1 package org.apache.turbine.services.jsp;
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.File;
25 import java.io.IOException;
26 import java.util.Arrays;
27
28 import javax.servlet.RequestDispatcher;
29 import javax.servlet.http.HttpServletRequest;
30
31 import org.apache.commons.configuration2.Configuration;
32 import org.apache.commons.lang3.StringUtils;
33 import org.apache.logging.log4j.LogManager;
34 import org.apache.logging.log4j.Logger;
35 import org.apache.turbine.Turbine;
36 import org.apache.turbine.pipeline.PipelineData;
37 import org.apache.turbine.services.InitializationException;
38 import org.apache.turbine.services.pull.ApplicationTool;
39 import org.apache.turbine.services.pull.tools.TemplateLink;
40 import org.apache.turbine.services.template.BaseTemplateEngineService;
41 import org.apache.turbine.util.RunData;
42 import org.apache.turbine.util.TurbineException;
43
44 /**
45 * This is a Service that can process JSP templates from within a Turbine
46 * screen.
47 *
48 * @author <a href="mailto:john.mcnally@clearink.com">John D. McNally</a>
49 * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
50 * @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a>
51 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
52 */
53 public class TurbineJspService
54 extends BaseTemplateEngineService
55 implements JspService
56 {
57 /** The base path[s] prepended to filenames given in arguments */
58 private String[] templatePaths;
59
60 /** The relative path[s] prepended to filenames */
61 private String[] relativeTemplatePaths;
62
63 /** The buffer size for the output stream. */
64 private int bufferSize;
65
66 /** Logging */
67 private static Logger log = LogManager.getLogger(TurbineJspService.class);
68
69 /**
70 * Load all configured components and initialize them. This is
71 * a zero parameter variant which queries the Turbine Servlet
72 * for its config.
73 *
74 * @throws InitializationException Something went wrong in the init
75 * stage
76 */
77 @Override
78 public void init()
79 throws InitializationException
80 {
81 try
82 {
83 initJsp();
84 registerConfiguration(JspService.JSP_EXTENSION);
85 setInit(true);
86 }
87 catch (Exception e)
88 {
89 throw new InitializationException(
90 "TurbineJspService failed to initialize", e);
91 }
92 }
93
94 /**
95 * Adds some convenience objects to the request. For example an instance
96 * of TemplateLink which can be used to generate links to other templates.
97 *
98 * @param pipelineData the Turbine PipelineData object
99 */
100 @Override
101 public void addDefaultObjects(PipelineData pipelineData)
102 {
103 HttpServletRequest req = pipelineData.get(Turbine.class, HttpServletRequest.class);
104
105 //
106 // This is a place where an Application Pull Tool is used
107 // in a regular Java Context. We have no Pull Service with the
108 // Jsp Paging stuff, but we can run our Application Tool by Hand:
109 //
110 ApplicationTool templateLink = new TemplateLink();
111 templateLink.init(pipelineData);
112
113 req.setAttribute(LINK, templateLink);
114 req.setAttribute(PIPELINE_DATA, pipelineData);
115 }
116
117 /**
118 * Returns the default buffer size of the JspService
119 *
120 * @return The default buffer size.
121 */
122 @Override
123 public int getDefaultBufferSize()
124 {
125 return bufferSize;
126 }
127
128 /**
129 * executes the JSP given by templateName.
130 *
131 * @param pipelineData A PipelineData Object
132 * @param templateName The template to execute
133 * @param isForward whether to perform a forward or include.
