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.UnsupportedEncodingException;
21 import java.net.URLEncoder;
22 import java.nio.charset.StandardCharsets;
23
24 /**
25 * Encodes URL Strings using the UTF-8 encoding.
26 *
27 * @see URLEncoder
28 * @since 1.5
29 */
30 final class UrlEncoderStringLookup extends AbstractStringLookup {
31
32 /**
33 * Defines the singleton for this class.
34 */
35 static final UrlEncoderStringLookup INSTANCE = new UrlEncoderStringLookup();
36
37 /**
38 * Constructs a new instance.
39 */
40 private UrlEncoderStringLookup() {
41 // empty
42 }
43
44 String encode(final String key, final String enc) throws UnsupportedEncodingException {
45 return URLEncoder.encode(key, enc);
46 }
47
48 @Override
49 public String lookup(final String key) {
50 if (key == null) {
51 return null;
52 }
53 final String enc = StandardCharsets.UTF_8.name();
54 try {
55 return encode(key, enc);
56 } catch (final UnsupportedEncodingException e) {
57 // Can't happen since UTF-8 is required by the Java specification.
58 throw IllegalArgumentExceptions.format(e, "%s: source=%s, encoding=%s", e, key, enc);
59 }
60 }
61
62 }