win32shellviewer.java

一个用java写的mail.里面的代码值得我们去研究！学习。

/*
** $Id: Win32ShellViewer.java,v 1.5 2001/05/07 12:37:22 kunugi Exp $
**
** Copyright (c) 2000-2001 Jeff Gay
** on behalf of ICEMail.org <http://www.icemail.org>
** Copyright (c) 1998-2000 by Timothy Gerard Endres
** 
** This program is free software.
** 
** You may redistribute it and/or modify it under the terms of the GNU
** General Public License as published by the Free Software Foundation.
** Version 2 of the license should be included with this distribution in
** the file LICENSE, as well as License.html. If the license is not
** included with this distribution, you may find a copy at the FSF web
** site at 'www.gnu.org' or 'www.fsf.org', or you may write to the
** Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139 USA.
**
** THIS SOFTWARE IS PROVIDED AS-IS WITHOUT WARRANTY OF ANY KIND,
** NOT EVEN THE IMPLIED WARRANTY OF MERCHANTABILITY. THE AUTHOR
** OF THIS SOFTWARE, ASSUMES _NO_ RESPONSIBILITY FOR ANY
** CONSEQUENCE RESULTING FROM THE USE, MODIFICATION, OR
** REDISTRIBUTION OF THIS SOFTWARE. 
*/

package org.icemail.mail;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.IOException;

import javax.activation.CommandObject;
import javax.activation.DataHandler;
import javax.activation.MimeType;
import javax.activation.MimeTypeParseException;

import javax.swing.JOptionPane;

import org.icemail.Package; 

import org.icemail.util.ComponentFactory; 
import org.icemail.util.FileUtilities; 
import org.icemail.util.UserProperties; 

import com.ice.jni.dde.JNIDDE;
import com.ice.jni.dde.DDEException;
import com.ice.jni.registry.Registry;
import com.ice.jni.registry.RegistryKey;
import com.ice.jni.registry.RegistryException;
import com.ice.jni.registry.NoSuchKeyException;


/**
 * Class Win32ShellViewer implements a CommandObject for the Java Activation Framework.
 * Win32ShellViewer tries to write the contents of the data source (source of the provided
 * data hander) to a file. The file is written to an appropriately named file based on
 * the MIME type of the data handler. The file is then 'opened' using the Win32 operating
 * system, which starts up the appropriate application to view the data.
 * <p>
 * The only verb supported is "view". And as you've already guessed, allows the data to
 * be viewed by appropriate application.
 * <p>
 * A lot of this is made possible via the ICE JNI library.
 */
public class Win32ShellViewer
  implements CommandObject
{
  private static final int Debug_ = Package.DEBUG ? Package.getLevel( "Win32ShellViewer" ) : 0;


  /**
   * Construct an empty viewer, which can be loaded later.
   */
  public
  Win32ShellViewer() {
  }

  /**
   * Initialize the command object from the data handler as described by the verb.
   * <p>
   * Implements CommandObject.setCommandContext().
   * <p>
   * @param verb the command from the activation framework
   * @param dh the datahandler containing the data contents and type
   * @see javax.activation.CommandObject
   */
  public void
  setCommandContext( String verb, DataHandler dh ) throws IOException {
    if ( Package.DEBUG && Package.isTraceable( "Win32ShellViewer" ) ) {
      System.out.println( "Win32ShellViewer.setCommandContext(s,dh): " + verb );
    }

    if ( verb == null || dh == null )
      throw new IOException( "Invalid parameters to Win32ShellViewer.setCommandContext()" );
    if ( ! verb.equalsIgnoreCase( "view" ) )
      throw new IOException( "Only 'view' accepted to Win32ShellViewer.setCommandContext()" );

    viewContent( dh );
  }

  /**
   * sets the current message to be displayed in the viewer
   */
  private void
  viewContent( DataHandler dataHandler ) {
    if ( Package.DEBUG && Package.isTraceable( "Win32ShellViewer" ) ) {
      System.out.println( "Win32ShellViewer.viewContent()" );
    }

    MimeType mimeType = null;
    String contentType = null;
    InputStream content = null;

    try {
      JNIDDE dde = new JNIDDE(); // Do this just to check the dll
      RegistryKey rkey = Registry.HKEY_CLASSES_ROOT;

      contentType = dataHandler.getContentType().toLowerCase();

      if ( Package.DEBUG && Debug_ > 0 ) {
        System.err.println( "Win32ShellViewer.viewContent(): contentType = '" + contentType + "'" );
      }

      mimeType = new MimeType( contentType );

      String tempDirName = ICEMail.getTempFileManager().getDirectory();

      if ( Package.DEBUG && Debug_ > 0 ) {
        System.err.println( "Win32ShellViewer.viewContent(): tempDirName = '" + tempDirName + "'" );
      }

      rkey = rkey.openSubKey( "MIME\\Database\\Content Type\\" + mimeType.getBaseType() );

      String fileNameSuffix = rkey.getStringValue( "Extension" );

      rkey.closeKey();

      if ( Package.DEBUG && Debug_ > 0 ) {
        System.err.println( "Win32ShellViewer.viewContent(): fileNameSuffix = '" + fileNameSuffix + "'" );
      }

      String tempFileName = null;

