app/src/main/java/org/apache/roller/weblogger/ui/rendering/velocity/WebappResourceLoader.java - roller - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  *  contributor license agreements.  The ASF licenses this file to You
  * under the Apache License, Version 2.0 (the "License"); you may not
  * use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.  For additional information regarding
  * copyright in this work, please see the NOTICE file in the top level
  * directory of this distribution.
  */

 package org.apache.roller.weblogger.ui.rendering.velocity;

 import java.io.File;
 import java.io.InputStream;
 import java.util.HashMap;
 import java.util.Map;

 import javax.servlet.ServletContext;

 import org.apache.commons.collections.ExtendedProperties;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.roller.weblogger.ui.core.RollerContext;
 import org.apache.velocity.exception.ResourceNotFoundException;
 import org.apache.velocity.runtime.resource.Resource;
 import org.apache.velocity.runtime.resource.loader.ResourceLoader;

 /**
  * Loads Velocity resources from the webapp.
  *
  * All resource urls begin from the root of the webapp. If a resource path is
  * relative (does not begin with a /) then it is prefixed with the path
  * /WEB-INF/velocity/, which is where Roller keeps its velocity files.
  *
  * Resource loader that uses the ServletContext of a webapp to load Velocity
  * templates. (it's much easier to use with servlets than the standard
  * FileResourceLoader, in particular the use of war files is transparent).
  *
  * The default search path is '/' (relative to the webapp root), but you can
  * change this behaviour by specifying one or more paths by mean of as many
  * webapp.resource.loader.path properties as needed in the velocity.properties
  * file.
  *
  * All paths must be relative to the root of the webapp.
  *
  * To enable caching and cache refreshing the webapp.resource.loader.cache and
  * webapp.resource.loader.modificationCheckInterval properties need to be set in
  * the velocity.properties file ... auto-reloading of global macros requires the
  * webapp.resource.loader.cache property to be set to 'false'.
  *
  */
 public class WebappResourceLoader extends ResourceLoader {

 	private static Log log = LogFactory.getLog(WebappResourceLoader.class);

 	// The root paths for templates (relative to webapp's root).
 	protected String[] paths = null;
 	protected Map<String, String> templatePaths = null;
 	protected ServletContext servletContext = null;

 	/**
 	 * This is abstract in the base class, so we need it. <br>
 	 * NOTE: this expects that the ServletContext has already been placed in the
 	 * runtime's application attributes under its full class name (i.e.
 	 * "javax.servlet.ServletContext").
 	 *
 	 * @param configuration
 	 *            the {@link ExtendedProperties} associated with this resource
 	 *            loader.
 	 */
 	public void init(ExtendedProperties configuration) {

 		if (log.isDebugEnabled()) {
 			log.debug("WebappResourceLoader: initialization starting.");
         }

 		// get configured paths
 		paths = configuration.getStringArray("path");
 		if (paths == null || paths.length == 0) {
 			paths = new String[1];
 			paths[0] = "/";
 		} else {
 			// make sure the paths end with a '/'
 			for (int i = 0; i < paths.length; i++) {
 				if (!paths[i].endsWith("/")) {
 					paths[i] += '/';
 				}
 				if (log.isDebugEnabled()) {
                     log.debug("WebappResourceLoader: added template path - '"
                             + paths[i] + "'");
                 }
 			}
 		}

 		// get the ServletContext
 		servletContext = RollerContext.getServletContext();

 		if (log.isDebugEnabled()) {
 			log.debug("Servlet Context = "
 					+ servletContext.getRealPath("/WEB-INF/velocity/"));
         }

 		// init the template paths map
 		templatePaths = new HashMap<String, String>();

 		if (log.isDebugEnabled()) {
             log.debug("WebappResourceLoader: initialization complete.");
         }
 	}

 	/**
 	 * Get an InputStream so that the Runtime can build a template with it.
 	 *
 	 * @param name
 	 *            name of template to get
 	 * @return InputStream containing the template
 	 * @throws ResourceNotFoundException if template not found in classpath.
 	 *
 	 */
 	public InputStream getResourceStream(String name) {

 		InputStream result = null;
 		Exception exception = null;

 		if (name == null || name.length() == 0) {
 			throw new ResourceNotFoundException(
 					"WebappResourceLoader: No template name provided");
 		}

