How to use JCO and RFC

Question

Hi guys, please help me out
I'm new to JCO and do not have any idea about it.
Here is my situation, for testing, I want to call an ABP RFC FM in SAP just to return a single text message to Java application through parameter.
(Of course, I have access to SAP from my company and I do not have any Java compiler in my computer).
From my understanding, there 2 main things to concern (Please correct me if i'm wrong and please tell me the steps I should do)
1) Software installation and configuration
   What software do I need to install on my computer, is
   it JCO, SAPGUI, Java Compiler? What kind of
   configurations do I need for JCO?  
2) Programming
   a) SAP side
      Write an ABAP RFC FM just to return a text message
      to Java application through parameters (No problem
      with this step)
   b) My computer side
      Write a Java application to call ABP RFC FM
      Do you guys have any simple source code example for
      this?? Please remember that this Java application
      simply call an ABAP RFC FM to get just a single
      text message.
I really appreciate your help
Thank you

Answer 1

Hi Dean,
USe Eclipse for Java programming.
If you are downloading the latest version of JCO, make sure you have latest version of SAP Gui as there are version issues as the librfc.dll needs to be of compatible version.
As far as your sample code is concerned, here it is ...
import com.sap.mw.jco.*;
public class CallFunction extends Object {
     public static void main(String args[]) {
          CallFunction app = new CallFunction();
     int count;
     JCO.Client mConnection;
     JCO.Repository mRepository;
     public CallFunction() {
          try {
               // Logon info
                    mConnection = JCO.createClient("500", // SAP client
                                               "username", // userid
                                               "password", // password
                                                  null, // language
                                         "server name", // application server host name
                                                "00"); // system number
               mConnection.connect();
               mRepository = new JCO.Repository("MY_connection", mConnection);
          } catch (Exception ex) {
               ex.printStackTrace();
               System.exit(1);
          JCO.Function function = null;
          try {
               function = this.createFunction("ABAP_FM");
                 mConnection.execute(function);
               System.out.println(
                    function.getTableParameterList().getValue("Exporting_Message"));
          } catch (Exception ex) {
               ex.printStackTrace();
               System.exit(1);
     public JCO.Function createFunction(String name) throws Exception {
          try {
               IFunctionTemplate ft =
                    mRepository.getFunctionTemplate(name.toUpperCase());
               if (ft == null)
                    return null;
               return ft.getFunction();
          } catch (Exception ex) {
               throw new Exception("Problem retrieving JCO.Function object.");
Here in this mention ur function module in place of ABAP_FM and exporting parameter in place of Exporting_Message.
Regards,
Tanveer.
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