    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 {
    039        semiColonRequired, semiColonOptional, errorIfNoSemiColon
    040    }
    041
    042    // TODO?: Create an OptionsSet class to hide some of the conditional logic below
    043    private final EnumSet<OPTION> options;
    044
    045    /**
    046     * Create a UnicodeUnescaper.
    047     *
    048     * The constructor takes a list of options, only one type of which is currently
    049     * available (whether to allow, error or ignore the semi-colon on the end of a
    050     * numeric entity to being missing).
    051     *
    052     * For example, to support numeric entities without a ';':
    053     *    new NumericEntityUnescaper(NumericEntityUnescaper.OPTION.semiColonOptional)
    054     * and to throw an IllegalArgumentException when they're missing:
    055     *    new NumericEntityUnescaper(NumericEntityUnescaper.OPTION.errorIfNoSemiColon)
    056     *
    057     * Note that the default behaviour is to ignore them.
    058     *
    059     * @param options to apply to this unescaper
    060     */
    061    public NumericEntityUnescaper(final OPTION... options) {
    062        if (options.length > 0) {
    063            this.options = EnumSet.copyOf(Arrays.asList(options));
    064        } else {
    065            this.options = EnumSet.copyOf(Arrays.asList(OPTION.semiColonRequired));
    066        }
    067    }
    068
    069    /**
    070     * Whether the passed in option is currently set.
    071     *
    072     * @param option to check state of
    073     * @return whether the option is set
    074     */
    075    public boolean isSet(final OPTION option) {
    076        return options != null && options.contains(option);
    077    }
    078
    079    /**
    080     * {@inheritDoc}
    081     */
    082    @Override
    083    public int translate(final CharSequence input, final int index, final Writer out) throws IOException {
    084        final int seqEnd = input.length();
    085        // Uses -2 to ensure there is something after the &#
    086        if (input.charAt(index) == '&' && index < seqEnd - 2 && input.charAt(index + 1) == '#') {
    087            int start = index + 2;
    088            boolean isHex = false;
    089
    090            final char firstChar = input.charAt(start);
    091            if (firstChar == 'x' || firstChar == 'X') {
    092                start++;
    093                isHex = true;
    094
    095                // Check there's more than just an x after the &#
    096                if (start == seqEnd) {
    097                    return 0;
    098                }
    099            }
    100
    101            int end = start;
    102            // Note that this supports character codes without a ; on the end
    103            while (end < seqEnd && ( input.charAt(end) >= '0' && input.charAt(end) <= '9' ||
    104                                    input.charAt(end) >= 'a' && input.charAt(end) <= 'f' ||
    105                                    input.charAt(end) >= 'A' && input.charAt(end) <= 'F' ) ) {
    106                end++;
    107            }
    108
    109            final boolean semiNext = end != seqEnd && input.charAt(end) == ';';
    110
    111            if (!semiNext) {
    112                if (isSet(OPTION.semiColonRequired)) {
    113                    return 0;
    114                } else
    115                if (isSet(OPTION.errorIfNoSemiColon)) {
    116                    throw new IllegalArgumentException("Semi-colon required at end of numeric entity");
    117                }
    118            }
    119
    120            int entityValue;
    121            try {
    122                if (isHex) {
    123                    entityValue = Integer.parseInt(input.subSequence(start, end).toString(), 16);
    124                } else {
    125                    entityValue = Integer.parseInt(input.subSequence(start, end).toString(), 10);
    126                }
    127            } catch(final NumberFormatException nfe) {
    128                return 0;
    129            }
    130
    131            if (entityValue > 0xFFFF) {
    132                final char[] chars = Character.toChars(entityValue);
    133                out.write(chars[0]);
    134                out.write(chars[1]);
    135            } else {
    136                out.write(entityValue);
    137            }
    138
    139            return 2 + end - start + (isHex ? 1 : 0) + (semiNext ? 1 : 0);
    140        }
    141        return 0;
    142    }
    143}