Hexdump for Java byte array

gistfile1.java

        StringBuilder output = new StringBuilder();
        int col = 0;
        int pos = 0;
        String[] chars = new String[16];
        for (byte b : array) {
            if (col == 0) {
                output.append("\n" + String.format("%04x", pos) + ": ");
            }
            output.append(String.format("%02x ", b));
            if (b > 31 && b < 128) {
                chars[col] = String.format("%c", b);
            }
            else {
                chars[col] = ".";
            }
            pos ++;
            col ++;
            if (col == 16) {
                col = 0;
                output.append("   ");
                for (String c : chars) {
                    output.append(c);
                }
            }
        }
        System.err.println(output.toString());