This version is still in development and is not considered stable yet. For the latest stable version, please use Spring Batch Documentation 5.1.2!spring-doc.cn

This version is still in development and is not considered stable yet. For the latest stable version, please use Spring Batch Documentation 5.1.2!spring-doc.cn

There are many scenarios where errors encountered while processing should not result in Step failure but should be skipped instead. This is usually a decision that must be made by someone who understands the data itself and what meaning it has. Financial data, for example, may not be skippable because it results in money being transferred, which needs to be completely accurate. Loading a list of vendors, on the other hand, might allow for skips. If a vendor is not loaded because it was formatted incorrectly or was missing necessary information, there probably are not issues. Usually, these bad records are logged as well, which is covered later when discussing listeners.spring-doc.cn

The following Java example shows an example of using a skip limit:spring-doc.cn

Java Configuration
@Bean
public Step step1(JobRepository jobRepository, PlatformTransactionManager transactionManager) {
	return new StepBuilder("step1", jobRepository)
				.<String, String>chunk(10, transactionManager)
				.reader(flatFileItemReader())
				.writer(itemWriter())
				.faultTolerant()
				.skipLimit(10)
				.skip(FlatFileParseException.class)
				.build();
}

The following XML example shows an example of using a skip limit:spring-doc.cn

XML Configuration
<step id="step1">
   <tasklet>
      <chunk reader="flatFileItemReader" writer="itemWriter"
             commit-interval="10" skip-limit="10">
         <skippable-exception-classes>
            <include class="org.springframework.batch.item.file.FlatFileParseException"/>
         </skippable-exception-classes>
      </chunk>
   </tasklet>
</step>

In the preceding example, a FlatFileItemReader is used. If, at any point, a FlatFileParseException is thrown, the item is skipped and counted against the total skip limit of 10. Exceptions (and their subclasses) that are declared might be thrown during any phase of the chunk processing (read, process, or write). Separate counts are made of skips on read, process, and write inside the step execution, but the limit applies across all skips. Once the skip limit is reached, the next exception found causes the step to fail. In other words, the eleventh skip triggers the exception, not the tenth.spring-doc.cn

One problem with the preceding example is that any other exception besides a FlatFileParseException causes the Job to fail. In certain scenarios, this may be the correct behavior. However, in other scenarios, it may be easier to identify which exceptions should cause failure and skip everything else.spring-doc.cn

The following Java example shows an example excluding a particular exception:spring-doc.cn

Java Configuration
@Bean
public Step step1(JobRepository jobRepository, PlatformTransactionManager transactionManager) {
	return new StepBuilder("step1", jobRepository)
				.<String, String>chunk(10, transactionManager)
				.reader(flatFileItemReader())
				.writer(itemWriter())
				.faultTolerant()
				.skipLimit(10)
				.skip(Exception.class)
				.noSkip(FileNotFoundException.class)
				.build();
}

The following XML example shows an example excluding a particular exception:spring-doc.cn

XML Configuration
<step id="step1">
    <tasklet>
        <chunk reader="flatFileItemReader" writer="itemWriter"
               commit-interval="10" skip-limit="10">
            <skippable-exception-classes>
                <include class="java.lang.Exception"/>
                <exclude class="java.io.FileNotFoundException"/>
            </skippable-exception-classes>
        </chunk>
    </tasklet>
</step>

By identifying java.lang.Exception as a skippable exception class, the configuration indicates that all Exceptions are skippable. However, by “excluding” java.io.FileNotFoundException, the configuration refines the list of skippable exception classes to be all Exceptions except FileNotFoundException. Any excluded exception class is fatal if encountered (that is, they are not skipped).spring-doc.cn

For any exception encountered, the skippability is determined by the nearest superclass in the class hierarchy. Any unclassified exception is treated as 'fatal'.spring-doc.cn

The order of the skip and noSkip method calls does not matter.spring-doc.cn

The order of the <include/> and <exclude/> elements does not matter.spring-doc.cn