jpos : How to pack DE 55 - jpos

Question

I receive data as below for DE55 in hex
<field id="55" value="3546324130323038343038323032353830303935303530303030303030303030394130333032313031313943303130303946303230363030303030303030323130313946313030383031303130334130303030304441433139463141303230383430394632363038393044324530373242333534463233413946323730313830394633363032303030353946333730343132333435363738" type="binary"/>
The other end of the system expects the values as below in binary format
where 303736
3037365F2A02084082025800950500000000009A030210119C01009F02060000000021019F1008010103A00000DAC19F1A0208409F260890D2E072B354F23A9F2701809F360200059F370412345678
<field id="55" value="5F2A02084082025800950500000000009A030210119C01009F02060000000021019F1008010103A00000DAC19F1A0208409F260890D2E072B354F23A9F2701809F360200059F370412345678" type="binary"/>
my packager settings I am using is below , is there any class (field packager) available in jpos which will give my desired output or do I have to create a new custom field packager.
when I use the below , value is send as received in the request message
<isofield
id="55"
length="999"
name="INTEGRATED CIRCUIT CARD (ICC) SYSTEM-RELATED DATA"
class="org.jpos.iso.IFA_LLLBINARY"/>
please advise what field packager can I use for DE55 to get the desired.
Incase if I want to create new custom field packager what should I be doing ?
thanks in advance

Answer 1

I created a custom FieldPackager as below which pass bytes of array to the packager
public byte[] pack(ISOComponent c) throws ISOException
{
try
{
byte[] data1 = c.getBytes();
String de55_received = ISOUtil.hexString(data1);
byte[] de55_orig_value = DatatypeConverter.parseHexBinary(de55_received);
String de55_value = new String(de55_orig_value);
int de55length = de55_value.length();
byte[] de55_data = new byte[de55length / 2];
for (int i = 0; i < de55length; i += 2) {
de55_data[i / 2] = (byte) ((Character.digit(de55_value.charAt(i), 16) << 4)
+ Character.digit(de55_value.charAt(i+1), 16));
}
System.out.println(de55_data);
System.out.println(DatatypeConverter.printHexBinary(de55_data));
byte[] data = de55_data;
int packedLength = prefixer.getPackedLength();
if (packedLength == 0 && data.length != getLength()) {
throw new ISOException("Binary data length not the same as the packager length (" + data.length + "/" + getLength() + ")");
}
byte[] ret = new byte[interpreter.getPackedLength(data.length) + packedLength];
prefixer.encodeLength(data.length, ret);
interpreter.interpret(data, ret, packedLength);
return ret;
} catch(Exception e) {
throw new ISOException(makeExceptionMessage(c, "packing"), e);
}