org.apache.bval.util.Escapes Maven / Gradle / Ivy
/**
* Copyright (C) 2006-2018 Talend Inc. - www.talend.com
*
* Licensed 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.bval.util;
import java.io.IOException;
import java.io.Writer;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
// taken from commons-lang3
public final class Escapes {
private static final CharSequenceTranslator UNESCAPE_JAVA =
new AggregateTranslator(
new OctalUnescaper(), // .between('\1', '\377'),
new UnicodeUnescaper(),
new LookupTranslator(new String[][] {
{"\\b", "\b"},
{"\\n", "\n"},
{"\\t", "\t"},
{"\\f", "\f"},
{"\\r", "\r"}
}),
new LookupTranslator(
new String[][] {
{"\\\\", "\\"},
{"\\\"", "\""},
{"\\'", "'"},
{"\\", ""}
})
);
private Escapes() {
// no-op
}
public static int unescapeJava(final CharSequence from, final int offset, final Writer output) {
// return StringEscapeUtils.UNESCAPE_JAVA.translate(path, pos.getIndex(), target);
return UNESCAPE_JAVA.translate(from, offset, output);
}
protected interface CharSequenceTranslator {
int translate(CharSequence input, int index, Writer out);
}
private static class AggregateTranslator implements CharSequenceTranslator {
private final CharSequenceTranslator[] translators;
private AggregateTranslator(final CharSequenceTranslator... translators) {
this.translators = translators;
}
@Override
public int translate(final CharSequence input, final int index, final Writer out) {
for (final CharSequenceTranslator translator : translators) {
final int consumed = translator.translate(input, index, out);
if(consumed != 0) {
return consumed;
}
}
return 0;
}
}
private static class OctalUnescaper implements CharSequenceTranslator {
@Override
public int translate(final CharSequence input, final int index, final Writer out) {
final int remaining = input.length() - index - 1;
final StringBuilder builder = new StringBuilder();
if (input.charAt(index) == '\\' && remaining > 0 && isOctalDigit(input.charAt(index + 1))) {
final int next = index + 1;
final int next2 = index + 2;
final int next3 = index + 3;
builder.append(input.charAt(next));
if (remaining > 1 && isOctalDigit(input.charAt(next2))) {
builder.append(input.charAt(next2));
if (remaining > 2 && isZeroToThree(input.charAt(next)) && isOctalDigit(input.charAt(next3))) {
builder.append(input.charAt(next3));
}
}
try {
out.write(Integer.parseInt(builder.toString(), 8));
} catch (IOException e) {
throw new IllegalStateException(e);
}
return 1 + builder.length();
}
return 0;
}
private boolean isOctalDigit(final char ch) {
return ch >= '0' && ch <= '7';
}
private boolean isZeroToThree(final char ch) {
return ch >= '0' && ch <= '3';
}
}
public static class UnicodeUnescaper implements CharSequenceTranslator {
@Override
public int translate(final CharSequence input, final int index, final Writer out) {
if (input.charAt(index) == '\\' && index + 1 < input.length() && input.charAt(index + 1) == 'u') {
int i = 2;
while (index + i < input.length() && input.charAt(index + i) == 'u') {
i++;
}
if (index + i < input.length() && input.charAt(index + i) == '+') {
i++;
}
if (index + i + 4 <= input.length()) {
// Get 4 hex digits
final CharSequence unicode = input.subSequence(index + i, index + i + 4);
try {
final int value = Integer.parseInt(unicode.toString(), 16);
out.write((char) value);
} catch (final NumberFormatException nfe) {
throw new IllegalArgumentException("Unable to parse unicode value: " + unicode, nfe);
} catch (final IOException e) {
throw new IllegalStateException(e);
}
return i + 4;
}
throw new IllegalArgumentException("Less than 4 hex digits in unicode value: '" + input.subSequence(index, input.length())
+ "' due to end of CharSequence");
}
return 0;
}
}
public static class LookupTranslator implements CharSequenceTranslator {
private final Map lookupMap;
private final Set prefixSet;
private final int shortest;
private final int longest;
private LookupTranslator(final String[][] lookup) {
lookupMap = new HashMap<>();
prefixSet = new HashSet<>();
int _shortest = Integer.MAX_VALUE;
int _longest = 0;
if (lookup != null) {
for (final CharSequence[] seq : lookup) {
this.lookupMap.put(seq[0].toString(), seq[1].toString());
this.prefixSet.add(seq[0].charAt(0));
final int sz = seq[0].length();
if (sz < _shortest) {
_shortest = sz;
}
if (sz > _longest) {
_longest = sz;
}
}
}
shortest = _shortest;
longest = _longest;
}
@Override
public int translate(final CharSequence input, final int index, final Writer out) {
if (prefixSet.contains(input.charAt(index))) {
int max = longest;
if (index + longest > input.length()) {
max = input.length() - index;
}
for (int i = max; i >= shortest; i--) {
final CharSequence subSeq = input.subSequence(index, index + i);
final String result = lookupMap.get(subSeq.toString());
if (result != null) {
try {
out.write(result);
} catch (final IOException e) {
throw new IllegalStateException(e);
}
return i;
}
}
}
return 0;
}
}
}