 		// names are <template>|<deviceType>
 		// loading weblog.vm etc will not have the type so only check for
 		// one.
 		String[] split = name.split("\\|", 2);
 		if (split.length < 1) {
 			throw new ResourceNotFoundException("Invalid ThemeRL key " + name);
 		}

 		String savedPath = templatePaths.get(name);
 		if (savedPath != null) {
 			result = servletContext.getResourceAsStream(savedPath + split[0]);
 		}

 		if (result == null) {
             for (String pathSegment : paths) {
 				String path = pathSegment + split[0];
 				try {
 					result = servletContext.getResourceAsStream(path);

 					// save the path and exit the loop if we found the template
 					if (result != null) {
 						templatePaths.put(name, pathSegment);
 						break;
 					}
 				} catch (NullPointerException npe) {
 					// no servletContext was set, whine about it!
 					throw npe;
 				} catch (Exception e) {
 					// only save the first one for later throwing
 					if (exception == null) {
 						if (log.isDebugEnabled()) {
 							log.debug("WebappResourceLoader: Could not load "
 									+ path, e);
 						}
 						exception = e;
 					}
 				}
 			}
 		}

 		// If we never found the template
 		if (result == null) {
 			String msg = "WebappResourceLoader: Resource '" + name
 					+ "' not found.";

 			// convert to a general Velocity ResourceNotFoundException
 			if (exception == null) {
 				throw new ResourceNotFoundException(msg);
 			} else {
 				msg += "  Due to: " + exception;
 				throw new ResourceNotFoundException(msg, exception);
 			}
 		}

 		return result;
 	}

 	/**
 	 * Gets the cached file.
 	 *
 	 * @param rootPath
 	 *            the root path
 	 * @param fileName
 	 *            the file name
 	 *
 	 * @return the cached file
 	 */
 	private File getCachedFile(String rootPath, String fileName) {

 		// We do this when we cache a resource, so do it again to ensure a match
 		while (fileName.startsWith("/")) {
 			fileName = fileName.substring(1);
 		}

 		String savedPath = templatePaths.get(fileName);

 		// names are <template>|<deviceType>
 		// loading weblog.vm etc will not have the type so only check for
 		// one.
 		String[] split = fileName.split("\\|", 2);
 		return new File(rootPath + savedPath, split[0]);

 	}

 	/**
 	 * Checks to see if a resource has been deleted, moved or modified. When
 	 * using the resource.loader.cache=true option
 	 *
 	 * @param resource
 	 *            Resource The resource to check for modification
 	 *
 	 * @return boolean True if the resource has been modified
 	 */
 	public boolean isSourceModified(Resource resource) {

 		String rootPath = servletContext.getRealPath("/");
 		if (rootPath == null) {
 			// RootPath is null if the servlet container cannot translate the
 			// virtual path to a real path for any reason (such as when the
 			// content is being made available from a .war archive)
 			return false;
 		}

 		// first, try getting the previously found file
 		String fileName = resource.getName();
 		File cachedFile = getCachedFile(rootPath, fileName);
 		if (!cachedFile.exists()) {
 			// then the source has been moved and/or deleted
 			return true;
 		}

 		/*
 		 * Check to see if the file can now be found elsewhere before it is
 		 * found in the previously saved path
 		 */
 		File currentFile = null;
 		for (String path : paths) {
 			currentFile = new File(rootPath + path, fileName);
 			if (currentFile.canRead()) {
 				/*
 				 * stop at the first resource found (just like in
 				 * getResourceStream())
 				 */
 				break;
 			}
 		}

 		// If the current is the cached and it is readable
 		if (cachedFile.equals(currentFile) && cachedFile.canRead()) {
 			// then (and only then) do we compare the last modified values
 			return (cachedFile.lastModified() != resource.getLastModified());
 		} else {
 			// We found a new file for the resource or the resource is no longer
 			// readable.
 			return true;
 		}
 	}

 	/**
 	 * Checks to see when a resource was last modified
 	 *
 	 * @param resource
 	 *            Resource the resource to check
 	 *
 	 * @return long The time when the resource was last modified or 0 if the
 	 *         file can't be read
 	 */
 	public long getLastModified(Resource resource) {

 		String rootPath = servletContext.getRealPath("/");
 		if (rootPath == null) {
 			// RootPath is null if the servlet container cannot translate the
 			// virtual path to a real path for any reason (such as when the
 			// content is being made available from a .war archive)
 			return 0;
 		}

