Skippable Exception - spring-batch

Question

I am trying to skip all the exceptions during the batch run using the following config:
<chunk reader="aaaFileReader" writer="aaaDBWriter"
commit-interval="100" skip-limit="100000">
<skippable-exception-classes>
<include class="java.lang.Exception" />
<exclude
class="org.springframework.jdbc.CannotGetJdbcConnectionException" />
</skippable-exception-classes>
</chunk>
<listeners>
<listener ref="aaabatchFailureListener" />
</listeners>
And I handle the exception in my listener. But when Spring Batch actually encounters an exception its not being skipped and the batch run ends with a failed state. The actual exception is a FlatFileParse Exception. How do I skip the FlatFileParseException?
Here is the log :
:18:21.257 [main] DEBUG o.s.b.repeat.support.RepeatTemplate - Handling fatal exception explicitly (rethrowing first of 1): org.springframework.batch.core.step.skip.NonSkippableReadException: Non-skippable exception during read
15:18:21.257 [main] ERROR o.s.batch.core.step.AbstractStep - Encountered an error executing the step
org.springframework.batch.core.step.skip.NonSkippableReadException: Non-skippable exception during read
at org.springframework.batch.core.step.item.FaultTolerantChunkProvider.read(FaultTolerantChunkProvider.java:81) ~[spring-batch-core.jar:na]
at org.springframework.batch.core.step.item.SimpleChunkProvider$1.doInIteration(SimpleChunkProvider.java:106) ~[spring-batch-core.jar:na]
at org.springframework.batch.repeat.support.RepeatTemplate.getNextResult(RepeatTemplate.java:367) ~[spring-batch-infrastructure.jar:na]
at org.springframework.batch.repeat.support.RepeatTemplate.executeInternal(RepeatTemplate.java:215) ~[spring-batch-infr
Caused by: org.springframework.batch.item.file.FlatFileParseException: Parsing error at line: 5, input=[0254285458908060150983101150983 AK00055002035201401081044000804CK5861 00Twist,Oliver AT&T 20121208 ]
at org.springframework.batch.

Answer 1

You can add the FlatFileParseException class on your batch job config, for example:
<batch:chunk reader="customImportReader" writer="customImporter" processor="customProcessor" commit-interval="1" skip-limit="10">
<batch:skippable-exception-classes>
<batch:include class="org.springframework.batch.item.file.FlatFileParseException" />
</batch:skippable-exception-classes>
</batch:chunk>

Answer 2

As per Spring Batch Documentation some of the exceptions are not qualified as skippable.
In your case its clear from logs that org.springframework.batch.item.file.FlatFileParseException is not a skippable excepotion hence re throwing org.springframework.batch.core.step.skip.NonSkippableReadException.
Read more about Configuring Skip Logic section that says:
For any exception encountered, the skippability will be determined by the nearest superclass in the class hierarchy. Any unclassifed exception will be treated as 'fatal'.
Read more about NonSkippableReadException that says:
Fatal exception to be thrown when a read operation could not be skipped.

Answer 3

Create a custom fileReader and Override the doRead() method to always throw you CustomException.
public class CustomFlatFileItemReader extends FlatFileItemReader {
#Override
protected T doRead() throws Exception {
T itemRead=null;
try {
itemRead= super.doRead();
} catch (FlatFileParseException e) {
throw new MyException(e.getMessage(), e);
}
return itemRead;}
}
Override your job skip policy to always skip your custom exception as below:
.skipPolicy((Throwable T, int skipCount) -> {
if (T instanceof BatchServiceException)
return true;
else
return false;