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.lang3.text.translate;
18
19 import java.io.IOException;
20 import java.io.Writer;
21
22 import org.apache.commons.lang3.CharUtils;
23
24 /**
25 * Translate escaped octal Strings back to their octal values.
26 *
27 * For example, "\45" should go back to being the specific value (a %).
28 *
29 * Note that this currently only supports the viable range of octal for Java; namely
30 * 1 to 377. This is because parsing Java is the main use case.
31 *
32 * @since 3.0
33 * @deprecated As of <a href="https://commons.apache.org/proper/commons-lang/changes-report.html#a3.6">3.6</a>, use Apache Commons Text
34 * <a href="https://commons.apache.org/proper/commons-text/javadocs/api-release/org/apache/commons/text/translate/OctalUnescaper.html">
35 * OctalUnescaper</a>.
36 */
37 @Deprecated
38 public class OctalUnescaper extends CharSequenceTranslator {
39
40 /**
41 * Constructs a new instance.
42 */
43 public OctalUnescaper() {
44 // empty
45 }
46
47 /**
48 * Checks if the given char is the character representation of one of the digit from 0 to 3.
49 *
50 * @param ch the char to check.
51 * @return true if the given char is the character representation of one of the digits from 0 to 3.
52 */
53 private boolean isZeroToThree(final char ch) {
54 return ch >= '0' && ch <= '3';
55 }
56
57 /**
58 * {@inheritDoc}
59 */
60 @Override
61 public int translate(final CharSequence input, final int index, final Writer out) throws IOException {
62 final int remaining = input.length() - index - 1; // how many characters left, ignoring the first \
63 final StringBuilder builder = new StringBuilder();
64 if (input.charAt(index) == '\\' && remaining > 0 && CharUtils.isOctal(input.charAt(index + 1))) {
65 final int next = index + 1;
66 final int next2 = index + 2;
67 final int next3 = index + 3;
68 // we know this is good as we checked it in the if block above
69 builder.append(input.charAt(next));
70 if (remaining > 1 && CharUtils.isOctal(input.charAt(next2))) {
71 builder.append(input.charAt(next2));
72 if (remaining > 2 && isZeroToThree(input.charAt(next)) && CharUtils.isOctal(input.charAt(next3))) {
73 builder.append(input.charAt(next3));
74 }
75 }
76 out.write(Integer.parseInt(builder.toString(), 8));
77 return 1 + builder.length();
78 }
79 return 0;
80 }
81 }