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Diffstat (limited to 'velocity-engine-core/src/main/java/org/apache/velocity/runtime/resource/loader/JarResourceLoader.java')
| -rw-r--r-- | velocity-engine-core/src/main/java/org/apache/velocity/runtime/resource/loader/JarResourceLoader.java | 263 |
1 files changed, 263 insertions, 0 deletions
diff --git a/velocity-engine-core/src/main/java/org/apache/velocity/runtime/resource/loader/JarResourceLoader.java b/velocity-engine-core/src/main/java/org/apache/velocity/runtime/resource/loader/JarResourceLoader.java new file mode 100644 index 00000000..23db3743 --- /dev/null +++ b/velocity-engine-core/src/main/java/org/apache/velocity/runtime/resource/loader/JarResourceLoader.java @@ -0,0 +1,263 @@ +package org.apache.velocity.runtime.resource.loader; + +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. 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. + */ + +import org.apache.velocity.exception.ResourceNotFoundException; +import org.apache.velocity.exception.VelocityException; +import org.apache.velocity.runtime.RuntimeConstants; +import org.apache.velocity.runtime.resource.Resource; +import org.apache.velocity.util.ExtProperties; + +import org.apache.commons.io.FilenameUtils; +import org.apache.commons.lang3.StringUtils; + +import java.io.IOException; +import java.io.InputStream; +import java.io.Reader; +import java.util.HashMap; +import java.util.List; +import java.util.ListIterator; +import java.util.Map; + +/** + * <p> + * ResourceLoader to load templates from multiple Jar files. + * </p> + * <p> + * The configuration of the JarResourceLoader is straightforward - + * You simply add the JarResourceLoader to the configuration via + * </p> + * <pre><code> + * resource.loaders = jar + * resource.loader.jar.class = org.apache.velocity.runtime.resource.loader.JarResourceLoader + * resource.loader.jar.path = list of JAR <URL>s + * </code></pre> + * + * <p> So for example, if you had a jar file on your local filesystem, you could simply do</p> + * <pre><code> + * resource.loader.jar.path = jar:file:/opt/myfiles/jar1.jar + * </code></pre> + * <p> Note that jar specification for the <code>.path</code> configuration property + * conforms to the same rules for the java.net.JarUrlConnection class. + * </p> + * + * <p> For a working example, see the unit test case, + * org.apache.velocity.test.MultiLoaderTestCase class + * </p> + * + * @author <a href="mailto:mailmur@yahoo.com">Aki Nieminen</a> + * @author <a href="mailto:daveb@miceda-data.com">Dave Bryson</a> + * @version $Id$ + */ +public class JarResourceLoader extends ResourceLoader +{ + /** + * Maps entries to the parent JAR File + * Key = the entry *excluding* plain directories + * Value = the JAR URL + */ + private Map<String, String> entryDirectory = new HashMap<>(559); + + /** + * Maps JAR URLs to the actual JAR + * Key = the JAR URL + * Value = the JAR + */ + private Map<String, JarHolder> jarfiles = new HashMap<>(89); + + /** + * Called by Velocity to initialize the loader + * @param configuration + */ + @Override + public void init(ExtProperties configuration) + { + log.trace("JarResourceLoader: initialization starting."); + + List<String> paths = configuration.getList(RuntimeConstants.RESOURCE_LOADER_PATHS); + + if (paths != null) + { + log.debug("JarResourceLoader # of paths: {}", paths.size() ); + + for (ListIterator<String> it = paths.listIterator(); it.hasNext(); ) + { + String jar = StringUtils.trim(it.next()); + it.set(jar); + loadJar(jar); + } + } + + log.trace("JarResourceLoader: initialization complete."); + } + + private void loadJar( String path ) + { + log.debug("JarResourceLoader: trying to load \"{}\"", path); + + // Check path information + if ( path == null ) + { + String msg = "JarResourceLoader: can not load JAR - JAR path is null"; + log.error(msg); + throw new RuntimeException(msg); + } + if ( !path.startsWith("jar:") ) + { + String msg = "JarResourceLoader: JAR path must start with jar: -> see java.net.JarURLConnection for information"; + log.error(msg); + throw new RuntimeException(msg); + } + if (!path.contains("!/")) + { + path += "!/"; + } + + // Close the jar if it's already open + // this is useful for a reload + closeJar( path ); + + // Create a new JarHolder + JarHolder temp = new JarHolder( rsvc, path, log ); + // Add it's entries to the entryCollection + addEntries(temp.getEntries()); + // Add it to the Jar table + jarfiles.put(temp.getUrlPath(), temp); + } + + /** + * Closes a Jar file and set its URLConnection + * to null. + */ + private void closeJar( String path ) + { + if ( jarfiles.containsKey(path) ) + { + JarHolder theJar = jarfiles.get(path); + theJar.close(); + } + } + + /** + * Copy all the entries into the entryDirectory + * It will overwrite any duplicate keys. + */ + private void addEntries( Map<String, String> entries ) + { + entryDirectory.putAll( entries ); + } + + /** + * Get a Reader so that the Runtime can build a + * template with it. + * + * @param source name of template to get + * @param encoding asked encoding + * @return InputStream containing the template + * @throws ResourceNotFoundException if template not found + * in the file template path. + * @since 2.0 + */ + @Override + public Reader getResourceReader(String source, String encoding ) + throws ResourceNotFoundException + { + Reader result = null; + + if (org.apache.commons.lang3.StringUtils.isEmpty(source)) + { + throw new ResourceNotFoundException("Need to have a resource!"); + } + + String normalizedPath = FilenameUtils.normalize( source, true ); + + if ( normalizedPath == null || normalizedPath.length() == 0 ) + { + String msg = "JAR resource error: argument " + normalizedPath + + " contains .. and may be trying to access " + + "content outside of template root. Rejected."; + + log.error( "JarResourceLoader: {}", msg ); + + throw new ResourceNotFoundException ( msg ); + } + + /* + * if a / leads off, then just nip that :) + */ + if ( normalizedPath.startsWith("/") ) + { + normalizedPath = normalizedPath.substring(1); + } + + if ( entryDirectory.containsKey( normalizedPath ) ) + { + String jarurl = entryDirectory.get( normalizedPath ); + + if ( jarfiles.containsKey( jarurl ) ) + { + JarHolder holder = (JarHolder)jarfiles.get( jarurl ); + InputStream rawStream = holder.getResource( normalizedPath ); + try + { + return buildReader(rawStream, encoding); + } + catch (Exception e) + { + if (rawStream != null) + { + try + { + rawStream.close(); + } + catch (IOException ioe) {} + } + String msg = "JAR resource error: Exception while loading " + source; + log.error(msg, e); + throw new VelocityException(msg, e, rsvc.getLogContext().getStackTrace()); + } + } + } + + throw new ResourceNotFoundException( "JarResourceLoader Error: cannot find resource " + + source ); + + } + + // TODO: SHOULD BE DELEGATED TO THE JARHOLDER + + /** + * @see ResourceLoader#isSourceModified(org.apache.velocity.runtime.resource.Resource) + */ + @Override + public boolean isSourceModified(Resource resource) + { + return true; + } + + /** + * @see ResourceLoader#getLastModified(org.apache.velocity.runtime.resource.Resource) + */ + @Override + public long getLastModified(Resource resource) + { + return 0; + } +} |