Signed Overpunch or Zoned Decimal or what are these weird characters in numeric fields ???

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We interface to many different systems and sometimes we get to talk to IBM Mainframes or message formats that uses Signed Overpunch

Where we see numberic values like “100000{” , “100999I”, or “100495N”

Signed Overpunch is used in order to save a byte the last character can indicate both sign (+ / -) and value.

These types are defined in COBOL Copybook this looks like:

S9(3)V9(4);

which equate to :

100000{ = 100.0000

100999I = 100.9999

100495N = -100.4955

Here is a snippet of Java Code that we use to handle this:

    public static final char[] gt_0 = { 
        '{', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I' 
    };
    public static final char[] lt_0 = { 
        '}', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R' 
    };

   protected static String convertToCobolSignedString (String aString) {
        int aInt = Integer.parseInt(aString);
        char[] conv = (aInt >= 0) ? gt_0 : lt_0;
        int lastChar = (int) aInt % 10;
        StringBuffer sb = new StringBuffer (Integer.toString(aInt));
        sb.setCharAt (sb.length()-1, conv[lastChar]);
        return sb.toString();
    }
 

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