1 package org.apache.turbine.pipeline;
2
3
4 /*
5 * Licensed to the Apache Software Foundation (ASF) under one
6 * or more contributor license agreements. See the NOTICE file
7 * distributed with this work for additional information
8 * regarding copyright ownership. The ASF licenses this file
9 * to you under the Apache License, Version 2.0 (the
10 * "License"); you may not use this file except in compliance
11 * with the License. You may obtain a copy of the License at
12 *
13 * http://www.apache.org/licenses/LICENSE-2.0
14 *
15 * Unless required by applicable law or agreed to in writing,
16 * software distributed under the License is distributed on an
17 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
18 * KIND, either express or implied. See the License for the
19 * specific language governing permissions and limitations
20 * under the License.
21 */
22
23
24 import java.io.IOException;
25
26 import org.apache.turbine.util.RunData;
27 import org.apache.turbine.util.TurbineException;
28
29 /**
30 * Valve that can be used as the basis of Valve implementations.
31 *
32 * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
33 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
34 * @version $Id: AbstractValve.java 1706239 2015-10-01 13:18:35Z tv $
35 */
36 public abstract class AbstractValve
37 implements Valve
38 {
39 /**
40 * Initialize this valve for use in a pipeline.
41 *
42 * @throws Exception
43 */
44 @Override
45 public void initialize()
46 throws Exception
47 {
48 // empty
49 }
50
51 /**
52 * @see org.apache.turbine.pipeline.Valve#invoke(PipelineData, ValveContext)
53 */
54 @Override
55 public abstract void invoke(PipelineData data, ValveContext context)
56 throws IOException, TurbineException;
57
58
59 /**
60 * utility for getting RunData out of the pipelineData object.
61 * @param pipelineData
62 * @return the RunData object extracted from pipelineData
63 */
64 public final RunData getRunData(PipelineData pipelineData)
65 {
66 if(!(pipelineData instanceof RunData))
67 {
68 throw new RuntimeException("Can't cast pipelineData to rundata");
69 }
70 return (RunData)pipelineData;
71 }
72
73 }