Java SAP Communication

Question

I have to connect to SAP R/3 system from a standalone Java application using JCo3.0. As per my understanding, there are 2 ways to connect with SAP system:

• JCo Client
• JCo Server

Now my application sends and receives data from SAP system. Do I need to use JCo Client/Server?

Answer 1

The 2 ways to connect to an SAP on-premise system via the RFC protocol are:

1. Inbound RFC communication (as an RFC client / Java calls ABAP)
2. Outbound RFC communication (as an RFC server / ABAP calls Java)

For inbound RFCs you need to use a JCoDestination for executing a remote function module at ABAP side. For outbound RFCs you need to register a JCoServer at the SAP gateway which will then receive incoming requests from ABAP side in order to process a remote function module at Java side. In both communication directions there is a request and potentially also a response to this request, so the data flow is usually in both directions, regardless if you are doing inbound or outbound RFC communication. Inbound and outbound just distinguishes who initiates the RFC call.

Answer 2

The solution that worked for me with R3 and sapjco3.jar is the following:

package com.example.springsocial.sap;

import java.io.File;
import java.io.FileOutputStream;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;

import com.sap.conn.jco.JCoDestination;
import com.sap.conn.jco.JCoDestinationManager;
import com.sap.conn.jco.JCoFunction;
import com.sap.conn.jco.JCoParameterList;
import com.sap.conn.jco.JCoTable;
import com.sap.conn.jco.ext.DestinationDataProvider;

public class SAPrfc {
    static String   IP="192.168.1.1",
                    USER="userName",
                    PASSWORD="myPassword",
                    CLIENT="100",// Mandatory number
                    SYSNR="00", // instance number
                    LANG="es", // language (es or en)
                    DESTINATION_NAME = "SAPconnection";

    private static JCoDestination destination;
    private static JCoParameterList outputTableParameterList;
    private static Map<String, Object> inputParameter;

    private static JCoFunction function;
    public static String rfcName="";
    public static String tableName="";

    public SAPrfc() throws Exception {
        setConnection();
        initConnection();
        clearParameters();
    }

    public static void setConnection() {
        System.out.println("setConnection in SAPrfc class");
        Properties connectProperties = new Properties();
        connectProperties.setProperty(DestinationDataProvider.JCO_ASHOST,   IP);
        connectProperties.setProperty(DestinationDataProvider.JCO_SYSNR,    SYSNR);
        connectProperties.setProperty(DestinationDataProvider.JCO_CLIENT,   CLIENT);
        connectProperties.setProperty(DestinationDataProvider.JCO_USER,     USER);
        connectProperties.setProperty(DestinationDataProvider.JCO_PASSWD,   PASSWORD);
        connectProperties.setProperty(DestinationDataProvider.JCO_LANG,     LANG);
        createDestinationDataFile(DESTINATION_NAME,connectProperties);
    }

    private static void createDestinationDataFile(String destinationName, Properties connectProperties){
        File destCfg = new File(destinationName+".jcoDestination");
        try{
            FileOutputStream fos = new FileOutputStream(destCfg, false);
            connectProperties.store(fos, "for tests only !");
            fos.close();
        }catch (Exception e){
            throw new RuntimeException("Unable to create the destination files", e);
        }
    }

    public static void initConnection() throws Exception {
        System.out.println("initConnection in SAPrfc class");
        destination = JCoDestinationManager.getDestination(DESTINATION_NAME);
        System.out.println("Attributes:");
        System.out.println(destination.getAttributes());
        System.out.println();
        destination.ping();
    } 

    public static void setRfcName(String rfcNameParam) {rfcName= rfcNameParam; };
    public static void setTableName(String tableNameParam) {tableName= tableNameParam; };

    public static JCoParameterList getOutputTableParamList() { return outputTableParameterList;};
    public static JCoTable getOutputTable() { return outputTableParameterList.getTable(tableName);};

    public static void clearParameters() { inputParameter= new HashMap<>(); };
    public static void addParameter(String paramName, Object paramValue) { inputParameter.put(paramName, paramValue); }
    public static void setParameters() {
        if (inputParameter!=null)
            for(Map.Entry<String, Object> entry : inputParameter.entrySet()) {
                function.getImportParameterList().setValue(entry.getKey(), entry.getValue());
            }
    }

    public static void executeRFC() throws Exception {
        if (rfcName.equals(""))
            throw new Exception("Es requerido el nombre de una RFC");

        destination = JCoDestinationManager.getDestination(DESTINATION_NAME);
        function = destination.getRepository().getFunction(rfcName);

        if (function == null)
            throw new RuntimeException("BAPI_COMPANYCODE_GETLIST not found in SAP.");

        setParameters();
        function.execute(destination);
        if (function.getExportParameterList().getFieldCount()==0) 
            throw new Exception("Error al obtener los datos");


        String resultado = function.getExportParameterList().getString("RESULTADO").toString();
        if (!resultado.equals("X"))// correct
            throw new Exception(function.getExportParameterList().getString("MENSAJE").toString());

        outputTableParameterList = function.getTableParameterList();
        setRfcName("");
        clearParameters();
    }

    public static void main(String[] args) {
        try {
            //RFC without parameters
            SAPrfc.setRfcName("ZMMF_CAT_ALMACENES");
            SAPrfc.clearParameters();
            SAPrfc.executeRFC();    
            SAPrfc.setTableName("TI_ALMACENES");
            JCoTable table = SAPrfc.getOutputTable();
            String WERKS,LGORT,LGOBE;
            for (int i = 0; i < table.getNumRows(); i++, table.nextRow()){
                 WERKS = table.getString("WERKS");
                 LGORT = table.getString("LGORT");
                 LGOBE = table.getString("LGOBE");
                 System.out.println("[" + i + "] - WERKS : "+WERKS+" LGORT: "+LGORT+" LGOBE: "+LGOBE );
            }

            //RFC with parameters
            SAPrfc.setRfcName("ZMMF_CAT_MATERIALES");
            SAPrfc.clearParameters();
            SAPrfc.addParameter("IWERKS", 2010);
            SAPrfc.executeRFC();    
            SAPrfc.setTableName("TI_MATERIALES");
            JCoTable table2 = SAPrfc.getOutputTable();
            String MATNR,MAKTX,DUN14,BISMT;
            for (int i = 0; i < table2.getNumRows(); i++, table2.nextRow()){
                 MATNR = table2.getString("MATNR");
                 MAKTX = table2.getString("MAKTX");
                 DUN14 = table2.getString("DUN14");
                 BISMT = table2.getString("BISMT");
                 System.out.println("[" + i + "] - MATNR : "+MATNR+" MAKTX: "+MAKTX+" DUN14: "+DUN14+" BISMT: "+BISMT );
            }

            //RFC without parameters
            SAPrfc.setRfcName("ZMMF_CAT_TIPO_MOV");
            SAPrfc.clearParameters();
            SAPrfc.executeRFC();    
            SAPrfc.setTableName("TI_TIPO_MOV");
            JCoTable table3 = SAPrfc.getOutputTable();
            String ACTION,DDTEXT;
            for (int i = 0; i < table3.getNumRows(); i++, table3.nextRow()){
                ACTION = table3.getString("ACTION");
                DDTEXT = table3.getString("DDTEXT");
                System.out.println("[" + i + "] - ACTION : "+ACTION+" DDTEXT: "+DDTEXT);
            }
        }catch (Exception ex) {
            System.out.println("Exception "+ex);
        }
    }       
}