 		File cachedFile = getCachedFile(rootPath, resource.getName());
 		if (cachedFile.canRead()) {
 			return cachedFile.lastModified();
 		} else {
 			return 0;
 		}

 	}
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. The ASF licenses this file to You
	* under the Apache License, Version 2.0 (the "License"); you may not
	* use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License. For additional information regarding
	* copyright in this work, please see the NOTICE file in the top level
	* directory of this distribution.
	*/

	package org.apache.roller.weblogger.ui.rendering.velocity;

	import java.io.File;
	import java.io.InputStream;
	import java.util.HashMap;
	import java.util.Map;

	import javax.servlet.ServletContext;

	import org.apache.commons.collections.ExtendedProperties;
	import org.apache.commons.logging.Log;
	import org.apache.commons.logging.LogFactory;
	import org.apache.roller.weblogger.ui.core.RollerContext;
	import org.apache.velocity.exception.ResourceNotFoundException;
	import org.apache.velocity.runtime.resource.Resource;
	import org.apache.velocity.runtime.resource.loader.ResourceLoader;

	/**
	* Loads Velocity resources from the webapp.
	*
	* All resource urls begin from the root of the webapp. If a resource path is
	* relative (does not begin with a /) then it is prefixed with the path
	* /WEB-INF/velocity/, which is where Roller keeps its velocity files.
	*
	* Resource loader that uses the ServletContext of a webapp to load Velocity
	* templates. (it's much easier to use with servlets than the standard
	* FileResourceLoader, in particular the use of war files is transparent).
	*
	* The default search path is '/' (relative to the webapp root), but you can
	* change this behaviour by specifying one or more paths by mean of as many
	* webapp.resource.loader.path properties as needed in the velocity.properties
	* file.
	*
	* All paths must be relative to the root of the webapp.
	*
	* To enable caching and cache refreshing the webapp.resource.loader.cache and
	* webapp.resource.loader.modificationCheckInterval properties need to be set in
	* the velocity.properties file ... auto-reloading of global macros requires the
	* webapp.resource.loader.cache property to be set to 'false'.
	*
	*/
	public class WebappResourceLoader extends ResourceLoader {

	private static Log log = LogFactory.getLog(WebappResourceLoader.class);

	// The root paths for templates (relative to webapp's root).
	protected String[] paths = null;
	protected Map<String, String> templatePaths = null;
	protected ServletContext servletContext = null;

	/**
	* This is abstract in the base class, so we need it. <br>
	* NOTE: this expects that the ServletContext has already been placed in the
	* runtime's application attributes under its full class name (i.e.
	* "javax.servlet.ServletContext").
	*
	* @param configuration
	* the {@link ExtendedProperties} associated with this resource
	* loader.
	*/
	public void init(ExtendedProperties configuration) {

	if (log.isDebugEnabled()) {
	log.debug("WebappResourceLoader: initialization starting.");
	}

	// get configured paths
	paths = configuration.getStringArray("path");
	if (paths == null \|\| paths.length == 0) {
	paths = new String[1];
	paths[0] = "/";
	} else {
	// make sure the paths end with a '/'
	for (int i = 0; i < paths.length; i++) {
	if (!paths[i].endsWith("/")) {
	paths[i] += '/';
	}
	if (log.isDebugEnabled()) {
	log.debug("WebappResourceLoader: added template path - '"
	+ paths[i] + "'");
	}
	}
	}

	// get the ServletContext
	servletContext = RollerContext.getServletContext();

	if (log.isDebugEnabled()) {
	log.debug("Servlet Context = "
	+ servletContext.getRealPath("/WEB-INF/velocity/"));
	}

	// init the template paths map
	templatePaths = new HashMap<String, String>();

	if (log.isDebugEnabled()) {
	log.debug("WebappResourceLoader: initialization complete.");
	}
	}

	/**
	* Get an InputStream so that the Runtime can build a template with it.
	*
	* @param name
	* name of template to get
	* @return InputStream containing the template
	* @throws ResourceNotFoundException if template not found in classpath.
	*
	*/
	public InputStream getResourceStream(String name) {

	InputStream result = null;
	Exception exception = null;

	if (name == null \|\| name.length() == 0) {
	throw new ResourceNotFoundException(
	"WebappResourceLoader: No template name provided");
	}

