java - 在java中使用热敏打印机打印收据

Question

我必须使用 Java 通过热敏打印机打印收据。我已经做了一切。我的程序从数据库中获取数据并使用特殊字符、制表符和\n 转换为一个字符串。然后将字符串传递给另一个将其转换为图形的方法。

问题是当我单击打印按钮时，会出现白纸。我注意到我的字符串的前 4-5 个字符打印在纸币最末端右上角的账单的最后一行。我的打印机是 Epson TM - T81。

  public void printThisBill()
  {

      DefaultTableModel mod = (DefaultTableModel) jTable1.getModel();
      DateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy");
      DateFormat timeFormat = new SimpleDateFormat("HH:mm");
      //get current date time with Date()
      Date date = new Date();
      Date time = new Date();
      String Date = dateFormat.format(date);
      String Time = timeFormat.format(time);
      String Header = 
            "   ****Super Market****       \n"
            + "Date: "+Date+"     Time: "+Time+"\n"
            + "---------------------------------\n"
            + "Name          Qty    Rate     Amt\n"
            + "---------------------------------\n";

      String amt  =    
            "\n \n \nTotal Amount = "+  amt()   +"\n"
            + "Tax ="   +  tax()    + "\n"
            + "*********************************\n"
            + "Thank you. \n";

      String bill = Header;
      int i = 0;
      do
      {

         String name =     ""+ mod.getValueAt(i, 2);
         String qty =      ""+ mod.getValueAt(i, 3);
         String rate =     ""+ mod.getValueAt(i, 4);
         String amount =   ""+ mod.getValueAt(i, 6);

         if(name.length() > 12)
         {
             name = name.substring(0, 12)+"  ";
         }
         else
         {
             for(int j= name.length()-12; j<= name.length(); j++);
             {
                 name = name+" ";
             } 
         }


         if(qty.length()<=5)
         {
             for(int j= 0; j<= qty.length()-5; j++);
             {
                qty = qty+" ";
             }
         }

         rate = rate;
         String items = 
             name+"\t"+qty+"\t"+rate+"\t"+amount+"\n";

         bill = bill+ items;       
         i++;

     } while(i <= mod.getRowCount()-1);

     bill = bill+amt;
     System.out.println(bill);
     printCard(bill);
     dispose();
 }

而打印账单的方法是:

public static void printCard(final String bill )
{
       Printable contentToPrint = new Printable(){
       @Override
        public int print(Graphics graphics, PageFormat pageFormat, int page) throws PrinterException 
        {
           if (page > 0) {
                return NO_SUCH_PAGE;
            }
            pageFormat.setOrientation(PageFormat.LANDSCAPE);
            Graphics2D g2d = (Graphics2D)graphics.create();

            g2d.setPaint(Color.black);
            g2d.setFont(new Font("Arial", Font.BOLD, 10));
            g2d.translate(pageFormat.getImageableX(), pageFormat.getImageableX());



            g2d.drawString(bill, 0, 0);

            return PAGE_EXISTS;
         }
       };

       PrinterJob job = PrinterJob.getPrinterJob();
       job.setPrintable(contentToPrint);
       //You can show a print dialog before printing by job by wrapping the following blocks with a conditional statement if(job.printDialog()){...}
       try 
       {
           job.print();
       } catch (PrinterException e) 
       {
           System.err.println(e.getMessage());
       }

 }

问题是什么，我该如何解决？我认为我没有在 drawString() 方法中设置正确的参数。

还是别的什么？任何帮助将不胜感激。!

Answer 1

我发现了这个:

Java Pos Thermal Printer Example

它对我有用。无需外部库。

import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.print.PageFormat;
import java.awt.print.Printable;
import java.awt.print.PrinterException;
import java.util.ArrayList;
import java.util.List;

import javax.print.Doc;
import javax.print.DocFlavor;
import javax.print.DocPrintJob;
import javax.print.PrintService;
import javax.print.PrintServiceLookup;
import javax.print.SimpleDoc;
import javax.print.attribute.HashPrintRequestAttributeSet;
import javax.print.attribute.PrintRequestAttributeSet;

public class PrinterService implements Printable {

    public List<String> getPrinters(){

        DocFlavor flavor = DocFlavor.BYTE_ARRAY.AUTOSENSE;
        PrintRequestAttributeSet pras = new HashPrintRequestAttributeSet();

        PrintService printServices[] = PrintServiceLookup.lookupPrintServices(
                flavor, pras);

        List<String> printerList = new ArrayList<String>();
        for(PrintService printerService: printServices){
            printerList.add( printerService.getName());
        }

        return printerList;
    }

    @Override
    public int print(Graphics g, PageFormat pf, int page)
            throws PrinterException {
        if (page > 0) { /* We have only one page, and 'page' is zero-based */
            return NO_SUCH_PAGE;
        }

        /*
         * User (0,0) is typically outside the imageable area, so we must
         * translate by the X and Y values in the PageFormat to avoid clipping
         */
        Graphics2D g2d = (Graphics2D) g;
        g2d.translate(pf.getImageableX(), pf.getImageableY());
        /* Now we perform our rendering */

        g.setFont(new Font("Roman", 0, 8));
        g.drawString("Hello world !", 0, 10);

        return PAGE_EXISTS;
    }

    public void printString(String printerName, String text) {

        // find the printService of name printerName
        DocFlavor flavor = DocFlavor.BYTE_ARRAY.AUTOSENSE;
        PrintRequestAttributeSet pras = new HashPrintRequestAttributeSet();

        PrintService printService[] = PrintServiceLookup.lookupPrintServices(
                flavor, pras);
        PrintService service = findPrintService(printerName, printService);

        DocPrintJob job = service.createPrintJob();

        try {

            byte[] bytes;

            // important for umlaut chars
            bytes = text.getBytes("CP437");

            Doc doc = new SimpleDoc(bytes, flavor, null);


            job.print(doc, null);

        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }

    public void printBytes(String printerName, byte[] bytes) {

        DocFlavor flavor = DocFlavor.BYTE_ARRAY.AUTOSENSE;
        PrintRequestAttributeSet pras = new HashPrintRequestAttributeSet();

        PrintService printService[] = PrintServiceLookup.lookupPrintServices(
                flavor, pras);
        PrintService service = findPrintService(printerName, printService);

        DocPrintJob job = service.createPrintJob();

        try {

            Doc doc = new SimpleDoc(bytes, flavor, null);

            job.print(doc, null);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private PrintService findPrintService(String printerName,
            PrintService[] services) {
        for (PrintService service : services) {
            if (service.getName().equalsIgnoreCase(printerName)) {
                return service;
            }
        }

        return null;
    }
}

还有主类:

public class Main {

    public static void main(String[] args) {

        PrinterService printerService = new PrinterService();

        System.out.println(printerService.getPrinters());

        //print some stuff. Change the printer name to your thermal printer name.
        printerService.printString("EPSON-TM-T20II", "\n\n testing testing 1 2 3eeeee \n\n\n\n\n\n\n\n\n\n\n\n\n\n\n");

        // cut that paper!
        byte[] cutP = new byte[] { 0x1d, 'V', 1 };

        printerService.printBytes("EPSON-TM-T20II", cutP);

    }

}