001/* URLDataSource.java -- Data source for a URL object. 002 Copyright (C) 2004 Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038package javax.activation; 039 040import java.io.InputStream; 041import java.io.IOException; 042import java.io.OutputStream; 043import java.net.URL; 044import java.net.URLConnection; 045 046/** 047 * DataSource implementation that retrieves its data from a URL. 048 * 049 * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a> 050 * @version 1.1 051 */ 052public class URLDataSource 053 implements DataSource 054{ 055 056 private final URL url; 057 private URLConnection connection; 058 059 /** 060 * Constructor. 061 * This will not open the connection to the URL. 062 */ 063 public URLDataSource(URL url) 064 { 065 this.url = url; 066 } 067 068 /** 069 * Returns the Content-Type header for the URL. 070 * In the case of failure or lack of such a header, 071 * returns "application/octet-stream". 072 */ 073 public String getContentType() 074 { 075 try 076 { 077 if (connection == null) 078 { 079 connection = url.openConnection(); 080 } 081 } 082 catch (IOException e) 083 { 084 } 085 String contentType = null; 086 if (connection != null) 087 { 088 contentType = connection.getContentType(); 089 } 090 if (contentType == null) 091 { 092 contentType = "application/octet-stream"; 093 } 094 return contentType; 095 } 096 097 /** 098 * Returns the result of <code>getFile</code> of the underlying URL. 099 */ 100 public String getName() 101 { 102 return url.getFile(); 103 } 104 105 public InputStream getInputStream() 106 throws IOException 107 { 108 connection = url.openConnection(); 109 if (connection != null) 110 { 111 connection.setDoInput(true); 112 return connection.getInputStream(); 113 } 114 return null; 115 } 116 117 public OutputStream getOutputStream() 118 throws IOException 119 { 120 connection = url.openConnection(); 121 if (connection != null) 122 { 123 connection.setDoOutput(true); 124 return connection.getOutputStream(); 125 } 126 return null; 127 } 128 129 /** 130 * Returns the underlying URL. 131 */ 132 public URL getURL() 133 { 134 return url; 135 } 136 137}