| 1 | package org.apache.velocity.runtime.resource; |
| 2 | |
| 3 | /* |
| 4 | * Copyright 2000-2001,2004 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.util.ArrayList; |
| 20 | import java.util.Hashtable; |
| 21 | import java.util.Vector; |
| 22 | |
| 23 | import java.io.InputStream; |
| 24 | import java.io.IOException; |
| 25 | |
| 26 | import org.apache.velocity.runtime.RuntimeServices; |
| 27 | import org.apache.velocity.runtime.RuntimeConstants; |
| 28 | |
| 29 | import org.apache.velocity.runtime.resource.ResourceFactory; |
| 30 | import org.apache.velocity.runtime.resource.loader.ResourceLoader; |
| 31 | import org.apache.velocity.runtime.resource.loader.ResourceLoaderFactory; |
| 32 | |
| 33 | import org.apache.velocity.exception.ResourceNotFoundException; |
| 34 | import org.apache.velocity.exception.ParseErrorException; |
| 35 | |
| 36 | import org.apache.commons.collections.ExtendedProperties; |
| 37 | |
| 38 | /** |
| 39 | * Class to manage the text resource for the Velocity |
| 40 | * Runtime. |
| 41 | * |
| 42 | * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a> |
| 43 | * @author <a href="mailto:paulo.gaspar@krankikom.de">Paulo Gaspar</a> |
| 44 | * @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a> |
| 45 | * @version $Id: ResourceManagerImpl.java,v 1.7.4.1 2004/03/03 23:23:01 geirm Exp $ |
| 46 | */ |
| 47 | public class ResourceManagerImpl implements ResourceManager |
| 48 | { |
| 49 | /** |
| 50 | * A template resources. |
| 51 | */ |
| 52 | public static final int RESOURCE_TEMPLATE = 1; |
| 53 | |
| 54 | /** |
| 55 | * A static content resource. |
| 56 | */ |
| 57 | public static final int RESOURCE_CONTENT = 2; |
| 58 | |
| 59 | /** |
| 60 | * token used to identify the loader internally |
| 61 | */ |
| 62 | private static final String RESOURCE_LOADER_IDENTIFIER = "_RESOURCE_LOADER_IDENTIFIER_"; |
| 63 | |
| 64 | /** |
| 65 | * Object implementing ResourceCache to |
| 66 | * be our resource manager's Resource cache. |
| 67 | */ |
| 68 | protected ResourceCache globalCache = null; |
| 69 | |
| 70 | /** |
| 71 | * The List of templateLoaders that the Runtime will |
| 72 | * use to locate the InputStream source of a template. |
| 73 | */ |
| 74 | protected ArrayList resourceLoaders = new ArrayList(); |
| 75 | |
| 76 | /** |
| 77 | * This is a list of the template input stream source |
| 78 | * initializers, basically properties for a particular |
| 79 | * template stream source. The order in this list |
| 80 | * reflects numbering of the properties i.e. |
| 81 | * |
| 82 | * <loader-id>.resource.loader.<property> = <value> |
| 83 | */ |
| 84 | private ArrayList sourceInitializerList = new ArrayList(); |
| 85 | |
| 86 | /** |
| 87 | * This is a map of public name of the template |
| 88 | * stream source to it's initializer. This is so |
| 89 | * that clients of velocity can set properties of |
| 90 | * a template source stream with its public name. |
| 91 | * So for example, a client could set the |
| 92 | * File.resource.path property and this would |
| 93 | * change the resource.path property for the |
| 94 | * file template stream source. |
| 95 | */ |
| 96 | private Hashtable sourceInitializerMap = new Hashtable(); |
| 97 | |
| 98 | /** |
| 99 | * Each loader needs a configuration object for |
| 100 | * its initialization, this flags keeps track of whether |
| 101 | * or not the configuration objects have been created |
| 102 | * for the resource loaders. |
| 103 | */ |
