Struts - Cannot find bean in any scope

[Juan Matias Lopez]

Hi, everyone. Im banging my head against the wall here. Im using Netbeans 7.0 to implement with the native Struts support an application to display a series of links in a page. Im getting the error:

HTTP Status 500 -
type Exception report
message
descriptionThe server encountered an internal error () that prevented it from fulfilling this request.
exception
javax.servlet.ServletException: javax.servlet.jsp.JspException: Cannot find bean: "linkListForm" in any scope
root cause
javax.servlet.jsp.JspException: Cannot find bean: "linkListForm" in any scope

(using Glassfish Server 3.1, also native).

Ive checked a lot of sites and forums, and nothing seems to fix this.

My struts-config:

<?xml version="1.0" encoding="UTF-8" ?>

<!DOCTYPE struts-config PUBLIC
          "-//Apache Software Foundation//DTD Struts Configuration 1.3//EN"
          "http://jakarta.apache.org/struts/dtds/struts-config_1_3.dtd">


<struts-config>
    <form-beans>
        <form-bean type="com.myapp.struts.LinkListForm" name="linkListForm"/>
        <form-bean type="com.myapp.struts.LoginForm" name="loginForm"/>
    </form-beans>
    
    <global-exceptions>
    
    </global-exceptions>

    <global-forwards>
        <forward name="welcome"  path="/Welcome.do"/>
    </global-forwards>

    <action-mappings>
        <action type="com.myapp.struts.LoginAction" name="loginForm" validate="true" input="/login.jsp" scope="request" path="/login"> 
        <forward name="exito" path="/admin.jsp"/> 
        <forward name="falla" path="/errorlogin.jsp"/>
        </action>
        <action type="com.myapp.struts.linkListAction" name="linkListForm" validate="false" input="/linkList.jsp" scope="request" path="/linkList">
        <forward name="mostrarlista" path="/linkList.jsp"/>
        </action>
    </action-mappings>
    
    <controller processorClass="org.apache.struts.tiles.TilesRequestProcessor"/>

    <message-resources parameter="com.myapp.struts.ApplicationResource"/>    
    
   
    <plug-in className="org.apache.struts.tiles.TilesPlugin" >
        <set-property property="definitions-config" value="/WEB-INF/tiles-defs.xml" />      
        <set-property property="moduleAware" value="true" />
   </plug-in>
    
   <plug-in className="org.apache.struts.validator.ValidatorPlugIn">
        <set-property
            property="pathnames"
            value="/WEB-INF/validator-rules.xml,/WEB-INF/validation.xml"/>
    </plug-in>
  
</struts-config>

linkListAction:

package com.myapp.struts;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;

/**
 *
 * @author BassDX
 */
public class linkListAction extends org.apache.struts.action.Action {

    /**
     * This is the action called from the Struts framework.
     * @param mapping The ActionMapping used to select this instance.
     * @param form The optional ActionForm bean for this request.
     * @param request The HTTP Request we are processing.
     * @param response The HTTP Response we are processing.
     * @throws java.lang.Exception
     * @return
     */
    
    @Override
    public ActionForward execute(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response)
            throws Exception {
        
        LinkListForm linklistform= (LinkListForm) form;
        
        listaLinks lista=new listaLinks();
        HttpSession session=request.getSession(true);
        linklistform.setLinks(lista.lista(session));
        session.setAttribute("linkListForm", linklistform.getLinks());
        
        
        return mapping.findForward("mostrarlista");
    }
}

LinkListForm:

package com.myapp.struts;

import java.util.Collection;
import java.util.ArrayList;
import javax.servlet.http.HttpServletRequest;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionForm;

public class LinkListForm extends ActionForm {
    
    private Collection links;

    public Collection getLinks() {
        return links;
    }

    public void setLinks(Collection links) {
        this.links = links;
    }
    
    @Override
    public void reset(ActionMapping arg0, HttpServletRequest arg1) {
        links = new ArrayList();
    }
    
}

and the jps that is giving the error:

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@taglib uri="/WEB-INF/fmt.tld" prefix="fmt"%>
<%@taglib uri="/WEB-INF/struts-html.tld" prefix="html"%>
<%@taglib uri="/WEB-INF/struts-logic.tld" prefix="logic"%>
<%@taglib uri="/WEB-INF/struts-bean.tld" prefix="bean"%>

<!DOCTYPE html>
<html>
    
    <head>
        <link rel="stylesheet" href="http://netbeans.org/netbeans.css" type="text/css">
	<fmt:setBundle basename="com.myapp.struts.ApplicationResource" />
	<title><fmt:message key="login.title"/></title>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    </head>
    <body>
        <table>
            <logic:empty name="linkListForm" property="links">
                <tr>
                    <td colspan="5">No Hay Links Ingresados. Por que no agregas uno?</td>
                </tr>
            </logic:empty>
            <logic:notEmpty name="linkListForm" property="links">
                <logic:iterate name="linkListForm" property="links" id="link">
                    <tr>
                        <td colspan="2"><bean:write name="link" property="dir"/></td>
                        <td colspan="3"><bean:write name="link" property="comentario"/></td>
                    </tr>
                </logic:iterate>
            </logic:notEmpty>    
        </table>    
    </body>
</html>

I really dont know what to do. Im a newbie in Struts. If it helps, when I press "ctrol+click" on name="linkListForm" Netbeans says The file linkListForm was not found.

