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Diffstat (limited to 'src/main/java/org/apache/commons/lang3/text/translate/CharSequenceTranslator.java')
| -rw-r--r-- | src/main/java/org/apache/commons/lang3/text/translate/CharSequenceTranslator.java | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/src/main/java/org/apache/commons/lang3/text/translate/CharSequenceTranslator.java b/src/main/java/org/apache/commons/lang3/text/translate/CharSequenceTranslator.java new file mode 100644 index 000000000..afbb91960 --- /dev/null +++ b/src/main/java/org/apache/commons/lang3/text/translate/CharSequenceTranslator.java @@ -0,0 +1,139 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.commons.lang3.text.translate; + +import java.io.IOException; +import java.io.StringWriter; +import java.io.UncheckedIOException; +import java.io.Writer; +import java.util.Locale; +import java.util.Objects; + +/** + * An API for translating text. + * Its core use is to escape and unescape text. Because escaping and unescaping + * is completely contextual, the API does not present two separate signatures. + * + * @since 3.0 + * @deprecated As of 3.6, use Apache Commons Text + * <a href="https://commons.apache.org/proper/commons-text/javadocs/api-release/org/apache/commons/text/translate/CharSequenceTranslator.html"> + * CharSequenceTranslator</a> instead + */ +@Deprecated +public abstract class CharSequenceTranslator { + + static final char[] HEX_DIGITS = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'}; + + /** + * Translate a set of code points, represented by an int index into a CharSequence, + * into another set of code points. The number of code points consumed must be returned, + * and the only IOExceptions thrown must be from interacting with the Writer so that + * the top level API may reliably ignore StringWriter IOExceptions. + * + * @param input CharSequence that is being translated + * @param index int representing the current point of translation + * @param out Writer to translate the text to + * @return int count of code points consumed + * @throws IOException if and only if the Writer produces an IOException + */ + public abstract int translate(CharSequence input, int index, Writer out) throws IOException; + + /** + * Helper for non-Writer usage. + * @param input CharSequence to be translated + * @return String output of translation + */ + public final String translate(final CharSequence input) { + if (input == null) { + return null; + } + try { + final StringWriter writer = new StringWriter(input.length() * 2); + translate(input, writer); + return writer.toString(); + } catch (final IOException ioe) { + // this should never ever happen while writing to a StringWriter + throw new UncheckedIOException(ioe); + } + } + + /** + * Translate an input onto a Writer. This is intentionally final as its algorithm is + * tightly coupled with the abstract method of this class. + * + * @param input CharSequence that is being translated + * @param writer Writer to translate the text to + * @throws IOException if and only if the Writer produces an IOException + */ + public final void translate(final CharSequence input, final Writer writer) throws IOException { + Objects.requireNonNull(writer, "writer"); + if (input == null) { + return; + } + int pos = 0; + final int len = input.length(); + while (pos < len) { + final int consumed = translate(input, pos, writer); + if (consumed == 0) { + // inlined implementation of Character.toChars(Character.codePointAt(input, pos)) + // avoids allocating temp char arrays and duplicate checks + final char c1 = input.charAt(pos); + writer.write(c1); + pos++; + if (Character.isHighSurrogate(c1) && pos < len) { + final char c2 = input.charAt(pos); + if (Character.isLowSurrogate(c2)) { + writer.write(c2); + pos++; + } + } + continue; + } + // contract with translators is that they have to understand code points + // and they just took care of a surrogate pair + for (int pt = 0; pt < consumed; pt++) { + pos += Character.charCount(Character.codePointAt(input, pos)); + } + } + } + + /** + * Helper method to create a merger of this translator with another set of + * translators. Useful in customizing the standard functionality. + * + * @param translators CharSequenceTranslator array of translators to merge with this one + * @return CharSequenceTranslator merging this translator with the others + */ + public final CharSequenceTranslator with(final CharSequenceTranslator... translators) { + final CharSequenceTranslator[] newArray = new CharSequenceTranslator[translators.length + 1]; + newArray[0] = this; + System.arraycopy(translators, 0, newArray, 1, translators.length); + return new AggregateTranslator(newArray); + } + + /** + * Returns an upper case hexadecimal {@link String} for the given + * character. + * + * @param codePoint The code point to convert. + * @return An upper case hexadecimal {@link String} + */ + public static String hex(final int codePoint) { + return Integer.toHexString(codePoint).toUpperCase(Locale.ENGLISH); + } + +} |