libjava/classpath/javax/activation/URLDataSource.java

   1 /* URLDataSource.java -- Data source for a URL object.
   2    Copyright (C) 2004 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38 package javax.activation;
  39
  40 import java.io.InputStream;
  41 import java.io.IOException;
  42 import java.io.OutputStream;
  43 import java.net.URL;
  44 import java.net.URLConnection;
  45
  46 /**
  47  * DataSource implementation that retrieves its data from a URL.
  48  *
  49  * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a>
  50  * @version 1.1
  51  */
  52 public class URLDataSource
  53     implements DataSource
  54 {
  55
  56   private final URL url;
  57   private URLConnection connection;
  58
  59   /**
  60    * Constructor.
  61    * This will not open the connection to the URL.
  62    */
  63   public URLDataSource(URL url)
  64   {
  65     this.url = url;
  66   }
  67
  68   /**
  69    * Returns the Content-Type header for the URL.
  70    * In the case of failure or lack of such a header,
  71    * returns "application/octet-stream".
  72    */
  73   public String getContentType()
  74   {
  75     try
  76       {
  77         if (connection == null)
  78           {
  79             connection = url.openConnection();
  80           }
  81       }
  82     catch (IOException e)
  83       {
  84       }
  85     String contentType = null;
  86     if (connection != null)
  87       {
  88         contentType = connection.getContentType();
  89       }
  90     if (contentType == null)
  91       {
  92         contentType = "application/octet-stream";
  93       }
  94     return contentType;
  95   }
  96
  97   /**
  98    * Returns the result of <code>getFile</code> of the underlying URL.
  99    */
 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 }