java.lang.NullPointerException calling MailMerge.executeWithRegions

onof80 · December 23, 2021, 7:43am

Hello,
I’m using aspose.words to fill a document with mailmerge.
It works perfectly except in a single machine running linux on PowerPc using openjdk. I get this error randomly but very often:

java.lang.NullPointerException
	at com.aspose.words.zzZFG.flush(Unknown Source)
	at com.aspose.words.zzYUG.zza(Unknown Source)
	at com.aspose.words.zz8R.zzG(Unknown Source)
	at com.aspose.words.zz8S.zzZGE(Unknown Source)
	at com.aspose.words.zzZ5T.zzYTl(Unknown Source)
	at com.aspose.words.Document.updatePageLayout(Unknown Source)
	at com.aspose.words.zz3U.zzZAp(Unknown Source)
	at com.aspose.words.zz3V.zzFi(Unknown Source)
	at com.aspose.words.zz0S.zzY5(Unknown Source)
	at com.aspose.words.zz0S.zzZuv(Unknown Source)
	at com.aspose.words.zzZHW.zzZ7V(Unknown Source)
	at com.aspose.words.zzZHW.zzZ(Unknown Source)
	at com.aspose.words.MailMerge.zzZ(Unknown Source)
	at com.aspose.words.MailMerge.executeWithRegions(Unknown Source)

Which can be the root cause?
The docx to fill is small: about 30Kb. My steps are very basic:

Documet pDOCUMENT = new Document(w_FULL_PATH_TEMPLATE);
DataSet pDataSet = fillDataSet();
pDOCUMENT.getMailMerge().setFieldMergingCallback( new HandleMergeImageFieldFromBlob() );
pDOCUMENT.getMailMerge().executeWithRegions(pDataSet);

I add that:

The problem occurs if I comment out the .setFieldMergingCallback line as well
Once the problem occurs I have to restart the web application in order to make the executeWithRegions call. Just as the errors put the library in a “dirty” state

alexey.noskov · December 23, 2021, 11:38am

@onof80 Could you please attach your template and sample data that will allow us to reproduce the issue? We will investigate the problem and provide you more information.

onof80 · December 23, 2021, 11:45am

Hi alexy,
I’m attaching one of the templates. On that machine I get the error also with an empty dataset:

DataSet pDataSet = new DataSet();

hira_8108_procedure.docx (32.8 KB)

onof80 · December 23, 2021, 1:53pm

I add that the same problem occurs also calling updateFields (insteand of calling executeWithMerge):

||at com.aspose.words.zzZFG.flush(Unknown Source)|
||at com.aspose.words.zzYUG.zza(Unknown Source)|
||at com.aspose.words.zz8R.zzG(Unknown Source)|
||at com.aspose.words.zz8S.zzZGE(Unknown Source)|
||at com.aspose.words.zzZ5T.zzYTl(Unknown Source)|
||at com.aspose.words.Document.updatePageLayout(Unknown Source)|
||at com.aspose.words.zz3U.zzZAp(Unknown Source)|
||at com.aspose.words.zz3V.zzFi(Unknown Source)|
||at com.aspose.words.zz0S.zzY5(Unknown Source)|
||at com.aspose.words.zz0S.zzZ(Unknown Source)|
||at com.aspose.words.zz0S.zzZ3(Unknown Source)|
||at com.aspose.words.Range.updateFields(Unknown Source)|
||at com.aspose.words.Document.updateFields(Unknown Source)|

alexey.noskov · December 23, 2021, 4:59pm

@onof80 Which version of Aspose.Words do you use? I have checked your scenario on my side using the latest 21.12 version of Aspose.Words for Java and the problem is not reproducible.

onof80 · December 23, 2021, 5:03pm

We are using the version 19.11. Has it been fixed in later versions ?

onof80 · December 23, 2021, 5:38pm

Anyway I get the same error with the 21.12 version, with slight different stack trace:

java.lang.NullPointerException
	at com.aspose.words.zzYvM.flush(Unknown Source)
	at com.aspose.words.zzWY6.zzZcq(Unknown Source)
	at com.aspose.words.zzZ9A.zzZqK(Unknown Source)
	at com.aspose.words.zzZ9A.zzZo9(Unknown Source)
	at com.aspose.words.zzXc9.zzZaS(Unknown Source)
	at com.aspose.words.zzXF7.zzYzS(Unknown Source)
	at com.aspose.words.zzWY6.zzZcq(Unknown Source)
	at com.aspose.words.zzWvZ.zzYzS(Unknown Source)
	at com.aspose.words.zzYfF.zzZp8(Unknown Source)
	at com.aspose.words.zzYfF.zzUH(Unknown Source)
	at com.aspose.words.zzZ9c.zzYVX(Unknown Source)
	at com.aspose.words.Document.updatePageLayout(Unknown Source)

alexey.noskov · December 23, 2021, 6:16pm

@onof80 I tried with your template and the following code:

Document doc = new Document("C:\\Temp\\in.docx");
DataSet pDataSet = new DataSet();
doc.getMailMerge().executeWithRegions(pDataSet);
doc.save("C:\\Temp\\out.pdf");

and the problem is not reproducible on my side.

onof80 · December 24, 2021, 10:28am

It doesn’t occur systematically, but after a number of execution.
I’m now running just the following code, similar to yours, in a web application servlet in tomcat 9, and I get the error after a random number of calls.
I wonder why the error occurs in the flush function. Is it involved in cleaning the java.io.tmpdir files ?