| 104 | private boolean resourceLoaderInitializersActive = false; |
| 105 | |
| 106 | /** |
| 107 | * switch to turn off log notice when a resource is found for |
| 108 | * the first time. |
| 109 | */ |
| 110 | private boolean logWhenFound = true; |
| 111 | |
| 112 | protected RuntimeServices rsvc = null; |
| 113 | |
| 114 | /** |
| 115 | * Initialize the ResourceManager. |
| 116 | */ |
| 117 | public void initialize( RuntimeServices rs ) |
| 118 | throws Exception |
| 119 | { |
| 120 | rsvc = rs; |
| 121 | |
| 122 | rsvc.info("Default ResourceManager initializing. (" + this.getClass() + ")"); |
| 123 | |
| 124 | ResourceLoader resourceLoader; |
| 125 | |
| 126 | assembleResourceLoaderInitializers(); |
| 127 | |
| 128 | for (int i = 0; i < sourceInitializerList.size(); i++) |
| 129 | { |
| 130 | ExtendedProperties configuration = (ExtendedProperties) sourceInitializerList.get(i); |
| 131 | String loaderClass = configuration.getString("class"); |
| 132 | |
| 133 | if ( loaderClass == null) |
| 134 | { |
| 135 | rsvc.error( "Unable to find '" |
| 136 | + configuration.getString(RESOURCE_LOADER_IDENTIFIER) |
| 137 | + ".resource.loader.class' specification in configuation." |
| 138 | + " This is a critical value. Please adjust configuration."); |
| 139 | continue; |
| 140 | } |
| 141 | |
| 142 | resourceLoader = ResourceLoaderFactory.getLoader( rsvc, loaderClass); |
| 143 | resourceLoader.commonInit( rsvc, configuration); |
| 144 | resourceLoader.init(configuration); |
| 145 | resourceLoaders.add(resourceLoader); |
| 146 | |
| 147 | } |
| 148 | |
| 149 | /* |
| 150 | * now see if this is overridden by configuration |
| 151 | */ |
| 152 | |
| 153 | logWhenFound = rsvc.getBoolean( RuntimeConstants.RESOURCE_MANAGER_LOGWHENFOUND, true ); |
| 154 | |
| 155 | /* |
| 156 | * now, is a global cache specified? |
| 157 | */ |
| 158 | |
| 159 | String claz = rsvc.getString( RuntimeConstants.RESOURCE_MANAGER_CACHE_CLASS ); |
| 160 | |
| 161 | Object o = null; |
| 162 | |
| 163 | if ( claz != null && claz.length() > 0 ) |
| 164 | { |
| 165 | try |
| 166 | { |
| 167 | o = Class.forName( claz ).newInstance(); |
| 168 | } |
| 169 | catch (ClassNotFoundException cnfe ) |
| 170 | { |
| 171 | String err = "The specified class for ResourceCache (" |
| 172 | + claz |
| 173 | + ") does not exist (or is not accessible to the current classlaoder)."; |
| 174 | rsvc.error( err ); |
| 175 | |
| 176 | o = null; |
| 177 | } |
| 178 | |
| 179 | if (!(o instanceof ResourceCache) ) |
| 180 | { |
| 181 | String err = "The specified class for ResourceCache (" |
| 182 | + claz |
| 183 | + ") does not implement org.apache.runtime.resource.ResourceCache." |
| 184 | + " ResourceManager. Using default ResourceCache implementation."; |
| 185 | |
| 186 | rsvc.error( err); |
| 187 | |
| 188 | o = null; |
| 189 | } |
| 190 | } |
| 191 | |
| 192 | /* |
| 193 | * if we didn't get through that, just use the default. |
| 194 | */ |
| 195 | |
| 196 | if ( o == null) |
| 197 | o = new ResourceCacheImpl(); |
| 198 | |
| 199 | globalCache = (ResourceCache) o; |
| 200 | |
| 201 | globalCache.initialize( rsvc ); |
| 202 | |
| 203 | rsvc.info("Default ResourceManager initialization complete."); |
| 204 | |
| 205 | } |
| 206 | |
| 207 | /** |
| 208 | * This will produce a List of Hashtables, each |
| 209 | * hashtable contains the intialization info for |
| 210 | * a particular resource loader. This Hastable |
| 211 | * will be passed in when initializing the |
| 212 | * the template loader. |
| 213 | */ |
