[Java] Stampare un file TXT

[pireda]

Devo implementare in un'applicazione java la possibilità di stampare un determinato file TXT (il file di log degli errori), una volta creato il pulsante "Stampa"....Cosa devo fare?

[abcd1000]

salva il seguente codice in un file Print.java

mport java.awt.*;
import java.awt.event.*;
import java.awt.print.*;
import javax.swing.*;

/**
* A small program to show how to print the contents of a
* JTextArea.
*/
public class Print extends JFrame implements ActionListener,
Printable{
JTextArea textArea;
JTextPane myEditor;

/**
* Constructor. Set up the GUI.
*/
public Print( JTextPane editor){
myEditor=editor;
pack( );
setSize( new Dimension(300,300));
addWindowListener( new CloseWindow( ));
String text = myEditor.getText();
textArea = new JTextArea( text);
getContentPane().add( textArea, BorderLayout.CENTER);
JButton button = new JButton( "Print");
button.addActionListener( this);
getContentPane().add( button, BorderLayout.SOUTH);
show( );
}

/**
* Called when the user clicks on the print button.
*/
public void actionPerformed( ActionEvent e){
PrinterJob printJob = PrinterJob.getPrinterJob( );
printJob.setPrintable( this);
if (printJob.printDialog()) {
try {
printJob.print( );
}
catch( Exception PrintException){ }
}
}

/**
* This method does the actual work - the printing.
* It uses JTextAreas printAll(Graphics) method. If
* n is "greater or equal to 1" then the requested
* page does not exist. n must be 0 for the page to be
* printed.
* @param g - the context into which the page is
* drawn.
* @param f - the size and orientation of the page
* being drawn.
* @param n - the zero based index of the page to be
* drawn.
*/
public int print( Graphics g, PageFormat f, int n)
throws PrinterException{
if( n >= 1) {
System.out.print( "I am in here");
return Printable.NO_SUCH_PAGE;
}
System.out.println( "now I am in here");
g.translate( 100, 100);
textArea.printAll( g);
return Printable.PAGE_EXISTS;
}

/**
* The main method.
*/
public static void main( String s[]){
//new Print( myEditor);
}
}

/**
* Allow this frame to close.
*/
class CloseWindow extends WindowAdapter{
public void windowClosing( WindowEvent e){
//System.exit( 0);
}
}

[pireda]

Fatto, ma come va usato?

[abcd1000]

nell'azione del pulsante che deve stampare scrivi

if (editor!=null)
new Print(editor);

dove editor è il pannello (non il testo!) che contiene il testo da stampare

Io per esempio uso un JTextPane editor;

[pireda]

Io sono riuscito a farlo funzionare decommentando le 2 linee alla fine (forse te le eri dimenticate) e togliendo tutti i riferimenti a myEditor (che non può essere passato dal metodo main come facevi tu perché è un metodo statico)

[abcd1000]

bravo!
me li ero dimenticati

[pireda]

Ho notato però che se il testo è molto lungo non mi viene stampato su più pagine, alla fine della prima la stampa si interrompe, come posso risolvere questo problema?

[abcd1000]

se il testo e' più lungo di una pagina il codice che ti ho postato non va bene e non so aiutarti

[pireda]

AAAAAAAAHHHHHHHHRRGGGGG!!!!
Non potevi buttarmi più giu di morale...

[Angelo1974]

Prova con una di queste classi....è probabile che possa fare al tuo caso modificandola, sono sicuro che almeno 1 ritornava + di una pagina...dagli 1 occhio:
import java.awt.print.*;
import java.awt.*;

public class MindPrint implements Printable
{

public int print(Graphics grap,
PageFormat pageFormat, int pageIndex) throws PrinterException
{
if(pageIndex > 0)
return NO_SUCH_PAGE;

System.out.println("getImageableX == " + pageFormat.getImageableX());
System.out.println("getImageableY == " + pageFormat.getImageableY());
System.out.println("getImageableWidth == " + pageFormat.getImageableWidth());
System.out.println("getImageableHeight == " + pageFormat.getImageableHeight());

grap.drawString("Ready to roll out!", (int)pageFormat.getImageableX(),
(int)pageFormat.getImageableY()+5);
grap.setColor(Color.black);
grap.drawLine((int)pageFormat.getImageableX(), (int)pageFormat.getImageableY(),
(int)pageFormat.getImageableWidth(), (int)pageFormat.getImageableHeight());

return PAGE_EXISTS;

}
}


import javax.swing.*;
import java.awt.*;
import java.awt.print.*;
import java.awt.event.*;

public class PrintForm extends JFrame implements Printable
{

public PrintForm()
{
setSize(200, 300);
setTitle("PrintForm");

