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1   // ========================================================================
2   // Copyright (c) 2009-2010 Intalio, Inc.
3   // ------------------------------------------------------------------------
4   // All rights reserved. This program and the accompanying materials
5   // are made available under the terms of the Eclipse Public License v1.0
6   // and Apache License v2.0 which accompanies this distribution.
7   // The Eclipse Public License is available at 
8   // http://www.eclipse.org/legal/epl-v10.html
9   // The Apache License v2.0 is available at
10  // http://www.opensource.org/licenses/apache2.0.php
11  // You may elect to redistribute this code under either of these licenses. 
12  // ========================================================================
13  package org.eclipse.jetty.osgi.boot.jasper;
14  
15  import java.io.File;
16  import java.io.InputStream;
17  import java.net.URL;
18  import java.util.ArrayList;
19  import java.util.HashSet;
20  
21  import javax.servlet.Servlet;
22  import javax.servlet.jsp.JspContext;
23  import javax.servlet.jsp.JspFactory;
24  
25  import org.apache.jasper.Constants;
26  import org.apache.jasper.compiler.Localizer;
27  import org.apache.jasper.xmlparser.ParserUtils;
28  import org.eclipse.jetty.osgi.boot.JettyBootstrapActivator;
29  import org.eclipse.jetty.osgi.boot.OSGiAppProvider;
30  import org.eclipse.jetty.osgi.boot.utils.BundleFileLocatorHelper;
31  import org.eclipse.jetty.osgi.boot.utils.WebappRegistrationCustomizer;
32  import org.osgi.framework.Bundle;
33  import org.osgi.framework.FrameworkUtil;
34  import org.xml.sax.EntityResolver;
35  import org.xml.sax.InputSource;
36  import org.xml.sax.SAXException;
37  
38  /**
39   * Fix various shortcomings with the way jasper parses the tld files.
40   * Plugs the JSTL tlds assuming that they are packaged with the bundle that contains the JSTL classes.
41   * <p>
42   * Pluggable tlds at the server level are handled by {@link PluggableWebAppRegistrationCustomizerImpl}.
43   * </p>
44   */
45  public class WebappRegistrationCustomizerImpl implements WebappRegistrationCustomizer
46  {
47      
48  	/**
49  	 * Default name of a class that belongs to the jstl bundle.
50  	 * From that class we locate the corresponding bundle and register it
51  	 * as a bundle that contains tld files.
52  	 */
53  	private static String DEFAULT_JSTL_BUNDLE_CLASS = "org.apache.taglibs.standard.tag.el.core.WhenTag";
54  	//used to be "org.apache.jasper.runtime.JspFactoryImpl" but now 
55  	//the standard tag library implementation are stored in a separate bundle.
56  	
57  	//DISABLED please use the tld bundle argument for the OSGiAppProvider
58  //	/**
59  //	 * Default name of a class that belongs to the bundle where the Java server Faces tld files are defined.
60  //	 * This is the sun's reference implementation. 
61  //	 */
62  //	private static String DEFAUT_JSF_IMPL_CLASS = "com.sun.faces.config.ConfigureListener";
63  
64  	/**
65  	 * Default jsp factory implementation.
66  	 * Idally jasper is osgified and we can use services.
67  	 * In the mean time we statically set the jsp factory implementation.
68  	 * bug #299733
69  	 */
70  	private static String DEFAULT_JSP_FACTORY_IMPL_CLASS = "org.apache.jasper.runtime.JspFactoryImpl";
71  	
72      public WebappRegistrationCustomizerImpl()
73      {
74          fixupDtdResolution();
75          
76          try
77          {
78            //sanity check:
79              Class cl = getClass().getClassLoader().loadClass("org.apache.jasper.servlet.JspServlet");
80              //System.err.println("found the jsp servlet: " + cl.getName());
81          }
82          catch (Exception e)
83          {
84              System.err.println("Unable to locate the JspServlet: jsp support unavailable.");
85              e.printStackTrace();
86              return;
87          }
88          try
89          {
90              //bug #299733
91              JspFactory fact = JspFactory.getDefaultFactory();
92              if (fact == null)
93              {   //bug #299733
94                  //JspFactory does a simple Class.getForName("org.apache.jasper.runtime.JspFactoryImpl")
95                  //however its bundles does not import the jasper package
96                  //so it fails. let's help things out:
97                  fact = (JspFactory)JettyBootstrapActivator.class.getClassLoader()
98                      .loadClass(DEFAULT_JSP_FACTORY_IMPL_CLASS).newInstance();
99                  JspFactory.setDefaultFactory(fact);
100             }
101     
102         }
103         catch (Exception e)
104         {
105             System.err.println("Unable to set the JspFactory: jsp support incomplete.");
106             e.printStackTrace();
107         }
108     }
109     
110     /**
111      * The jasper TldScanner expects a URLClassloader to parse a jar for the /META-INF/*.tld it may contain. We place the bundles that we know contain such
112      * tag-libraries. Please note that it will work if and only if the bundle is a jar (!) Currently we just hardcode the bundle that contains the jstl
113      * implemenation.
114      * 
115      * A workaround when the tld cannot be parsed with this method is to copy and paste it inside the WEB-INF of the webapplication where it is used.
116      * 
117      * Support only 2 types of packaging for the bundle: - the bundle is a jar (recommended for runtime.) - the bundle is a folder and contain jars in the root
118      * and/or in the lib folder (nice for PDE developement situations) Unsupported: the bundle is a jar that embeds more jars.