| 214 | private void assembleResourceLoaderInitializers() |
| 215 | { |
| 216 | if (resourceLoaderInitializersActive) |
| 217 | { |
| 218 | return; |
| 219 | } |
| 220 | |
| 221 | Vector resourceLoaderNames = |
| 222 | rsvc.getConfiguration().getVector(RuntimeConstants.RESOURCE_LOADER); |
| 223 | |
| 224 | for (int i = 0; i < resourceLoaderNames.size(); i++) |
| 225 | { |
| 226 | /* |
| 227 | * The loader id might look something like the following: |
| 228 | * |
| 229 | * file.resource.loader |
| 230 | * |
| 231 | * The loader id is the prefix used for all properties |
| 232 | * pertaining to a particular loader. |
| 233 | */ |
| 234 | String loaderID = |
| 235 | resourceLoaderNames.get(i) + "." + RuntimeConstants.RESOURCE_LOADER; |
| 236 | |
| 237 | ExtendedProperties loaderConfiguration = |
| 238 | rsvc.getConfiguration().subset(loaderID); |
| 239 | |
| 240 | /* |
| 241 | * we can't really count on ExtendedProperties to give us an empty set |
| 242 | */ |
| 243 | |
| 244 | if ( loaderConfiguration == null) |
| 245 | { |
| 246 | rsvc.warn("ResourceManager : No configuration information for resource loader named '" |
| 247 | + resourceLoaderNames.get(i) + "'. Skipping."); |
| 248 | continue; |
| 249 | } |
| 250 | |
| 251 | /* |
| 252 | * add the loader name token to the initializer if we need it |
| 253 | * for reference later. We can't count on the user to fill |
| 254 | * in the 'name' field |
| 255 | */ |
| 256 | |
| 257 | loaderConfiguration.setProperty( RESOURCE_LOADER_IDENTIFIER, resourceLoaderNames.get(i)); |
| 258 | |
| 259 | /* |
| 260 | * Add resources to the list of resource loader |
| 261 | * initializers. |
| 262 | */ |
| 263 | sourceInitializerList.add(loaderConfiguration); |
| 264 | } |
| 265 | |
| 266 | resourceLoaderInitializersActive = true; |
| 267 | } |
| 268 | |
| 269 | /** |
| 270 | * Gets the named resource. Returned class type corresponds to specified type |
| 271 | * (i.e. <code>Template</code> to <code>RESOURCE_TEMPLATE</code>). |
| 272 | * |
| 273 | * @param resourceName The name of the resource to retrieve. |
| 274 | * @param resourceType The type of resource (<code>RESOURCE_TEMPLATE</code>, |
| 275 | * <code>RESOURCE_CONTENT</code>, etc.). |
| 276 | * @param encoding The character encoding to use. |
| 277 | * @return Resource with the template parsed and ready. |
| 278 | * @throws ResourceNotFoundException if template not found |
| 279 | * from any available source. |
| 280 | * @throws ParseErrorException if template cannot be parsed due |
| 281 | * to syntax (or other) error. |
| 282 | * @throws Exception if a problem in parse |
| 283 | */ |
| 284 | public Resource getResource(String resourceName, int resourceType, String encoding ) |
| 285 | throws ResourceNotFoundException, ParseErrorException, Exception |
| 286 | { |
| 287 | /* |
| 288 | * Check to see if the resource was placed in the cache. |
| 289 | * If it was placed in the cache then we will use |
| 290 | * the cached version of the resource. If not we |
| 291 | * will load it. |
| 292 | */ |
| 293 | |
| 294 | Resource resource = globalCache.get(resourceName); |
| 295 | |
| 296 | if( resource != null) |
| 297 | { |
| 298 | /* |
| 299 | * refresh the resource |
| 300 | */ |
| 301 | |
| 302 | try |
| 303 | { |
| 304 | refreshResource( resource, encoding ); |
| 305 | } |
| 306 | catch( ResourceNotFoundException rnfe ) |
| 307 | { |
| 308 | /* |
| 309 | * something exceptional happened to that resource |
| 310 | * this could be on purpose, |
| 311 | * so clear the cache and try again |
