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 * http://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
18 package org.apache.commons.text.lookup;
19
20 import java.io.InputStream;
21 import java.nio.file.Files;
22 import java.nio.file.Path;
23 import java.util.Properties;
24
25 import org.apache.commons.lang3.StringUtils;
26
27 /**
28 * Looks up keys from a properties file.
29 * <p>
30 * Looks up the value for a given key in the format "Document::Key".
31 * </p>
32 * <p>
33 * Note the use of "::" instead of ":" to allow for "C:" drive letters in paths.
34 * </p>
35 * <p>
36 * For example: "com/domain/document.properties:key".
37 * </p>
38 *
39 * @see Properties
40 * @since 1.5
41 */
42 final class PropertiesStringLookup extends AbstractPathFencedLookup {
43
44 /**
45 * Defines the singleton for this class.
46 */
47 static final PropertiesStringLookup INSTANCE = new PropertiesStringLookup((Path[]) null);
48
49 /** Separates file and key. */
50 static final String SEPARATOR = "::";
51
52 /**
53 * Creates a lookup key for a given file and key.
54 */
55 static String toPropertyKey(final String file, final String key) {
56 return AbstractStringLookup.toLookupKey(file, SEPARATOR, key);
57 }
58
59 /**
60 * Constructs a new instance.
61 *
62 * @param fences The fences guarding Path resolution.
63 */
64 PropertiesStringLookup(final Path... fences) {
65 super(fences);
66 }
67
68 /**
69 * Looks up the value for the key in the format "DocumentPath:XPath".
70 * <p>
71 * For example: "com/domain/document.xml::/path/to/node".
72 * </p>
73 * <p>
74 * Note the use of "::" instead of ":" to allow for "C:" drive letters in paths.
75 * </p>
76 *
77 * @param key the key to be looked up, may be null
78 * @return The value associated with the key.
79 */
80 @Override
81 public String lookup(final String key) {
82 if (key == null) {
83 return null;
84 }
85 final String[] keys = key.split(SEPARATOR);
86 final int keyLen = keys.length;
87 if (keyLen < 2) {
88 throw IllegalArgumentExceptions.format("Bad properties key format [%s]; expected format is %s.", key,
89 toPropertyKey("DocumentPath", "Key"));
90 }
91 final String documentPath = keys[0];
92 final String propertyKey = StringUtils.substringAfter(key, SEPARATOR);
93 try {
94 final Properties properties = new Properties();
95 try (InputStream inputStream = Files.newInputStream(getPath(documentPath))) {
96 properties.load(inputStream);
97 }
98 return properties.getProperty(propertyKey);
99 } catch (final Exception e) {
100 throw IllegalArgumentExceptions.format(e, "Error looking up properties [%s] and key [%s].", documentPath,
101 propertyKey);
102 }
103 }
104
105 }