I'm using Barcode4J library to generate barcodes. I am returned a BufferedImage that I can display as an ImageIcon on a JLabel and save to a file but I can't for the life of me print it to a printer, the drawString and drawRect work as expected but the image is blank. I've posted some code below; I don't know how to make it a SSCCE of this but if anyone can point me in any direction I would be most grateful.

    snippet:
import org.krysalis.barcode4j.impl.code128.Code128Bean;
import org.krysalis.barcode4j.output.bitmap.BitmapCanvasProvider;
import org.krysalis.barcode4j.tools.UnitConv;


public class BarcodeBean extends Code128Bean implements Printable{

    BufferedImage _bImage;

    
    public void createBarcode2Print(BarcodeBean bean, String barcodeValue) throws FileNotFoundException, IOException {

        final int dpi = 150;
        
        BufferedImage image;
        BitmapCanvasProvider canvas = null;

        if (barcodeValue == null) {
            barcodeValue = "0123456789-000-0001";
        }
        
        bean.setModuleWidth(UnitConv.in2mm(2.0f / dpi));

        bean.doQuietZone(false);

        try {

            
            canvas = new BitmapCanvasProvider(
                    dpi, BufferedImage.TYPE_BYTE_BINARY, false, 0);
            

            //Generate the barcode
            bean.generateBarcode(canvas, barcodeValue);

            image = canvas.getBufferedImage();
            
            //Signal end of generation
        //    canvas.finish();
            
        } finally {
            
             canvas.finish();
        }

        
        printImage(image);
        
        int stop = 0;

    }
    
    public void printImage(BufferedImage arg_image){
        
        _bImage = arg_image;
        createLabel();
        
    }



    private void createLabel() {
        
        PrinterJob printJob = PrinterJob.getPrinterJob();
        Book book = new Book();
        
        PageFormat format = new PageFormat();
        
        format.setOrientation(PageFormat.PORTRAIT);
        
        java.awt.print.Paper paper = new java.awt.print.Paper();
        

        paper.setSize(612.0, 792.0); //portrait
        
        double hgt = paper.getHeight();
        double wdth = paper.getWidth();
        
        paper.setImageableArea(0, 0, wdth, hgt);
        
        format.setPaper(paper);
        
        book.append(this, format);
        
        printJob.setPageable(book);

            if (printJob.printDialog()) {
                try {

                    printJob.print();

                } catch (PrinterException ex) {

                    ex.printStackTrace();
                }
            }
   


}

    @Override
    public int print(Graphics graphics, PageFormat pageFormat, int pageIndex) throws PrinterException {
        
        Graphics2D graphics2d = (Graphics2D)graphics;
        graphics2d.translate(pageFormat.getImageableX(), pageFormat.getImageableY());
        
        graphics.setColor(Color.black);
        graphics2d.setColor(Color.black);
        
        int imageWidth = _bImage.getWidth(null);    // 378
        int imageHeight = _bImage.getHeight(null);  // 110
        
        int imageableWidth = (int)pageFormat.getImageableWidth();   // 612
        int imageableHeight = (int)pageFormat.getImageableHeight(); // 792
        

        
        graphics2d.drawString("Print barcode between this and...", 10, 30);
        
        graphics2d.drawRect(10, 40, imageWidth, imageHeight);
        
        graphics2d.drawImage(_bImage, 10, 60, imageWidth, imageHeight, null);
                
        graphics2d.drawString("This.............................", 10, 180);
                
        graphics2d.dispose();
        return Printable.PAGE_EXISTS;
        
    }
        
}

CodePudding user response：

I can't say I know why, it's possible that the Barcode4J is using their own implementation of BufferedImage or something, but, if I make a copy of the BufferedImage returned from Barcode4J, I can make it work.

What I mean by that is, if I create a new instance of BufferedImage and draw the instance from Barcode4J onto it and use it, I can make it work...

canvas = new BitmapCanvasProvider(
        dpi, BufferedImage.TYPE_BYTE_BINARY, false, 0);
bean.generateBarcode(canvas, barcodeValue);
BufferedImage bardcode = canvas.getBufferedImage();

image = new BufferedImage(bardcode.getWidth(), bardcode.getHeight(), BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = image.createGraphics();
g2d.drawImage(bardcode, 0, 0, null);
g2d.dispose();

graphics2d.dispose(); ← That might be the problem. Never dispose of a Graphics unless you created it.