Steps to create JCO to call R3 Function module in ISA CRM b2b webshop

Question

Hi experts,
Can u help me in creating a JCo connection to R3 from CRM isa b2b webshop.
See i am working on CRM 5.0 isa . I have a default jco connection calling to CRM.
But i wanted an another JCO to call FM of R3.
Can u pls give me the steps in creating this jco (XCM, Xml, changes etc )?
Hope you have understood my question.
Pls reply,
thanks in advance,
Niraja.

Answer 1

Hi Niraja,
The second option would be easy to do, as the connection is already made you can just use the connection pool.
I feel maintaining/creating two connections would lead to performance issues.
So its better to go with FM in CRM to FM in R/3
If you want to go for a different connection or connection pool then follow this example
In the world of database connectivity, creating individual connections to a database system is technically expensive and often incurs unwanted overhead in both client and server-side applications. Connection pools allow your application to check connections out from a pool and release a connection once the transaction has completed. This tip briefly explores the value and implementation of using connection pools in JCo.
The following code presents two classes that demonstrate the use of a connection pool and its restrictions. You should be able to pull code from this example when adding pooling to your own Java/JCo application.
The first JCo application does not use pooling:
import com.sap.mw.jco.*;
public class JcoTest {
private static JCO.Client theConnection;
private static IRepository theRepository;
public static void main(String[] args) {
  createConnection();
  retrieveRepository();
  try {
  JCO.Function function = getFunction("RFC_READ_TABLE");
  JCO.ParameterList listParams = function.getImportParameterList();
  listParams.setValue("BSAUTHORS", "QUERY_TABLE");
  theConnection.execute(function);
  JCO.Table tableList = function.getTableParameterList().getTable("DATA");
  if (tableList.getNumRows() > 0) {
   do {
    for (JCO.FieldIterator fI = tableList.fields();
      fI.hasMoreElements();)
      JCO.Field tabField = fI.nextField();
      System.out.println(tabField.getName()
           + ":t" +
           tabField.getString());
     System.out.println("n");
   while (tableList.nextRow() == true);
  catch (Exception ex) {
   ex.printStackTrace();
private static void createConnection() {
  try {
   theConnection = JCO.createClient("000", "DDIC", "minisap", "en", "sincgo", "00");
   theConnection.connect();
  catch (Exception ex) {
   System.out.println("Failed to connect to SAP system");
private static void retrieveRepository() {
  try {
   theRepository = new JCO.Repository("saprep", theConnection);
  catch (Exception ex)
   System.out.println("failed to retrieve repository");
  public static JCO.Function getFunction(String name) {
    try {
         return theRepository.getFunctionTemplate(name.toUpperCase()).getFunction();
    catch (Exception ex) {
     ex.printStackTrace();
      return null;
To add connection pooling you simply add this code to the beginning of the main method:
    if (connPool == null) {
      JCO.addClientPool(POOL_NAME,
                        5,
                        "000",
                        "bcuser",
                        "minisap",
                        "EN",
                        "sincgo",
                        "00");
And replace the call to the createConnection() method with this:
         theConnection = JCO.getClient(POOL_NAME);
The code should now look like this:
import com.sap.mw.jco.*;
public class JcoTest {
private static JCO.Client theConnection;
private static IRepository theRepository;
    private static final String POOL_NAME = "myPool";
public static void main(String[] args) {
    JCO.Pool connPool = JCO.getClientPoolManager().getPool(POOL_NAME);
    if (connPool == null) {
      JCO.addClientPool(POOL_NAME,
                        5,      //number of connections in the pool
                        "client",
                        "username",
                        "paswword",
                        "EN",
                        "hostname",
                        "00");
        theConnection = JCO.getClient(POOL_NAME);
  retrieveRepository();
  try {
  JCO.Function function = getFunction("RFC_READ_TABLE");
  JCO.ParameterList listParams = function.getImportParameterList();
  listParams.setValue("BSAUTHORS", "QUERY_TABLE");
  theConnection.execute(function);
  JCO.Table tableList = function.getTableParameterList().getTable("DATA");
  if (tableList.getNumRows() > 0) {
   do {
    for (JCO.FieldIterator fI = tableList.fields();
      fI.hasMoreElements();)
      JCO.Field tabField = fI.nextField();
      System.out.println(tabField.getName()
           + ":t" +
           tabField.getString());
     System.out.println("n");
   while (tableList.nextRow() == true);
  catch (Exception ex) {
   ex.printStackTrace();
  JCO.releaseClient(theConnection);
private static void retrieveRepository() {
  try {
   theRepository = new JCO.Repository("saprep", theConnection);
  catch (Exception ex)
   System.out.println("failed to retrieve repository");
  public static JCO.Function getFunction(String name) {
    try {
         return theRepository.getFunctionTemplate(name.toUpperCase()).getFunction();
    catch (Exception ex) {
     ex.printStackTrace();
      return null;
Now, when this class executes, it will create a pool of 5 SAP connections. Once created, a single connection is retrieved and executed against. After the call to SAP has finished, the connections are released with:
JCO.releaseClient(theConnection);
You can easily integrate this code in any application that acts as a server or requires multiple users to access SAP via the Web.
Regards,
Sateesh Chandra