Source for javax.activation.URLDataSource

   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: }