问题
The following 4 questions didn't help, therefore this isn't a duplicate:
ONE, TWO, THREE, FOUR
I need to find a way to discover if the Printer that my system reports is available to print or not.
Printer page:
In the picture, the printer "THERMAL" is available to print, but "HPRT PPTII-A(USB)" isn't available to print. The System shows me that, by making the non-available printer shaded
Using the following code, I'm able to find all the printers in the system
public static List<String> getAvailablePrinters() {
DocFlavor flavor = DocFlavor.SERVICE_FORMATTED.PRINTABLE;
PrintRequestAttributeSet aset = new HashPrintRequestAttributeSet();
PrintService[] services = PrintServiceLookup.lookupPrintServices(flavor, aset);
ArrayList<String> names = new ArrayList<String>();
for (PrintService p : services) {
Attribute at = p.getAttribute(PrinterIsAcceptingJobs.class);
if (at == PrinterIsAcceptingJobs.ACCEPTING_JOBS) {
names.add(p.getName());
}
}
return names;
}
output:
[HPRT PPTII-A(USB), THERMAL]
The problem is: This code shows all the printers that the system have ever installed.
What I need: This list should contain only the really available printers to print. In this example, it should only show "THERMAL", and not show "HPRT PPTII-A(USB)"
How can this be achieved?
回答1:
If it is okay that the solution is Windows-specific, try WMI4Java. Here is my situation:
As you can see, my default printer "Kyocera Mita FS-1010" is inactive (greyed out) because I simply switched it off.
Now add this to your Maven POM:
<dependency>
<groupId>com.profesorfalken</groupId>
<artifactId>WMI4Java</artifactId>
<version>1.4.2</version>
</dependency>
Then it is as easy as this to list all printers with their respective status:
package de.scrum_master.app;
import com.profesorfalken.wmi4java.WMI4Java;
import com.profesorfalken.wmi4java.WMIClass;
import java.util.Arrays;
public class Printer {
public static void main(String[] args) {
System.out.println(
WMI4Java
.get()
.properties(Arrays.asList("Name", "WorkOffline"))
.getRawWMIObjectOutput(WMIClass.WIN32_PRINTER)
);
}
}
The console log looks as follows:
Name : WEB.DE Club SmartFax
WorkOffline : False
Name : Send To OneNote 2016
WorkOffline : False
Name : Microsoft XPS Document Writer
WorkOffline : False
Name : Microsoft Print to PDF
WorkOffline : False
Name : Kyocera Mita FS-1010 KX
WorkOffline : True
Name : FreePDF
WorkOffline : False
Name : FinePrint
WorkOffline : False
Name : Fax
WorkOffline : False
Please note that WorkOffline is True for the Kyocera printer. Probably this is what you wanted to find out.
And now a little modification in order to filter the printers list so as to only show active printers:
WMI4Java
.get()
.properties(Arrays.asList("Name", "WorkOffline"))
.filters(Arrays.asList("$_.WorkOffline -eq 0"))
.getRawWMIObjectOutput(WMIClass.WIN32_PRINTER)
Update: I was asked how to get a list of active printer names. Well, this is not so easy due to a shortcoming in WMI4Java for which I have just filed a pull request. It causes us to parse and filter the raw WMI output, but the code is still pretty straightforward:
package de.scrum_master.app;
import com.profesorfalken.wmi4java.WMI4Java;
import com.profesorfalken.wmi4java.WMIClass;
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;
public class Printer {
public static void main(String[] args) {
String rawOutput = WMI4Java
.get()
.properties(Arrays.asList("Name", "WorkOffline"))
.filters(Arrays.asList("$_.WorkOffline -eq 0"))
.getRawWMIObjectOutput(WMIClass.WIN32_PRINTER);
List<String> printers = Arrays.stream(rawOutput.split("(\r?\n)"))
.filter(line -> line.startsWith("Name"))
.map(line -> line.replaceFirst(".* : ", ""))
.sorted()
.collect(Collectors.toList());
System.out.println(printers);
}
}
The console output looks like this:
[Fax, FinePrint, FreePDF, Microsoft Print to PDF, Microsoft XPS Document Writer, Send To OneNote 2016, WEB.DE Club SmartFax]
回答2:
Windows solution, query WMI "win32_printer" object:
public static void main(String[] args) {
// select printer that have state = 0 and status = 3, which indicates that printer can print
ProcessBuilder builder = new ProcessBuilder("powershell.exe", "get-wmiobject -class win32_printer | Select-Object Name, PrinterState, PrinterStatus | where {$_.PrinterState -eq 0 -And $_.PrinterStatus -eq 3}");
String fullStatus = null;
Process reg;
builder.redirectErrorStream(true);
try {
reg = builder.start();
fullStatus = getStringFromInputStream(reg.getInputStream());
reg.destroy();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
System.out.print(fullStatus);
}
For converting InputStream to String look here: comprehensive StackOverflow answer, or you can simply use:
public static String getStringFromInputStream(InputStream is) {
ByteArrayOutputStream result = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int length;
try {
while ((length = is.read(buffer)) != -1) {
result.write(buffer, 0, length);
}
} catch (IOException e1) {
e1.printStackTrace();
}
// StandardCharsets.UTF_8.name() > JDK 7
String finalResult = "";
try {
finalResult = result.toString("UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return finalResult;
}
Output:
Name PrinterState PrinterStatus
---- ------------ -------------
Foxit Reader PDF Printer 0 3
Send to OneNote 2010 0 3
Microsoft XPS Document Writer 0 3
Microsoft Print to PDF 0 3
Fax 0 3
\\192.168.50.192\POS_PRINTER 0 3
As you can see, you now have all the printers that are in working state in the string.
You can use your existing method (getAvailablePrinters()) and e.g. add something like this:
ArrayList<String> workingPrinter = new ArrayList<String>();
System.out.println("Working printers:");
for(String printer : getAvailablePrinters()){
if(fullStatus.contains("\n" + printer + " ")){ // add a newline character before the printer name and space after so that it catches exact name
workingPrinter.add(printer);
System.out.println(printer);
}
}
And now you will have a nice list of working printers.
Console output:
Working printers:
Send to OneNote 2010
Foxit Reader PDF Printer
Microsoft XPS Document Writer
Microsoft Print to PDF
Fax
\\192.168.50.192\POS_PRINTER
Of course you have to be careful with the names with this approach - e.g. if "POS_PRINTER" is in all printers but not in working printers list, it could still get added to the workingPrinters list, if there is a working printer named "POS_PRINTER 1" as that name contains "\nPOS_PRINTER " string...
来源：https://stackoverflow.com/questions/41775357/finding-if-printer-is-online-and-ready-to-print