struts2.0+java.lang.NullPointerException

this is Index.jsp page:

import java.util.ArrayList;
import java.util.Iterator;
import java.util.Map;
import org.apache.struts2.interceptor.ApplicationAware;
import org.omg.CORBA.Request;

import com.my.User;
import com.opensymphony.xwork2.ActionSupport;
public class adduser extends ActionSupport implements ApplicationAware {

String username;
	String password;
	String city;
	Map application;
	
		public String getUsername() {
			return username;
		}

public void setUsername(String username) {
			this.username = username;
		}

public String getPassword() {
			return password;
		}

public void setPassword(String password) {
			this.password = password;
		}

public String getCity() {
			return city;
		}

public void setCity(String city) {
			this.city = city;
		}

public String execute() throws Exception
		{     
			System.out.println(application.get("users"));
			
			ArrayList users=(ArrayList)application.get("users");
				
				
			if(users==null)
			{
				System.out.println("New Array List :");
				users=new ArrayList();
				
			}
			if(getUser(username)==null)
			{
				users.add(buildusers());
				application.put("users", users);
			}
			else
			{
				
				return SUCCESS;
			}
		
			System.out.println("Success");
			return SUCCESS;
		}

public void setApplication(Map application) {
			this.application=application;
		}
		
		
		
		public User buildusers()
		{
			User user=new User();
			user.setUsername(username);
			user.setPassword(password);
			user.setCity(city);
			return user;
		}
		
		
		public User getUser(String username)
		{
			User user=new User(); 
			boolean found=false;
			ArrayList users=(ArrayList)application.get("users");
			if(users!=null)
			{
				Iterator it=users.iterator();
				while(it.hasNext())
				{
					user=(User)it.next();
					if(username.equals(user.getUsername()))
					{
						found=true;
						break;
					}
				}
				if(found)
				{
					return user;
				}
			}
			
			return null;
			
		}
	
}

this is like simple data collection form it will collect info then display its contents?
please some one sort out this problem i got stuck with this problem from last 3 days

.

can you please tell me that where are you getting null pointer exception.?
please point out the line where you got exception.

Thanks
Raza!

ya

Struts Problem Report
Struts has detected an unhandled exception:

Messages:
File: org/apache/struts2/convention/annotation/AnnotationTools.java
Line number: 45

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Stacktraces
java.lang.NullPointerException
org.apache.struts2.convention.annotation.AnnotationTools.findAnnotation(AnnotationTools.java:45)
org.apache.struts2.convention.ConventionsServiceImpl.determineResultPath(ConventionsServiceImpl.java:62)
org.apache.struts2.convention.ConventionsServiceImpl.determineResultPath(ConventionsServiceImpl.java:98)
org.apache.struts2.convention.ConventionUnknownHandler.determinePath(ConventionUnknownHandler.java:385)
org.apache.struts2.convention.ConventionUnknownHandler.handleUnknownResult(ConventionUnknownHandler.java:274)
com.opensymphony.xwork2.DefaultUnknownHandlerManager.handleUnknownResult(DefaultUnknownHandlerManager.java:76)
com.opensymphony.xwork2.DefaultActionInvocation.createResult(DefaultActionInvocation.java:215)
com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:356)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:266)
com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:165)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:252)
org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:122)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:179)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:94)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:235)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:89)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:130)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:267)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:126)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:138)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:165)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:179)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52)
org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:488)
org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:395)
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581)
org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
java.lang.Thread.run(Thread.java:619)

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You are seeing this page because development mode is enabled. Development mode, or devMode, enables extra debugging behaviors and reports to assist developers. To disable this mode, set:

struts.devMode=false

What libraries are you deploying? Are you *trying* to use the convention plugin, or is this by accident?

Why on earth are you importing org.omg.CORBA.Request??? Why are you using the JSTL core prefix "c" for the S2 tag library?! Use "s" and save people a LOT of headache. Why do you create a new User() in getUser() only to overwrite it later? Why do you return Action.SUCCESS in your action, but name your results "SUCCESS", which is *not* the value of Action.SUCCESS? (That may be the source of your error, by the way, but since you're deploying the convention library, it's trying to determine the result its own way.)