001/* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 * 019 */ 020package org.apache.mina.statemachine.context; 021 022import org.apache.mina.statemachine.State; 023import org.apache.mina.statemachine.StateMachine; 024 025/** 026 * {@link StateContext} objects are used to store the current {@link State} and 027 * any application specific attributes for a specific client of a 028 * {@link StateMachine}. Since {@link StateMachine}s are singletons and shared 029 * by all clients using the {@link StateMachine} this is where client specific 030 * data needs to be stored. 031 * 032 * @author <a href="http://mina.apache.org">Apache MINA Project</a> 033 */ 034public interface StateContext { 035 /** 036 * @return the current {@link State}. This is only meant for internal use. 037 */ 038 State getCurrentState(); 039 040 /** 041 * Sets the current {@link State}. This is only meant for internal use. 042 * Don't call it directly! 043 * 044 * @param state the new current {@link State}. 045 */ 046 void setCurrentState(State state); 047 048 /** 049 * Returns the value of the attribute with the specified key or 050 * <code>null</code>if not found. 051 * 052 * @param key the key. 053 * @return the value or <code>null</code>. 054 */ 055 Object getAttribute(Object key); 056 057 /** 058 * Sets the value of the attribute with the specified key. 059 * 060 * @param key the key. 061 * @param value the value. 062 */ 063 void setAttribute(Object key, Object value); 064}