Printer Tray Selection in Java (win and linux)

Marco Molteni

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I published on github a small project (MediaTrayTest) that allows to interactively list the printer trays and ask to the printer to print an empty page using the selected tray.

As many of you know, this should work without any problem for Windows platforms but it’s possible that it won’t work using Linux / Unix platforms. It’s a known issue of the JRE, you can read more at the end of the article).

Here what happen when you execute the Main.class (you have to run it using java Main in the Terminal/Console, it cannot work with an ide):

Write the printer name or press enter for [Network_printer_example] 
 
IPP Printer : Network_printer_example 
0 : Auto - sun.print.CustomMediaTray 
1 : Stack Bypass - sun.print.CustomMediaTray 
2 : Drawer 1 - sun.print.CustomMediaTray 
3 : Drawer 2 - sun.print.CustomMediaTray 
4 : Drawer 3 - sun.print.CustomMediaTray 
5 : Drawer 4 - sun.print.CustomMediaTray 
6 : Side Paper Deck - sun.print.CustomMediaTray 
Select tray target id : 
3 
Selected tray : Drawer 2 
Do you want to print a test page? [y/n] 
y 
Trying to print an empty page on : Drawer 2</pre>

The code is self explaining and commented:

 public static void main(String args[]) { 
 
    // get default printer 
    PrintService defaultPrintService = PrintServiceLookup.lookupDefaultPrintService(); 
 
    // suggest the use of the default printer 
    System.out.println("Write the printer name or press enter for [" + defaultPrintService.getName() + "]"); 
 
    Console console = System.console(); 
 
    // read from the console the name of the printer 
    String printerName = console.readLine(); 
 
    // if there is no input, use the default printer 
    if (printerName == null || printerName.equals("")) { 
        printerName = defaultPrintService.getName(); 
    } 
 
    // the printer is selected 
    AttributeSet aset = new HashAttributeSet(); 
    aset.add(new PrinterName(printerName, null)); 
 
    // selection of all print services 
    PrintService[] services = PrintServiceLookup.lookupPrintServices(null, aset); 
    // we store all the tray in a hashmap 
    Map&lt;Integer, Media&gt; trayMap = new HashMap&lt;Integer, Media&gt;(10); 
 
    // we chose something compatible with the printable interface 
    DocFlavor flavor = DocFlavor.SERVICE_FORMATTED.PRINTABLE; 
 
    for (PrintService service : services) { 
        System.out.println(service); 
 
        // we retrieve all the supported attributes of type Media 
        // we can receive MediaTray, MediaSizeName, ... 
        Object o = service.getSupportedAttributeValues(Media.class, flavor, null); 
        if (o != null && o.getClass().isArray()) { 
            for (Media media : (Media[]) o) { 
                // we collect the MediaTray available 
                if (media instanceof MediaTray) { 
                    System.out.println(media.getValue() + " : " + media + " - " + media.getClass().getName()); 
                    trayMap.put(media.getValue(), media); 
                } 
            } 
        } 
    } 
 
    System.out.println("Select tray target id : "); 
    String mediaId = console.readLine(); 
 
    MediaTray selectedTray = (MediaTray) trayMap.get(Integer.valueOf(mediaId)); 
    System.out.println("Selected tray : " + selectedTray.toString()); 
 
    System.out.println("Do you want to print a test page? [y/n]"); 
    String printPage = console.readLine(); 
    if (printPage.equalsIgnoreCase("Y")) { 
 
        // we have to add the MediaTray selected as attribute 
        PrintRequestAttributeSet attributes = new HashPrintRequestAttributeSet(); 
        attributes.add(selectedTray); 
 
        // we create the printer job, it print a specified document with a set of job attributes 
        DocPrintJob job = services[0].createPrintJob(); 
 
        try { 
            System.out.println("Trying to print an empty page on : " + selectedTray.toString()); 
            // we create a document that implements the printable interface 
            Doc doc = new SimpleDoc(new PrintableDemo(), DocFlavor.SERVICE_FORMATTED.PRINTABLE, null); 
 
            // we print using the selected attributes (paper tray) 
            job.print(doc, attributes); 
 
        } catch (Exception e) { 
            e.printStackTrace(); 
        } 
    } 
} 
 
static class PrintableDemo implements Printable { 
 
    @Override 
    public int print(Graphics pg, PageFormat pf, int pageNum) { 
        // we print an empty page 
        if (pageNum &gt;= 1) 
            return Printable.NO_SUCH_PAGE; 
        pg.drawString("", 10, 10); 
        return Printable.PAGE_EXISTS; 
    } 
}

Linux / Unix / Mac?

The paper tray selection doesn’t work well (or at all) on Unix platforms.

You can find the following open bugs for the selection of the paper tray with Linux:

https://bugs.openjdk.java.net/browse/JDK-6357887

https://bugs.openjdk.java.net/browse/JDK-7107175

https://bugs.openjdk.java.net/browse/JDK-7107138

We are working to find a solution and override some JRE (rt.jar) classes to use the paper tray in Linux/Unix.

The problem is in sun.print.PSPrinterJob.java. The print attributes passed are not read at all.

java.print.UnixPrintJob.java read the attributes and it transforms them in a cups string in the print method (there are some errors in this method too), this can give you an idea about how correct PSPrinterJob.

Adding this code to PSPrinterJob solved our problem.

if (super.attributes != null){ 
Attribute[]attrs = super.attributes.toArray(); 
CustomMediaTray customTray = null; 
for (int i=0; i&lt;attrs.length; i++) { 
    Attribute attr = attrs[i]; 
    Class category = attr.getCategory(); 
 
    if (category == Media.class) { 
        if (attr instanceof CustomMediaTray) { 
            customTray = (CustomMediaTray)attr; 
            String choice = customTray.getChoiceName(); 
            if (choice != null) { 
                if (mOptions == null){ 
                    mOptions = ""; 
                } 
            mOptions += " media="+choice; 
        } 
    } 
  }