Problem to BC4J and Struts

Question

import model.common.BalancedModule;
import oracle.jbo.html.BC4JContext;
import org.apache.struts.validator.ValidatorForm;
import org.apache.struts.action.ActionErrors;
import org.apache.struts.action.ActionError;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionMapping;
import javax.servlet.http.HttpServletRequest;
public class LoginForm extends ValidatorForm
protected String username;
protected String password;
public void setUsername(String username)
{ this.username = username;
public String getUsername()
{ return this.username = username;
public void setPassword(String password)
{ this.password = password;
public String getPassword()
{ return this.password;
public void reset(ActionMapping mapping, HttpServletRequest request)
{  username ="";
password = "";
public ActionErrors validate(ActionMapping mapping, HttpServletRequest request)
{ ActionErrors errors = new ActionErrors();
//capturando el contexto del servidor
if (this.username == null || this.username.length()<1)
errors.add("username", new ActionError("error.username.required") );
if (this.password == null || this.password.length()<1)
errors.add("password", new ActionError("error.password.required") );
BC4JContext context = BC4JContext.getContext(request);
//utilizando la clase del model y asimilando el contexto al objeto
BalancedModule ts = (BalancedModule)context.getApplicationModule();
if (!ts.validSignon(username,password))
errors.add("signin",new ActionError("error.signin.logininvalid"));
return errors;
return
java.lang.NullPointerException
     at com.sanpablo.form.LoginForm.validate(LoginForm.java:41)
     at org.apache.struts.action.RequestProcessor.processValidate(RequestProcessor.java:942)
     at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:255)
     at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1485)
     at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:527)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
     at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.ResourceFilterChain.doFilter(ResourceFilterChain.java:65)
     at oracle.security.jazn.oc4j.JAZNFilter.doFilter(Unknown Source)
     at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.EvermindFilterChain.doFilter(EvermindFilterChain.java:16)
     at oracle.adf.model.servlet.ADFBindingFilter.doFilter(ADFBindingFilter.java:228)
     at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:600)
     at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:317)
     at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:790)
     at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.HttpRequestHandler.run(HttpRequestHandler.java:270)
     at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.HttpRequestHandler.run(HttpRequestHandler.java:112)
     at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:192)
     at java.lang.Thread.run(Thread.java:534)
help me

Answer 1

I'm not sure, but I think a better way to handle this is to write the login method in the app module, like you did, pass the username & password via action mappings in struts, and then use the return value to control navigation and session login attribute handling.
I had difficulties calling the application module from struts actions reliably.