| 312 | */ |
| 313 | |
| 314 | globalCache.remove( resourceName ); |
| 315 | |
| 316 | return getResource( resourceName, resourceType, encoding ); |
| 317 | } |
| 318 | catch( ParseErrorException pee ) |
| 319 | { |
| 320 | rsvc.error( |
| 321 | "ResourceManager.getResource() exception: " + pee); |
| 322 | |
| 323 | throw pee; |
| 324 | } |
| 325 | catch( Exception eee ) |
| 326 | { |
| 327 | rsvc.error( |
| 328 | "ResourceManager.getResource() exception: " + eee); |
| 329 | |
| 330 | throw eee; |
| 331 | } |
| 332 | } |
| 333 | else |
| 334 | { |
| 335 | try |
| 336 | { |
| 337 | /* |
| 338 | * it's not in the cache, so load it. |
| 339 | */ |
| 340 | |
| 341 | resource = loadResource( resourceName, resourceType, encoding ); |
| 342 | |
| 343 | if (resource.getResourceLoader().isCachingOn()) |
| 344 | { |
| 345 | globalCache.put(resourceName, resource); |
| 346 | } |
| 347 | } |
| 348 | catch( ResourceNotFoundException rnfe2 ) |
| 349 | { |
| 350 | rsvc.error( |
| 351 | "ResourceManager : unable to find resource '" + resourceName + |
| 352 | "' in any resource loader."); |
| 353 | |
| 354 | throw rnfe2; |
| 355 | } |
| 356 | catch( ParseErrorException pee ) |
| 357 | { |
| 358 | rsvc.error( |
| 359 | "ResourceManager.getResource() parse exception: " + pee); |
| 360 | |
| 361 | throw pee; |
| 362 | } |
| 363 | catch( Exception ee ) |
| 364 | { |
| 365 | rsvc.error( |
| 366 | "ResourceManager.getResource() exception new: " + ee); |
| 367 | |
| 368 | throw ee; |
| 369 | } |
| 370 | } |
| 371 | |
| 372 | return resource; |
| 373 | } |
| 374 | |
| 375 | /** |
| 376 | * Loads a resource from the current set of resource loaders |
| 377 | * |
| 378 | * @param resourceName The name of the resource to retrieve. |
| 379 | * @param resourceType The type of resource (<code>RESOURCE_TEMPLATE</code>, |
| 380 | * <code>RESOURCE_CONTENT</code>, etc.). |
| 381 | * @param encoding The character encoding to use. |
| 382 | * @return Resource with the template parsed and ready. |
| 383 | * @throws ResourceNotFoundException if template not found |
| 384 | * from any available source. |
| 385 | * @throws ParseErrorException if template cannot be parsed due |
| 386 | * to syntax (or other) error. |
| 387 | * @throws Exception if a problem in parse |
| 388 | */ |
| 389 | protected Resource loadResource(String resourceName, int resourceType, String encoding ) |
| 390 | throws ResourceNotFoundException, ParseErrorException, Exception |
| 391 | { |
| 392 | Resource resource = ResourceFactory.getResource(resourceName, resourceType); |
| 393 | |
| 394 | resource.setRuntimeServices( rsvc ); |
| 395 | |
| 396 | resource.setName( resourceName ); |
| 397 | resource.setEncoding( encoding ); |
| 398 | |
| 399 | /* |
| 400 | * Now we have to try to find the appropriate |
| 401 | * loader for this resource. We have to cycle through |
| 402 | * the list of available resource loaders and see |
| 403 | * which one gives us a stream that we can use to |
| 404 | * make a resource with. |
| 405 | */ |
| 406 | |
| 407 | long howOldItWas = 0; // Initialize to avoid warnings |
| 408 | |
| 409 | ResourceLoader resourceLoader = null; |
| 410 | |
| 411 | for (int i = 0; i < resourceLoaders.size(); i++) |
| 412 | { |
| 413 | resourceLoader = (ResourceLoader) resourceLoaders.get(i); |
| 414 | resource.setResourceLoader(resourceLoader); |
| 415 | |
| 416 | /* |
| 417 | * catch the ResourceNotFound exception |
| 418 | * as that is ok in our new multi-loader environment |
| 419 | */ |
