// // ======================================================================== // Copyright (c) 1995-2013 Mort Bay Consulting Pty. Ltd. // ------------------------------------------------------------------------ // All rights reserved. This program and the accompanying materials // are made available under the terms of the Eclipse Public License v1.0 // and Apache License v2.0 which accompanies this distribution. // // The Eclipse Public License is available at // http://www.eclipse.org/legal/epl-v10.html // // The Apache License v2.0 is available at // http://www.opensource.org/licenses/apache2.0.php // // You may elect to redistribute this code under either of these licenses. // ======================================================================== // package org.klomp.snark.web; import java.util.ArrayList; import java.util.Enumeration; import java.util.List; import java.util.StringTokenizer; /* ------------------------------------------------------------ */ /** Byte range inclusive of end points. * <PRE> * * parses the following types of byte ranges: * * bytes=100-499 * bytes=-300 * bytes=100- * bytes=1-2,2-3,6-,-2 * * given an entity length, converts range to string * * bytes 100-499/500 * * </PRE> * * Based on RFC2616 3.12, 14.16, 14.35.1, 14.35.2 * @version $version$ * */ public class InclusiveByteRange { long first = 0; long last = 0; public InclusiveByteRange(long first, long last) { this.first = first; this.last = last; } public long getFirst() { return first; } public long getLast() { return last; } /* ------------------------------------------------------------ */ /** * @param headers Enumeration of Range header fields. * @param size Size of the resource. * @return List of satisfiable ranges */ public static List<InclusiveByteRange> satisfiableRanges(Enumeration<?> headers, long size) { List<InclusiveByteRange> satRanges = null; // walk through all Range headers headers: while (headers.hasMoreElements()) { String header = (String) headers.nextElement(); StringTokenizer tok = new StringTokenizer(header,"=,",false); String t=null; try { // read all byte ranges for this header while (tok.hasMoreTokens()) { try { t = tok.nextToken().trim(); long first = -1; long last = -1; int d = t.indexOf('-'); if (d < 0 || t.indexOf('-',d + 1) >= 0) { if ("bytes".equals(t)) continue; continue headers; } else if (d == 0) { if (d + 1 < t.length()) last = Long.parseLong(t.substring(d + 1).trim()); else { continue; } } else if (d + 1 < t.length()) { first = Long.parseLong(t.substring(0,d).trim()); last = Long.parseLong(t.substring(d + 1).trim()); } else first = Long.parseLong(t.substring(0,d).trim()); if (first == -1 && last == -1) continue headers; if (first != -1 && last != -1 && (first > last)) continue headers; if (first < size) { if (satRanges == null) satRanges = new ArrayList<InclusiveByteRange>(4); InclusiveByteRange range = new InclusiveByteRange(first,last); satRanges.add(range); } } catch (NumberFormatException e) { continue; } } } catch(Exception e) { } } return satRanges; } /* ------------------------------------------------------------ */ public long getFirst(long size) { if (first<0) { long tf=size-last; if (tf<0) tf=0; return tf; } return first; } /* ------------------------------------------------------------ */ public long getLast(long size) { if (first<0) return size-1; if (last<0 ||last>=size) return size-1; return last; } /* ------------------------------------------------------------ */ public long getSize(long size) { return getLast(size)-getFirst(size)+1; } /* ------------------------------------------------------------ */ public String toHeaderRangeString(long size) { StringBuilder sb = new StringBuilder(40); sb.append("bytes "); sb.append(getFirst(size)); sb.append('-'); sb.append(getLast(size)); sb.append("/"); sb.append(size); return sb.toString(); } /* ------------------------------------------------------------ */ public static String to416HeaderRangeString(long size) { StringBuilder sb = new StringBuilder(40); sb.append("bytes */"); sb.append(size); return sb.toString(); } /* ------------------------------------------------------------ */ @Override public String toString() { StringBuilder sb = new StringBuilder(60); sb.append(Long.toString(first)); sb.append(":"); sb.append(Long.toString(last)); return sb.toString(); } }