<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-batch</artifactId>
</dependency>
<dependency>
  <groupId>com.h2database</groupId>
  <artifactId>h2</artifactId>
  <scope>runtime</scope>
</dependency>

@SpringBootApplication
@EnableBatchProcessing
public class PkslowBatchJobMain {
    public static void main(String[] args) {
        SpringApplication.run(PkslowBatchJobMain.class, args);
    }
}

package com.pkslow.batch.entity;
public class Employee {
    String id;
    String firstName;
    String lastName;
}

@Value("input/inputData*.csv")
private Resource[] inputResources;

@Bean
public MultiResourceItemReader<Employee> multiResourceItemReader()
{
  MultiResourceItemReader<Employee> resourceItemReader = new MultiResourceItemReader<Employee>();
  resourceItemReader.setResources(inputResources);
  resourceItemReader.setDelegate(reader());
  return resourceItemReader;
}

@Bean
public FlatFileItemReader<Employee> reader()
{
  FlatFileItemReader<Employee> reader = new FlatFileItemReader<Employee>();
  //跳過csv文件第一行，為表頭
  reader.setLinesToSkip(1);
  reader.setLineMapper(new DefaultLineMapper() {
    {
      setLineTokenizer(new DelimitedLineTokenizer() {
        {
          //字段名
          setNames(new String[] { "id", "firstName", "lastName" });
        }
      });
      setFieldSetMapper(new BeanWrapperFieldSetMapper<Employee>() {
        {
          //轉(zhuǎn)換化后的目標(biāo)類
          setTargetType(Employee.class);
        }
      });
    }
  });
  return reader;
}

public ItemProcessor<Employee, Employee> itemProcessor() {
  return employee -> {
    employee.setLastName(employee.getLastName().toUpperCase());
    return employee;
  };
}

private Resource outputResource = new FileSystemResource("output/outputData.csv");

@Bean
public FlatFileItemWriter<Employee> writer()
{
  FlatFileItemWriter<Employee> writer = new FlatFileItemWriter<>();
  writer.setResource(outputResource);
  //是否為追加模式
  writer.setAppendAllowed(true);
  writer.setLineAggregator(new DelimitedLineAggregator<Employee>() {
    {
      //設(shè)置分割符
      setDelimiter(",");
      setFieldExtractor(new BeanWrapperFieldExtractor<Employee>() {
        {
          //設(shè)置字段
          setNames(new String[] { "id", "firstName", "lastName" });
        }
      });
    }
  });
  return writer;
}

@Bean
public Step csvStep() {
  return stepBuilderFactory.get("csvStep").<Employee, Employee>chunk(5)
    .reader(multiResourceItemReader())
    .processor(itemProcessor())
    .writer(writer())
    .build();
}

@Bean
public Job pkslowCsvJob() {
  return jobBuilderFactory
    .get("pkslowCsvJob")
    .incrementer(new RunIdIncrementer())
    .start(csvStep())
    .build();
}

public class PkslowWriteListener implements ItemWriteListener<Employee> {
    private static final Log logger = LogFactory.getLog(PkslowWriteListener.class);
    @Override
    public void beforeWrite(List<? extends Employee> list) {
        logger.info("beforeWrite: " + list);
    }

    @Override
    public void afterWrite(List<? extends Employee> list) {
        logger.info("afterWrite: " + list);
    }

    @Override
    public void onWriteError(Exception e, List<? extends Employee> list) {
        logger.info("onWriteError: " + list);
    }
}

@Bean
public Step csvStep() {
  return stepBuilderFactory.get("csvStep").<Employee, Employee>chunk(5)
    .reader(multiResourceItemReader())
    .listener(new PkslowReadListener())
    .processor(itemProcessor())
    .listener(new PkslowProcessListener())
    .writer(writer())
    .listener(new PkslowWriteListener())
    .build();
}