1 /* 2 * Copyright (C) 2010 Google Inc. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.google.clearsilver.jsilver.resourceloader; 18 19 import com.google.clearsilver.jsilver.exceptions.JSilverTemplateNotFoundException; 20 21 import java.io.IOException; 22 import java.io.InputStream; 23 import java.io.InputStreamReader; 24 import java.io.Reader; 25 26 /** 27 * Loads resources from classpath, alongside a given class. 28 * 29 * <p>For example, suppose the classpath contains: 30 * <pre> 31 * com/foo/SomeThing.class 32 * com/foo/my-template.cs 33 * com/foo/subdir/another-template.cs 34 * </pre> 35 * 36 * <p>You can access the resources in the class's package like this: 37 * <pre> 38 * ResourceLoader loader = new ClassResourceLoader(SomeThing.class); 39 * loader.open("my-template.cs"); 40 * loader.open("subdir/my-template.cs"); 41 * </pre> 42 * Or by using a relative path: 43 * <pre> 44 * ResourceLoader loader = new ClassResourceLoader(Something.class, "subdir"); 45 * loader.open("my-template.cs"); 46 * </pre> 47 * 48 * @see ResourceLoader 49 * @see ClassLoaderResourceLoader 50 */ 51 public class ClassResourceLoader extends BufferedResourceLoader { 52 53 private final Class<?> cls; 54 private final String basePath; 55 56 public ClassResourceLoader(Class<?> cls) { 57 this.cls = cls; 58 this.basePath = "/" + cls.getPackage().getName().replace('.', '/'); 59 } 60 61 /** 62 * Load resources from the given subdirectory {@code basePath}, 63 * relative to the .class file of {@code cls}. 64 */ 65 public ClassResourceLoader(Class<?> cls, String basePath) { 66 this.cls = cls; 67 this.basePath = basePath; 68 } 69 70 @Override 71 public Reader open(String name) throws IOException { 72 InputStream stream = cls.getResourceAsStream(basePath + '/' + name); 73 return stream == null ? null : buffer(new InputStreamReader(stream, getCharacterSet())); 74 } 75 76 @Override 77 public Reader openOrFail(String name) throws JSilverTemplateNotFoundException, IOException { 78 Reader reader = open(name); 79 if (reader == null) { 80 throw new JSilverTemplateNotFoundException("No '" + name + "' as class resource of " 81 + cls.getName()); 82 } else { 83 return reader; 84 } 85 } 86 87 } 88