JButton btn = new JButton("Print");
btn.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
doPrint();
}
});

getContentPane().setLayout(new BorderLayout());
getContentPane().add(BorderLayout.SOUTH, btn);

setVisible(true);
}

private void doPrint()
{
PrinterJob pj = PrinterJob.getPrinterJob();
if(!pj.printDialog())
return;
pj.setJobName("PrintForm printing self!");
try
{
pj.setPrintable(this);
pj.print();
} catch(PrinterException ex)
{
System.out.println(ex);
return;
}
}

public int print(Graphics g, PageFormat pf, int index)
{
if(index >= 1)
return NO_SUCH_PAGE;

paintAll(g);
return PAGE_EXISTS;
}

public static void main(String ag[])
{
new PrintForm().show();
}
}

public class Example2 {

//--- Private instances declarations
private final static int POINTS_PER_INCH = 72;


/**
* Constructor: Example2


*
*/
public Example2 () {

//--- Create a new PrinterJob object
PrinterJob printJob = PrinterJob.getPrinterJob ();

//--- Create a new book to add pages to
Book book = new Book ();

//--- Add the cover page using the default page format for this print job
book.append (new IntroPage (), printJob.defaultPage ());

//--- Add the document page using a landscape page format
PageFormat documentPageFormat = new PageFormat ();
documentPageFormat.setOrientation (PageFormat.LANDSCAPE);
book.append (new Document (), documentPageFormat);

//--- Tell the printJob to use the Book as the Pageable object
printJob.setPageable (book);

//--- Show the print dialog box. If the user clicks the
//--- print button, we then proceed to print, else we cancel
//--- the process.
if (printJob.printDialog()) {
try {
//printJob.pageDialog(new PageFormat());
printJob.print();
} catch (Exception PrintException) {
PrintException.printStackTrace();
}
}
}


/**
* Class: IntroPage


*
* This class defines the painter for the cover page by implementing the
* Printable interface.


*
* @author Jean-Pierre Dube <jpdube@videotron.ca>
* @version 1.0
* @since 1.0
* @see Printable
*/
private class IntroPage implements Printable {


/**
* Method: print


*
* @param g a value of type Graphics
* @param pageFormat a value of type PageFormat
* @param page a value of type int
* @return a value of type int
*/
public int print (Graphics g, PageFormat pageFormat, int page) {

//--- Create the Graphics2D object
Graphics2D g2d = (Graphics2D) g;

//--- Translate the origin to 0,0 for the top left corner
g2d.translate (pageFormat.getImageableX (), pageFormat.getImageableY ());

//--- Set the default drawing color to black
g2d.setPaint (Color.black);

//--- Draw a border around the page
Rectangle2D.Double border = new Rectangle2D.Double (0,
0,
pageFormat.getImageableWidth (),
pageFormat.getImageableHeight ());
g2d.draw (border);

//--- Print the title
String titleText = "Printing in Java Part 2";
Font titleFont = new Font ("helvetica", Font.BOLD, 36);
g2d.setFont (titleFont);

//--- Compute the horizontal center of the page
FontMetrics fontMetrics = g2d.getFontMetrics ();
double titleX = (pageFormat.getImageableWidth () / 2) - (fontMetrics.stringWidth (titleText) / 2);
double titleY = 3 * POINTS_PER_INCH;
g2d.drawString (titleText, (int) titleX, (int) titleY);

return (PAGE_EXISTS);
}
}



/**
* Class: Document


*
* This class is the painter for the document content.


*
*
* @author Jean-Pierre Dube <jpdube@videotron.ca>
* @version 1.0
* @since 1.0
* @see Printable
*/
private class Document implements Printable {


/**
* Method: print


*
* @param g a value of type Graphics
* @param pageFormat a value of type PageFormat
* @param page a value of type int
* @return a value of type int
*/
public int print (Graphics g, PageFormat pageFormat, int page) {


//--- Create the Graphics2D object
Graphics2D g2d = (Graphics2D) g;

//--- Translate the origin to 0,0 for the top left corner
g2d.translate (pageFormat.getImageableX (), pageFormat.getImageableY ());
//--- Set the drawing color to black
g2d.setPaint (Color.black);

//--- Draw a border around the page using a 12 point border
g2d.setStroke (new BasicStroke (12));
Rectangle2D.Double border = new Rectangle2D.Double (0,
0,
pageFormat.getImageableWidth (),
pageFormat.getImageableHeight ());

g2d.draw (border);

//--- Print the text one inch from the top and left margins
g2d.drawString ("This the content page", POINTS_PER_INCH, POINTS_PER_INCH);

//--- Validate the page
return (PAGE_EXISTS);

}
}
public static void main (String[] args){
Example2 e = new Example2();
}
} // Example2