1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * https://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.configuration2.io;
18
19 import java.io.File;
20 import java.net.URL;
21
22 import org.apache.commons.lang3.StringUtils;
23
24 /**
25 * A specialized implementation of {@code FileLocationStrategy} which tries to construct a file path from the locator's
26 * base path and file name.
27 * <p>
28 * This strategies ignores the URL stored in the passed in {@link FileLocator}. It generates a path by concatenating the
29 * base path (if present) and the file name. If the resulting path points to a valid file, the corresponding URL is
30 * returned.
31 * </p>
32 * <p>
33 * See {@link AbstractFileLocationStrategy} learn how to grant an deny URL schemes and hosts.
34 * </p>
35 *
36 * @see AbstractFileLocationStrategy
37 * @since 2.0
38 */
39 public class BasePathLocationStrategy extends AbstractFileLocationStrategy {
40
41 /**
42 * Builds new instances of {@link ProvidedURLLocationStrategy}.
43 *
44 * @return a new builder.
45 * @since 2.15.0
46 */
47 public static StrategyBuilder<BasePathLocationStrategy> builder() {
48 return new StrategyBuilder<>(BasePathLocationStrategy::new);
49 }
50
51 /**
52 * Constructs a new instance where URL resources are bound by {@link AbstractFileLocationStrategy.AbstractBuilder}.
53 */
54 public BasePathLocationStrategy() {
55 // empty
56 }
57
58 /**
59 * Constructs a new instance where URL resources are bound by {@link AbstractFileLocationStrategy.AbstractBuilder}.
60 *
61 * @param builder How to build the instance.
62 * @since 2.15.0
63 */
64 public BasePathLocationStrategy(final AbstractBuilder<?, ?> builder) {
65 super(builder);
66 }
67
68 /**
69 * {@inheritDoc} This implementation uses utility methods from {@code FileLocatorUtils} to generate a {@code File} from
70 * the locator's base path and file name. If this {@code File} exists, its URL is returned.
71 */
72 @Override
73 public URL locate(final FileSystem fileSystem, final FileLocator locator) {
74 if (StringUtils.isNotEmpty(locator.getFileName())) {
75 final File file = FileLocatorUtils.constructFile(locator.getBasePath(), locator.getFileName());
76 if (file.isFile()) {
77 return check(FileLocatorUtils.convertFileToURL(file));
78 }
79 }
80 return null;
81 }
82 }