    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.lang3.text.translate;
    018
    019import java.io.IOException;
    020import java.io.Writer;
    021import java.util.Arrays;
    022import java.util.EnumSet;
    023
    024/**
    025 * Translate XML numeric entities of the form &amp;#[xX]?\d+;? to
    026 * the specific codepoint.
    027 *
    028 * Note that the semi-colon is optional.
    029 *
    030 * @since 3.0
    031 * @deprecated as of 3.6, use commons-text
    032 * <a href="https://commons.apache.org/proper/commons-text/javadocs/api-release/org/apache/commons/text/translate/NumericEntityUnescaper.html">
    033 * NumericEntityUnescaper</a> instead
    034 */
    035@Deprecated
    036public class NumericEntityUnescaper extends CharSequenceTranslator {
    037
    038    public enum OPTION { semiColonRequired, semiColonOptional, errorIfNoSemiColon }
    039
    040    // TODO?: Create an OptionsSet class to hide some of the conditional logic below
    041    private final EnumSet<OPTION> options;
    042
    043    /**
    044     * Create a UnicodeUnescaper.
    045     *
    046     * The constructor takes a list of options, only one type of which is currently
    047     * available (whether to allow, error or ignore the semi-colon on the end of a
    048     * numeric entity to being missing).
    049     *
    050     * For example, to support numeric entities without a ';':
    051     *    new NumericEntityUnescaper(NumericEntityUnescaper.OPTION.semiColonOptional)
    052     * and to throw an IllegalArgumentException when they're missing:
    053     *    new NumericEntityUnescaper(NumericEntityUnescaper.OPTION.errorIfNoSemiColon)
    054     *
    055     * Note that the default behaviour is to ignore them.
    056     *
    057     * @param options to apply to this unescaper
    058     */
    059    public NumericEntityUnescaper(final OPTION... options) {
    060        if(options.length > 0) {
    061            this.options = EnumSet.copyOf(Arrays.asList(options));
    062        } else {
    063            this.options = EnumSet.copyOf(Arrays.asList(new OPTION[] { OPTION.semiColonRequired }));
    064        }
    065    }
    066
    067    /**
    068     * Whether the passed in option is currently set.
    069     *
    070     * @param option to check state of
    071     * @return whether the option is set
    072     */
    073    public boolean isSet(final OPTION option) {
    074        return options != null && options.contains(option);
    075    }
    076
    077    /**
    078     * {@inheritDoc}
    079     */
    080    @Override
    081    public int translate(final CharSequence input, final int index, final Writer out) throws IOException {
    082        final int seqEnd = input.length();
    083        // Uses -2 to ensure there is something after the &#
    084        if(input.charAt(index) == '&' && index < seqEnd - 2 && input.charAt(index + 1) == '#') {
    085            int start = index + 2;
    086            boolean isHex = false;
    087
    088            final char firstChar = input.charAt(start);
    089            if(firstChar == 'x' || firstChar == 'X') {
    090                start++;
    091                isHex = true;
    092
    093                // Check there's more than just an x after the &#
    094                if(start == seqEnd) {
    095                    return 0;
    096                }
    097            }
    098
    099            int end = start;
    100            // Note that this supports character codes without a ; on the end
    101            while(end < seqEnd && ( input.charAt(end) >= '0' && input.charAt(end) <= '9' ||
    102                                    input.charAt(end) >= 'a' && input.charAt(end) <= 'f' ||
    103                                    input.charAt(end) >= 'A' && input.charAt(end) <= 'F' ) ) {
    104                end++;
    105            }
    106
    107            final boolean semiNext = end != seqEnd && input.charAt(end) == ';';
    108
    109            if(!semiNext) {
    110                if(isSet(OPTION.semiColonRequired)) {
    111                    return 0;
    112                } else
    113                if(isSet(OPTION.errorIfNoSemiColon)) {
    114                    throw new IllegalArgumentException("Semi-colon required at end of numeric entity");
    115                }
    116            }
    117
    118            int entityValue;
    119            try {
    120                if(isHex) {
    121                    entityValue = Integer.parseInt(input.subSequence(start, end).toString(), 16);
    122                } else {
    123                    entityValue = Integer.parseInt(input.subSequence(start, end).toString(), 10);
    124                }
    125            } catch(final NumberFormatException nfe) {
    126                return 0;
    127            }
    128
    129            if(entityValue > 0xFFFF) {
    130                final char[] chars = Character.toChars(entityValue);
    131                out.write(chars[0]);
    132                out.write(chars[1]);
    133            } else {
    134                out.write(entityValue);
    135            }
    136
    137            return 2 + end - start + (isHex ? 1 : 0) + (semiNext ? 1 : 0);
    138        }
    139        return 0;
    140    }
    141}