Selecting a SAP Server at Runtime for JCo Based Application

[Former Member]

Selecting a SAP Server at Runtime for JCo Based Application

In one of my recent projects we had an requirement for selecting a SAP Server at runtime. The older system being built in Visual Basic provided the flexibility of choosing the servers with the help of BAPI ActiveX objects. Currently, migrating to web based application (Lotus Domino), they prefered the same kind of functionality. This being very unique, we developed an alternative method to achieve the same. This weblog explains the same with a sample codes and screen shots which will make it more meaningful. The Login screen had a look as shown below,



In Visual Basic we can use the BAPI ActiveX Component to access SAP and perform the required operations. Further it also provided the chance to select a Server at runtime. Please refer the below VB code which will display a SAP logon Pad at runtime.

' Declaration for the necessary objectsDim objBAPICortrol, objConnection, objCompanyCodes As ObjectDim login As BooleanPrivate Sub Form_Load()' Setting the necessary variables for R/3 connectionSet objBAPICortrol = CreateObject("SAP.Functions")Set objConnection = objBAPICortrol.Connection' Establish a connectionIf objConnection.Logon(0) Then    login = True    Logoff.Enabled = True    MsgBox "Connection Established"End IfEnd SubPrivate Sub Logoff_Click()If login = True ThenobjConnection.LogoffSet objConnection = NothingSet objBAPICortrol = NothingEndEnd IfEnd Sub

Now let us see how the same can be achieved using Java. The details that are displayed in SAP Logon Pad are available in C:\WINNT\saplogon.ini file.



Now we must read the required parameters from this file. I wrote a java code that will perfrom the required operation. For the readers reference a similar type of java code is given below.
/** * Project      :SAPJCOTutorial * Date         :Aug 12, 2005 * Programmed By: Kathirvel Balakrishnan * Company      : Wipro Technologies * Designation  : Project Engineer */package com.MyJCoPrograms;import java.io.BufferedReader;import java.io.FileReader;import java.io.InputStreamReader;import com.sap.mw.jco.*;/** * SelectSAPServerAndAccess */public class SelectSAPServerAndAccess { // Path for the Configuration File String configFile = "c:/WINNT/saplogon.ini"; // Stores the list of server details String configFileDate[] = new String[100]; String serverIp[] = new String[50]; String serverDescription[] = new String[50]; String systemNumber[] = new String[50];  // JCo Related Declaration JCO.Client myConnection = null;  int count = 0, choice; public void ReadSapLogonDetail() {  try {   BufferedReader in = new BufferedReader(new FileReader(configFile));   String line = null;   while ((line = in.readLine()) != null) {    configFileDate[count] = line;    count = count + 1;   }   in.close();  } catch (Exception e1) {   // TODO: handle exception   System.out.println(e1.toString());  } } public void GetServerEntries() {  int i = 0, ip1 = 0, sy1 = 0, de1 = 0;  while (i < count) {   if (configFileDate[i].compareTo("[Server]") == 0) {    i = i + 1;    while (configFileDate[i].substring(0, 4).equals("Item")) {     String[] temp = configFileDate[i].split("\\=");     serverIp[ip1] = temp[1];     ip1 = ip1 + 1;     i = i + 1;    }   }   if (configFileDate[i].compareTo("[Database]") == 0) {    i = i + 1;    while (configFileDate[i].substring(0, 4).equals("Item")) {     String[] temp = configFileDate[i].split("\\=");     systemNumber[sy1] = temp[1];     sy1 = sy1 + 1;     i = i + 1;    }   }   if (configFileDate[i].compareTo("[Description]") == 0) {    i = i + 1;    while (configFileDate[i].substring(0, 4).equals("Item")) {     String[] temp = configFileDate[i].split("\\=");     serverDescription[de1] = temp[1];     de1 = de1 + 1;     i = i + 1;    }   }      i = i + 1;  } } public void GetServerToConnect(){  int v = 0;  System.out.println("The List Server Available To Access");  while(serverDescription[v] != null){   System.out.println("[Choice : "+ v +"] -> [Server :"+serverDescription[v]+"]");   v = v + 1;  }  System.out.println("Please Enter Your Choice For Server To Connect\n");  System.out.print("Choice ->");  try{    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));   choice = Integer.valueOf(in.readLine()).intValue();   System.out.println("Entered Choice:"+choice);   }catch (Exception e2) {   // TODO: handle exception   System.out.println(e2.toString());  } }  public void ConnectToServer(){  try {   myConnection =    JCO.createClient(     "client",     "username",     "password",     "language",     serverIp[choice],     systemNumber[choice]);   System.out.println("systemNumber[choice]:"+systemNumber[choice]);     myConnection.connect();   System.out.println("Connection Successfully Established To Server:"+serverDescription[choice]);   myConnection.disconnect();  }catch (Exception e3) {   // TODO: handle exception   System.out.println(e3.toString());  }   }  public static void main(String[] args) {  SelectSAPServerAndAccess selectServer = new SelectSAPServerAndAccess();  selectServer.ReadSapLogonDetail();  selectServer.GetServerEntries();  selectServer.GetServerToConnect();  selectServer.ConnectToServer(); }}

The code performs the extraction of required details in saplogon.ini file and prompts for a choice of server. The sample code above just implements the following steps,
1. Read Details from saplogon.ini file
2. Extract the Server entry details
3. Get the choice of Server from user to establish a connection
4. Establishes a connection to the server using JCo.

Note: I did not perform much of the code optimization as it was just to explain the logic, i leave it in your hands to take it from here.

The result of the program is given below.



Thus simple way to achieve the Server selection functionality at runtime using java. Hope this was useful to you.