/* | |
* 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 behavior 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(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; | |
} | |
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; | |
} | |
} |