| 1 | package org.apache.velocity.runtime.resource.loader; |
| 2 | |
| 3 | /* |
| 4 | * Copyright 2001,2004 The Apache Software Foundation. |
| 5 | * |
| 6 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 7 | * you may not use this file except in compliance with the License. |
| 8 | * You may obtain a copy of the License at |
| 9 | * |
| 10 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 11 | * |
| 12 | * Unless required by applicable law or agreed to in writing, software |
| 13 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 15 | * See the License for the specific language governing permissions and |
| 16 | * limitations under the License. |
| 17 | */ |
| 18 | |
| 19 | import java.io.File; |
| 20 | import java.io.InputStream; |
| 21 | import java.io.FileInputStream; |
| 22 | import java.io.BufferedInputStream; |
| 23 | import java.io.FileNotFoundException; |
| 24 | |
| 25 | import java.util.Hashtable; |
| 26 | import java.util.Vector; |
| 27 | |
| 28 | import org.apache.velocity.util.StringUtils; |
| 29 | |
| 30 | import org.apache.velocity.runtime.resource.Resource; |
| 31 | |
| 32 | import org.apache.velocity.exception.ResourceNotFoundException; |
| 33 | |
| 34 | import org.apache.commons.collections.ExtendedProperties; |
| 35 | |
| 36 | /** |
| 37 | * A loader for templates stored on the file system. |
| 38 | * |
| 39 | * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a> |
| 40 | * @version $Id: FileResourceLoader.java,v 1.19.4.1 2004/03/03 23:23:02 geirm Exp $ |
| 41 | */ |
| 42 | public class FileResourceLoader extends ResourceLoader |
| 43 | { |
| 44 | /** |
| 45 | * The paths to search for templates. |
| 46 | */ |
| 47 | private Vector paths = null; |
| 48 | |
| 49 | /** |
| 50 | * Used to map the path that a template was found on |
| 51 | * so that we can properly check the modification |
| 52 | * times of the files. |
| 53 | */ |
| 54 | private Hashtable templatePaths = new Hashtable(); |
| 55 | |
| 56 | public void init( ExtendedProperties configuration) |
| 57 | { |
| 58 | rsvc.info("FileResourceLoader : initialization starting."); |
| 59 | |
| 60 | paths = configuration.getVector("path"); |
| 61 | |
| 62 | /* |
| 63 | * lets tell people what paths we will be using |
| 64 | */ |
| 65 | |
| 66 | int sz = paths.size(); |
| 67 | |
| 68 | for( int i=0; i < sz; i++) |
| 69 | { |
| 70 | rsvc.info("FileResourceLoader : adding path '" + (String) paths.get(i) + "'"); |
| 71 | } |
| 72 | |
| 73 | rsvc.info("FileResourceLoader : initialization complete."); |
| 74 | } |
| 75 | |
| 76 | /** |
| 77 | * Get an InputStream so that the Runtime can build a |
| 78 | * template with it. |
| 79 | * |
| 80 | * @param name name of template to get |
| 81 | * @return InputStream containing the template |
| 82 | * @throws ResourceNotFoundException if template not found |
| 83 | * in the file template path. |
| 84 | */ |
| 85 | public synchronized InputStream getResourceStream(String templateName) |
| 86 | throws ResourceNotFoundException |
| 87 | { |
| 88 | /* |
| 89 | * Make sure we have a valid templateName. |
| 90 | */ |
| 91 | if (templateName == null || templateName.length() == 0) |
| 92 | { |
| 93 | /* |
| 94 | * If we don't get a properly formed templateName then |
| 95 | * there's not much we can do. So we'll forget about |
| 96 | * trying to search any more paths for the template. |
| 97 | */ |
| 98 | throw new ResourceNotFoundException( |
| 99 | "Need to specify a file name or file path!"); |
| 100 | } |
| 101 | |
| 102 | String template = StringUtils.normalizePath(templateName); |
| 103 | if ( template == null || template.length() == 0 ) |
| 104 | { |
| 105 | String msg = "File resource error : argument " + template + |
| 106 | " contains .. and may be trying to access " + |
| 107 | "content outside of template root. Rejected."; |
| 108 | |
| 109 | rsvc.error( "FileResourceLoader : " + msg ); |
| 110 | |
| 111 | throw new ResourceNotFoundException ( msg ); |
| 112 | } |
| 113 | |
| 114 | /* |
| 115 | * if a / leads off, then just nip that :) |
| 116 | */ |
| 117 | if (template.startsWith("/")) |
| 118 | { |
| 119 | template = template.substring(1); |
| 120 | } |
| 121 | |
| 122 | int size = paths.size(); |
