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'databene commons' is an open source Java library by Volker Bergmann.
It provides extensions to the Java core library by utility classes, abstract concepts
and concrete implementations.
/*
* Copyright (C) 2004-2015 Volker Bergmann ([email protected]).
* All rights reserved.
*
* 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.databene.commons.version;
import java.text.ParseException;
import java.text.ParsePosition;
import java.util.ArrayList;
import java.util.List;
import org.databene.commons.Parser;
import org.databene.commons.StringUtil;
/**
* Parses a {@link VersionNumber}.
* Created: 10.03.2011 16:28:06
* @since 0.5.8
* @author Volker Bergmann
*/
public class VersionNumberParser extends Parser{
@Override
public VersionNumber parseObject(String text, ParsePosition pos) {
List components = new ArrayList();
List delimiters = new ArrayList();
if (StringUtil.isEmpty(text)) {
components.add(new NumberVersionNumberComponent(1));
} else {
String delimiter;
do {
components.add(parseComponent(text, pos));
delimiter = parseDelimiter(text, pos);
if (delimiter != null)
delimiters.add(delimiter);
} while (delimiter != null);
}
return new VersionNumber(components, delimiters);
}
private static String parseDelimiter(String number, ParsePosition pos) {
int index = pos.getIndex();
if (index >= number.length())
return null;
char c = number.charAt(index);
if (c == '.' || c == '-' || c == '_') {
pos.setIndex(pos.getIndex() + 1);
return String.valueOf(c);
} else
return (Character.isLetterOrDigit(c) ? "" : null);
}
private static VersionNumberComponent parseComponent(String number, ParsePosition pos) {
char c = number.charAt(pos.getIndex());
if (Character.isDigit(c))
return parseNumberOrDateComponent(number, pos);
else
return new StringVersionNumberComponent(parseLetters(number, pos));
}
private static VersionNumberComponent parseNumberOrDateComponent(String text, ParsePosition pos) {
String number = parseNonNegativeInteger(text, pos);
if (number.length() == 8) {
try {
return new DateVersionNumberComponent(number);
} catch (ParseException e) {
// oops - no date. Fall back to NumberVersionNumberComponent in the following code
}
}
return new NumberVersionNumberComponent(number);
}
private static String parseNonNegativeInteger(String number, ParsePosition pos) {
int index = pos.getIndex();
StringBuffer result = new StringBuffer(2);
char c;
while (index < number.length() && Character.isDigit(c = number.charAt(index))) {
result.append(c);
index++;
}
pos.setIndex(index);
return result.toString();
}
private static String parseLetters(String number, ParsePosition pos) {
int index = pos.getIndex();
StringBuffer result = new StringBuffer(10);
char c;
while (index < number.length() && Character.isLetter(c = number.charAt(index))) {
result.append(c);
index++;
}
pos.setIndex(index);
return result.toString();
}
}