我无法使用 CSV 文件中的值填充 H2 数据库

Question

我正在尝试使用 CSV 文件中的值填充 H2 数据库，如下所示：

@Component
public class DBWriterOrder implements ItemWriter<OrderEntity> {

private OrderRepository orderRepository;

@Autowired
public DBWriterOrder(OrderRepository orderRepository) {
    this.orderRepository = orderRepository;
}

@Override
public void write(List<? extends OrderEntity> orders) throws Exception {
    System.out.println("Data Saved for Orders: " + orders);
    orderRepository.saveAll(orders);

     }
}

---

@Component
public class ProcessorOrder implements ItemProcessor<OrderEntity, OrderEntity> {

public SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy");

@Override
public OrderEntity process(OrderEntity orderEntity) throws Exception {

    Date deliveryDate = sdf.parse(orderEntity.getDeliveryDate().toString());
    long deliveryDateInMillis = deliveryDate.getTime();
    orderEntity.setDeliveryDate(deliveryDateInMillis);

    Date lastUpdated = sdf.parse(orderEntity.getLastUpdated().toString());
    long lastUpdatedInMillis = lastUpdated.getTime();
    orderEntity.setLastUpdated(lastUpdatedInMillis);


    return orderEntity;
    }
}

---

@Configuration
@EnableBatchProcessing
public class SpringBatchConfigOrder {

@Bean
public Job jobOrder(JobBuilderFactory jobBuilderFactory,
               StepBuilderFactory stepBuilderFactory,
               ItemReader<OrderEntity> itemReader,
               ItemProcessor<OrderEntity, OrderEntity> itemProcessor,
               ItemWriter<OrderEntity> itemWriter
) {

    Step step = stepBuilderFactory.get("ETL-file-load")
            .<OrderEntity, OrderEntity>chunk(100)
            .reader(itemReader)
            .processor(itemProcessor)
            .writer(itemWriter)
            .build();


    return jobBuilderFactory.get("ETL-Load")
            .incrementer(new RunIdIncrementer())
            .start(step)
            .build();
}

@Bean
public FlatFileItemReader<OrderEntity> itemReaderOrder() {

    FlatFileItemReader<OrderEntity> flatFileItemReader = new FlatFileItemReader<>();
    flatFileItemReader.setResource(new FileSystemResource("src/main/resources/orders.csv"));
    flatFileItemReader.setName("CSV-Reader");
    flatFileItemReader.setLinesToSkip(1);
    flatFileItemReader.setLineMapper(lineMapperOrder());
    return flatFileItemReader;
}

@Bean
public LineMapper<OrderEntity> lineMapperOrder() {

    DefaultLineMapper<OrderEntity> defaultLineMapper = new DefaultLineMapper<>();
    DelimitedLineTokenizer lineTokenizer = new DelimitedLineTokenizer();

    lineTokenizer.setDelimiter(",");
    lineTokenizer.setStrict(false);
    lineTokenizer.setNames("id","destination","deliveryDate","statusOrder","lastUpdated");

    BeanWrapperFieldSetMapper<OrderEntity> fieldSetMapper = new BeanWrapperFieldSetMapper<>();
    fieldSetMapper.setTargetType(OrderEntity.class);

    defaultLineMapper.setLineTokenizer(lineTokenizer);
    defaultLineMapper.setFieldSetMapper(fieldSetMapper);

    return defaultLineMapper;
   }

}

---

@RestController
@RequestMapping("/loadOrder")
public class OrderLoadController {

@Autowired
JobLauncher jobLauncherOrder;

@Autowired
Job jobOrder;

@GetMapping
public BatchStatus load() throws JobParametersInvalidException, JobExecutionAlreadyRunningException, JobRestartException, JobInstanceAlreadyCompleteException {


    Map<String, JobParameter> maps = new HashMap<>();
    maps.put("time", new JobParameter(System.currentTimeMillis()));
    JobParameters parameters = new JobParameters(maps);
    JobExecution jobExecution = jobLauncherOrder.run(jobOrder, parameters);

    System.out.println("JobExecution: " + jobExecution.getStatus());

    System.out.println("Batch is Running...");
    while (jobExecution.isRunning()) {
        System.out.println("...");
    }

    return jobExecution.getStatus();
    }
}

---

这也是我的实体类：

@Entity(name = "orders")
@Data
public class OrderEntity {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;

@ManyToOne(fetch = FetchType.EAGER)
private DestinationEntity destination;

private Long deliveryDate;

@Enumerated(value = EnumType.STRING)
private OrderStatus statusOrder;

private Long lastUpdated;

}

---

这是我的 CSV 文件：

id,destination,deliveryDate,statusOrder,lastUpdated
1,Ploiesti,15-12-2021,NEW,15-12-2021
2,Ploiesti,15-12-2021,NEW,15-12-2021
3,Pitesti,15-12-2021,NEW,15-12-2021
4,Pitesti,15-12-2021,NEW,15-12-2021
5,Pitesti,15-12-2021,NEW,15-12-2021

