无法从Swing中的特定打印机打印文档

Question

I am writing a code that should find list of printers on client machine and set a particulate printer for print a Doc. But I was goggling on net and I found code some think like that:

package org.ui;
import java.io.FileInputStream;
import javax.print.*;
import javax.print.attribute.HashPrintRequestAttributeSet;
import javax.print.attribute.PrintRequestAttributeSet;
public class Printing {
    public static void main (String [] args) {       
        DocFlavor flavor = DocFlavor.INPUT_STREAM.AUTOSENSE;
        PrintRequestAttributeSet aset = new HashPrintRequestAttributeSet ();       
        PrintService [] pservices = PrintServiceLookup.lookupPrintServices (flavor, aset);
        try {
            int printer = getPrinter(pservices);
            if(printer == -1) {
                throw new Exception("No network printer found");
            }
            DocPrintJob pj = pservices[0].createPrintJob();
            FileInputStream fis = new FileInputStream ("c:///file.txt");
            Doc doc = new SimpleDoc (fis, flavor, null);
            pj.print (doc, aset);
        }
        catch (Exception ex) {
            ex.printStackTrace ();
        } 
    }
    private static int getPrinter(PrintService[] pservices) {
        int printer = -1;
        for(int i = 0; i<pservices.length; i++) {
            if(pservices[i].getName().contains("\\\\")) {
                System.out.println("network printer: " + pservices[i].toString());   
                printer = i;
                break;
            }        
        }
        return printer;
    }
}

But I am unable to get print on paper, can anyone tell me whats the problem in this code? Its a desktop application.

Answer 1

According to the documentation of print()

[...] When the print method returns, printing may not yet have completed as printing may happen asynchronously, perhaps in a different thread. Application clients which want to monitor the success or failure should register a PrintJobListener.

This means that you need to register a PrintJobListener to be able to tell what the problem is:

Try:

pj.addPrintJobListener(new PrintJobListener() {
  @Override
  void printDataTransferCompleted(PrintJobEvent pje) {
    System.out.println("Transfer completed");
  }
  @Override
  void printJobCanceled(PrintJobEvent pje) {
    System.out.println("Cancelled");
  }
  @Override
  void printJobCompleted(PrintJobEvent pje) {
    System.out.println("Completed");
  }
  @Override
  void printJobFailed(PrintJobEvent pje) {
    System.out.println("Failed");
  }
  @Override
  void printJobNoMoreEvents(PrintJobEvent pje) {
    System.out.println("No more events");
  }
  @Override
  void printJobRequiresAttention(PrintJobEvent pje) {
    System.out.println("Check printer");
  }
});

before calling print() and see what gets outputed to the console