Document doc = new Document(TPLPATH);
DataSet pDataSet = new DataSet();
doLog("Executing.. ");
doc.getMailMerge().executeWithRegions(pDataSet);
doc.save(SAFEFOLDER);
doLog("Saved in " + SAFEFOLDER);

The error is:

java.lang.NullPointerException
	at com.aspose.words.zzYvM.flush(Unknown Source)
	at com.aspose.words.zzWY6.zzZcq(Unknown Source)
	at com.aspose.words.zzZ9A.zzZqK(Unknown Source)
	at com.aspose.words.zzZ9A.zzZo9(Unknown Source)
	at com.aspose.words.zzXc9.zzZaS(Unknown Source)
	at com.aspose.words.zzXF7.zzYzS(Unknown Source)
	at com.aspose.words.zzWY6.zzZcq(Unknown Source)
	at com.aspose.words.zzWvZ.zzYzS(Unknown Source)
	at com.aspose.words.zzYfF.zzZp8(Unknown Source)
	at com.aspose.words.zzYfF.zzUH(Unknown Source)
	at com.aspose.words.zzZ9c.zzYVX(Unknown Source)
	at com.aspose.words.Document.updatePageLayout(Unknown Source)
	at com.aspose.words.zzWlQ.zzVUt(Unknown Source)
	at com.aspose.words.zzhL.zzYuK(Unknown Source)
	at com.aspose.words.zzWU9.zza9(Unknown Source)
	at com.aspose.words.zzWU9.zzZqK(Unknown Source)
	at com.aspose.words.zzWU9.zzZp8(Unknown Source)
	at com.aspose.words.zzWU9.zz8Y(Unknown Source)
	at com.aspose.words.Document.zzWBq(Unknown Source)
	at com.aspose.words.Document.zzZqK(Unknown Source)
	at com.aspose.words.Document.zzZp8(Unknown Source)
	at com.aspose.words.Document.save(Unknown Source)
	at com.aspose.words.Document.save(Unknown Source)
	at hira_ftestasposeR.Page_1(hira_ftestasposeR.java:136)

alexey.noskov · December 26, 2021, 5:49am

@onof80 Thank you for additional information. I will consult with our Java developers and provide you more information.

onof80 · December 28, 2021, 9:46am

I have to rectify: on that machine we are using Linux for ppc64 running RedHat openjdk 1.8.0_302

alexey.noskov · December 28, 2021, 1:08pm

@onof80 Thank you for additional information. I have logged the issue as WORDSJAVA-2676. Our Java developers will deeply investigate the problem. Once analysis of the issue is done, we will provide you more information.

alexey.noskov · August 22, 2022, 5:28am

@onof80 We have completed analyzing the issue. It looks like a random issue in multithread environment + saving document to the single file: doc.save("C:\\Temp\\out.pdf"); + Exception in a flush() method. Could you please try incrementing the output file name for every saving.

onof80 · November 23, 2022, 9:23am

Hi alexey,
thank you for your answer but I tried and it does not work.
The only solution we found so far is to move the webapp in a x86 environment.

alexey.noskov · November 23, 2022, 9:29am

@onof80 The issue has been closed as not a bug. This is a random issue in multithread environment + saving document to the single file: doc.save("C:\\Temp\\out.pdf"); + Exception in a flush() method.
Please try incrementing the output file name for every saving to avoid the problem.

onof80 · March 10, 2023, 8:01am

Hi alexey,
I tried but it didn’t work. I tried with a random generated file name as well.
The problem occurs to us only on powerpc architecure.
We arrived to state that we can’t use aspose words on powerpc.

And I add that the same problem, on powerpc, occurs also calling executeWithRegions, not only saving:

at com.aspose.words.zzXIL.flush(Unknown Source)
at com.aspose.words.zzV3.zzYFC(Unknown Source)
at com.aspose.words.zzVWV.zzYhn(Unknown Source)
at com.aspose.words.zzVWV.zzKW(Unknown Source)
at com.aspose.words.zzYH7.zzXUp(Unknown Source)
at com.aspose.words.zzW7K.zzZv8(Unknown Source)
at com.aspose.words.zzV3.zzYFC(Unknown Source)
at com.aspose.words.zzVSK.zzZv8(Unknown Source)
at com.aspose.words.zzYz3.zzXWH(Unknown Source)
at com.aspose.words.zzYz3.zzWxz(Unknown Source)
at com.aspose.words.zzW0z.zzW5v(Unknown Source)
at com.aspose.words.Document.updatePageLayout(Unknown Source)
at com.aspose.words.zzZ9b.zzYxD(Unknown Source)
at com.aspose.words.zzYws.zzVVw(Unknown Source)
at com.aspose.words.zzYHL.zzWeP(Unknown Source)
at com.aspose.words.zzYHL.zzZiW(Unknown Source)
at com.aspose.words.zzYMo.zzZYi(Unknown Source)
at com.aspose.words.zzYMo.zzXWH(Unknown Source)
at com.aspose.words.MailMerge.zzXWH(Unknown Source)
at com.aspose.words.MailMerge.executeWithRegions(Unknown Source)

alexey.noskov · March 11, 2023, 6:28am

@onof80 Thank you for additional information. We will take a look at the issue once again and let you know if we find something.

alexey.maslov · March 13, 2023, 8:27am

@onof80,

This issue has been logged as WORDSJAVA-2833. We will keep you posted and will let you know as soon as the issue is resolved. Please accept our apologies for the inconvenience.