| 420 | |
| 421 | try |
| 422 | { |
| 423 | if (resource.process()) |
| 424 | { |
| 425 | /* |
| 426 | * FIXME (gmj) |
| 427 | * moved in here - technically still |
| 428 | * a problem - but the resource needs to be |
| 429 | * processed before the loader can figure |
| 430 | * it out due to to the new |
| 431 | * multi-path support - will revisit and fix |
| 432 | */ |
| 433 | |
| 434 | if ( logWhenFound ) |
| 435 | { |
| 436 | rsvc.info("ResourceManager : found " + resourceName + |
| 437 | " with loader " + resourceLoader.getClassName() ); |
| 438 | } |
| 439 | |
| 440 | howOldItWas = resourceLoader.getLastModified( resource ); |
| 441 | break; |
| 442 | } |
| 443 | } |
| 444 | catch( ResourceNotFoundException rnfe ) |
| 445 | { |
| 446 | /* |
| 447 | * that's ok - it's possible to fail in |
| 448 | * multi-loader environment |
| 449 | */ |
| 450 | } |
| 451 | } |
| 452 | |
| 453 | /* |
| 454 | * Return null if we can't find a resource. |
| 455 | */ |
| 456 | if (resource.getData() == null) |
| 457 | { |
| 458 | throw new ResourceNotFoundException( |
| 459 | "Unable to find resource '" + resourceName + "'"); |
| 460 | } |
| 461 | |
| 462 | /* |
| 463 | * some final cleanup |
| 464 | */ |
| 465 | |
| 466 | resource.setLastModified( howOldItWas ); |
| 467 | |
| 468 | resource.setModificationCheckInterval( |
| 469 | resourceLoader.getModificationCheckInterval()); |
| 470 | |
| 471 | resource.touch(); |
| 472 | |
| 473 | return resource; |
| 474 | } |
| 475 | |
| 476 | /** |
| 477 | * Takes an existing resource, and 'refreshes' it. This |
| 478 | * generally means that the source of the resource is checked |
| 479 | * for changes according to some cache/check algorithm |
| 480 | * and if the resource changed, then the resource data is |
| 481 | * reloaded and re-parsed. |
| 482 | * |
| 483 | * @param resource resource to refresh |
| 484 | * |
| 485 | * @throws ResourceNotFoundException if template not found |
| 486 | * from current source for this Resource |
| 487 | * @throws ParseErrorException if template cannot be parsed due |
| 488 | * to syntax (or other) error. |
| 489 | * @throws Exception if a problem in parse |
| 490 | */ |
| 491 | protected void refreshResource( Resource resource, String encoding ) |
| 492 | throws ResourceNotFoundException, ParseErrorException, Exception |
| 493 | { |
| 494 | /* |
| 495 | * The resource knows whether it needs to be checked |
| 496 | * or not, and the resource's loader can check to |
| 497 | * see if the source has been modified. If both |
| 498 | * these conditions are true then we must reload |
| 499 | * the input stream and parse it to make a new |
| 500 | * AST for the resource. |
| 501 | */ |
| 502 | if ( resource.requiresChecking() ) |
| 503 | { |
| 504 | /* |
| 505 | * touch() the resource to reset the counters |
| 506 | */ |
| 507 | |
| 508 | resource.touch(); |
| 509 | |
| 510 | if( resource.isSourceModified() ) |
| 511 | { |
| 512 | /* |
| 513 | * now check encoding info. It's possible that the newly declared |
| 514 | * encoding is different than the encoding already in the resource |
| 515 | * this strikes me as bad... |
| 516 | */ |
| 517 | |
| 518 | if (!resource.getEncoding().equals( encoding ) ) |
| 519 | { |
| 520 | rsvc.error("Declared encoding for template '" + resource.getName() |
| 521 | + "' is different on reload. Old = '" + resource.getEncoding() |
| 522 | + "' New = '" + encoding ); |
| 523 | |
| 524 | resource.setEncoding( encoding ); |
| 525 | } |
| 526 | |
| 527 | /* |
