Since PrintServiceLookup.looupPrintServices is returning a printer service even 
when IPP printer is not accessible. Attributes we want get for the related 
print service should not be null(like print data formats/DocFlavors). Spec also 
mentions the same as pointed by Prasanta(returns at least one Doc Flavor).

 

By doing this we will avoid NPE. Also having user to select another printer 
from dialog(if selected printer is not available) is better than throwing NPE. 
Present changes are fine.

 

Thanks,

Jay

 

From: Jayathirth D V 
Sent: Thursday, December 10, 2015 5:10 PM
To: Prasanta Sadhukhan
Cc: 2d-dev@openjdk.java.net; Rajeev Chamyal; Philip Race; Sergey Bylokhov
Subject: RE: [OpenJDK 2D-Dev] [9] RFR: Test 
closed/javax/print/attribute/Services_getDocFl.java fails with 
NullpointerException (8040139)

 

Fix looks good to me.

 

From: prasanta sadhukhan 
Sent: Thursday, December 10, 2015 1:40 PM
To: Philip Race; Sergey Bylokhov
Cc: HYPERLINK "mailto:2d-dev@openjdk.java.net"2d-dev@openjdk.java.net; Rajeev 
Chamyal
Subject: Re: [OpenJDK 2D-Dev] [9] RFR: Test 
closed/javax/print/attribute/Services_getDocFl.java fails with 
NullpointerException (8040139)

 

Thanks Phil for your approval.
I have opened up the closed test also. Here's the updated webrev:
http://cr.openjdk.java.net/~jdv/prasanta/8040139/webrev.01/

Sergey, would be able to +1 this?

Also, in addition to what Phil mentioned that it is expensive to enumerate for 
available printers in the network, we simply go for this fix to return an array 
with one entry in DocFlavor 
if the printer(s) already registered/added are not available and when user goes 
to print through the dialog, they would see the printer is "stopped" or "unable 
to connect" instead of a NPE.

Regards
Prasanta

On 12/10/2015 12:17 PM, Philip Race wrote:

I had to hunt for this since you did not include the bug number in the subject 
line.
The fix is fine although you really should explain to people why this approach 
is
taken rather than ignoring the printer. i.e it is prohibitively expensive to use
"lpstat -p" when simply enumerating available printers.

And I think the closed test can be opened. I don't see any problem with it and
it was developed internally.

-phil.


On 12/2/15, 2:35 AM, prasanta sadhukhan wrote: 

Hi All,

Please review a fix for jdk9 
Bug: https://bugs.openjdk.java.net/browse/JDK-8040139
webrev: HYPERLINK 
"http://cr.openjdk.java.net/%7Ejdv/prasanta/8040139/webrev.00/"http://cr.openjdk.java.net/~jdv/prasanta/8040139/webrev.00/

It seems if a IPP printer is not accessible, 
PrintServiceLookup.lookupPrintServices will return the printer service but 
PrintService.getSupportedDocFlavors() will return null
since for the printer there is no way to answer the questions as to what it 
supports and if after that someone tries to access flavors.length it will cause 
NPE.
However, as per spec
https://docs.oracle.com/javase/8/docs/api/index.html?javax/print/PrintService.html
it clearly says,     

Returns:

Array of supported doc flavors, should have at least one element.


so returning null is a violation of spec. 
I have added a fix to return DocService.SERVICE_FORMATTED flavor for such case.

Could not add a reg testcase as it will need an inaccessible printer.

Regards
Prasanta

 

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