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.StringWriter;
21 import java.io.UncheckedIOException;
22 import java.io.Writer;
23 import java.util.Locale;
24 import java.util.Objects;
25
26 import org.apache.commons.lang3.ArrayUtils;
27
28 /**
29 * An API for translating text.
30 * Its core use is to escape and unescape text. Because escaping and unescaping
31 * is completely contextual, the API does not present two separate signatures.
32 *
33 * @since 3.0
34 * @deprecated As of <a href="https://commons.apache.org/proper/commons-lang/changes-report.html#a3.6">3.6</a>, use Apache Commons Text
35 * <a href="https://commons.apache.org/proper/commons-text/javadocs/api-release/org/apache/commons/text/translate/CharSequenceTranslator.html">
36 * CharSequenceTranslator</a>.
37 */
38 @Deprecated
39 public abstract class CharSequenceTranslator {
40
41 static final char[] HEX_DIGITS = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
42
43 /**
44 * Returns an upper case hexadecimal {@link String} for the given
45 * character.
46 *
47 * @param codePoint The code point to convert.
48 * @return An upper case hexadecimal {@link String}.
49 */
50 public static String hex(final int codePoint) {
51 return Integer.toHexString(codePoint).toUpperCase(Locale.ENGLISH);
52 }
53
54 /**
55 * Constructs a new instance.
56 */
57 public CharSequenceTranslator() {
58 // empty
59 }
60
61 /**
62 * Helper for non-Writer usage.
63 *
64 * @param input CharSequence to be translated.
65 * @return String output of translation.
66 */
67 public final String translate(final CharSequence input) {
68 if (input == null) {
69 return null;
70 }
71 try {
72 final StringWriter writer = new StringWriter(input.length() * 2);
73 translate(input, writer);
74 return writer.toString();
75 } catch (final IOException ioe) {
76 // this should never ever happen while writing to a StringWriter
77 throw new UncheckedIOException(ioe);
78 }
79 }
80
81 /**
82 * Translate a set of code points, represented by an int index into a CharSequence,
83 * into another set of code points. The number of code points consumed must be returned,
84 * and the only IOExceptions thrown must be from interacting with the Writer so that
85 * the top level API may reliably ignore StringWriter IOExceptions.
86 *
87 * @param input CharSequence that is being translated.
88 * @param index int representing the current point of translation.
89 * @param out Writer to translate the text to.
90 * @return int count of code points consumed.
91 * @throws IOException if and only if the Writer produces an IOException.
92 */
93 public abstract int translate(CharSequence input, int index, Writer out) throws IOException;
94
95 /**
96 * Translate an input onto a Writer. This is intentionally final as its algorithm is
97 * tightly coupled with the abstract method of this class.
98 *
99 * @param input CharSequence that is being translated.
100 * @param writer Writer to translate the text to.
101 * @throws IOException if and only if the Writer produces an IOException.
102 */
103 @SuppressWarnings("resource") // Caller closes writer
104 public final void translate(final CharSequence input, final Writer writer) throws IOException {
105 Objects.requireNonNull(writer, "writer");
106 if (input == null) {
107 return;
108 }
109 int pos = 0;
110 final int len = input.length();
111 while (pos < len) {
112 final int consumed = translate(input, pos, writer);
113 if (consumed == 0) {
114 // inlined implementation of Character.toChars(Character.codePointAt(input, pos))
115 // avoids allocating temp char arrays and duplicate checks
116 final char c1 = input.charAt(pos);
117 writer.write(c1);
118 pos++;
119 if (Character.isHighSurrogate(c1) && pos < len) {
120 final char c2 = input.charAt(pos);
121 if (Character.isLowSurrogate(c2)) {
122 writer.write(c2);
123 pos++;
124 }
125 }
126 continue;
127 }
128 // contract with translators is that they have to understand code points
129 // and they just took care of a surrogate pair
130 for (int pt = 0; pt < consumed; pt++) {
131 pos += Character.charCount(Character.codePointAt(input, pos));
132 }
133 }
134 }
135
136 /**
137 * Helper method to create a merger of this translator with another set of
138 * translators. Useful in customizing the standard functionality.
139 *
140 * @param translators CharSequenceTranslator array of translators to merge with this one.
141 * @return CharSequenceTranslator merging this translator with the others.
142 */
143 public final CharSequenceTranslator with(final CharSequenceTranslator... translators) {
144 final CharSequenceTranslator[] newArray = new CharSequenceTranslator[translators.length + 1];
145 newArray[0] = this;
146 return new AggregateTranslator(ArrayUtils.arraycopy(translators, 0, newArray, 1, translators.length));
147 }
148
149 }