001/** 002 * Copyright 2015 DuraSpace, Inc. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016package org.fcrepo.http.commons.domain; 017 018import static java.lang.Long.parseLong; 019import static java.util.regex.Pattern.compile; 020 021import java.util.regex.Matcher; 022import java.util.regex.Pattern; 023 024/** 025 * Range header parsing logic 026 * 027 * @author awoods 028 */ 029public class Range { 030 031 private final long start; 032 033 private final long end; 034 035 private static Pattern rangePattern = 036 compile("^bytes\\s*=\\s*(\\d*)\\s*-\\s*(\\d*)"); 037 038 /** 039 * Unbounded Range 040 */ 041 public Range() { 042 this(0, -1); 043 } 044 045 /** 046 * Left-bounded range 047 * @param start the start 048 */ 049 public Range(final long start) { 050 this(start, -1L); 051 } 052 053 /** 054 * Left and right bounded range 055 * @param start the start 056 * @param end the end 057 */ 058 public Range(final long start, final long end) { 059 this.start = start; 060 this.end = end; 061 } 062 063 /** 064 * Does this range actually impose limits 065 * @return true if the range imposes limits 066 */ 067 public boolean hasRange() { 068 return !(start == 0 && end == -1); 069 } 070 071 /** 072 * Length contained in the range 073 * @return length of the range 074 */ 075 public long size() { 076 if (end == -1) { 077 return -1; 078 } 079 return end - start + 1; 080 } 081 082 /** 083 * Start of the range 084 * @return start of the range 085 */ 086 public long start() { 087 return start; 088 } 089 090 /** 091 * End of the range 092 * @return end of the range 093 */ 094 public long end() { 095 return end; 096 } 097 098 /** 099 * Convert an HTTP Range header to a Range object 100 * @param source the source 101 * @return range object 102 */ 103 public static Range convert(final String source) { 104 105 final Matcher matcher = rangePattern.matcher(source); 106 107 if (!matcher.matches()) { 108 return new Range(); 109 } 110 111 matcher.matches(); 112 final String from = matcher.group(1); 113 final String to = matcher.group(2); 114 115 final long start; 116 117 if (from.equals("")) { 118 start = 0; 119 } else { 120 start = parseLong(from); 121 } 122 123 final long end; 124 if (to.equals("")) { 125 end = -1; 126 } else { 127 end = parseLong(to); 128 } 129 130 return new Range(start, end); 131 } 132}