001 /* URLDataSource.java -- Data source for a URL object.
002 Copyright (C) 2004 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038 package javax.activation;
039
040 import java.io.InputStream;
041 import java.io.IOException;
042 import java.io.OutputStream;
043 import java.net.URL;
044 import 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 */
052 public 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 }