org.mycore.common.content.util.Range Maven / Gradle / Ivy
/*
* This file is part of *** M y C o R e ***
* See http://www.mycore.de/ for details.
*
* MyCoRe is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* MyCoRe is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with MyCoRe. If not, see .
*/
package org.mycore.common.content.util;
import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;
class Range {
public long start;
public long end;
public long length;
public static final String RANGE_UNIT = "bytes";
public boolean validate() {
if (end >= length) {
//set 'end' to content size
end = length - 1;
}
return start >= 0 && end >= 0 && start <= end && length > 0;
}
public static List parseRanges(final String rangeHeader, long fileLength) throws IllegalArgumentException {
if (rangeHeader == null) {
return null;
}
// We operate on byte level only
if (!rangeHeader.startsWith(RANGE_UNIT)) {
throw new IllegalArgumentException();
}
String rangeValue = rangeHeader.substring(RANGE_UNIT.length() + 1);
final ArrayList result = new ArrayList<>();
final StringTokenizer commaTokenizer = new StringTokenizer(rangeValue, ",");
// Parsing the range list
long lastByte = 0;
while (commaTokenizer.hasMoreTokens()) {
final String rangeDefinition = commaTokenizer.nextToken().trim();
final Range currentRange = new Range();
currentRange.length = fileLength;
final int dashPos = rangeDefinition.indexOf('-');
if (dashPos == -1) {
throw new IllegalArgumentException();
}
if (dashPos == 0) {
try {
//offset is negative
final long offset = Long.parseLong(rangeDefinition);
currentRange.start = fileLength + offset;
currentRange.end = fileLength - 1;
} catch (final NumberFormatException e) {
throw new IllegalArgumentException(e);
}
} else {
try {
currentRange.start = Long.parseLong(rangeDefinition.substring(0, dashPos));
if (dashPos < rangeDefinition.length() - 1) {
currentRange.end = Long.parseLong(rangeDefinition.substring(dashPos + 1));
} else {
currentRange.end = fileLength - 1;
}
} catch (final NumberFormatException e) {
throw new IllegalArgumentException(e);
}
}
if (!currentRange.validate() || lastByte > currentRange.start) {
throw new IllegalArgumentException();
}
lastByte = currentRange.end;
result.add(currentRange);
}
return result;
}
}