Uploading multiple purchase order using csv file Java connector

Hi gurus,

                Im new to this platform,as i want to upload purchase order from client programming ie from java to sap..but its creating 1 record.not multiple

           header.add("COMP_CODE");

           header.add("DOC_TYPE");

           header.add("VENDOR");

           header.add("PURCH_ORG");

           header.add("PUR_GROUP");

//of this structure POHEADER.         

           JCoStructure headerx = function.getImportParameterList().getStructure("POHEADERX");

           headerx.setValue("COMP_CODE","X");

           headerx.setValue("DOC_TYPE","X");

           headerx.setValue("VENDOR","X");

           headerx.setValue("PURCH_ORG","X");

           headerx.setValue("PUR_GROUP","X");

//of structure POHEADERX

and

poitemlist.add("PO_ITEM");                            //of po_

           poitemlist.add("MATERIAL");

           poitemlist.add("PLANT");

         //  poitemlist.add("MATL_GROUP");

           poitemlist.add("QUANTITY");

           poitemlist.add("NET_PRICE");

           co.setValue("PO_ITEM","10");                     //of structure po_itemx

           co.setValue("MATERIAL","X");

           co.setValue("PLANT","X");

           co.setValue("QUANTITY","X");

           co.setValue("NET_PRICE","X");

in flat file they are iterating the input values using for loop

  for (int i = 0; i < dataList.size(); i++) {

                JCoStructure codes = function.getImportParameterList().getStructure("POHEADER");

               /* JCoTable code2 = function.getTableParameterList().getTable("POITEM");

                code2.appendRow();*/

                ArrayList<String> listArray = dataList.get(i);

                java.util.Iterator<String> iterator = listArray.iterator();

                for (int j = 0; j < header.size(); j++) {

                    codes.setValue(header.get(j), iterator.next());

                }

....but the problem is in 'X'.. for multiple record creation.

i hav to trigger the input values using the 'X' with multiple input values in coding which is poor performance...how can i use this in for loop.

please help.