import org.springframework.stereotype.Component;
import org.springframework.batch.core.*;
import javax.validation.*;

@Component
public class ValidationTasklet implements Tasklet {

  private final ReadService readService;
  private final WriteService writeService;
  private final Validator validator;

  @Override
  public RepeatStatus execute(StepContribution sc, ChunkContext cc){

    // read the input file
    List<User> userList = readService.readFile("/path/to/input/file");

    // validate the input
    List<User> validUserList = userList.stream()
     .map( user -> {
       Set<ConstraintViolation<User> violations = validator.validate(user);
       return violations.isEmpty() ? user : null;
     })
     .filter(Objects::nonNull)
     .collect(Collectors.toList());

   // write the output file
   writeService.writeFile(validUserList,"/path/to/output/file");

   return RepeatStatus.FINISHED;
   }

  // Constructor
}