001/* 002 * Licensed to DuraSpace under one or more contributor license agreements. 003 * See the NOTICE file distributed with this work for additional information 004 * regarding copyright ownership. 005 * 006 * DuraSpace licenses this file to you under the Apache License, 007 * Version 2.0 (the "License"); you may not use this file except in 008 * compliance with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, software 013 * distributed under the License is distributed on an "AS IS" BASIS, 014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 015 * See the License for the specific language governing permissions and 016 * limitations under the License. 017 */ 018package org.fcrepo.http.commons.domain; 019 020import static java.lang.Long.parseLong; 021import static java.util.regex.Pattern.compile; 022 023import java.util.regex.Matcher; 024import java.util.regex.Pattern; 025 026/** 027 * Range header parsing logic 028 * 029 * @author awoods 030 */ 031public class Range { 032 033 private final long start; 034 035 private final long end; 036 037 private static Pattern rangePattern = 038 compile("^bytes\\s*=\\s*(\\d*)\\s*-\\s*(\\d*)"); 039 040 /** 041 * Unbounded Range 042 */ 043 public Range() { 044 this(0, -1); 045 } 046 047 /** 048 * Left-bounded range 049 * @param start the start 050 */ 051 public Range(final long start) { 052 this(start, -1L); 053 } 054 055 /** 056 * Left and right bounded range 057 * @param start the start 058 * @param end the end 059 */ 060 public Range(final long start, final long end) { 061 this.start = start; 062 this.end = end; 063 } 064 065 /** 066 * Does this range actually impose limits 067 * @return true if the range imposes limits 068 */ 069 public boolean hasRange() { 070 return !(start == 0 && end == -1); 071 } 072 073 /** 074 * Length contained in the range 075 * @return length of the range 076 */ 077 public long size() { 078 if (end == -1) { 079 return -1; 080 } 081 return end - start + 1; 082 } 083 084 /** 085 * Start of the range 086 * @return start of the range 087 */ 088 public long start() { 089 return start; 090 } 091 092 /** 093 * End of the range 094 * @return end of the range 095 */ 096 public long end() { 097 return end; 098 } 099 100 /** 101 * Convert an HTTP Range header to a Range object 102 * @param source the source 103 * @return range object 104 */ 105 public static Range convert(final String source) { 106 107 final Matcher matcher = rangePattern.matcher(source); 108 109 if (!matcher.matches()) { 110 return new Range(); 111 } 112 113 final String from = matcher.group(1); 114 final String to = matcher.group(2); 115 116 final long start; 117 118 if (from.equals("")) { 119 start = 0; 120 } else { 121 start = parseLong(from); 122 } 123 124 final long end; 125 if (to.equals("")) { 126 end = -1; 127 } else { 128 end = parseLong(to); 129 } 130 131 return new Range(start, end); 132 } 133}