001/* 002 * (C) Copyright 2015 Nuxeo SA (http://nuxeo.com/) and contributors. 003 * 004 * All rights reserved. This program and the accompanying materials 005 * are made available under the terms of the GNU Lesser General Public License 006 * (LGPL) version 2.1 which accompanies this distribution, and is available at 007 * http://www.gnu.org/licenses/lgpl-2.1.html 008 * 009 * This library is distributed in the hope that it will be useful, 010 * but WITHOUT ANY WARRANTY; without even the implied warranty of 011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 012 * Lesser General Public License for more details. 013 * 014 * Contributors: 015 * Florent Guillaume 016 */ 017package org.nuxeo.ecm.core.io.download; 018 019import java.io.IOException; 020 021import javax.servlet.http.HttpServletRequest; 022 023import org.apache.commons.logging.Log; 024import org.apache.commons.logging.LogFactory; 025import org.nuxeo.common.utils.RFC2231; 026import org.nuxeo.ecm.core.io.download.DownloadService.ByteRange; 027 028/** 029 * Helper class related to the download service. 030 * 031 * @since 7.3 032 */ 033public class DownloadHelper { 034 035 private static final Log log = LogFactory.getLog(DownloadHelper.class); 036 037 public static final String INLINE = "inline"; 038 039 // tomcat catalina 040 private static final String CLIENT_ABORT_EXCEPTION = "ClientAbortException"; 041 042 // jetty (with CamelCase "Eof") 043 private static final String EOF_EXCEPTION = "EofException"; 044 045 // utility class 046 private DownloadHelper() { 047 } 048 049 /** 050 * Parses a byte range. 051 * 052 * @param range the byte range as a string 053 * @param length the file length 054 * @return the byte range, or {@code null} if it couldn't be parsed. 055 */ 056 public static ByteRange parseRange(String range, long length) { 057 try { 058 // TODO does no support multiple ranges 059 if (!range.startsWith("bytes=") || range.indexOf(',') >= 0) { 060 return null; 061 } 062 int i = range.indexOf('-', 6); 063 if (i < 0) { 064 return null; 065 } 066 String start = range.substring(6, i).trim(); 067 String end = range.substring(i + 1).trim(); 068 long rangeStart = 0; 069 long rangeEnd = length - 1; 070 if (start.isEmpty()) { 071 if (end.isEmpty()) { 072 return null; 073 } 074 rangeStart = length - Integer.parseInt(end); 075 if (rangeStart < 0) { 076 rangeStart = 0; 077 } 078 } else { 079 rangeStart = Integer.parseInt(start); 080 if (!end.isEmpty()) { 081 rangeEnd = Integer.parseInt(end); 082 } 083 } 084 if (rangeStart > rangeEnd) { 085 return null; 086 } 087 return new ByteRange(rangeStart, rangeEnd); 088 } catch (NumberFormatException e) { 089 return null; 090 } 091 } 092 093 /** 094 * Generates a {@code Content-Disposition} string based on the servlet request for a given filename. 095 * <p> 096 * The value follows RFC2231. 097 * 098 * @param request the http servlet request 099 * @param filename the filename 100 * @return a full string to set as value of a {@code Content-Disposition} header 101 */ 102 public static String getRFC2231ContentDisposition(HttpServletRequest request, String filename) { 103 return getRFC2231ContentDisposition(request, filename, null); 104 } 105 106 /** 107 * Generates a {@code Content-Disposition} string for a given filename. 108 * <p> 109 * The value follows RFC2231. 110 * 111 * @param request the http servlet request 112 * @param filename the filename 113 * @param inline how to set the content disposition; {@code TRUE} for {@code inline}, {@code FALSE} for 114 * {@code attachment}, or {@code null} to detect from {@code inline} request parameter or attribute 115 * @return a full string to set as value of a {@code Content-Disposition} header 116 * @since 7.10 117 */ 118 public static String getRFC2231ContentDisposition(HttpServletRequest request, String filename, Boolean inline) { 119 String userAgent = request.getHeader("User-Agent"); 120 boolean binline; 121 if (inline == null) { 122 String inlineParam = request.getParameter(INLINE); 123 if (inlineParam == null) { 124 inlineParam = (String) request.getAttribute(INLINE); 125 } 126 binline = inlineParam != null && !"false".equals(inlineParam); 127 } else { 128 binline = inline.booleanValue(); 129 } 130 return RFC2231.encodeContentDisposition(filename, binline, userAgent); 131 } 132 133 public static boolean isClientAbortError(Throwable t) { 134 int loops = 20; // no infinite loop 135 while (t != null && loops > 0) { 136 if (t instanceof IOException) { 137 // handle all IOException that are ClientAbortException by looking 138 // at their class name since the package name is not the same for 139 // jboss, glassfish, tomcat and jetty and we don't want to add 140 // implementation specific build dependencies to this project 141 String name = t.getClass().getSimpleName(); 142 if (CLIENT_ABORT_EXCEPTION.equals(name) || EOF_EXCEPTION.equals(name)) { 143 return true; 144 } 145 } 146 loops--; 147 t = t.getCause(); 148 } 149 return false; 150 } 151 152 public static void logClientAbort(Exception e) { 153 log.debug("Client disconnected: " + unwrapException(e).getMessage()); 154 } 155 156 private static Throwable unwrapException(Throwable t) { 157 while (t.getCause() != null) { 158 t = t.getCause(); 159 } 160 return t; 161 } 162 163 /** 164 * Re-throws the passed exception except if it corresponds to a client disconnect, for which logging doesn't bring 165 * us anything. 166 * 167 * @param e the original exception 168 * @throws IOException if this is not a client disconnect 169 */ 170 public static void handleClientDisconnect(IOException e) throws IOException { 171 if (isClientAbortError(e)) { 172 logClientAbort(e); 173 } else { 174 // unexpected problem, let traditional error management handle it 175 throw e; 176 } 177 } 178 179}