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 package org.apache.commons.lang3.text.translate;
18
19 import java.io.IOException;
20 import java.io.Writer;
21
22 /**
23 * Translate escaped octal Strings back to their octal values.
24 *
25 * For example, "\45" should go back to being the specific value (a %).
26 *
27 * Note that this currently only supports the viable range of octal for Java; namely
28 * 1 to 377. This is because parsing Java is the main use case.
29 *
30 * @since 3.0
31 * @deprecated As of 3.6, use Apache Commons Text
32 * <a href="https://commons.apache.org/proper/commons-text/javadocs/api-release/org/apache/commons/text/translate/OctalUnescaper.html">
33 * OctalUnescaper</a> instead
34 */
35 @Deprecated
36 public class OctalUnescaper extends CharSequenceTranslator {
37
38 /**
39 * Constructs a new instance.
40 */
41 public OctalUnescaper() {
42 // empty
43 }
44
45 /**
46 * Checks if the given char is an octal digit. Octal digits are the character representations of the digits 0 to 7.
47 * @param ch the char to check
48 * @return true if the given char is the character representation of one of the digits from 0 to 7
49 */
50 private boolean isOctalDigit(final char ch) {
51 return ch >= '0' && ch <= '7';
52 }
53
54 /**
55 * Checks if the given char is the character representation of one of the digit from 0 to 3.
56 * @param ch the char to check
57 * @return true if the given char is the character representation of one of the digits from 0 to 3
58 */
59 private boolean isZeroToThree(final char ch) {
60 return ch >= '0' && ch <= '3';
61 }
62
63 /**
64 * {@inheritDoc}
65 */
66 @Override
67 public int translate(final CharSequence input, final int index, final Writer out) throws IOException {
68 final int remaining = input.length() - index - 1; // how many characters left, ignoring the first \
69 final StringBuilder builder = new StringBuilder();
70 if (input.charAt(index) == '\\' && remaining > 0 && isOctalDigit(input.charAt(index + 1)) ) {
71 final int next = index + 1;
72 final int next2 = index + 2;
73 final int next3 = index + 3;
74
75 // we know this is good as we checked it in the if block above
76 builder.append(input.charAt(next));
77
78 if (remaining > 1 && isOctalDigit(input.charAt(next2))) {
79 builder.append(input.charAt(next2));
80 if (remaining > 2 && isZeroToThree(input.charAt(next)) && isOctalDigit(input.charAt(next3))) {
81 builder.append(input.charAt(next3));
82 }
83 }
84
85 out.write( Integer.parseInt(builder.toString(), 8) );
86 return 1 + builder.length();
87 }
88 return 0;
89 }
90 }