/*
* 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.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Locale;
public class Ranges {
private final String units;
private final List<Entry> entries;
public Ranges(String units, List<Entry> entries) {
// Units are lower case (RFC 9110, section 14.1)
if (units == null) {
this.units = null;
} else {
this.units = units.toLowerCase(Locale.ENGLISH);
}
this.entries = Collections.unmodifiableList(entries);
}
public List<Entry> getEntries() {
return entries;
}
public String getUnits() {
return units;
}
public static class Entry {
private final long start;
private final long end;
public Entry(long start, long end) {
this.start = start;
this.end = end;
}
public long getStart() {
return start;
}
public long getEnd() {
return end;
}
}
/**
* Parses a Range header from an HTTP header.
*
* @param input a reader over the header text
*
* @return a set of ranges parsed from the input, or null if not valid
*
* @throws IOException if there was a problem reading the input
*/
public static Ranges parse(StringReader input) throws IOException {
// Units (required)
String units = HttpParser.readToken(input);
if (units == null || units.isEmpty()) {
return null;
}
// Must be followed by '='
if (HttpParser.skipConstant(input, "=") != SkipResult.FOUND) {
return null;
}
// Range entries
List<Entry> entries = new ArrayList<>();
SkipResult skipResult;
do {
long start = HttpParser.readLong(input);
// Must be followed by '-'
if (HttpParser.skipConstant(input, "-") != SkipResult.FOUND) {
return null;
}
long end = HttpParser.readLong(input);
if (start == -1 && end == -1) {
// Invalid range
return null;
}
entries.add(new Entry(start, end));
skipResult = HttpParser.skipConstant(input, ",");
if (skipResult == SkipResult.NOT_FOUND) {
// Invalid range
return null;
}
} while (skipResult == SkipResult.FOUND);
return new Ranges(units, entries);
}
}