| 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.InputStream; |
| 20 | |
| 21 | import org.apache.velocity.runtime.resource.Resource; |
| 22 | import org.apache.velocity.exception.ResourceNotFoundException; |
| 23 | |
| 24 | import org.apache.commons.collections.ExtendedProperties; |
| 25 | |
| 26 | /** |
| 27 | * ClasspathResourceLoader is a simple loader that will load |
| 28 | * templates from the classpath. |
| 29 | * <br> |
| 30 | * <br> |
| 31 | * Will load templates from from multiple instances of |
| 32 | * and arbitrary combinations of : |
| 33 | * <ul> |
| 34 | * <li> jar files |
| 35 | * <li> zip files |
| 36 | * <li> template directories (any directory containing templates) |
| 37 | * </ul> |
| 38 | * This is a configuration-free loader, in that there are no |
| 39 | * parameters to be specified in the configuration properties, |
| 40 | * other than specifying this as the loader to use. For example |
| 41 | * the following is all that the loader needs to be functional : |
| 42 | * <br> |
| 43 | * <br> |
| 44 | * resource.loader = class |
| 45 | * class.resource.loader.class = |
| 46 | * org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader |
| 47 | * <br> |
| 48 | * <br> |
| 49 | * To use, put your template directories, jars |
| 50 | * and zip files into the classpath or other mechanisms that make |
| 51 | * resources accessable to the classloader. |
| 52 | * <br> |
| 53 | * <br> |
| 54 | * This makes deployment trivial for web applications running in |
| 55 | * any Servlet 2.2 compliant servlet runner, such as Tomcat 3.2 |
| 56 | * and others. |
| 57 | * <br> |
| 58 | * <br> |
| 59 | * For a Servlet Spec v2.2 servlet runner, |
| 60 | * just drop the jars of template files into the WEB-INF/lib |
| 61 | * directory of your webapp, and you won't have to worry about setting |
| 62 | * template paths or altering them with the root of the webapp |
| 63 | * before initializing. |
| 64 | * <br> |
| 65 | * <br> |
| 66 | * I have also tried it with a WAR deployment, and that seemed to |
| 67 | * work just fine. |
| 68 | * |
| 69 | * @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a> |
| 70 | * @version $Id: ClasspathResourceLoader.java,v 1.8.4.1 2004/03/03 23:23:02 geirm Exp $ |
| 71 | */ |
| 72 | public class ClasspathResourceLoader extends ResourceLoader |
| 73 | { |
| 74 | |
| 75 | /** |
| 76 | * This is abstract in the base class, so we need it |
| 77 | */ |
| 78 | public void init( ExtendedProperties configuration) |
| 79 | { |
| 80 | rsvc.info("ClasspathResourceLoader : initialization starting."); |
| 81 | rsvc.info("ClasspathResourceLoader : initialization complete."); |
| 82 | } |
| 83 | |
| 84 | /** |
| 85 | * Get an InputStream so that the Runtime can build a |
| 86 | * template with it. |
| 87 | * |
| 88 | * @param name name of template to get |
| 89 | * @return InputStream containing the template |
| 90 | * @throws ResourceNotFoundException if template not found |
| 91 | * in classpath. |
| 92 | */ |
| 93 | public synchronized InputStream getResourceStream( String name ) |
| 94 | throws ResourceNotFoundException |
| 95 | { |
| 96 | InputStream result = null; |
| 97 | |
| 98 | if (name == null || name.length() == 0) |
| 99 | { |
| 100 | throw new ResourceNotFoundException ("No template name provided"); |
| 101 | } |
| 102 | |
| 103 | try |
| 104 | { |
| 105 | ClassLoader classLoader = this.getClass().getClassLoader(); |
| 106 | result= classLoader.getResourceAsStream( name ); |
| 107 | } |
| 108 | catch( Exception fnfe ) |
| 109 | { |
| 110 | /* |
| 111 | * log and convert to a general Velocity ResourceNotFoundException |
| 112 | */ |
| 113 | |
| 114 | throw new ResourceNotFoundException( fnfe.getMessage() ); |
| 115 | } |
| 116 | |
| 117 | return result; |
| 118 | } |
| 119 | |
| 120 | /** |
| 121 | * Defaults to return false. |
| 122 | */ |
| 123 | public boolean isSourceModified(Resource resource) |
| 124 | { |
| 125 | return false; |
| 126 | } |
| 127 | |
| 128 | /** |
| 129 | * Defaults to return 0 |
| 130 | */ |
| 131 | public long getLastModified(Resource resource) |
| 132 | { |
| 133 | return 0; |
| 134 | } |
| 135 | } |
| 136 | |