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.maven.index.reader;
20
21 import java.io.Closeable;
22 import java.io.IOException;
23 import java.io.InputStream;
24
25 /**
26 * Maven Index resource abstraction, that should be handled as a resource (is {@link Closeable}. That means, that
27 * implementations could perform any extra activity as FS locking or so (if uses FS as backing store). Is used by single
28 * thread only.
29 *
30 * @since 5.1.2
31 */
32 public interface ResourceHandler extends Closeable {
33 /**
34 * Handle of content.
35 */
36 interface Resource extends Closeable {
37 /**
38 * Returns the {@link InputStream} stream of the resource, if exists, {@code null} otherwise. The stream should
39 * be closed by caller, otherwise resource leaks might be introduced.
40 */
41 InputStream read() throws IOException;
42
43 /**
44 * Default close method is no-op, override if implementation requires.
45 */
46 @Override
47 default void close() throws IOException {
48 // nothing
49 }
50 }
51
52 /**
53 * Returns the {@link Resource} with {@code name}, non {@code null}.
54 *
55 * @param name Resource name, guaranteed to be non-{@code null} and is FS and URL safe string.
56 */
57 Resource locate(String name) throws IOException;
58
59 /**
60 * Default close method is no-op, override if implementation requires.
61 */
62 @Override
63 default void close() throws IOException {
64 // nothing
65 }
66 }