I'm currently trying to migrate an EAR Project
-The old Project-
EJB 2.0
Jboss 5.0.1
-New Project-
EJB 3.0
Wildfly 13.0.0Final
Its session beans which I have managed to create and I can call upon it. the logic in it self seems to work. The issues I'm having is one of the follow ups seems to forget what it was doing.
the current issue I'm seeing is the following:
In the Web application in an class we are creating an object of Another class which we then trigger its parent method. this parent method then calls upon a class with it self as an argument which then checks which type it is and then stars a session bean depending on what type. which then calls on the arguments function performExecute() in this function we call upon a Query and actually get the correct results, we then add the resultsets values to a private dto member. and then performExecute is done. and we are back at the web applications class and we then try to access the same dto member with a get function. this returns a nullpointer. I'm wondering if I've forgotten something in my session beans?
Old sessionbean:
public class TxNotSupportedCommandServerBean implements SessionBean {
SessionContext sessionContext;
public void ejbCreate() throws CreateException {}
public void ejbRemove() {
sessionContext = null;
}
public void ejbActivate() {}
public void ejbPassivate() {}
public void setSessionContext(SessionContext sessionContext) {
this.sessionContext = sessionContext;
}
public void executeCommand(TargetableCommand cmd) throws CommandException {
try {
cmd.performExecute();
}
catch (CommandException ex) {
throw ex;
}
}
}
The new one:
@Stateless
@Remote
@TransactionManagement(value=TransactionManagementType.CONTAINER)
@TransactionAttribute(value=REQUIRED)
public class TxNotSupportedCmdServerBean implements TxNotSupportedCmdServerRemote{
/**
* Default constructor.
*/
public TxNotSupportedCmdServerBean() {
// TODO Auto-generated constructor stub
}
public void executeCommand(TargetableCommand cmd) throws CommandException {
try {
cmd.performExecute();
}
catch (CommandException ex) {
throw ex;
}
}
}
Both these are in the EJB.Jar
the interface is implemented in the EJBClient.jar
The old Interface:
public interface TxNotSupportedCommandServerLocal extends EJBLocalObject {
public void executeCommand(TargetableCommand cmd) throws CommandException;
}
The new Interface:
public interface TxNotSupportedCmdServerRemote {
public void executeCommand(TargetableCommand cmd) throws CommandException;
}
Now here come s the next set of files that is also in the EJBClient.jar
TargetableCommand:
public abstract class TargetableCommand implements Command {
private boolean constraintViolated;
protected RequestContext requestContext;
protected String dataSourceName;
public TargetableCommand(RequestContext requestContext, String dataSourceName) {
this.requestContext = requestContext;
this.dataSourceName = dataSourceName;
}
public TargetableCommand(RequestContext requestContext) {
this.requestContext = requestContext;
}
public TargetableCommand(String dataSourceName) {
this.dataSourceName = dataSourceName;
}
public TargetableCommand() {
}
public void setConstraintViolated(boolean constraintViolated) {
this.constraintViolated = constraintViolated;
}
public boolean isConstraintViolated() {
return constraintViolated;
}
public abstract void performExecute() throws CommandException;
public void execute() throws CommandException {
CommandTarget.executeCommand(this);
}
}
Command:
public interface Command extends Serializable {
public void execute() throws CommandException;
}
The commented code is the old session beans.
CommandTarget:
public class CommandTarget {
public CommandTarget() {
}
/**
* Exekverar ett kommando i rätt miljö, t.ex. med eller utan transaktionshantering
* @param cmd TargetableCommand Kommandot som ska utföras
* @throws CommandException
*/
public static void executeCommand(TargetableCommand cmd) throws CommandException {
Context context = null;
try {
ServiceLocator sl = ServiceLocator.getInstance();
// if (cmd instanceof TxRequired) {
// TxRequiredCommandServerLocalHome cmdSrvHome = (TxRequiredCommandServerLocalHome) sl.getEJBLocalHome("TxRequiredCommandServer");
// TxRequiredCommandServerLocal cmdSrv = cmdSrvHome.create();
// cmdSrv.executeCommand(cmd);
// }
// else if(cmd instanceof TxNotSupported) {
// TxNotSupportedCommandServerLocalHome cmdSrvHome = (TxNotSupportedCommandServerLocalHome) sl.getEJBLocalHome("TxNotSupportedCommandServer");
// TxNotSupportedCommandServerLocal cmdSrv = cmdSrvHome.create();
// cmdSrv.executeCommand(cmd);
// }
// else {
// throw new CommandException("Cannot instanciate command server");
// }
//
System.out.println("CT: Inside commandTarget. about to diffrientate what instance");
context = JNDILookupClass.getInitialContext();
if (cmd instanceof TxRequired) {
System.out.println("CT: TxRequired");
TxRequiredCmdServerRemote cmdSrv = (TxRequiredCmdServerRemote)context.lookup(JNDILookupClass.getLookupName("TxRequiredCmdServerRemoteBean", TxRequiredCmdServerRemote.class.getName()));
cmdSrv.executeCommand(cmd);
}
else if(cmd instanceof TxNotSupported) {
System.out.println("CT: TxNotSupported");
System.out.println("CT: cmd: " + cmd.getClass());
TxNotSupportedCmdServerRemote cmdSrv = (TxNotSupportedCmdServerRemote)context.lookup(JNDILookupClass.getLookupName("TxNotSupportedCmdServerBean", TxNotSupportedCmdServerRemote.class.getName()));
cmdSrv.executeCommand(cmd);
}
else {
throw new CommandException("Cannot instanciate command server");
}
}
catch (CommandException ex) {
throw ex;
}
// catch (CreateException ex) {
// throw new CommandException(ex);
// }
//new catch
catch(NamingException ex) {
throw new CommandException(ex);
}
catch (ServiceLocatorException ex) {
throw new CommandException(ex);
}
}
}
Phew ...
