001 package org.apache.turbine.modules.screens; 002 003 /* 004 * Licensed to the Apache Software Foundation (ASF) under one 005 * or more contributor license agreements. See the NOTICE file 006 * distributed with this work for additional information 007 * regarding copyright ownership. The ASF licenses this file 008 * to you under the Apache License, Version 2.0 (the 009 * "License"); you may not use this file except in compliance 010 * with the License. You may obtain a copy of the License at 011 * 012 * http://www.apache.org/licenses/LICENSE-2.0 013 * 014 * Unless required by applicable law or agreed to in writing, 015 * software distributed under the License is distributed on an 016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 017 * KIND, either express or implied. See the License for the 018 * specific language governing permissions and limitations 019 * under the License. 020 */ 021 022 023 // Turbine stuff. 024 025 import org.apache.ecs.ConcreteElement; 026 import org.apache.turbine.modules.Screen; 027 import org.apache.turbine.pipeline.PipelineData; 028 import org.apache.turbine.util.RunData; 029 030 /** 031 * Base class for writing Screens that output binary data. This class 032 * is provided as a helper class for those who want to write Screens 033 * that output raw binary data. For example, it may be extended into 034 * a Screen that outputs a SVG file or a SWF (Flash Player format) 035 * movie. The only thing one has to do is to implement the two 036 * methods <code>getContentType(RunData data)</code> and 037 * <code>doOutput(RunData data)</code> (see below). 038 * 039 * <p> You migth want to take a look at the ImageServer screen class 040 * contained in the TDK.<br> 041 * 042 * @author <a href="mailto:rkoenig@chez.com">Regis Koenig</a> 043 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a> 044 * @version $Id: RawScreen.java 938645 2010-04-27 20:57:51Z tv $ 045 */ 046 public abstract class RawScreen extends Screen 047 { 048 /** 049 * Build the Screen. This method actually makes a call to the 050 * doOutput() method in order to generate the Screen content. 051 * 052 * @deprecated Use PipelineData version instead. 053 * @param data Turbine information. 054 * @return A ConcreteElement. 055 * @exception Exception, a generic exception. 056 */ 057 protected final ConcreteElement doBuild(RunData data) 058 throws Exception 059 { 060 data.getResponse().setContentType(getContentType(data)); 061 data.declareDirectResponse(); 062 doOutput(data); 063 return null; 064 } 065 066 /** 067 * Build the Screen. This method actually makes a call to the 068 * doOutput() method in order to generate the Screen content. 069 * 070 * @param data Turbine information. 071 * @return A ConcreteElement. 072 * @exception Exception, a generic exception. 073 */ 074 protected final ConcreteElement doBuild(PipelineData pipelineData) 075 throws Exception 076 { 077 RunData data = getRunData(pipelineData); 078 return doBuild(data); 079 } 080 081 082 /** 083 * Set the content type. This method should be overidden to 084 * actually set the real content-type header of the output. 085 * 086 * @deprecated Use PipelineData version instead. 087 * @param data Turbine information. 088 * @return A String with the content type. 089 */ 090 protected abstract String getContentType(RunData data); 091 092 /** 093 * Set the content type. This method should be overidden to 094 * actually set the real content-type header of the output. 095 * 096 * @param data Turbine information. 097 * @return A String with the content type. 098 */ 099 protected String getContentType(PipelineData pipelineData) 100 { 101 RunData data = getRunData(pipelineData); 102 return getContentType(data); 103 } 104 105 106 /** 107 * Actually output the dynamic content. The OutputStream can be 108 * accessed like this: <pre>OutputStream out = 109 * data.getResponse().getOutputStream();</pre>. 110 * 111 * @deprecated Use PipelineData version instead. 112 * @param data Turbine information. 113 * @exception Exception, a generic exception. 114 */ 115 protected abstract void doOutput(RunData data) 116 throws Exception; 117 118 /** 119 * Actually output the dynamic content. The OutputStream can be 120 * accessed like this: <pre>OutputStream out = 121 * data.getResponse().getOutputStream();</pre>. 122 * 123 * @param data Turbine information. 124 * @exception Exception, a generic exception. 125 */ 126 protected void doOutput(PipelineData pipelineData) 127 throws Exception 128 { 129 RunData data = getRunData(pipelineData); 130 doOutput(data); 131 } 132 133 134 /** 135 * The layout must be set to null. 136 * 137 * @deprecated Use PipelineData version instead. 138 * @param data Turbine information. 139 * @return A null String. 140 */ 141 public final String getLayout(RunData data) 142 { 143 return null; 144 } 145 146 /** 147 * The layout must be set to null. 148 * 149 * @param data Turbine information. 150 * @return A null String. 151 */ 152 public final String getLayout(PipelineData pipelineData) 153 { 154 return null; 155 } 156 157 158 159 }