Batch processing with Spring Batch

package com.example.demo.batch;

import com.example.demo.model.User;
import com.example.demo.model.UserDTO;
import org.springframework.batch.core.Job;
import org.springframework.batch.core.Step;
import org.springframework.batch.core.job.builder.JobBuilder;
import org.springframework.batch.core.repository.JobRepository;
import org.springframework.batch.core.step.builder.StepBuilder;
import org.springframework.batch.item.ItemProcessor;
import org.springframework.batch.item.database.JdbcBatchItemWriter;
import org.springframework.batch.item.database.JdbcPagingItemReader;
import org.springframework.batch.item.database.builder.JdbcBatchItemWriterBuilder;
import org.springframework.batch.item.database.builder.JdbcPagingItemReaderBuilder;
import org.springframework.batch.item.file.FlatFileItemReader;
import org.springframework.batch.item.file.builder.FlatFileItemReaderBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.ClassPathResource;
import org.springframework.transaction.PlatformTransactionManager;

import javax.sql.DataSource;

@Configuration
public class BatchConfig {

    @Bean
    public Job userImportJob(JobRepository jobRepository, Step importStep) {
        return new JobBuilder("userImportJob", jobRepository)
            .start(importStep)
            .build();
    }

    @Bean
    public Step importStep(JobRepository jobRepository,
                          PlatformTransactionManager transactionManager,
                          FlatFileItemReader<UserDTO> reader,
                          UserProcessor processor,
                          JdbcBatchItemWriter<User> writer) {
        return new StepBuilder("importStep", jobRepository)
            .<UserDTO, User>chunk(100, transactionManager)
            .reader(reader)
            .processor(processor)
            .writer(writer)
            .faultTolerant()
            .skip(Exception.class)
            .skipLimit(10)
            .build();
    }

    @Bean
    public FlatFileItemReader<UserDTO> csvReader() {
        return new FlatFileItemReaderBuilder<UserDTO>()
            .name("userCsvReader")
            .resource(new ClassPathResource("users.csv"))
            .delimited()
            .names("name", "email", "age")
            .targetType(UserDTO.class)
            .linesToSkip(1)
            .build();
    }

    @Bean
    public UserProcessor processor() {
        return new UserProcessor();
    }

    @Bean
    public JdbcBatchItemWriter<User> databaseWriter(DataSource dataSource) {
        return new JdbcBatchItemWriterBuilder<User>()
            .dataSource(dataSource)
            .sql("INSERT INTO users (name, email, age) VALUES (:name, :email, :age)")
            .beanMapped()
            .build();
    }

    public static class UserProcessor implements ItemProcessor<UserDTO, User> {
        @Override
        public User process(UserDTO dto) throws Exception {
            if (dto.email() == null || !dto.email().contains("@")) {
                return null; // Skip invalid records
            }

            User user = new User();
            user.setName(dto.name().toUpperCase());
            user.setEmail(dto.email().toLowerCase());
            user.setAge(dto.age());
            return user;
        }
    }
}