or implied. See the License for the 16 * specific language governing permissions and limitations 17 * under the License. 18 * 19 */ 20 package org.apache.mina.filter.codec.statemachine; 21 22 import org.apache.mina.core.buffer.IoBuffer; 23 import org.apache.mina.core.session.IoSession; 24 import org.apache.mina.filter.codec.ProtocolDecoderOutput; 25 26 /** 27 * Represents a state in a decoder state machine used by 28 * {@link DecodingStateMachine}. 29 * 30 * @author The Apache MINA Project (dev@mina.apache.org) 31 */ 32 public interface DecodingState { 33 /** 34 * Invoked when data is available for this state. 35 * 36 * @param in the data to be decoded. 37 * @param out used to write decoded objects. 38 * @return the next state if a state transition was triggered (use 39 * <code>this</code> for loop transitions) or <code>null</code> if 40 * the state machine has reached its end. 41 * @throws Exception if the read data violated protocol specification. 42 */ 43 DecodingState decode(IoBuffer in, ProtocolDecoderOutput out) 44 throws Exception; 45 46 /** 47 * Invoked when the associated {@link IoSession} is closed. This method is 48 * useful when you deal with protocols which don't specify the length of a 49 * message (e.g. HTTP responses without <tt>content-length</tt> header). 50 * Implement this method to process the remaining data that 51 * {@link #decode(IoBuffer, ProtocolDecoderOutput)} method didn't process 52 * completely. 53 * 54 * @param out used to write decoded objects. 55 * @return the next state if a state transition was triggered (use 56 * <code>this</code> for loop transitions) or <code>null</code> if 57 * the state machine has reached its end. 58 * @throws Exception if the read data violated protocol specification. 59 */ 60 DecodingState finishDecode(ProtocolDecoderOutput out) throws Exception; 61 }