在Windows上从Java Applet静默下载和打印PDF文档

Question

I want to download a PDF and print it. I want to do this completely silently with no dialogue boxes displayed to the user. I am currently using a self-signed applet (will sign using an authority when we deploy). It works as desired on Linux and OS X, but not Windows. On Windows it shows the user a dialogue box to save the file (of type .xps). After the file saves it is sent silently to the printer, so my issue is currently how to get the document to save silently without the user seeing the dialogue. Code below. I'm using Apache PDFBox. I've read I may need to use PrivilegedAction, but I don't see why as the issue isn't that I can't download a file, but that I can't do so silently.

/**
 * Print Applet
 * Author: kareem
 * Date: 12-02-20
 * Time: 10:57 AM
 */

import java.applet.Applet;
import java.awt.print.PrinterException;
import java.io.*;
import java.net.*;
import org.apache.pdfbox.pdmodel.PDDocument;
import netscape.javascript.*;

public class PrintApplet extends Applet {
    public void init() {
        String callbackURL = this.getParameter("callbackurl");
        String fileToPrint = this.getParameter("file");
        String successCallback = this.getParameter("successcallback");
        String failureCallback = this.getParameter("failurecallback");
        String published = this.getParameter("published");
        JSObject window = JSObject.getWindow(this);
        if (fileToPrint == null || callbackURL == null) {
            window.call(failureCallback, new String[] { "Missing required parameters." });
        } else {
            try {
                URL printURL;
                printURL = new URL(fileToPrint);
                PDDocument doc;
                doc = PDDocument.load(printURL);
                doc.silentPrint();
                try {
                    URL updateOrderUrl = new URL(callbackURL);
                    HttpURLConnection updateOrderHTTP = (HttpURLConnection) updateOrderUrl.openConnection();
                    updateOrderHTTP.setDoOutput(true);
                    updateOrderHTTP.setDoInput(true);
                    updateOrderHTTP.setRequestMethod("PUT");
                    String updateOrderData = URLEncoder.encode("printed", "UTF-8") + "=" + URLEncoder.encode(String.valueOf(System.currentTimeMillis()/1000) + "&" + URLEncoder.encode("published", "UTF-8") + "=" + URLEncoder.encode(published, "UTF-8"), "UTF-8");
                    OutputStreamWriter out = new OutputStreamWriter(updateOrderHTTP.getOutputStream());
                    out.write(updateOrderData);
                    updateOrderHTTP.getInputStream();
                    out.close();
                    window.call(successCallback, null);
                } catch(Exception e) {
                    window.call(failureCallback, new String[] { "Server callback failed." });
                }
            } catch (MalformedURLException e) {
                System.out.println("Malformed URL Exception: " + e.getMessage());
                window.call(failureCallback, new String[] { "Invalid print file URL." });
            } catch (IOException e) {
                System.out.println("IO Exception: " + e.getMessage());
                window.call(failureCallback, new String[] { "Print file could not be loaded." });
            } catch(PrinterException e) {
                System.out.println("Printer exception: " + e.getMessage());
                window.call(failureCallback, new String[] { e.getMessage() });
            }
        }
    }
}

Answer 1

I had the same problem, and found the answer above in the comments: Our default printer was set to Microsoft XPS document writer.

I am mentioning it here incase anyone glosses over the comments and thinks there is no answer.

Please 1up yms's comment instead of this answer.