Spring Batch : PassThroughFieldExtractor with BigDecimal formatting

Question

I\'m using Spring Batch to extract a CSV file from a DB table which has a mix of column types. The sample table SQL schema is

[product] [varchar](16) NOT NULL,
         


        

Answer 1

You can

1. Write your own BigDecimalToStringConverter implements Converter<BigDecimal, String> to format big decimal without trailing 0's
2. Create a new ConversionService (MyConversionService) and register into the custom converter
3. Extends DelimitedLineAggregator, inject MyConversionService, override doAggregate() to format fields using injected conversion service

---

public class MyConversionService extends DefaultConversionService {
  public MyConversionService() {
    super();
    addConverter(new BigDecimalToStringConverter());
  }
}

---

public class MyFieldLineAggregator<T> extends DelimitedLineAggregator<T> {
  private ConversionService cs = new MyConversionService();

  public String doAggregate(Object[] fields) {
    for(int i = 0;i < fields.length;i++) {
      final Object o = fields[i];
      if(cs.canConvert(o.getClass(), String.class)) {
        fields[i] = cs.convert(o, String.class);
      }
    }
    return super.doAggregate(fields);
  }
}