| 528 | * read how old the resource is _before_ |
| 529 | * processing (=>reading) it |
| 530 | */ |
| 531 | long howOldItWas = resource.getResourceLoader().getLastModified( resource ); |
| 532 | |
| 533 | /* |
| 534 | * read in the fresh stream and parse |
| 535 | */ |
| 536 | |
| 537 | resource.process(); |
| 538 | |
| 539 | /* |
| 540 | * now set the modification info and reset |
| 541 | * the modification check counters |
| 542 | */ |
| 543 | |
| 544 | resource.setLastModified( howOldItWas ); |
| 545 | } |
| 546 | } |
| 547 | } |
| 548 | |
| 549 | /** |
| 550 | * Gets the named resource. Returned class type corresponds to specified type |
| 551 | * (i.e. <code>Template</code> to <code>RESOURCE_TEMPLATE</code>). |
| 552 | * |
| 553 | * @param resourceName The name of the resource to retrieve. |
| 554 | * @param resourceType The type of resource (<code>RESOURCE_TEMPLATE</code>, |
| 555 | * <code>RESOURCE_CONTENT</code>, etc.). |
| 556 | * @return Resource with the template parsed and ready. |
| 557 | * @throws ResourceNotFoundException if template not found |
| 558 | * from any available source. |
| 559 | * @throws ParseErrorException if template cannot be parsed due |
| 560 | * to syntax (or other) error. |
| 561 | * @throws Exception if a problem in parse |
| 562 | * |
| 563 | * @deprecated Use |
| 564 | * {@link #getResource(String resourceName, int resourceType, |
| 565 | * String encoding )} |
| 566 | */ |
| 567 | public Resource getResource(String resourceName, int resourceType ) |
| 568 | throws ResourceNotFoundException, ParseErrorException, Exception |
| 569 | { |
| 570 | return getResource( resourceName, resourceType, RuntimeConstants.ENCODING_DEFAULT); |
| 571 | } |
| 572 | |
| 573 | /** |
| 574 | * Determines is a template exists, and returns name of the loader that |
| 575 | * provides it. This is a slightly less hokey way to support |
| 576 | * the Velocity.templateExists() utility method, which was broken |
| 577 | * when per-template encoding was introduced. We can revisit this. |
| 578 | * |
| 579 | * @param resourceName Name of template or content resource |
| 580 | * @return class name of loader than can provide it |
| 581 | */ |
| 582 | public String getLoaderNameForResource(String resourceName ) |
| 583 | { |
| 584 | ResourceLoader resourceLoader = null; |
| 585 | |
| 586 | /* |
| 587 | * loop through our loaders... |
| 588 | */ |
| 589 | for (int i = 0; i < resourceLoaders.size(); i++) |
| 590 | { |
| 591 | resourceLoader = (ResourceLoader) resourceLoaders.get(i); |
| 592 | |
| 593 | InputStream is = null; |
| 594 | |
| 595 | /* |
| 596 | * if we find one that can provide the resource, |
| 597 | * return the name of the loaders's Class |
| 598 | */ |
| 599 | try |
| 600 | { |
| 601 | is=resourceLoader.getResourceStream( resourceName ); |
| 602 | |
| 603 | if( is != null) |
| 604 | { |
| 605 | return resourceLoader.getClass().toString(); |
| 606 | } |
| 607 | } |
| 608 | catch( ResourceNotFoundException e) |
| 609 | { |
| 610 | /* |
| 611 | * this isn't a problem. keep going |
| 612 | */ |
| 613 | } |
| 614 | finally |
| 615 | { |
| 616 | /* |
| 617 | * if we did find one, clean up because we were |
| 618 | * returned an open stream |
| 619 | */ |
| 620 | if (is != null) |
| 621 | { |
| 622 | try |
| 623 | { |
| 624 | is.close(); |
| 625 | } |
| 626 | catch( IOException ioe) |
| 627 | { |
| 628 | } |
| 629 | } |
| 630 | } |
| 631 | } |
| 632 | |
| 633 | return null; |
| 634 | } |
| 635 | } |
| 636 | |
| 637 | |