---

当我调用端点 localhost:8082/loadController 时，我的数据库没有被填充，它仍然是空的，我得到的只是控制台中的这个错误：

 org.springframework.batch.item.file.FlatFileParseException: Parsing error at line: 2 in resource=[file [C:\Users\ALEX\Desktop\FinalProject\demo\src\main\resources\orders.csv]], input=[1,Ploiesti,15-12-2021,NEW,15-12-2021]
    at org.springframework.batch.item.file.FlatFileItemReader.doRead(FlatFileItemReader.java:189) ~[spring-batch-infrastructure-4.3.4.jar:4.3.4]

 Caused by: org.springframework.validation.BindException: 
org.springframework.validation.BeanPropertyBindingResult: 3 errors
 Field error in object 'target' on field 'lastUpdated': rejected value [15-12-2021]; codes [typeMismatch.target.lastUpdated,typeMismatch.lastUpdated,typeMismatch.java.lang.Long,typeMismatch]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [target.lastUpdated,lastUpdated]; arguments []; default message [lastUpdated]]; default message [Failed to convert property value of type 'java.lang.String' to required type 'java.lang.Long' for property 'lastUpdated'; nested exception is java.lang.NumberFormatException: For input string: "15-12-2021"]
 Field error in object 'target' on field 'destination': rejected value [Ploiesti]; codes [typeMismatch.target.destination,typeMismatch.destination,typeMismatch.com.example.demo.destination.DestinationEntity,typeMismatch]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [target.destination,destination]; arguments []; default message [destination]]; default message [Failed to convert property value of type 'java.lang.String' to required type 'com.example.demo.destination.DestinationEntity' for property 'destination'; nested exception is java.lang.IllegalStateException: Cannot convert value of type 'java.lang.String' to required type 'com.example.demo.destination.DestinationEntity' for property 'destination': no matching editors or conversion strategy found]
 Field error in object 'target' on field 'deliveryDate': rejected value [15-12-2021]; codes [typeMismatch.target.deliveryDate,typeMismatch.deliveryDate,typeMismatch.java.lang.Long,typeMismatch]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [target.deliveryDate,deliveryDate]; arguments []; default message [deliveryDate]]; default message [Failed to convert property value of type 'java.lang.String' to required type 'java.lang.Long' for property 'deliveryDate'; nested exception is java.lang.NumberFormatException: For input string: "15-12-2021"]

---

最后，我的问题是我应该怎么做，我应该怎么做才能把事情做好？ 我更喜欢完整的代码解决方案，因为我不够先进，无法自己解决这个问题，只能通过指示来解决。

Answer 1

看起来您需要自定义FieldSetMapper，因为您不仅需要将String 转换为Date，然后再转换为Long，还需要通过其名称查找DestinationEntity。这是一个将String 转换为Date 的示例

public class PersonFieldSetMapper implements FieldSetMapper<Person> {

  @Override
  public Person mapFieldSet(FieldSet fieldSet) throws BindException {
    return new Person(fieldSet.readLong("id"),
            fieldSet.readString("firstName"),
            fieldSet.readString("lastName"),
            fieldSet.readDate("birthdate", "yyyy-MM-dd HH:mm:ss"));
  }
}

示例取自这里https://www.dineshonjava.com/spring-batch-read-from-csv-and-write-to-relational-db/

您还需要以某种方式将Map<String, DestinationEntity> 属性添加到此FieldSetMapper 以查找DestinationEntity

Answer 2

您可以使用如下所示的 FieldSetMapper 并从您的代码中替换 Mapper。对每个字段使用基于索引的读取。像id 将是 0 索引

public class OrderEntityMapper implements FieldSetMapper<OrderEntity> {

@Override
public OrderEntity mapFieldSet(FieldSet fieldSet) throws BindException {
    OrderEntity order=new OrderEntity();
    order.setId(fieldSet.readLong(0));
    // other fields
    return order;
}

然后替换BeanWrapperFieldSetMapper<OrderEntity> fieldSetMapper = new BeanWrapperFieldSetMapper<>()like

@Bean
public LineMapper<OrderEntity> lineMapperOrder() {

    DefaultLineMapper<OrderEntity> defaultLineMapper = new DefaultLineMapper<>();
    DelimitedLineTokenizer lineTokenizer = new DelimitedLineTokenizer();

    lineTokenizer.setDelimiter(",");
    lineTokenizer.setStrict(false);
    lineTokenizer.setNames("id","destination","deliveryDate","statusOrder","lastUpdated");

      defaultLineMapper.setLineTokenizer(lineTokenizer);
    defaultLineMapper.setFieldSetMapper(new OrderEntityMapper());

    return defaultLineMapper;
   }

}