    // First consult the MIME header for a name
      String mimeName = mimeType.getParameter( "name" );

      if ( Package.DEBUG && Debug_ > 0 ) {
        System.err.println( "Win32ShellViewer.viewContent(): mimeName = '" + mimeName + "'" );
      }

      if ( mimeName != null &&
           FileUtilities.fileEqualsExtension( mimeName, fileNameSuffix ) ) {
        tempFileName = tempDirName + File.separator + mimeName;
      } else {
      // Second, consult the DataHandler for a name
        String dhName = dataHandler.getName();

        if ( Package.DEBUG && Debug_ > 0 ) {
          System.err.println( "Win32ShellViewer: dhName = '" + dhName + "'" );
        }

        if ( dhName != null &&
             FileUtilities.fileEqualsExtension ( dhName, fileNameSuffix ) ) {
          tempFileName = tempDirName + File.separator + dhName;
        } else {
          if ( mimeName != null && mimeName.length() > 0 ) {
            tempFileName = tempDirName + File.separator + mimeName;
          } else if ( dhName != null && dhName.length() > 0  ) {
            tempFileName = tempDirName + File.separator + dhName;
          } else {
            tempFileName = ICEMail.getTempFileManager().getFilename( fileNameSuffix );
          }

          String regContentType = null;

          int sufIdx = tempFileName.lastIndexOf( "." );
          if ( sufIdx != -1 ) {
            String regSuffix = tempFileName.substring( sufIdx );

            try {
              RegistryKey skey = Registry.HKEY_CLASSES_ROOT;
              skey = skey.openSubKey( regSuffix );
              regContentType = skey.getStringValue( "Content Type" );
              skey.closeKey();
            } catch ( Exception ex ) {
            }
          }

          if ( Package.DEBUG && Debug_ > 0 ) {
            System.err.println( "Win32ShellViewer: reContentType = '" + regContentType + "'" );
          }

          if ( regContentType == null || ! mimeType.match( regContentType ) ) {
            tempFileName = tempFileName + fileNameSuffix;
          }
        }
      }

      if ( Package.DEBUG && Debug_ > 0 ) {
        System.err.println( "Win32ShellViewer: tempFileName = '" + tempFileName + "'" );
      }

      content = dataHandler.getInputStream();

    // write the contents to a temporary file
      FileOutputStream xfos = new FileOutputStream( tempFileName );

      byte[] xbuffer = new byte[ 32 * 1024 ];
      int    xcount;
      for ( ; ; ) {
        xcount = content.read( xbuffer, 0, xbuffer.length );
        if ( xcount == -1 )
          break;
        xfos.write( xbuffer, 0, xcount );
      }

      xfos.close();
      content.close();

      JNIDDE.shellExecute( "open", tempFileName, null, tempDirName, JNIDDE.SW_SHOWNORMAL );
    } catch ( FileNotFoundException ex ) {
    // ex.printStackTrace( System.err );
      Object[] xargs = new Object[1];
      xargs[0] = ex.getMessage();
      ComponentFactory.showDialog( ICEMail.getBundle(), "WinViewer.FileNotFound",
                                   0, JOptionPane.ERROR_MESSAGE, xargs );
    } catch ( NoSuchKeyException ex ) {
    // ex.printStackTrace( System.err );
      Object[] xargs = new Object[0];
      xargs[0] = ( mimeType == null ? contentType : mimeType.getBaseType() );

      xargs[1] = ex.getMessage();
      ComponentFactory.showDialog( ICEMail.getBundle(), "WinViewer.NoSuchKey",
                                   0, JOptionPane.ERROR_MESSAGE, xargs );
    } catch ( UnsatisfiedLinkError ex ) {
    // er.printStackTrace( System.err );
      Object[] xargs = new Object[1];
      xargs[0] = ex.getMessage();
      ComponentFactory.showDialog( ICEMail.getBundle(), "WinViewer.UnsatisfiedLink",
                                   0, JOptionPane.ERROR_MESSAGE, xargs );
    } catch ( DDEException ex ) {
    // ex.printStackTrace( System.err );
      Object[] xargs = new Object[1];
      xargs[0] = ex.getMessage();
      ComponentFactory.showDialog( ICEMail.getBundle(), "WinViewer.DDE",
                                   0, JOptionPane.ERROR_MESSAGE, xargs );
    } catch ( RegistryException ex ) {
    //ex.printStackTrace( System.err );
      Object[] xargs = new Object[1];
      xargs[0] = ex.getMessage();
      ComponentFactory.showDialog( ICEMail.getBundle(), "WinViewer.Registry",
                                   0, JOptionPane.ERROR_MESSAGE, xargs );
    } catch ( IOException ex ) {
    //ex.printStackTrace( System.err );
      Object[] xargs = new Object[1];
      xargs[0] = ex.getMessage();
      ComponentFactory.showDialog( ICEMail.getBundle(), "WinViewer.IO",
                                   0, JOptionPane.ERROR_MESSAGE, xargs );
    } catch ( MimeTypeParseException ex ) {
    // ex.printStackTrace( System.err );
      Object[] xargs = new Object[1];
      xargs[0] = ex.getMessage();
      ComponentFactory.showDialog( ICEMail.getBundle(), "WinViewer.MimeTypeParse",
                                   0, JOptionPane.ERROR_MESSAGE, xargs );
    }
  }

}