Struts2: type Exception report

HTTP Status 500 -

---

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: Unable to instantiate Action, com.action.LoginAction,  defined for 'login' in namespace '/'null - action - file:/C:/apache-tomcat-6.0.14/webapps/WebProject/WEB-INF/classes/struts.xml:23:75
 org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:518)
 org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:421)

root cause

Unable to instantiate Action, com.action.LoginAction,  defined for 'login' in namespace '/'null - action - file:/C:/apache-tomcat-6.0.14/webapps/WebProject/WEB-INF/classes/struts.xml:23:75
 com.opensymphony.xwork2.DefaultActionInvocation.createAction(DefaultActionInvocation.java:289)
 com.opensymphony.xwork2.DefaultActionInvocation.init(DefaultActionInvocation.java:360)
 com.opensymphony.xwork2.DefaultActionInvocation.access$000(DefaultActionInvocation.java:38)
 com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:78)
 com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
 com.opensymphony.xwork2.DefaultActionInvocation.<init>(DefaultActionInvocation.java:70)
 com.opensymphony.xwork2.DefaultActionInvocation.<init>(DefaultActionInvocation.java:66)
 com.opensymphony.xwork2.DefaultActionProxy.prepare(DefaultActionProxy.java:189)
 org.apache.struts2.impl.StrutsActionProxyFactory.createActionProxy(StrutsActionProxyFactory.java:41)
 org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:497)
 org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:421)

root cause

java.lang.NullPointerException
 com.LoginAction.<init>(LoginAction.java:35)
 sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
 sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
 sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
 java.lang.reflect.Constructor.newInstance(Constructor.java:513)
 java.lang.Class.newInstance0(Class.java:355)
 java.lang.Class.newInstance(Class.java:308)
 com.opensymphony.xwork2.ObjectFactory.buildBean(ObjectFactory.java:121)
 com.opensymphony.xwork2.ObjectFactory.buildBean(ObjectFactory.java:152)
 com.opensymphony.xwork2.ObjectFactory.buildBean(ObjectFactory.java:141)
 com.opensymphony.xwork2.ObjectFactory.buildAction(ObjectFactory.java:111)
 com.opensymphony.xwork2.DefaultActionInvocation.createAction(DefaultActionInvocation.java:270)
 com.opensymphony.xwork2.DefaultActionInvocation.init(DefaultActionInvocation.java:360)
 com.opensymphony.xwork2.DefaultActionInvocation.access$000(DefaultActionInvocation.java:38)
 com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:78)
 com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
 com.opensymphony.xwork2.DefaultActionInvocation.<init>(DefaultActionInvocation.java:70)
 com.opensymphony.xwork2.DefaultActionInvocation.<init>(DefaultActionInvocation.java:66)
 com.opensymphony.xwork2.DefaultActionProxy.prepare(DefaultActionProxy.java:189)
 org.apache.struts2.impl.StrutsActionProxyFactory.createActionProxy(StrutsActionProxyFactory.java:41)
 org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:497)
 org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:421)

note The full stack trace of the root cause is available in the Apache Tomcat/6.0.14 logs.

---

Apache Tomcat/6.0.14

FreeMarker template error!

FreeMarker template error!

Expression parameters.doubleId is undefined on line 47, column 108 in template/simple/optiontransferselect.ftl.
The problematic instruction:
----------
==> ${parameters.doubleId?html} [on line 47, column 106 in template/simple/optiontransferselect.ftl]
in include "/${parameters.templateDir}/simple/optiontransferselect.ftl" [on line 2, column 1 in template/xhtml/optiontransferselect.ftl]
----------

Java backtrace for programmers:
----------
freemarker.core.InvalidReferenceException: Expression parameters.doubleId is undefined on line 47, column 108 in template/simple/optiontransferselect.ftl.
at freemarker.core.TemplateObject.assertNonNull(TemplateObject.java:124)
at freemarker.core.Expression.getStringValue(Expression.java:118)
at freemarker.core.Expression.getStringValue(Expression.java:93)
at freemarker.core.StringBuiltins$StringBuiltIn._getAsTemplateModel(StringBuiltins.java:71)
at freemarker.core.Expression.getAsTemplateModel(Expression.java:89)
at freemarker.core.Expression.getStringValue(Expression.java:93)
at freemarker.core.DollarVariable.accept(DollarVariable.java:76)
at freemarker.core.Environment.visit(Environment.java:196)
at freemarker.core.MixedContent.accept(MixedContent.java:92)
at freemarker.core.Environment.visit(Environment.java:196)
at freemarker.core.IfBlock.accept(IfBlock.java:82)
at freemarker.core.Environment.visit(Environment.java:196)
at freemarker.core.MixedContent.accept(MixedContent.java:92)
at freemarker.core.Environment.visit(Environment.java:196)
at freemarker.core.ConditionalBlock.accept(ConditionalBlock.java:79)
at freemarker.core.Environment.visit(Environment.java:196)
at freemarker.core.MixedContent.accept(MixedContent.java:92)
at freemarker.core.Environment.visit(Environment.java:196)
at freemarker.core.Environment.include(Environment.java:1375)
at freemarker.core.Include.accept(Include.java:155)
at freemarker.core.Environment.visit(Environment.java:196)
at freemarker.core.MixedContent.accept(MixedContent.java:92)
at freemarker.core.Environment.visit(Environment.java:196)
at freemarker.core.Environment.process(Environment.java:176)
at freemarker.template.Template.process(Template.java:232)
at org.apache.struts2.components.template.FreemarkerTemplateEngine.renderTemplate(FreemarkerTemplateEngine.java:148)
at org.apache.struts2.components.UIBean.mergeTemplate(UIBean.java:530)
at org.apache.struts2.components.UIBean.end(UIBean.java:484)
at org.apache.struts2.views.jsp.ComponentTagSupport.doEndTag(ComponentTagSupport.java:43)
at org.apache.jsp.viewContent_jsp._jspx_meth_s_005foptiontransferselect_005f0(viewContent_jsp.java:215)
at org.apache.jsp.viewContent_jsp._jspService(viewContent_jsp.java:108)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:414)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:263)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:584)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Thread.java:619)

