Error while displaying a page

Question

Hi techies..
I installed JDK and Tomcat in my Redhat linux and downloaded the Sap Java connector and installed it witout any problem. But the problem now is in one of the pages i'm establishing the connection for R/3 and while displating that page i get the error
javax.servlet.ServletException: Cannot allocate servlet instance for path /examples/servlet/response
and the root cause is java.lang.NoClassDefFoundError: com/sap/mw/jco/JCO$Record
can any one pls guide me how to procede.
Regards
Sriram

Answer 1

hii Ivaylo Ivanov
Thnk you for you help. The problem was with the paths of some .so file (eque of dlls). I placed the librfccm.so and libsapjco.so in the same folder where sapcar.jar is and then set the LD_LIBRARY_PATH to the above path. it worked fine.but the problem is when i run the below class file : Java example2.. it gives me error saying the following error
Exception in thread "main" java.lang.NoCLassDefFoundError: Example2
given the program. any help?
Example2.java
Property of SAP AG, Walldorf
(c) Copyright SAP AG, Walldorf, 2000-2003.
All rights reserved.
import com.sap.mw.jco.*;
@version 1.0
@author  SAP AG, Walldorf
public class Example2 {
  // The MySAP.com system we gonna be using
  static final String SID = "R3";
  // The repository we will be using
  IRepository repository;
  public Example2()
    try {
      // Add a connection pool to the specified system
      //    The pool will be saved in the pool list to be used
      //    from other threads by JCO.getClient(SID).
      //    The pool must be explicitely removed by JCO.removeClientPool(SID)
      JCO.addClientPool( SID,         // Alias for this pool
                         10,          // Max. number of connections
                         "210",       // SAP client
                         "abap",   // userid
                         "new",     // password
                         "EN",        // language
                         "10.11.20.2", // host name
                         "00" );
      // Create a new repository
      //    The repository caches the function and structure definitions
      //    to be used for all calls to the system SID. The creation of
      //    redundant instances cause performance and memory waste.
      repository = JCO.createRepository("MYRepository", SID);
    catch (JCO.Exception ex) {
      System.out.println("Caught an exception: \n" + ex);
  // Retrieves and prints information about the remote system
  public void systemInfo()
    try {
      // Get a function template from the repository
      IFunctionTemplate ftemplate = repository.getFunctionTemplate("RFC_SYSTEM_INFO");
      // if the function definition was found in backend system
      if(ftemplate != null) {
        // Create a function from the template
        JCO.Function function = ftemplate.getFunction();
        // Get a client from the pool
        JCO.Client client = JCO.getClient(SID);
        // We can call 'RFC_SYSTEM_INFO' directly since it does not need any input parameters
        client.execute(function);
        // The export parameter 'RFCSI_EXPORT' contains a structure of type 'RFCSI'
        JCO.Structure s = function.getExportParameterList().getStructure("RFCSI_EXPORT");
        // Use enumeration to loop over all fields of the structure
        System.out.println("System info for " + SID + ":\n" +
        for (JCO.FieldIterator e = s.fields(); e.hasMoreElements(); ) {
          JCO.Field field = e.nextField();
          System.out.println(field.getName() + ":\t" + field.getString());
        }//for
        System.out.println("\n\n");
        // Release the client into the pool
        JCO.releaseClient(client);
      else {
         System.out.println("Function RFC_SYSTEM_INFO not found in backend system.");
     catch (Exception ex) {
       System.out.println("Caught an exception: \n" + ex);
  // Retrieves and displays a sales order list
  public void salesOrders()
     JCO.Client client = null;
    try {
      // Get a function template from the repository
      IFunctionTemplate ftemplate = repository.getFunctionTemplate("BAPI_SALESORDER_GETLIST");
      // if the function definition was found in backend system
      if(ftemplate != null) {
          // Create a function from the template
          JCO.Function function = ftemplate.getFunction();
          // Get a client from the pool
          client = JCO.getClient(SID);
          // Fill in input parameters
          JCO.ParameterList input = function.getImportParameterList();
          input.setValue("0000001200", "CUSTOMER_NUMBER"   );
          input.setValue(      "1000", "SALES_ORGANIZATION");
          input.setValue(         "0", "TRANSACTION_GROUP" );
          // Call the remote system
          client.execute(function);
          // Print return message
          JCO.Structure ret = function.getExportParameterList().getStructure("RETURN");
          System.out.println("BAPI_SALES_ORDER_GETLIST RETURN: " + ret.getString("MESSAGE"));
          // Get table containing the orders
          JCO.Table sales_orders = function.getTableParameterList().getTable("SALES_ORDERS");
          // Print results
          if (sales_orders.getNumRows() > 0) {
            // Loop over all rows
            do {
              System.out.println("----
              // Loop over all columns in the current row
              for (JCO.FieldIterator e = sales_orders.fields(); e.hasMoreElements(); ) {
                 JCO.Field field = e.nextField();
                 System.out.println(field.getName() + ":\t" + field.getString());
              }//for
            } while(sales_orders.nextRow());
          else {
            System.out.println("No results found");
          }//if
      else {
         System.out.println("Function BAPI_SALESORDER_GETLIST not found in backend system.");
       }//if
    catch (Exception ex) {
      System.out.println("Caught an exception: \n" + ex);
    finally {
       // Release the client to the pool
      JCO.releaseClient(client);
  protected void cleanUp() {
    JCO.removeClientPool(SID);
  public static void main(String[] argv)
    Example2 e = new Example2();
    e.systemInfo();
    e.salesOrders();
    e.cleanUp();
Regards
Sriram