如何使用Univocity例程验证CSV标头？

Question

当我在Java上迭代时，我使用Univocity解析器和例程。有什么方法来验证CSV头吗？当我编辑CSV并添加无效的标头时，它只是插入到给定的bean null中，而没有任何错误。

模型类：

public class Customer {

@Format(formats ="yyyy-MM-dd")
@Parsed(field="C_DAY")
private Date day;

@Parsed(field="C_ID")
private Long id;

@Parsed(field="C_TYPE")
private String type;

@Format(formats ="yyyy-MM-dd")
@Parsed(field="C_ORIGIN_DATE")
private Date originDate;

@Format(formats ="yyyy-MM-dd")
@Parsed(field="C_REL_DATE")
private Date relDate;

@Parsed(field="C_LEGAL_ID")
private String legalId;

@Parsed(field="C_NAME")
private String name;}

Parser:

    @Autowired
private CustomerDAO dao;

public void parse(File file) throws IOException, SQLException, CustomerValidationException, ParseException {
    CsvParserSettings parserSettings = new CsvParserSettings();
    parserSettings.getFormat().setLineSeparator("\n");
    parserSettings.setHeaderExtractionEnabled(false);
    CsvRoutines routines = new CsvRoutines(parserSettings);
    List<Customer> customers = new ArrayList<>();
    java.util.Date stamp = getTimestamp(file);
    dao.checkTimestampDate(stamp);


    for (Customer customer : routines.iterate(Customer.class, file, "UTF-8")) {
        validateFileDateWithFileName(stamp, customer.getDay());
        validateCustomer(customer);
        customers.add(customer);
    }
    dao.save(customers);
}

Answer 1

这里图书馆的作者。BeanListProcessor具有一个可以设置为true的strictHeaderValidationEnabled属性，以确保类中的所有标头都存在于输入中。

在这种情况下，您不能使用CsvRoutines，因为该类实现了使用自己的内部行处理器的方便方法，因此您的类将被忽略。试试下面的代码：

    CsvParserSettings parserSettings = new CsvParserSettings();
    parserSettings.getFormat().setLineSeparator("\n");

    final List<Customer> customers = new ArrayList<>();
    final java.util.Date stamp = getTimestamp(file);
    dao.checkTimestampDate(stamp);

    parserSettings.setProcessor(new BeanProcessor<Customer>() {
        @Override
        public void beanProcessed(Customer customer, ParsingContext context) {
            validateFileDateWithFileName(stamp, customer.getDay());
            validateCustomer(customer);
            customers.add(customer);
        }
    });

    new CsvParser(parserSettings).parse(file, "UTF-8");

    dao.save(customers);

希望这能有所帮助。

Answer 2

根据杰罗尼莫·巴克斯的回答。

如果您在bean上有@Header注释，或者知道确切的头，但仍然需要setHeaderExtractionEnabled(true)

public <T> List<T> parse(File file, Class<T> beanType, char delimiter, Charset charset) {
    String[] headers = beanType.getDeclaredAnnotation(Headers.class).sequence(); // or other source

    CsvParserSettings parserSettings = Csv.parseRfc4180(); // or some other
    parserSettings.detectFormatAutomatically(delimiter);
    parserSettings.setHeaderExtractionEnabled(true);

    // initialize new processor (stateful, should not be reused! See implementation of parseAll)
    BeanListProcessor<T> processor= new BeanListProcessor<>();
    processor.setStrictHeaderValidationEnabled(true);
    parserSettings.setProcessor(processor);

    CsvParser csvParser = new CsvParser(parserSettings);

    csvParser.parse(file, charset);

    // header validation
    String[] headersParsed = processor.getHeaders();
    if (!Arrays.equals(headers, headersParsed)) {
        String message = String.format("Header validation failed. Expected: %s, but was: %s",
            Arrays.toString(headers), Arrays.toString(headersParsed));
        throw new DataProcessingException(message);
    }

    return beanListProcessor.getBeans();
}