Ok now that's the important parts from EJBClient. now onwards to the Web.war
I'm only pasting the part that actually runs and were it returns a nullpoint
public class ActionIdentitetKonsultCommand implements Command {
private static Logger logger = Logger.getLogger(ActionIdentitetKonsultCommand.class);
public ActionIdentitetKonsultCommand() {
}
public String execute(RequestContext requestContext) throws CommandException {
GetPersonByPersnrEJBCommand personCmd;
logger.info("execute()");
try {
UserBean user = (UserBean) requestContext.getSession().getAttribute("user");
String kstnr = requestContext.getParameter("kstnr");
//Tilldela konsultuppgifter
personCmd = new GetPersonByPersnrEJBCommand();
personCmd.setPersnr(user.getPersnr());
System.out.println("AI: Before execute DTO " + personCmd.dto);
personCmd.execute();
System.out.println("AI: After execute DTO " + personCmd.dto);
logger.info("person hamtad med personnummer (EJB):");
logger.info(personCmd.getPerson().toString());
So the personCmd.getPerson().tostring() is what causes the nullpointer. GetPersonByPersnrEJBCommand():
public class GetPersonByPersnrEJBCommand extends TargetableCommand implements TxNotSupported {
public PersonDTO dto;
private long persnr;
public GetPersonByPersnrEJBCommand() {
}
public void setPersnr(long persnr) {
this.persnr = persnr;
}
public PersonDTO getPerson() {
return this.dto;
}
public void performExecute() throws CommandException {
try {
QueryPersonByPersnrCommand cmd = new QueryPersonByPersnrCommand();
cmd.setPersnr(persnr);
cmd.execute();
if(cmd.next()){
this.dto = new PersonDTO();
System.out.println("GP: inside PerformExecute DTO: " + dto);
dto.setPersnr(cmd.getPersnr());
dto.setEfternamn(cmd.getEfternamn());
dto.setFornamn(cmd.getFornamn());
dto.setEpostAdress(cmd.getEpostAdress());
dto.setKonsult((cmd.getKonsult() == 1));
dto.setAnsvarig((cmd.getAnsvarig() == 1));
System.out.println("GP: Inside Perform Execute DTO: " + dto);
}
}
catch (DataAccessCommandException ex) {
System.out.println("GetPersonByPersnrEJBCommand.performExecute misslyckades " + ex.getMessage());
throw new CommandException(ex);
}
}
}
So that's it; I don't understand why it forgets it. when we do sysouts inside the last class we see that both the dto and the cmd has data in them, but once the function ends and we are back in the class that called on this the data is empty. I'm suspecting its something to do with my session beans, I'm missing an property or something. because this code works with the old beans in the old JBOSS server. Hopefully someone can help me and others can learn from this as well as me.
I managed to solve this issue. Since the scope of the project is to get this to work. Its not a beautiful solution and with more time rewriting this would have been better. so onwards to the solution: We need to change in both the bean, targetableCommand, CommandTarget and in the GetPersonByPersnrEJBCommand
TargetableCommand - add method:
public TargetableCommand execute(TargetableCommand cmd) throws CommandException
{
return CommandTarget.executeCommand(cmd);
}
CommandTarget - We change the method executeCommand to return a TargetableCommand, and make sure that after the bean is done we return that cmd.
public static TargetableCommand executeCommand(TargetableCommand cmd) throws CommandException {
Context context = null;
try {
context = JNDILookupClass.getInitialContext();
if (cmd instanceof TxRequired) {
TxRequiredCmdServerRemote cmdSrv = (TxRequiredCmdServerRemote)context.lookup(JNDILookupClass.getLookupName("TxRequiredCmdServerRemoteBean", TxRequiredCmdServerRemote.class.getName()));
cmd = cmdSrv.executeCommand(cmd);
}
else if(cmd instanceof TxNotSupported) {
TxNotSupportedCmdServerRemote cmdSrv = (TxNotSupportedCmdServerRemote)context.lookup(JNDILookupClass.getLookupName("TxNotSupportedCmdServerBean", TxNotSupportedCmdServerRemote.class.getName()));
cmd = cmdSrv.executeCommand(cmd);
}
else {
throw new CommandException("Cannot instanciate command server");
}
}
catch (CommandException ex) {
throw ex;
}
catch(NamingException ex) {
throw new CommandException(ex);
}
}
return cmd;
}
The bean - cange the method Execute command to return Targetablecommand
public TargetableCommand executeCommand(TargetableCommand cmd) throws CommandException {
try {
cmd = cmd.performExecute();
}
catch (CommandException ex) {
throw ex;
}
return cmd;
}
Then lastly to get it all to work I had to create a new method in the classes that needed to do the perform execute so in the GetPersonByPersnrEJBCommand class i created the method wf13Layer(); wich is a just an extra step:
public void wf13Layer() throws CommandException
{
GetPersonByPersnrEJBCommand tmp;
try{
tmp = (GetPersonByPersnrEJBCommand) execute(this);
dto = tmp.getPerson();
} catch (Exception ex) {
throw new CommandException(ex);
}
}
This is what i did to make it work. as i said its not a beautiful solution but it works. IT seems to be a combination that once we cross between the projects the scope vanishes. and to obtain it futher we need to layer it like this. I really hope this helps someone at some point since theres till alot of old code running around out there.
Kind regards VeryTired