B4J Question Twain from java

#Region Project Attributes
    #MainFormWidth: 600
    #MainFormHeight: 600
    #AdditionalJar:uk.co.mmscomputing.device.twain.jar
#End Region

Sub Process_Globals
    Private fx As JFX
    Private MainForm As Form
 End Sub

Sub AppStart (Form1 As Form, Args() As String)
    MainForm = Form1
    'MainForm.RootPane.LoadLayout("Layout1") 'Load the layout file.
    MainForm.Show
    
    Private NativeMe As JavaObject
    NativeMe.InitializeNewInstance("b4j.example.main.TwainExample",Null)
    
End Sub

'Return true to allow the default exceptions handler to handle the uncaught exception.
Sub Application_Error (Error As Exception, StackTrace As String) As Boolean
    Return True
End Sub

#If Java
    import java.io.File;
import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;

import uk.co.mmscomputing.device.scanner.Scanner;
import uk.co.mmscomputing.device.scanner.ScannerDevice;
import uk.co.mmscomputing.device.scanner.ScannerListener;
import uk.co.mmscomputing.device.scanner.ScannerIOException;
import uk.co.mmscomputing.device.scanner.ScannerIOMetadata;

public static class TwainExample implements ScannerListener{

  //static TwainExample app; 

  Scanner scanner;

  public TwainExample() throws ScannerIOException{
    scanner=Scanner.getDevice();
    scanner.addListener(this);   
    scanner.acquire();
  }

  public void update(ScannerIOMetadata.Type type, ScannerIOMetadata metadata){
    if(type.equals(ScannerIOMetadata.ACQUIRED)){
      BufferedImage image=metadata.getImage();
      System.out.println("Have an image now!");
      try{
        ImageIO.write(image, "png", new File("mmsc_image.png"));
      }catch(Exception e){
        e.printStackTrace();
      }
    }else if(type.equals(ScannerIOMetadata.NEGOTIATE)){
      ScannerDevice device=metadata.getDevice();
      try{
//        device.setShowUserInterface(true);
//        device.setShowProgressBar(true);
//        device.setResolution(100);
      }catch(Exception e){
        e.printStackTrace();
      }
    }else if(type.equals(ScannerIOMetadata.STATECHANGE)){
      System.err.println(metadata.getStateStr());
      if(metadata.isFinished()){
        System.exit(0);
      }
    }else if(type.equals(ScannerIOMetadata.EXCEPTION)){
      metadata.getException().printStackTrace();
    }
  }
}
#End If