Did you code the java service? If yes, can you share it here.
For your perusal below is sample code snippet:
import java.util.zip.CRC32;
import java.util.zip.Checksum;
String input = "Mahesh";
byte bytes[] = input.getBytes();
Checksum checksum = new CRC32();
checksum.update(bytes, 0, bytes.length);
long checksumValue = checksum.getValue();
Print checksumValue
Check the working code at http://sagwebmethods-mahesh.blogspot.in/
#webMethods-General#Integration-Server-and-ESB#webMethods