119      * 
120      * @return array of URLs
121      * @throws Exception
122      */
123     public URL[] getJarsWithTlds(OSGiAppProvider provider, BundleFileLocatorHelper locatorHelper) throws Exception
124     {
125     	
126     	HashSet<Class<?>> classesToAddToTheTldBundles = new HashSet<Class<?>>();
127 
128     	//Look for the jstl bundle
129     	//We assume the jstl's tlds are defined there.
130     	//We assume that the jstl bundle is imported by this bundle
131     	//So we can look for this class using this bundle's classloader:
132     	Class<?> jstlClass = WebappRegistrationCustomizerImpl.class.getClassLoader().loadClass(DEFAULT_JSTL_BUNDLE_CLASS);
133     	
134     	classesToAddToTheTldBundles.add(jstlClass);
135     	
136         ArrayList<URL> urls = new ArrayList<URL>();
137     	for (Class<?> cl : classesToAddToTheTldBundles)
138     	{
139 	        Bundle tldBundle = FrameworkUtil.getBundle(cl);
140 	        File tldBundleLocation = locatorHelper.getBundleInstallLocation(tldBundle);
141 	        if (tldBundleLocation != null && tldBundleLocation.isDirectory())
142 	        {
143 	            // try to find the jar files inside this folder
144 	            for (File f : tldBundleLocation.listFiles())
145 	            {
146 	                if (f.getName().endsWith(".jar") && f.isFile())
147 	                {
148 	                    urls.add(f.toURI().toURL());
149 	                }
150 	                else if (f.isDirectory() && f.getName().equals("lib"))
151 	                {
152 	                    for (File f2 : tldBundleLocation.listFiles())
153 	                    {
154 	                        if (f2.getName().endsWith(".jar") && f2.isFile())
155 	                        {
156 	                            urls.add(f2.toURI().toURL());
157 	                        }
158 	                    }
159 	                }
160 	            }
161 	            
162 	        }
163 	        else if (tldBundleLocation != null)
164 	        {
165 	            urls.add(tldBundleLocation.toURI().toURL());
166 	        }
167     	}
168     	return urls.toArray(new URL[urls.size()]);
169     }
170 	
171     /**
172      * Jasper resolves the dtd when it parses a taglib descriptor. 
173      * It uses this code to do that: ParserUtils.getClass().getResourceAsStream(resourcePath); where
174      * resourcePath is for example: /javax/servlet/jsp/resources/web-jsptaglibrary_1_2.dtd Unfortunately, 
175      * the dtd file is not in the exact same classloader as
176      * ParserUtils class and the dtds are packaged in 2 separate bundles.
177      * OSGi does not look in the dependencies' classloader when a resource is searched.
178      * <p>
179      * The workaround consists of setting the entity resolver. That is a patch 
180      * added to the version of glassfish-jasper-jetty. IT is also present in the latest
181      * version of glassfish jasper. Could not use introspection to set new value
182      * on a static friendly field :(
183      * </p>
184      */
185     void fixupDtdResolution()
186     {
187         try
188         {
189             ParserUtils.setEntityResolver(new MyFixedupEntityResolver());
190 
191         }
192         catch (Exception e)
193         {
194             e.printStackTrace();
195         }
196 
197     }
198 
199     /**
200      * Instead of using the ParserUtil's classloader, we use a class that is indeed next to the resource for sure.
201      */
202     static class MyFixedupEntityResolver implements EntityResolver
203     {
204         /**
205          * Same values than in ParserUtils...
206          */
207         static final String[] CACHED_DTD_PUBLIC_IDS =
208         { Constants.TAGLIB_DTD_PUBLIC_ID_11, Constants.TAGLIB_DTD_PUBLIC_ID_12,
209           Constants.WEBAPP_DTD_PUBLIC_ID_22, Constants.WEBAPP_DTD_PUBLIC_ID_23, };
210 
211         static final String[] CACHED_DTD_RESOURCE_PATHS =
212         { Constants.TAGLIB_DTD_RESOURCE_PATH_11,
213           Constants.TAGLIB_DTD_RESOURCE_PATH_12,
214           Constants.WEBAPP_DTD_RESOURCE_PATH_22,
215           Constants.WEBAPP_DTD_RESOURCE_PATH_23, };
216 
217         // static final String[] CACHED_SCHEMA_RESOURCE_PATHS = {
218         // Constants.TAGLIB_SCHEMA_RESOURCE_PATH_20,
219         // Constants.TAGLIB_SCHEMA_RESOURCE_PATH_21,
220         // Constants.WEBAPP_SCHEMA_RESOURCE_PATH_24,
221         // Constants.WEBAPP_SCHEMA_RESOURCE_PATH_25,
222         // };
223         public InputSource resolveEntity(String publicId, String systemId) throws SAXException
224         {
225             for (int i = 0; i < CACHED_DTD_PUBLIC_IDS.length; i++)
226             {
227                 String cachedDtdPublicId = CACHED_DTD_PUBLIC_IDS[i];
228                 if (cachedDtdPublicId.equals(publicId))
229                 {
230                     String resourcePath = CACHED_DTD_RESOURCE_PATHS[i];
231                     InputStream input = null;
232                     input = Servlet.class.getResourceAsStream(resourcePath);
233                     if (input == null)
234                     {
235                         input = JspContext.class.getResourceAsStream(resourcePath);
236                         if (input == null)
237                         {
238                             // if that failed try again with the original code:
239                             // although it is likely not changed.
240                             input = this.getClass().getResourceAsStream(resourcePath);
241                         }
242                     }
243                     if (input == null)
244                     {
245                         throw new SAXException(Localizer.getMessage("jsp.error.internal.filenotfound",resourcePath));
246                     }
247                     InputSource isrc = new InputSource(input);
248                     return isrc;
249                 }
250             }
251 
252             return null;
253         }
254     }
255 	
256 }