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; 021 022/** 023 * {@link StateContextLookup} implementation which always returns the same 024 * {@link StateContext} instance. 025 * 026 * @author <a href="http://mina.apache.org">Apache MINA Project</a> 027 */ 028public class SingletonStateContextLookup implements StateContextLookup { 029 private final StateContext context; 030 031 /** 032 * Creates a new instance which always returns the same 033 * {@link DefaultStateContext} instance. 034 */ 035 public SingletonStateContextLookup() { 036 context = new DefaultStateContext(); 037 } 038 039 /** 040 * Creates a new instance which uses the specified {@link StateContextFactory} 041 * to create the single instance. 042 * 043 * @param contextFactory the {@link StateContextFactory} to use to create 044 * the singleton instance. 045 */ 046 public SingletonStateContextLookup(StateContextFactory contextFactory) { 047 if (contextFactory == null) { 048 throw new IllegalArgumentException("contextFactory"); 049 } 050 context = contextFactory.create(); 051 } 052 053 public StateContext lookup(Object[] eventArgs) { 054 return context; 055 } 056}