spring batch ItemReader FlatFileItemReader set cursor to start reading from a particular line or set linestoskip dynamically

filereader, skip, spring, spring-batch

Solution

Use `FlatFileItemReader.linesToSkip` property setted injecting job Parameter value.

<bean id="myReader" class="org.springframework.batch.item.file.FlatFileItemReader" scope="step">
    <property name="linesToSkip" value="file:#{jobParameters['cursor']}" />
</bean>

Problem

In my springbatch+quartz setup, I am reading a CSV File using FlatFileItemReader. I want to set the cursor for the reader to start the next jobinstance with the given parameters for reader. Is it possible? ``` <bean id="cvsFileItemReader" class="org.springframework.batch.item.file.FlatFileItemReader" scope="step">  <property name="resource" value="classpath:cvs/input/report.csv" /> <property name="lineMapper"> <bean class="org.springframework.batch.item.file.mapping.DefaultLineMapper"> <property name="lineTokenizer"> <bean class="org.springframework.batch.item.file.transform.DelimitedLineTokenizer"> <property name="names" value="id,impressions" /> </bean> </property> <property name="fieldSetMapper"> <bean class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper"> <property name="prototypeBeanName" value="report" /> </bean> </property> </bean> </property> </bean> ``` The idea is to continue reading the file where last failure occured in the next execution. I am putting an integer 'writecursor' for each line written in my customWriter. ``` public void write(List<? extends Report> items) throws Exception { System.out.println("writer..." + items.size() + " > "); for(Report item : items){ System.out.println("writing item id: " + item.getId()); System.out.println(item); } //getting stepExecution by implementing StepExecutionListener this.stepExecution.getExecutionContext().putInt("writecursor", ++writecursor); } ``` Now, in the customItemReadListener, I want to get the update writecursor value and then skip the lines from the top to start reading from writecursor ``` public class CustomItemReaderListener implements ItemReadListener<Report>, StepExecutionListener { ApplicationContext context = ApplicationContextUtils.getApplicationContext(); private StepExecution stepExecution; @Override public void beforeRead() { //Skip lines somehow } ``` Another thing I saw as a possible solution is to set linestoskip dynamically in itemreader. There is a thread here http://thisisurl.com/dynamic-value-for-linestoskip-in-itemreader but not answered yet. And here, http://forum.spring.io/forum/spring-projects/batch/100950-accessing-job-execution-context-from-itemwriter

Original source