Extended printer information in Java

Question

I'm trying to get some information about the printers on my system.
On Windows and Linux, with this code, only the PrinterName attribute is filled:

PrintService[] printServices = PrintServiceLookup.lookupPrintServices(null,null);
for( PrintService printService : printServices ) {
    log.info("Found print service: "+printService);
    log.info(printService.getAttribute(PrinterName.class));
    log.info(printService.getAttribute(PrinterLocation.class));
    log.info(printService.getAttribute(PrinterMakeAndModel.class));
    log.info(printService.getAttribute(PrinterMessageFromOperator.class));
    log.info(printService.getAttribute(PrinterMoreInfo.class));
    log.info(printService.getAttribute(PrinterMoreInfoManufacturer.class));
    log.info(printService.getAttribute(PrinterState.class));
    log.info(printService.getAttribute(PrinterStateReasons.class));
    log.info(printService.getAttribute(PrinterURI.class));
}

After using the toArray() function on it...

log.info("Found print service: "+printService);
for( Attribute a : printService.getAttributes().toArray() ) {
    log.info("* "+a.getName()+": "+a);
}

...this is the result:

Found print service: Win32 Printer : Brother MFC-9420CN BR-Script3
* color-supported: supported
* printer-name: Brother MFC-9420CN BR-Script3
* printer-is-accepting-jobs: accepting-jobs
* queued-job-count: 0

How do I get more information, like the printer comment?

Answer 1

There are other PrintServiceAttribute implementations, but if you want to fetch more...

This is a dirty code only, you can also fetch unsupported values for doc flavor:

PrintService[] printServices =
        PrintServiceLookup.lookupPrintServices(null, null); //get printers

for (PrintService printService : printServices) {
    System.out.println("Found print service: " + printService);

    Set<Attribute> attribSet = new LinkedHashSet<Attribute>();

    Class<? extends Attribute>[] supportedAttributeCategories = (Class<? extends Attribute>[]) printService.getSupportedAttributeCategories();

    for (Class<? extends Attribute> category : supportedAttributeCategories) {
        DocFlavor[] flavors = printService.getSupportedDocFlavors();
        for (DocFlavor flavor : flavors) {
            Object supportedAttributeValues = printService.getSupportedAttributeValues(category, flavor, printService.getAttributes());
            if (supportedAttributeValues instanceof Attribute) {
                Attribute attr = (Attribute) supportedAttributeValues;
                attribSet.add(attr);
            } else if (supportedAttributeValues != null) {
                Attribute[] attrs = (Attribute[]) supportedAttributeValues;
                for (Attribute attr : attrs) {
                    attribSet.add(attr);
                }
            }
        }
    }

    for (Attribute attr : attribSet) {
        System.out.println(attr.getName());

        System.out.println(printService.getDefaultAttributeValue(attr.getCategory()));
    }
}

Note: You may see repeated values, but they can be filtered.

Answer 2

Below is a modular, more understandable version of the code provided in hGx's answer:

public static Set<Attribute> getAttributes(PrintService printer) {
    Set<Attribute> set = new LinkedHashSet<Attribute>();

    //get the supported docflavors, categories and attributes
    Class<? extends Attribute>[] categories = (Class<? extends Attribute>[]) printer.getSupportedAttributeCategories();
    DocFlavor[] flavors = printer.getSupportedDocFlavors();
    AttributeSet attributes = printer.getAttributes();

    //get all the avaliable attributes
    for (Class<? extends Attribute> category : categories) {
        for (DocFlavor flavor : flavors) {
            //get the value
            Object value = printer.getSupportedAttributeValues(category, flavor, attributes);

            //check if it's something
            if (value != null) {
                //if it's a SINGLE attribute...
                if (value instanceof Attribute)
                    set.add((Attribute) value); //...then add it

                //if it's a SET of attributes...
                else if (value instanceof Attribute[])
                    set.addAll(Arrays.asList((Attribute[]) value)); //...then add its childs
            }
        }
    }

    return set;
}

This will return a Set with the Attributes discovered of the given printer.
Note: Duplicate values may appear. They can be filtered, however.