Struts 2 Exception : No result defined for action LoginAction

No result defined for action com.action.LoginAction and result input - action - file:struts.xml:10:75
com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:345)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:248)
com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:150)
org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:48)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:86)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216)
com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:123)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216)
com.opensymphony.xwork2.interceptor.ParametersInterceptor.intercept(ParametersInterceptor.java:161)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216)
com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:105)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216)
org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:83)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216)
org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:207)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216)
com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:74)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216)
com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:127)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216)
org.apache.struts2.interceptor.ProfilingActivationInterceptor.intercept(ProfilingActivationInterceptor.java:107)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216)
org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:206)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216)
com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:115)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216)
com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:143)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216)
com.opensymphony.xwork2.interceptor.PrepareInterceptor.intercept(PrepareInterceptor.java:115)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216)
org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:170)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216)
com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:123)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216)
com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:219)
com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:218)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:216)
org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:50)
org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:507)
org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:421)

Handling Cookies with WebRequest Class

WebRequest is an important class for establishing http connections programatically and fetching html page. You might well be aware about it's power. However I will be focussing on one limitation and a possible work-around.

While fetching some html content I hit upon a problem where it was expected for cookies to be enabled by the browser. Since I was making a hit using WebRequest class i was perplexed as to how to resolve it, untill better sense prevailed and I got the below solution.

Handling Cookies with WebRequest class

// Open a connection
HttpWebRequest WebRequestObject = (HttpWebRequest)HttpWebRequest.Create(Url);

// Set the Cookie Container under WebRequest object as a property
CookieContainer cookieJar = new CookieContainer();
WebRequestObject.CookieContainer = cookieJar;

// continue with your fetch

// A handy property is it seems that some page might take eternity to respond
WebRequestObject.Timeout = 5*60*1000; // (5 seconds) integer value in milliseconds

Updating auto-incremented id from SqlDataAdapter back into datatable

consider a table in your database .. else run the script to create

Create table person (
id int identity(1,1) not null,
name varchar(100) not null,
age int not null
)
-----------------
// C# sample code, should be in a proper .cs file to be executed

// some imports
using System;
using System.Data;
using System.Data.SqlClient;
// more imports

// ....
// some code
String connectionString = ""Persist Security Info=False;User ID=sa;Password=sa;Initial Catalog=master;Data Source=localhost;

// this is the query which we will require
String query = "insert into person (name, age) values (@NAME, @AGE);select @ROWID = @@identity";

DataTable dt = new DataTable();
dt.Columns.Add("ID", System.Type.GetType("System.Int32"));
dt.Columns.Add("NAME", System.Type.GetType("System.String"));
dt.Columns.Add("AGE", System.Type.GetType("System.Int32"));

dt.Rows.Add(new object[] {-1, "max", 10});

// check dt.Rows[0]["ID"] value it will be -1

// inserting the above table into database
SqlDataAdapter myAdapter =new SqlDataAdapter();
SqlConnection myConnection = new SqlConnection(ConnectionString);
myConnection.Open();
SqlCommand cmd = new SqlCommand(query, myConnection);
SqlParameter parmRowId =
cmd.Parameters.Add("@ROWID",DbType.Int32);
parmRowId.SourceColumn = "ID";
parmRowId.SourceVersion = DataRowVersion.Original;
parmRowId.Direction = ParameterDirection.Output;

SqlParameter parmID =
cmd.Parameters.Add("@NAME",DbType.Int32);
parmID.SourceColumn = "NAME";
parmID.SourceVersion = DataRowVersion.Original;

SqlParameter parmID =
cmd.Parameters.Add("@AGE",DbType.Int32);
parmID.SourceColumn = "AGE";
parmID.SourceVersion = DataRowVersion.Original;

myAdapter.InsertCommand = cmd;
// required to get back the auto-incrmented value
cmd.UpdatedRowSource = UpdateRowSource.OutputParameters;
myAdapter.Update(datatable);

// now check dt.Rows[0]["ID"] value it should be 1 or some auto-incremented value
// the above style can be used with your typed dataset too

// ... more code

Fetching last auto-incremented identity value

There are 3 of different ways for fetching the updated identity column value.

IDENT_CURRENT
SCOPE_IDENTITY
and @@IDENTITY
each of the above have a similar role to play except for some subtle differences.
One common tasks of theirs is that they return values inserted into IDENTITY columns.

IDENT_CURRENT is not limited by scope and session; it is limited to a specified table. IDENT_CURRENT returns the value generated for a specific table in any session and any scope.
SCOPE_IDENTITY and @@IDENTITY will return last identity values generated in any table in the current session. However, SCOPE_IDENTITY returns values inserted only within the current scope; @@IDENTITY is not limited to a specific scope.

for details refer
http://msdn.microsoft.com/en-us/library/aa259185(SQL.80).aspx

Programatically determining redirected URL

In order to detect the redirect, you have to use setFollowRedirects(false). Otherwise, you end up on the redirected page anyway with a responseCode of 200. However you will have to navigate the redirected url yourself.

using java.net.HttpURLConnection

URL url = new URL(urlstring);
// Determine if the url has redirected
HttpURLConnection.setFollowRedirects(false);
HttpURLConnection uc = (HttpURLConnection) url.openConnection();
if(uc.getResponseCode() == 300 uc.getResponseCode() == 302)
{
String newUrl = uc.getHeaderField("Location");

}