Review

On line 365 _code.charAt() is invoked without ensuring that the respective
string actually has sufficiently many characters. From the constant
initialization on line 363 we take that k will assume the values 0 and 1,
while _code might be any string.

• missing/condition/value_or_state

com/itextpdf/text/pdf/BarcodeEAN.java

getBarsSupplemental2(String)

class BarcodeEAN {
    /** Creates the bars for the barcode supplemental 2.
     * @param _code the text with 2 digits
     * @return the barcode
     */    
    public static byte[] getBarsSupplemental2(String _code) {
        int code[] = new int[2];
        for (int k = 0; k < code.length; ++k)
            code[k] = _code.charAt(k) - '0';
        byte bars[] = new byte[TOTALBARS_SUPP2];
        int pb = 0;
        int parity = (code[0] * 10 + code[1]) % 4;
        bars[pb++] = 1;
        bars[pb++] = 1;
        bars[pb++] = 2;
        byte sequence[] = PARITY2[parity];
        for (int k = 0; k < sequence.length; ++k) {
            if (k == 1) {
                bars[pb++] = 1;
                bars[pb++] = 1;
            }
            int c = code[k];
            byte stripes[] = BARS[c];
            if (sequence[k] == ODD) {
                bars[pb++] = stripes[0];
                bars[pb++] = stripes[1];
                bars[pb++] = stripes[2];
                bars[pb++] = stripes[3];
            }
            else {
                bars[pb++] = stripes[3];
                bars[pb++] = stripes[2];
                bars[pb++] = stripes[1];
                bars[pb++] = stripes[0];
            }
        }
        return bars;
    }   

}