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; 21 22 import org.apache.mina.core.buffer.IoBuffer; 23 import org.apache.mina.core.session.IoSession; 24 25 /** 26 * Decodes binary or protocol-specific data into higher-level message objects. 27 * MINA invokes {@link #decode(IoSession, IoBuffer, ProtocolDecoderOutput)} 28 * method with read data, and then the decoder implementation puts decoded 29 * messages into {@link ProtocolDecoderOutput} by calling 30 * {@link ProtocolDecoderOutput#write(Object)}. 31 * <p> 32 * Please refer to 33 * <a href="../../../../../xref-examples/org/apache/mina/examples/reverser/TextLineDecoder.html"><code>TextLineDecoder</code></a> 34 * example. 35 * 36 * @author The Apache MINA Project (dev@mina.apache.org) 37 * 38 * @see ProtocolDecoderException 39 */ 40 public interface ProtocolDecoder { 41 /** 42 * Decodes binary or protocol-specific content into higher-level message objects. 43 * MINA invokes {@link #decode(IoSession, IoBuffer, ProtocolDecoderOutput)} 44 * method with read data, and then the decoder implementation puts decoded 45 * messages into {@link ProtocolDecoderOutput}. 46 * 47 * @throws Exception if the read data violated protocol specification 48 */ 49 void decode(IoSession session, IoBuffer in, ProtocolDecoderOutput out) 50 throws Exception; 51 52 /** 53 * Invoked when the specified <tt>session</tt> is closed. This method is useful 54 * when you deal with the protocol which doesn't specify the length of a message 55 * such as HTTP response without <tt>content-length</tt> header. Implement this 56 * method to process the remaining data that {@link #decode(IoSession, IoBuffer, ProtocolDecoderOutput)} 57 * method didn't process completely. 58 * 59 * @throws Exception if the read data violated protocol specification 60 */ 61 void finishDecode(IoSession session, ProtocolDecoderOutput out) 62 throws Exception; 63 64 /** 65 * Releases all resources related with this decoder. 66 * 67 * @throws Exception if failed to dispose all resources 68 */ 69 void dispose(IoSession session) throws Exception; 70 }