Supercsv генерирует исключение

Question

Мой прецедент читает объекты из CSV, выполняя некоторые изменения в объектах, а затем записывая их в другой CSV. Я попытался изменить примеры supercsv, как показано ниже, но я получаю исключение SuperCsvConstraintViolationException, которое я не уверен, как обращаться.

public class ReadingWriting { 

    private static final String CSV_READ_FILENAME = "src/test/resources/customers.csv"; 
    public static final String CSV_WRITE_FILENAME = "target/writeWithCsvBeanWriter.csv"; 

    public static void main(String[] args) throws Exception { 
     readWithCsvBeanReader(); 
    } 

    /** 
    * Sets up the processors used for the examples. There are 10 CSV columns, so 10 processors are defined. Empty 
    * columns are read as null (hence the NotNull() for mandatory columns). 
    * 
    * @return the cell processors 
    */ 
    private static CellProcessor[] getProcessors() { 
     final String emailRegex = "[a-z0-9\\._]+@[a-z0-9\\.]+"; // just an example, not very robust! 
     StrRegEx.registerMessage(emailRegex, "must be a valid email address"); 
     final CellProcessor[] processors = new CellProcessor[]{ 
       new UniqueHashCode(), // customerNo (must be unique) 
       new NotNull(), // firstName 
       new NotNull(), // lastName 
       new ParseDate("dd/MM/yyyy"), // birthDate 
       new NotNull(), // mailingAddress 
       new Optional(new ParseBool()), // married 
       new Optional(new ParseInt()), // numberOfKids 
       new NotNull(), // favouriteQuote 
       new StrRegEx(emailRegex), // email 
       new LMinMax(0L, LMinMax.MAX_LONG) // loyaltyPoints 
     }; 
     return processors; 
    } 

    /** 
    * An example of reading using CsvBeanReader. 
    */ 
    private static void readWithCsvBeanReader() throws Exception { 

     ICsvBeanReader beanReader = null; 
     ICsvBeanWriter beanWriter = null; 

     try { 

      beanReader = new CsvBeanReader(new FileReader(CSV_READ_FILENAME), CsvPreference.STANDARD_PREFERENCE); 
      beanWriter = new CsvBeanWriter(new FileWriter(CSV_WRITE_FILENAME), CsvPreference.STANDARD_PREFERENCE); 

      final CellProcessor[] processors = getProcessors(); 

      // the header elements are used to map the values to the bean (names must match) 
      final String[] header = beanReader.getHeader(true); 
      beanWriter.writeHeader(header); 

      CustomerBean customer; 
      while ((customer = beanReader.read(CustomerBean.class, header, processors)) != null) { 
       System.out.println(String.format("lineNo=%s, rowNo=%s, customer=%s", beanReader.getLineNumber(), 
         beanReader.getRowNumber(), customer)); 

       beanWriter.write(customer, header, processors);//this line causes the below output 
       /* 
       lineNo=4, rowNo=2, customer=CustomerBean(customerNo=1, loyaltyPoints=0, mailingAddress=1600 Amphitheatre Parkway 
       Mountain View, CA 94043 
       United States) 
       Exception in thread "main" Disconnected from the target VM, address: '127.0.0.1:60782', transport: 'socket' 
       org.supercsv.exception.SuperCsvConstraintViolationException: duplicate value '1' encountered with hashcode 49 
       processor=org.supercsv.cellprocessor.constraint.UniqueHashCode 
       context={lineNo=2, rowNo=2, columnNo=1, rowSource=[1, John, Dunbar, Wed Jun 13 00:00:00 AEST 1945, 1600 Amphitheatre Parkway 
       Mountain View, CA 94043 
       United States, null, null, "May the Force be with you." - Star Wars, jdunbar@gmail.com, 0]} 
        at org.supercsv.cellprocessor.constraint.UniqueHashCode.execute(UniqueHashCode.java:78) 
        at org.supercsv.util.Util.executeCellProcessors(Util.java:93) 
        at org.supercsv.io.CsvBeanWriter.write(CsvBeanWriter.java:136) 
        at Reading.readWithCsvBeanReader(Reading.java:78) 
        at Reading.main(Reading.java:25) 

       Process finished with exit code 1 
       */ 
      } 
     } finally { 
      if (beanReader != null) { 
       beanReader.close(); 
      } 
      if(beanWriter != null) { 
       beanWriter.close(); 
      } 
     } 
    } 
} 

Answer 1

В процессоре вашей ячейки вы указываете, что номер клиента имеет уникальный хэш-код. В файле я подозреваю, что строка с тем же номером клиента.