/*
* 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.tomcat.util.http.parser;
import java.io.IOException;
import java.io.StringReader;
import java.util.Locale;
public class ContentRange {
private final String units;
private final long start;
private final long end;
private final long length;
public ContentRange(String units, long start, long end, long length) {
// Units are lower case (RFC 9110, section 14.1)
if (units == null) {
this.units = null;
} else {
this.units = units.toLowerCase(Locale.ENGLISH);
}
this.start = start;
this.end = end;
this.length = length;
}
/**
* @return rangeUnits in lower case.
*/
public String getUnits() {
return units;
}
public long getStart() {
return start;
}
public long getEnd() {
return end;
}
public long getLength() {
return length;
}
/**
* Parses a Content-Range header from an HTTP header.
*
* @param input a reader over the header text
*
* @return the range parsed from the input, or null if not valid
*
* @throws IOException if there was a problem reading the input
*/
public static ContentRange parse(StringReader input) throws IOException {
// Units (required)
String units = HttpParser.readToken(input);
if (units == null || units.isEmpty()) {
return null;
}
// Must be followed by SP. Parser is lenient and accepts any LWS here.
// No need for explicit check as something must have terminated the
// token and if that something was anything other than LWS the following
// call to readLong() will fail.
// Start
long start = HttpParser.readLong(input);
// Must be followed by '-'
if (HttpParser.skipConstant(input, "-") == SkipResult.NOT_FOUND) {
return null;
}
// End
long end = HttpParser.readLong(input);
// Must be followed by '/'
if (HttpParser.skipConstant(input, "/") == SkipResult.NOT_FOUND) {
return null;
}
// Length
long length = HttpParser.readLong(input);
// Doesn't matter what we look for, result should be EOF
SkipResult skipResult = HttpParser.skipConstant(input, "X");
if (skipResult != SkipResult.EOF) {
// Invalid range
return null;
}
ContentRange contentRange = new ContentRange(units, start, end, length);
if (!contentRange.isValid()) {
// Invalid content range
return null;
}
return contentRange;
}
/**
* @return <code>true</code> if the content range is valid, per RFC 9110 section 14.4
*/
public boolean isValid() {
return start >= 0 && end >= start && length > end;
}
}