Need help on JCo

Question

Hi,
I am getting error message while running JCo java code. I followed the given steps in the installation guide. I know i did something wrong in this.
I created a folder C:\JCO and unzipped the downloaded JCo files librfc32.dll, sapjcorfc.dll and sapjco.jar.
Copied the file librfc32.dll from C:\JCO directory to C:\WINNT\SYSTEM32
Added the path c:\JCO\sapjco.jar; in the environmental variables. [I followed the following --> Right Click on My Computer --> Properties --> Advanced --> Environment Variables --> Edited the existing path and added with java path like C:\j2sdk1.4.2_05\bin;c:\JCO\sapjco.jar;].
After this I am trying to execute the following code. It is copiling without any problem and giving error message while run mode.
C:\JCO>java Bapi1
Exception in thread "main" java.lang.NoClassDefFoundError: com/sap/mw/jco/JCO$Structure
******java code*****
import com.sap.mw.jco.*;
public class Bapi1 extends Object {
   JCO.Client mConnection;
   JCO.Repository mRepository;
   public Bapi1() {
      try {
         // Change the logon information to your own system/user
         mConnection =
            JCO.createClient("020", // SAP client
              "myuserid", // userid
              "****", // password
              "EN", // language
              "myerp server host name", // application server host name
              "00"); // system number
        mConnection.connect();
        mRepository = new JCO.Repository("SAPJCo", mConnection);
      catch (Exception ex) {
        ex.printStackTrace();
        System.exit(1);
      JCO.Function function = null;
      JCO.Table codes = null;
      try {
         function = this.createFunction("BAPI_COMPANYCODE_GETLIST");
         if (function == null) {
           System.out.println("BAPI_COMPANYCODE_GETLIST" +
                              " not found in SAP.");
           System.exit(1);
         mConnection.execute(function);
         JCO.Structure returnStructure =
           function.getExportParameterList().getStructure("RETURN");
         if (! (returnStructure.getString("TYPE").equals("") ||
                returnStructure.getString("TYPE").equals("S")) ) {
           System.out.println(returnStructure.getString("MESSAGE"));
           System.exit(1);
         codes =
           function.getTableParameterList().getTable("COMPANYCODE_LIST");
         for (int i = 0; i < codes.getNumRows(); i++) {
           codes.setRow(i);
           System.out.println(codes.getString("COMP_CODE") + '\t' +
                              codes.getString("COMP_NAME"));
      catch (Exception ex) {
        ex.printStackTrace();
        System.exit(1);
      try {
        codes.firstRow();
        for (int i = 0; i < codes.getNumRows(); i++, codes.nextRow()) {
          function = this.createFunction("BAPI_COMPANYCODE_GETDETAIL");
          if (function == null) {
            System.out.println("BAPI_COMPANYCODE_GETDETAIL" +
                               " not found in SAP.");
            System.exit(1);
     function.getImportParameterList().
       setValue(codes.getString("COMP_CODE"), "COMPANYCODEID");
     function.getExportParameterList().
       setActive(false, "COMPANYCODE_ADDRESS");
     mConnection.execute(function);
     JCO.Structure returnStructure =
       function.getExportParameterList().getStructure("RETURN");
     if (! (returnStructure.getString("TYPE").equals("") ||
            returnStructure.getString("TYPE").equals("S") ||
            returnStructure.getString("TYPE").equals("W")) ) {
        System.out.println(returnStructure.getString("MESSAGE"));
     JCO.Structure detail =
       function.getExportParameterList().
       getStructure("COMPANYCODE_DETAIL");
     System.out.println(detail.getString("COMP_CODE") + '\t' +
                        detail.getString("COUNTRY") + '\t' +
                        detail.getString("CITY"));
  catch (Exception ex) {
    ex.printStackTrace();
    System.exit(1);
  mConnection.disconnect();
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.");
public static void main (String args[]) {
   Bapi1 app = new Bapi1();

Answer 1

Hi Venu,
You have to add the java library sapjco.jar to the java classpath instead of the system classpath. You can do this by adding the -cp or -classpath parameter to your java call. So then you would get:
java -classpath C:JCOsapjco.jar Bapi1
Hope this helps,
Johan