Incorrect usage of StringBuilder in TransactionAwareBufferedWriter

[pstowski]

Method public void write(String str, int off, int len) of org.springframework.batch.support.transaction.TransactionAwareBufferedWriter
seems to be using java.lang.StringBuilder in wrong way:
according to documentation StringBuilder.append(java.lang.CharSequence,int,int)
third parameter is not length (as in append(char[],int,int)) but the end index of the subsequence.
this causes invalid parts of string are being appended and causes java.lang.IndexOutOfBoundsException when off > len

Using: spring-batch-infrastructure 4.2.4.RELEASE

[mrickly]

We ran into that bug too, via StaxEventItemWriter with the default transactional = true.

[mprcptbl]

Same problem, using StaxEventItemWriter.

[nfjcore]

I would like to start contributing to this project. This seems like a good issue to work on. Can someone provide steps how to reproduce the problem?

[fmbenhassine]

@nfjcore You are welcome! Please check our Contributor Guidelines. I did not work on this issue yet to validate the bug report, but the best way to start is by trying to create a failing test that reproduces the problem. I would be happy to review any PR that contains such a test with a corresponding fix. Let me know if you want me to assign this issue to you.

[niels5789]

@benas Thank you for the reply. I've read the Contributor Guidelines. And like the issue to be assigned to me.

[mprcptbl]

@niels5789 I don't have a simple testcase for this right now but you should be able to reproduce this by generating XML output using StaxEventItemWriter with the default transactional=true (e.g. create a simple Spring Batch job to do this) when your input data contains any XML special characters like ampersand. less than, etc.

[fmbenhassine]

In order to avoid any confusion about to whom this issue should be assigned, I'm not going to assign it to anyone. Everyone is welcome to contribute to the project. If a PR is opened for this bug, I will link it to this issue.

[fmbenhassine]

Fixed in #3843 .