Question about the FixedLengthWriter

[Eric Leray]

I am wondering if the FixedLengthWriter has the following feature:

- instead of writing a field in a file from left to right filling the remaining field size with the fillChar as in :
JOHN                               DOE                                1234 ...

is it possible to fill the same record fileds from right to left as in :
                               JOHN                                DOE 1234...

this is quite an important feature in order to translater properly numbers found in a file, especially if the expected fillChar is '0'.

In the following extract the numeric field can be problematic as it gives different values : 12340 or 01234
JOHN0000000000000000000000000000000DOE0000000000000000000000000000000012340...
0000000000000000000000000000000JOHN00000000000000000000000000000000DOE01234...

NB: using '0' as the fillChar is a mandatory requirement in my case.

any help or ideas on this will be much appreciated.

[Paul Zepernick]

Hi Eric,

I see the dilemma...  Currently there is no way to tell the writer to zero fill the string.  Here is a utility method that you could call on the string yourself before giving it to the writer.  I will look at getting this functionality added for a future release:

    public static String zeroFillString(String field, int numOfSpaces) {
        int spacesNeeded=0;
        //deletes any spaces in the string
         //calculates amount of 0's need to complete the field
        spacesNeeded=numOfSpaces - field.length();
                final StringBuffer sb = new StringBuffer();
                sb.append(field);
        for (int i=0; i < spacesNeeded; i++){
                        sb.insert(0, "0");
        }
        return sb.toString();

    }

So your code might look something like this:
writer.addRecordEntry("NUMERICFIELD", zeroFillString("100", 10));

I realize it stinks to have to basically define the field length in the code when it is already in the XML, but I don't have any other ideas at the moment.

Thanks,

Paul

[Guy de Pourtales]

Hi Eric and Paul

At a first look, it should be simpler to use java.text.NumberFormat to format the numeric field with the correct length and default front filling. Another solution is to create to new classes :

a. FrontFillFixedLengthWriter extends FixedLengthWriter and to overwrite its method "protected char[] formattedValue(Object value, final ColumnMetaData element)" to implement front filling instead of back filling
b. FrontFillFixedWriterFactory extends FixedWriterFactory overriding just "public Writer createWriter(final java.io.Writer output) throws IOException" to return  a FrontFillFixedLengthWriter insance.

A third solution is to implement a FormattedFixedLengthWriter accepting a java.text.Format subclass implementing different custom formatting options

Regards,

Guy

[Paul Zepernick]

Hi Guy,

Thanks very much for your suggestions and input...

Thanks,

Paul