	// names are <template>\|<deviceType>
	// loading weblog.vm etc will not have the type so only check for
	// one.
	String[] split = name.split("\\\|", 2);
	if (split.length < 1) {
	throw new ResourceNotFoundException("Invalid ThemeRL key " + name);
	}

	String savedPath = templatePaths.get(name);
	if (savedPath != null) {
	result = servletContext.getResourceAsStream(savedPath + split[0]);
	}

	if (result == null) {
	for (String pathSegment : paths) {
	String path = pathSegment + split[0];
	try {
	result = servletContext.getResourceAsStream(path);

	// save the path and exit the loop if we found the template
	if (result != null) {
	templatePaths.put(name, pathSegment);
	break;
	}
	} catch (NullPointerException npe) {
	// no servletContext was set, whine about it!
	throw npe;
	} catch (Exception e) {
	// only save the first one for later throwing
	if (exception == null) {
	if (log.isDebugEnabled()) {
	log.debug("WebappResourceLoader: Could not load "
	+ path, e);
	}
	exception = e;
	}
	}
	}
	}

	// If we never found the template
	if (result == null) {
	String msg = "WebappResourceLoader: Resource '" + name
	+ "' not found.";

	// convert to a general Velocity ResourceNotFoundException
	if (exception == null) {
	throw new ResourceNotFoundException(msg);
	} else {
	msg += " Due to: " + exception;
	throw new ResourceNotFoundException(msg, exception);
	}
	}

	return result;
	}

	/**
	* Gets the cached file.
	*
	* @param rootPath
	* the root path
	* @param fileName
	* the file name
	*
	* @return the cached file
	*/
	private File getCachedFile(String rootPath, String fileName) {

	// We do this when we cache a resource, so do it again to ensure a match
	while (fileName.startsWith("/")) {
	fileName = fileName.substring(1);
	}

	String savedPath = templatePaths.get(fileName);

	// names are <template>\|<deviceType>
	// loading weblog.vm etc will not have the type so only check for
	// one.
	String[] split = fileName.split("\\\|", 2);
	return new File(rootPath + savedPath, split[0]);

	}

	/**
	* Checks to see if a resource has been deleted, moved or modified. When
	* using the resource.loader.cache=true option
	*
	* @param resource
	* Resource The resource to check for modification
	*
	* @return boolean True if the resource has been modified
	*/
	public boolean isSourceModified(Resource resource) {

	String rootPath = servletContext.getRealPath("/");
	if (rootPath == null) {
	// RootPath is null if the servlet container cannot translate the
	// virtual path to a real path for any reason (such as when the
	// content is being made available from a .war archive)
	return false;
	}

	// first, try getting the previously found file
	String fileName = resource.getName();
	File cachedFile = getCachedFile(rootPath, fileName);
	if (!cachedFile.exists()) {
	// then the source has been moved and/or deleted
	return true;
	}

	/*
	* Check to see if the file can now be found elsewhere before it is
	* found in the previously saved path
	*/
	File currentFile = null;
	for (String path : paths) {
	currentFile = new File(rootPath + path, fileName);
	if (currentFile.canRead()) {
	/*
	* stop at the first resource found (just like in
	* getResourceStream())
	*/
	break;
	}
	}

	// If the current is the cached and it is readable
	if (cachedFile.equals(currentFile) && cachedFile.canRead()) {
	// then (and only then) do we compare the last modified values
	return (cachedFile.lastModified() != resource.getLastModified());
	} else {
	// We found a new file for the resource or the resource is no longer
	// readable.
	return true;
	}
	}

	/**
	* Checks to see when a resource was last modified
	*
	* @param resource
	* Resource the resource to check
	*
	* @return long The time when the resource was last modified or 0 if the
	* file can't be read
	*/
	public long getLastModified(Resource resource) {

	String rootPath = servletContext.getRealPath("/");
	if (rootPath == null) {
	// RootPath is null if the servlet container cannot translate the
	// virtual path to a real path for any reason (such as when the
	// content is being made available from a .war archive)
	return 0;
	}

	File cachedFile = getCachedFile(rootPath, resource.getName());
	if (cachedFile.canRead()) {
	return cachedFile.lastModified();
	} else {
	return 0;
	}

	}
	}