001 package org.apache.turbine.pipeline; 002 003 004 /* 005 * Licensed to the Apache Software Foundation (ASF) under one 006 * or more contributor license agreements. See the NOTICE file 007 * distributed with this work for additional information 008 * regarding copyright ownership. The ASF licenses this file 009 * to you under the Apache License, Version 2.0 (the 010 * "License"); you may not use this file except in compliance 011 * with the License. You may obtain a copy of the License at 012 * 013 * http://www.apache.org/licenses/LICENSE-2.0 014 * 015 * Unless required by applicable law or agreed to in writing, 016 * software distributed under the License is distributed on an 017 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 018 * KIND, either express or implied. See the License for the 019 * specific language governing permissions and limitations 020 * under the License. 021 */ 022 023 024 import java.io.IOException; 025 026 import org.apache.turbine.util.RunData; 027 import org.apache.turbine.util.TurbineException; 028 029 /** 030 * Valve that can be used as the basis of Valve implementations. 031 * 032 * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a> 033 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a> 034 * @version $Id: AbstractValve.java 757213 2009-03-22 16:43:31Z tv $ 035 */ 036 public abstract class AbstractValve 037 implements Valve 038 { 039 /** 040 * Initialize this valve for use in a pipeline. 041 * 042 * @throws Exception 043 */ 044 public void initialize() 045 throws Exception 046 { 047 // empty 048 } 049 050 /** 051 * @see org.apache.turbine.Valve#invoke(PipelineData, ValveContext) 052 */ 053 public abstract void invoke(PipelineData data, ValveContext context) 054 throws IOException, TurbineException; 055 056 057 /** 058 * utility for getting RunData out of the pielineData object. 059 * @param pipelineData 060 * @return 061 */ 062 public final RunData getRunData(PipelineData pipelineData) 063 { 064 if(!(pipelineData instanceof RunData)){ 065 throw new RuntimeException("Can't cast pipelineData to rundata"); 066 } 067 return (RunData)pipelineData; 068 } 069 070 }