| /* |
| * 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.text.translate; |
| |
| import java.io.IOException; |
| import java.io.Writer; |
| import java.util.Arrays; |
| import java.util.EnumSet; |
| |
| /** |
| * Translate XML numeric entities of the form &#[xX]?\d+;? to |
| * the specific codepoint. |
| * |
| * Note that the semi-colon is optional. |
| * |
| * @since 1.0 |
| */ |
| public class NumericEntityUnescaper extends CharSequenceTranslator { |
| |
| /** NumericEntityUnescaper option enum. */ |
| public enum OPTION { semiColonRequired, semiColonOptional, errorIfNoSemiColon } |
| |
| /** EnumSet of OPTIONS, given from the constructor. */ |
| private final EnumSet<OPTION> options; |
| |
| /** |
| * Create a UnicodeUnescaper. |
| * |
| * The constructor takes a list of options, only one type of which is currently |
| * available (whether to allow, error or ignore the semi-colon on the end of a |
| * numeric entity to being missing). |
| * |
| * For example, to support numeric entities without a ';': |
| * new NumericEntityUnescaper(NumericEntityUnescaper.OPTION.semiColonOptional) |
| * and to throw an IllegalArgumentException when they're missing: |
| * new NumericEntityUnescaper(NumericEntityUnescaper.OPTION.errorIfNoSemiColon) |
| * |
| * Note that the default behaviour is to ignore them. |
| * |
| * @param options to apply to this unescaper |
| */ |
| public NumericEntityUnescaper(final OPTION... options) { |
| if (options.length > 0) { |
| this.options = EnumSet.copyOf(Arrays.asList(options)); |
| } else { |
| this.options = EnumSet.copyOf(Arrays.asList(new OPTION[] {OPTION.semiColonRequired})); |
| } |
| } |
| |
| /** |
| * Whether the passed in option is currently set. |
| * |
| * @param option to check state of |
| * @return whether the option is set |
| */ |
| public boolean isSet(final OPTION option) { |
| return options != null && options.contains(option); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public int translate(final CharSequence input, final int index, final Writer out) throws IOException { |
| final int seqEnd = input.length(); |
| // Uses -2 to ensure there is something after the &# |
| if (input.charAt(index) == '&' && index < seqEnd - 2 && input.charAt(index + 1) == '#') { |
| int start = index + 2; |
| boolean isHex = false; |
| |
| final char firstChar = input.charAt(start); |
| if (firstChar == 'x' || firstChar == 'X') { |
| start++; |
| isHex = true; |
| |
| // Check there's more than just an x after the &# |
| if (start == seqEnd) { |
| return 0; |
| } |
| } |
| |
| int end = start; |
| // Note that this supports character codes without a ; on the end |
| while (end < seqEnd && (input.charAt(end) >= '0' && input.charAt(end) <= '9' |
| || input.charAt(end) >= 'a' && input.charAt(end) <= 'f' |
| || input.charAt(end) >= 'A' && input.charAt(end) <= 'F')) { |
| end++; |
| } |
| |
| final boolean semiNext = end != seqEnd && input.charAt(end) == ';'; |
| |
| if (!semiNext) { |
| if (isSet(OPTION.semiColonRequired)) { |
| return 0; |
| } else { |
| if (isSet(OPTION.errorIfNoSemiColon)) { |
| throw new IllegalArgumentException("Semi-colon required at end of numeric entity"); |
| } |
| } |
| } |
| |
| int entityValue; |
| try { |
| if (isHex) { |
| entityValue = Integer.parseInt(input.subSequence(start, end).toString(), 16); |
| } else { |
| entityValue = Integer.parseInt(input.subSequence(start, end).toString(), 10); |
| } |
| } catch (final NumberFormatException nfe) { |
| return 0; |
| } |
| |
| if (entityValue > 0xFFFF) { |
| final char[] chrs = Character.toChars(entityValue); |
| out.write(chrs[0]); |
| out.write(chrs[1]); |
| } else { |
| out.write(entityValue); |
| } |
| |
| return 2 + end - start + (isHex ? 1 : 0) + (semiNext ? 1 : 0); |
| } |
| return 0; |
| } |
| } |