134 *
135 * @throws TurbineException If a problem occurred while executing the JSP
136 */
137 @Override
138 public void handleRequest(PipelineData pipelineData, String templateName, boolean isForward)
139 throws TurbineException
140 {
141 if(!(pipelineData instanceof RunData))
142 {
143 throw new RuntimeException("Can't cast to rundata from pipeline data.");
144 }
145
146 RunData data = (RunData)pipelineData;
147
148 /** template name with relative path */
149 String relativeTemplateName = getRelativeTemplateName(templateName);
150
151 if (StringUtils.isEmpty(relativeTemplateName))
152 {
153 throw new TurbineException(
154 "Template " + templateName + " not found in template paths");
155 }
156
157 // get the RequestDispatcher for the JSP
158 RequestDispatcher dispatcher = data.getServletContext()
159 .getRequestDispatcher(relativeTemplateName);
160
161 try
162 {
163 if (isForward)
164 {
165 // forward the request to the JSP
166 dispatcher.forward(data.getRequest(), data.getResponse());
167 }
168 else
169 {
170 data.getResponse().getWriter().flush();
171 // include the JSP
172 dispatcher.include(data.getRequest(), data.getResponse());
173 }
174 }
175 catch (Exception e)
176 {
177 // Let's try hard to send the error message to the browser, to speed up debugging
178 try
179 {
180 data.getResponse().getWriter().print("Error encountered processing a template: "
181 + templateName);
182 e.printStackTrace(data.getResponse().getWriter());
183 }
184 catch (IOException ignored)
185 {
186 // ignore
187 }
188
189 // pass the exception to the caller according to the general
190 // contract for templating services in Turbine
191 throw new TurbineException(
192 "Error encountered processing a template: " + templateName, e);
193 }
194 }
195
196 /**
197 * executes the JSP given by templateName.
198 *
199 * @param pipelineData A PipelineData Object
200 * @param templateName The template to execute
201 *
202 * @throws TurbineException If a problem occurred while executing the JSP
203 */
204 @Override
205 public void handleRequest(PipelineData pipelineData, String templateName)
206 throws TurbineException
207 {
208 handleRequest(pipelineData, templateName, false);
209 }
210
211 /**
212 * This method sets up the template cache.
213 */
214 private void initJsp()
215 throws Exception
216 {
217 Configuration config = getConfiguration();
218
219 // Set relative paths from config.
220 // Needed for javax.servlet.RequestDispatcher
221 relativeTemplatePaths = config.getStringArray(TEMPLATE_PATH_KEY);
222
223 // Use Turbine Servlet to translate the template paths.
224 templatePaths = new String [relativeTemplatePaths.length];
225 for (int i=0; i < relativeTemplatePaths.length; i++)
226 {
227 relativeTemplatePaths[i] = warnAbsolute(relativeTemplatePaths[i]);
228
229 templatePaths[i] = Turbine.getRealPath(relativeTemplatePaths[i]);
230 }
231
232 bufferSize = config.getInt(JspService.BUFFER_SIZE_KEY,
233 JspService.BUFFER_SIZE_DEFAULT);
234 }
235
236 /**
237 * Determine whether a given template is available on the
238 * configured template pathes.
239 *
240 * @param template The name of the requested Template
241 * @return True if the template is available.
242 */
243 @Override
244 public boolean templateExists(String template)
245 {
246 return Arrays.stream(templatePaths).anyMatch(templatePath -> templateExists(templatePath, template));
247 }
248
249 /**
250 * Determine whether a given template exists on the supplied
251 * template path. This service ATM only supports file based
252 * templates so it simply checks for file existence.
253 *
254 * @param path The absolute (file system) template path
255 * @param template The name of the requested Template
256 * @return True if the template is available.
257 */
258 private boolean templateExists(String path, String template)
259 {
260 return new File(path, template).exists();
261 }
262
263 /**
264 * Searches for a template in the default.template path[s] and
265 * returns the template name with a relative path which is
266 * required by <a href="http://java.sun.com/products/servlet/2.3/javadoc/javax/servlet/ServletContext.html#getRequestDispatcher(java.lang.String)">
267 * javax.servlet.RequestDispatcher</a>
268 *
269 * @param template the name of the template
270 * @return String
271 */
272 @Override
273 public String getRelativeTemplateName(String template)
274 {
275 String relativeTemplate = warnAbsolute(template);
276
277 // Find which template path the template is in
278 // We have a 1:1 match between relative and absolute
279 // pathes so we can use the index for translation.
280 for (int i = 0; i < templatePaths.length; i++)
281 {
282 if (templateExists(templatePaths[i], relativeTemplate))
283 {
284 return relativeTemplatePaths[i] + "/" + relativeTemplate;
285 }
286 }
287 return null;
288 }
289
290 /**
291 * Warn if a template name or path starts with "/".
292 *
293 * @param template The template to test
294 * @return The template name with a leading / stripped off
295 */
296 private String warnAbsolute(String template)
297 {
298 if (template.startsWith("/"))
299 {
300 log.warn("Template {} has a leading /, which is wrong!", template);
301 return template.substring(1);
302 }
303 return template;
304 }
305 }