Operate the scanner in Java (using JNI)

This is a small example of using java to operate the scanner:
Package edu. ctgu. JTwacker;

Import java. awt. BorderLayout;
Import java. awt. Cursor;
Import java. awt. Dimension;
Import java. awt. Graphics;
Import java. awt. Rectangle;
Import java. awt. Toolkit;
Import java. awt. event. ActionEvent;
Import java. awt. event. ActionListener;
Import java. awt. event. WindowAdapter;
Import java. awt. event. javaswevent;
Import java. awt. event. WindowListener;
Import java. awt. image. BufferedImage;
Import java. io. File;
Import java. io. FileInputStream;

Import javax. swing. JButton;
Import javax. swing. JComboBox;
Import javax. swing. JFrame;
Import javax. swing. JPanel;
Import javax. swing. JScrollPane;
Import javax. swing. JToolBar;
Import javax. swing. SwingUtilities;

Import com.sun.image.codec.jpeg. Unzip codec;
Import com.sun.image.codec.jpeg. Unzip imagedecoder;

Import edu. ctgu. twain. JTwain;
/*
This is the frame that displays the scanned image.
*/
Public class JTwacker extends JFrame {

Class panel extends JPanel {

/** Image for the inner class
*/
Protected BufferedImage m1_panelbufferedimage;

/** Pnale to diaply the image
*/
Public Panel (){
// No op
}

/** Sets the bufferedimage into the class
* @ Param bi BufferedImage
*/
Public void setBufferedImage (BufferedImage bi ){
If (bi = null ){
Return;
}
M1_panelbufferedimage = bi;
Dimension d = new Dimension (m1_panelbufferedimage. getWidth (this ),
MJPEGPanelBufferedImage. getHeight (this ));
SetPreferredSize (d );
Revalidate ();
Repaint ();
}

/** Paints the component.
* @ Param g Graphics object used for the painting
*/
Public void paintComponent (Graphics g ){
Super. paintComponent (g );
Dimension d = getSize ();
G. setColor (getBackground ());
G. fillRect (0, 0, d. width, d. height );
If (m1_panelbufferedimage! = Null ){
G. drawImage (m1_panelbufferedimage, 0, 0, this );
}
}
}


Protected multicast panel mJpegPanel;


Protected BufferedImage mBufferedImage;

Protected JComboBox mSourcesCombo;

Protected JToolBar mToolBar;

/** Constructor
*/
Public JTwacker (){
Super ("test ");

Mpanel = new Panel ();
JScrollPane ps = new JScrollPane (mJpegPanel,
JScrollPane. VERTICAL_SCROLLBAR_ALWAYS,
JScrollPane. HORIZONTAL_SCROLLBAR_ALWAYS );
GetContentPane (). add (ps, BorderLayout. CENTER );

WindowListener wndCloser = new WindowAdapter (){
Public void windowClosing (WindowEvent e ){
System. exit (0 );
}
};
AddWindowListener (wndCloser );

MToolBar = new JToolBar ("Twain ");
MToolBar. setFloatable (false );
AddButtons ();
GetContentPane (). add (mToolBar, BorderLayout. NORTH );
SetSize (800,600 );

/* Center the frame */
Dimension screenDim = Toolkit. getdefatooltoolkit (). getScreenSize ();
Rectangle frameDim = getBounds ();
SetLocation (
(ScreenDim. width-frameDim. width)/2,
(ScreenDim. height-frameDim. height)/2
);
SetVisible (true );
}

Protected void addButtons (){

JButton _ AB = new JButton ("scan ");
_ AB. addActionListener (new ActionListener (){
Public void actionreceivmed (ActionEvent e ){
AcquireImage ();
}
});
MToolBar. add (_ AB );
MToolBar. addSeparator ();

If (edu. ctgu. twain. JTwain. getInstance (). isTwainAvailble ()){
String [] twainSources = JTwain. getInstance (). getAvailableSources ();
If (twainSources! = Null ){
MSourcesCombo = new JComboBox (twainSources );
} Else {
MSourcesCombo = new JComboBox ();
MSourcesCombo. addItem ("<none available> ");
}
} Else {
MSourcesCombo = new JComboBox ();
MSourcesCombo. addItem ("<none available> ");
}
MToolBar. add (mSourcesCombo );
}



Protected void acquireImage (){
If (JTwain. getInstance (). isTwainAvailble ()){
If (mSourcesCombo. getItemCount ()> 0 ){
String _ source = (String) mSourcesCombo. getSelectedItem ();
If (_ source! = Null ){
String _ filename = JTwain. getInstance (). acquire (_ source );
System. out. println (_ filename );

If (_ filename! = Null & _ filename. length ()> 0 ){
File fChoosen = new File (_ filename );
// Savetofile (fChoosen );
ShowImage (fChoosen );
} Else {
System. out. println ("Oh, what's wrong! ");
}
} // End if
} // End if
} // End if
}



Protected void showImage (final File file ){
If (file = null |! File. exists ()){
Return;
}
SetCursor (Cursor. getPredefinedCursor (Cursor. WAIT_CURSOR ));

Thread runner = new Thread (){
Public void run (){
Try {
FileInputStream in = new FileInputStream (file );
Required imagedecoder decoder = required codec. createJPEGDecoder (in );
MBufferedImage = decoder. decodeAsBufferedImage ();
In. close ();
SwingUtilities. invokeLater (new Runnable (){
Public void run (){
Reset ();
}
});
}
Catch (Exception ex ){
Ex. printStackTrace ();
}
SetCursor (Cursor. getPredefinedCursor (Cursor. DEFAULT_CURSOR ));
}
};
Runner. start ();
}

// Save the scanned image as a file and then upload it to the server or save it to the database.
Protected void savetofile (final File file ){
Try {
File mfile = new File ("c: \ dd.jpg ");
If (mfile. exists ()){
Mfile. delete ();
} Else {
File. renameTo (mfile );
}

} Catch (Exception e ){
E. printStackTrace ();
// TODO: handle exception
}
}

Protected void reset (){
If (mBufferedImage! = Null ){
MBufferedImage (mBufferedImage );

}
}


Public static void main (String argv []) {
New JTwacker ();
}

}

-------------------------


Package edu. ctgu. twain;

/*
This is the class that calls the dynamic link library.
*/
Public class JTwain {


Private static final JTwain mInstance = new JTwain ();
Protected final String DLL_NAME = "jtwain ";

Private JTwain (){
InitLib ();
}

Public static JTwain getInstance (){
Return mInstance;
}

Public native boolean isTwainAvailble ();

Public native String [] getAvailableSources ();

Public native String acquire ();

Public native String acquire (String sourceName );

Private void initLib (){

Try {


System. loadLibrary (DLL_NAME );
} Catch (Exception e ){
E. printStackTrace ();
}

Finally {
// System. out. println ("Loading:" + DLL_NAME + ". dll ");
}
}
}

Implement jtwain. dll files