| 123 | for (int i = 0; i < size; i++) |
| 124 | { |
| 125 | String path = (String) paths.get(i); |
| 126 | InputStream inputStream = findTemplate(path, template); |
| 127 | |
| 128 | if (inputStream != null) |
| 129 | { |
| 130 | /* |
| 131 | * Store the path that this template came |
| 132 | * from so that we can check its modification |
| 133 | * time. |
| 134 | */ |
| 135 | |
| 136 | templatePaths.put(templateName, path); |
| 137 | return inputStream; |
| 138 | } |
| 139 | } |
| 140 | |
| 141 | /* |
| 142 | * We have now searched all the paths for |
| 143 | * templates and we didn't find anything so |
| 144 | * throw an exception. |
| 145 | */ |
| 146 | String msg = "FileResourceLoader Error: cannot find resource " + |
| 147 | template; |
| 148 | |
| 149 | throw new ResourceNotFoundException( msg ); |
| 150 | } |
| 151 | |
| 152 | /** |
| 153 | * Try to find a template given a normalized path. |
| 154 | * |
| 155 | * @param String a normalized path |
| 156 | * @return InputStream input stream that will be parsed |
| 157 | * |
| 158 | */ |
| 159 | private InputStream findTemplate(String path, String template) |
| 160 | { |
| 161 | try |
| 162 | { |
| 163 | File file = new File( path, template ); |
| 164 | |
| 165 | if ( file.canRead() ) |
| 166 | { |
| 167 | return new BufferedInputStream( |
| 168 | new FileInputStream(file.getAbsolutePath())); |
| 169 | } |
| 170 | else |
| 171 | { |
| 172 | return null; |
| 173 | } |
| 174 | } |
| 175 | catch( FileNotFoundException fnfe ) |
| 176 | { |
| 177 | /* |
| 178 | * log and convert to a general Velocity ResourceNotFoundException |
| 179 | */ |
| 180 | return null; |
| 181 | } |
| 182 | } |
| 183 | |
| 184 | /** |
| 185 | * How to keep track of all the modified times |
| 186 | * across the paths. Note that a file might have |
| 187 | * appeared in a directory which is earlier in the |
| 188 | * path; so we should search the path and see if |
| 189 | * the file we find that way is the same as the one |
| 190 | * that we have cached. |
| 191 | */ |
| 192 | public boolean isSourceModified(Resource resource) |
| 193 | { |
| 194 | /* |
| 195 | * we assume that the file needs to be reloaded; |
| 196 | * if we find the original file and it's unchanged, |
| 197 | * then we'll flip this. |
| 198 | */ |
| 199 | boolean modified = true; |
| 200 | |
| 201 | String fileName = resource.getName(); |
| 202 | String path = (String) templatePaths.get(fileName); |
| 203 | File currentFile = null; |
| 204 | |
| 205 | for (int i = 0; currentFile == null && i < paths.size(); i++) |
| 206 | { |
| 207 | String testPath = (String) paths.get(i); |
| 208 | File testFile = new File(testPath, fileName); |
| 209 | if (testFile.canRead()) |
| 210 | { |
| 211 | currentFile = testFile; |
| 212 | } |
| 213 | } |
| 214 | File file = new File(path, fileName); |
| 215 | if (currentFile == null || !file.exists()) |
| 216 | { |
| 217 | /* |
| 218 | * noop: if the file is missing now (either the cached |
| 219 | * file is gone, or the file can no longer be found) |
| 220 | * then we leave modified alone (it's set to true); a |
| 221 | * reload attempt will be done, which will either use |
| 222 | * a new template or fail with an appropriate message |
| 223 | * about how the file couldn't be found. |
| 224 | */ |
| 225 | } |
| 226 | else if (currentFile.equals(file) && file.canRead()) |
| 227 | { |
| 228 | /* |
| 229 | * if only if currentFile is the same as file and |
| 230 | * file.lastModified() is the same as |
| 231 | * resource.getLastModified(), then we should use the |
| 232 | * cached version. |
| 233 | */ |
| 234 | modified = (file.lastModified() != resource.getLastModified()); |
| 235 | } |
| 236 | |
| 237 | /* |
| 238 | * rsvc.debug("isSourceModified for " + fileName + ": " + modified); |
| 239 | */ |
| 240 | return modified; |
| 241 | } |
| 242 | |
| 243 | public long getLastModified(Resource resource) |
| 244 | { |
| 245 | String path = (String) templatePaths.get(resource.getName()); |
| 246 | File file = new File(path, resource.getName()); |
| 247 | |
| 248 | if (file.canRead()) |
| 249 | { |
| 250 | return file.lastModified(); |
| 251 | } |
| 252 | else |
| 253 | { |
| 254 | return 0; |
| 255 | } |
| 256 | } |
| 257 | } |