Spring boot batch scheduler run once

Question

I started to learn Spring Boot Batch in version 2.1.4

I want to run my job in scheduler and this job runs only once. I mean ItemProcessor and ItemWriter run only once. ItemReader runs every time. anyone have an idea what I did wrong. In the future, I want to change scheduler to Java WatchService and pass filePath to the job but now parameter for filePath is like a string in the function parameter. This is my code:

This is my reader:

@Component
public class UserReaderImpl  {
    @StepScope
    public ItemReader<UserCsvStructure> read(String filepath) {
        FlatFileItemReader<UserCsvStructure> reader = new FlatFileItemReader();
        reader.setLinesToSkip(1);
        reader.setResource(new FileSystemResource(filepath));
        reader.setLineMapper(new DefaultLineMapper<UserCsvStructure>() {
            {
                setLineTokenizer(new DelimitedLineTokenizer() {
                    {
                        setNames(new String[]{"firstName","lastName","email"});
                    }
                });
                setFieldSetMapper(new BeanWrapperFieldSetMapper<UserCsvStructure>() {
                    {
                        setTargetType(UserCsvStructure.class);
                    }
                });
            }
        });
        return reader;
    }
}

This in my ItemProcessor

@StepScope
@Component
public class UserProcessorImpl implements ItemProcessor<UserCsvStructure, User> {
@Override
public User process(UserCsvStructure userCsvStructure) throws Exception {
    return User.builder()
            .email(userCsvStructure.getEmail())
            .firstName(userCsvStructure.getFirstName())
            .lastName(userCsvStructure.getLastName())
            .build();
}
}

This is my ItemWriter

@Component
@StepScope
public class UserWriterImpl implements ItemWriter<User>{
@Autowired
private UserRepository userRepository;

@Override
public void write(List<? extends User> list) throws Exception {
    System.out.println(list);
    userRepository.saveAll(list);
}
}

And this is my configuration

@Component
public class UserBatchCsvConfig {

@Autowired
public JobBuilderFactory jobBuilderFactory;

@Autowired
public StepBuilderFactory stepBuilderFactory;

@Autowired
private UserReaderImpl userReader;

@Autowired
private UserWriterImpl userWriter;

@Autowired
private UserProcessorImpl userProcessor;

public Job csvFileToDatabaseJob(UserJobCompletionNotificationListener listener, String fileName) {
    return jobBuilderFactory.get("userCsvProcess")
            .incrementer(new RunIdIncrementer())
            .listener(listener)
            .flow(csvFileToDatabaseStep(fileName))
            .end()
            .build();
}

private Step csvFileToDatabaseStep(String fileName) {
    return stepBuilderFactory.get("userCsvProcess")
            .<UserCsvStructure, User>chunk(1)
            .reader(userReader.read(fileName))
            .processor(userProcessor)
            .writer(userWriter)
            .build();
}

}

Last class is my scheduler:

@Component
public class UserCsvProcessor {

@Autowired
private JobLauncher jobLauncher;

@Autowired
private UserBatchCsvConfig job;

@Autowired
private UserJobCompletionNotificationListener userJobCompletionNotificationListener;

@Scheduled(fixedDelay = 10000)
public void runJob() throws Exception {
    jobLauncher.run(job.csvFileToDatabaseJob(userJobCompletionNotificationListener, "C:\\Users\\Anik\\Desktop\\angular\\test.csv"), new JobParameters());
}
}

I mean ItemProcessor and ItemWriter run only once. ItemReader runs every time.: That's not clear. What are you trying to achieve? — Mahmoud Ben Hassine
I trying to run the job many times. Every time, I got an error because spring batch told me this job is already running. And I achieve it by add params like below — Mateusz Sobczak

Mateusz Sobczak Mateusz Sobczak · Accepted Answer · 2019-05-04T17:20:15

I know what should I add in my code In UserCsvProcessor class I need to change my scheduled function to:

@Scheduled(fixedDelay = 10000)
public void runJob() throws Exception {
    JobParameters params = new JobParametersBuilder()
            .addString("JobID", String.valueOf(System.currentTimeMillis()))
            .toJobParameters();
    jobLauncher.run(job.csvFileToDatabaseJob(userJobCompletionNotificationListener, "C:\\Users\\Anik\\Desktop\\angular\\test.csv"), params);
}

If someone has other idea or better idea just add an answer

Spring boot batch scheduler run once

2 Answers