NullPointerException when printing to Host (IP:Port)

[Matteo Feltrin]

I'm trying to print to a printer through it's IP and Port, but when i launch the print it throw a NullPointerException.

Setting all the "null" parameters inside options property doesn't help neither

OS: Windows
QZTray Version: 2.2.2

If it can help, looking up at code, in PrintPDF.print() :177 method, job :184 is trying to be assigned the same service as output, but output.printer is NULL since the property is never assigned without having "name" in the configuration.

[DEBUG] 2023-10-20T12:27:04,707 @ qz.ws.PrintSocketClient:115
Message: {"call":"print","params":{"printer":{"host":"192.168.39.189","port":9100},"options":{"bounds":null,"colorType":"color","copies":1,"density":0,"duplex":false,"fallbackDensity":null,"interpolation":"bicubic","jobName":null,"legacy":false,"margins":0,"orientation":"portrait","paperThickness":null,"printerTray":null,"rasterize":"false","rotation":0,"scaleContent":"false","size":null,"units":"in","forceRaw":false,"encoding":null,"spool":null},"data":[{"type":"pdf","format":"base64","data":"A VERY LONG BASE64 ENCODED PDF FILE THAT I REMOVED FOR READING PURPORSES","timestamp":1697797624644,"uid":"qwpuev","position":{"x":1720,"y":696},"signAlgorithm":"SHA512"}
[TRACE] 2023-10-20T12:27:04,713 @ qz.ws.PrintSocketClient:160
Valid signature from company
[TRACE] 2023-10-20T12:27:04,714 @ qz.utils.PrintingUtilities:135
Waiting for processor, 0/16 already in use
[DEBUG] 2023-10-20T12:27:04,716 @ qz.utils.PrintingUtilities:195
Using qz.printer.action.PrintPDF to print
[WARN] 2023-10-20T12:27:04,716 @ qz.printer.PrintOptions:17
Cannot read null as a double for fallbackDensity, using default
[DEBUG] 2023-10-20T12:27:04,718 @ qz.printer.action.PrintPDF:162
Parsed 2 files for printing
[ERROR] 2023-10-20T12:27:04,718 @ qz.utils.PrintingUtilities:212
Failed to print
java.lang.NullPointerException: null
at qz.printer.PrintOutput.getPrintService(PrintOutput.java:61) ~[qz-tray.jar:?]
at qz.printer.action.PrintPDF.print(PrintPDF.java:183) ~[qz-tray.jar:?]
at qz.utils.PrintingUtilities.processPrintRequest(PrintingUtilities.java:202) ~[qz-tray.jar:?]
at qz.ws.PrintSocketClient.processMessage(PrintSocketClient.java:299) ~[qz-tray.jar:?]
at qz.ws.PrintSocketClient.onMessage(PrintSocketClient.java:165) ~[qz-tray.jar:?]
at jdk.internal.reflect.GeneratedMethodAccessor5.invoke(Unknown Source) ~[?:?]
at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:?]
at java.lang.reflect.Method.invoke(Unknown Source) ~[?:?]
at org.eclipse.jetty.websocket.common.events.annotated.CallableMethod.call(CallableMethod.java:70) ~[qz-tray.jar:?]
at org.eclipse.jetty.websocket.common.events.annotated.OptionalSessionCallableMethod.call(OptionalSessionCallableMethod.java:68) ~[qz-tray.jar:?]
at org.eclipse.jetty.websocket.common.events.JettyAnnotatedEventDriver.lambda$onTextFrame$1(JettyAnnotatedEventDriver.java:270) ~[qz-tray.jar:?]
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:883) ~[qz-tray.jar:?]
at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1034) ~[qz-tray.jar:?]
at java.lang.Thread.run(Unknown Source) ~[?:?]
[TRACE] 2023-10-20T12:27:04,718 @ qz.utils.PrintingUtilities:179
Returning processor back to pool

Thanks for any help

[Tres Finocchiaro]

Hi,

This is a duplicate of #1054. In short, print to host was never intended for Pixel API prints, just Raw API prints.

If your printer supports a PDF stream sent to it (many do) you could send it in Raw Base64 format, but you will lose any control over formatting (orientation, margins, size, duplex, etc).

We may eventually add driverless + printer discovery to the API, but if we do, this is a ways out, we'd need to implement some form of AirPrint or IPP Everywhere, or both, which is a considerable undertaking.

For now, I recommend mapping the printer locally if you need to use Pixel.

[Matteo Feltrin]

Ok thank you for the explanation, I had seen the issue you linked but it was not clear to me the reason, now it is!

[Tres Finocchiaro]

Closed as duplicate of #1054