1 /**
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. 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,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.creadur.whisker.app.load;
20
21 import java.io.IOException;
22 import java.io.InputStream;
23
24 import org.apache.creadur.whisker.app.StreamableResource;
25
26 /**
27 * Streams, on demand, the contents of a resource located on the class path.
28 */
29 public final class StreamableClassPathResource extends StreamableResource {
30
31 /**
32 * The full name <strong>including path</strong>
33 * of a resource on the class path.
34 */
35 private final String name;
36
37 /**
38 * Constructs an instance that streams the given class path resource
39 * on demand.
40 * @param name full name <strong>including path</strong> of
41 * a resource on the class path,
42 * not null
43 */
44 public StreamableClassPathResource(final String name) {
45 super();
46 this.name = name;
47 }
48
49
50 /**
51 * Gets the location on the class path of the resource to be streamed.
52 * @return not null
53 */
54 public String getName() {
55 return name;
56 }
57
58 /**
59 * Is this resource found on the classpath?
60 * @return true when the resource is found on the classpath,
61 * null otherwise
62 */
63 public boolean exists() {
64 try {
65 return open() != null;
66 } catch (IOException e) {
67 return false;
68 }
69 }
70
71 /**
72 * Opens a resource on the classpath.
73 * @return not null
74 * @see StreamableResource#open()
75 * @throws IOException when resource cannot be open
76 */
77 @Override
78 public InputStream open() throws IOException {
79 return getClass().getClassLoader().getResourceAsStream(name);
80 }
81
82 /**
83 * Suitable for logging.
84 * @return a description
85 */
86 @Override
87 public String toString() {
88 return "StreamableClassPathResource [name=" + name + "]";
89 }
90 }