Spring Batch Standards
Job Configuration
@Configuration
@RequiredArgsConstructor
public class UserExportJobConfig {
private final JobRepository jobRepository;
private final PlatformTransactionManager transactionManager;
@Bean
public Job userExportJob(Step exportStep) {
return new JobBuilder("userExportJob", jobRepository)
.incrementer(new RunIdIncrementer())
.start(exportStep)
.build();
}
@Bean
public Step exportStep(
ItemReader<User> reader,
ItemProcessor<User, UserDto> processor,
ItemWriter<UserDto> writer) {
return new StepBuilder("exportStep", jobRepository)
.<User, UserDto>chunk(100, transactionManager)
.reader(reader)
.processor(processor)
.writer(writer)
.faultTolerant()
.skipLimit(10)
.skip(DataAccessException.class)
.build();
}
}
Reader/Processor/Writer
@Bean
public JpaPagingItemReader<User> userReader(EntityManagerFactory emf) {
return new JpaPagingItemReaderBuilder<User>()
.name("userReader")
.entityManagerFactory(emf)
.queryString("SELECT u FROM User u WHERE u.status = 'ACTIVE'")
.pageSize(100)
.build();
}
@Bean
public ItemProcessor<User, UserDto> userProcessor() {
return user -> new UserDto(user.getId(), user.getName(), user.getEmail());
}
@Bean
public FlatFileItemWriter<UserDto> userWriter() {
return new FlatFileItemWriterBuilder<UserDto>()
.name("userWriter")
.resource(new FileSystemResource("output/users.csv"))
.delimited()
.names("id", "name", "email")
.build();
}
Job Execution
@Service
@RequiredArgsConstructor
public class JobLauncherService {
private final JobLauncher jobLauncher;
private final Job userExportJob;
public void runExport(String date) throws Exception {
JobParameters params = new JobParametersBuilder()
.addString("date", date)
.addLong("time", System.currentTimeMillis())
.toJobParameters();
JobExecution execution = jobLauncher.run(userExportJob, params);
log.info("Job status: {}", execution.getStatus());
}
}
References
- Chunk Processing - Sizing, transactions, error handling
ngxtm