To call an SAP function module from a Java application, you first need SAP JCo (Java Connector); you can download it from SAP’s site, though you need an account to do so.
To actually open the connection, use the tip code shown here.
Class jcoClass = Class.forName("com.sap.mw.jco.JCO", true, this.getClass().getClassLoader());Client client = JCO.createClient(clientNumber, user, passWord, lang, host, systemId);//all parameters are stringsclient.connect();Repository repository = new JCO.Repository("SAP", client);IFunctionTemplate functionTemplate = repository.getFunctionTemplate("YOUR_FUNCTIONAL_MODULE_NAME");Function function = functionTemplate.getFunction();ParameterList parameterList = function.getImportParameterList();parameterList.setValue("value1", "INPUT_PARAM_NAME");parameterList.setValue("value2", "INPUT_PARAM_NAME2");client.execute(function);