Spring: using of FlatFileItemReader - spring

Question

Could I use FlatFileItemReader not as reader of batch processing? I want to use it for parsing of File.
I have bean of reader:
<bean id="cvsFileItemReader" class="org.springframework.batch.item.file.FlatFileItemReader">
<property name="resource" value="file:${garmin.fs.in.received2}" />
<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,sales,qty,staffName,date" />
</bean>
</property>
<property name="fieldSetMapper">
<bean class="my.app.util.ReportFieldSetMapper" />
</property>
</bean>
</property>
</bean>
And I want to use it in my component:
#Component
public class Handler {
#Autowired
private FlatFileItemReader<Report> reader;
public File handleFile() {
try {
Report report = reader.read();
} catch (Exception e) {
e.printStackTrace();
}
return input;
}
}
But in line of code:
Report report = reader.read();
I got exception:
org.springframework.batch.item.ReaderNotOpenException: Reader must
be open before it can be read.
Is it possible to use spring batch reader in the following way?

Answer 1

As the exception implies, you have to call reader.open() before calling read() for the first time.
You should also call reader.close() when you are done.

Answer 2

As #GaryRussell wrote you can call open/close but - IMHO - use a SB component outside of SB domain is not a good approach because you couple your classes with SB classes too tight.
For me a better and more clear mode to operate is to use a CSV parsing library as BeanIO as main component and reuse it in your Handler as well as with BeanIOFlatFileItemReader as reader.

Answer 3

You have to implement ItemStream and override open, close and update method as below-
#Component
public class Handler implements ItemStream {
#Autowired
private FlatFileItemReader<Report> reader;
public File handleFile() {
try {
Report report = reader.read();
} catch (Exception e) {
e.printStackTrace();
}
return input;
}
#Override
public void open(ExecutionContext executionContext) {
reader.open(executionContext);
}
#Override
public void update(ExecutionContext executionContext) {
reader.update(executionContext);
}
#Override
public void close() {
reader.close();
}
}