Thanks in advance!

[Shankar Tanikella]

Hi Jaun, since you are setting the list in session as below

session.setAttribute("linkListForm", linklistform.getLinks());

mention scope="session" in all the places in JSP where ever it is being used. For example,

<logic:empty name="linkListForm" scope="session" property="links">  
// more code here...
             <logic:notEmpty name="linkListForm" scope="session" property="links">  
                 <logic:iterate name="linkListForm" scope="session" property="links" id="link"> 
// more code here...

Anyways, why would you need overload your session with a list? why wont don't you use use request instead?
However, the above should work for you

[Rajagopal Mani]

Hi Jaun, Please note the logical form-bean name & session attribute name are same which may lead fail. Remove the line where the collection links set in session scope & try.

[Juan Matias Lopez]

Thanks for the answers.

Shankar Tanikella wrote:Hi Jaun, since you are setting the list in session as below

session.setAttribute("linkListForm", linklistform.getLinks());

mention scope="session" in all the places in JSP where ever it is being used. For example,

<logic:empty name="linkListForm" scope="session" property="links">  
// more code here...
             <logic:notEmpty name="linkListForm" scope="session" property="links">  
                 <logic:iterate name="linkListForm" scope="session" property="links" id="link"> 
// more code here...

Anyways, why would you need overload your session with a list? why wont don't you use use request instead?
However, the above should work for you

I tried this, but it results in the same error:

type Exception report
message
descriptionThe server encountered an internal error () that prevented it from fulfilling this request.
exception
javax.servlet.ServletException: javax.servlet.jsp.JspException: Cannot find bean: "linkListForm" in scope: "session"
root cause
javax.servlet.jsp.JspException: Cannot find bean: "linkListForm" in scope: "session"

Could you give me an example using request? As I said, im not very familiar with this XD

Rajagopal Mani wrote:Hi Jaun, Please note the logical form-bean name & session attribute name are same which may lead fail. Remove the line where the collection links set in session scope & try.

Im not sure if I get this right, but I removed the line:
session.setAttribute("linkList", linklistform.getLinks());
and the error is the same.

[Shankar Tanikella]

Ha, firstly use html:form in your JSP and try whatever you tried before using request, it would be similar to below code
Action Class

    public ActionForward execute(ActionMapping mapping, ActionForm form,  
            HttpServletRequest request, HttpServletResponse response)  
            throws Exception {  
          
        LinkListForm linklistform= (LinkListForm) form;  
          
        listaLinks lista=new listaLinks();  
        // HttpSession session=request.getSession(true);  
        linklistform.setLinks(lista.lista(session));  
        // session.setAttribute("linkListForm", linklistform.getLinks());  
        request.setAttribute("LinkListForm", linklistform);  
          
        return mapping.findForward("mostrarlista");  
    } 

In your JSP

<!-- use html form here, in your JSP -->	
<html:form action="/linkList">
    <head>  
        <link rel="stylesheet" href="http://netbeans.org/netbeans.css" type="text/css">  
	<!-- More code -->	

            <logic:empty name="linkListForm" property="links">  
                <tr>  
                    <td colspan="5">No Hay Links Ingresados. Por que no agregas uno?</td>  
                </tr>  
            </logic:empty>
	
	<!-- More code -->	

Hope this time it works. again
Actually, you need not set the form in the request while using html:form

[Juan Matias Lopez]

Shankar Tanikella wrote:Ha, firstly use html:form in your JSP and try whatever you tried before using request, it would be similar to below code
Actually, you need not set the form in the request while using html:form

Thanks a lot! I finally could resolve that problem. Now, at least the page loads fine. But, as it seems to happen, new problems arised.

As I said, im trying to manipulate a collection of links. When I load that jsp, the collection apparently initiates empty. But I modified the listLinkAction and the container class (listaLinks) to add an element (for testing purposes). But the list always shows empty. I made several debbuging, and found out that the reset method of the form is used, but the execute() dont. I would be really glad if you could help me again XD

linklist.jsp

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@taglib uri="/WEB-INF/fmt.tld" prefix="fmt"%>
<%@taglib uri="/WEB-INF/struts-html.tld" prefix="html"%>
<%@taglib uri="/WEB-INF/struts-logic.tld" prefix="logic"%>
<%@taglib uri="/WEB-INF/struts-bean.tld" prefix="bean"%>

<!DOCTYPE html>

<html>
    <head>
        <link rel="stylesheet" href="http://netbeans.org/netbeans.css" type="text/css">
	<fmt:setBundle basename="com.myapp.struts.ApplicationResource" />
	<title><fmt:message key="login.title"/></title>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    </head>
    <body>
        <html:form action="/linkList.do">
        <table>
            <logic:empty name="linkListForm" property="links">
                <tr>
                    <td colspan="5">No Hay Links Ingresados. Por que no agregas uno?</td>
                </tr>
            </logic:empty>
            <logic:notEmpty name="linkListForm" property="links">
                <logic:iterate name="linkListForm" property="links" id="link">
                    <tr>
                        <td colspan="2"><bean:write name="link" property="dir"/></td>
                        <td colspan="3"><bean:write name="link" property="comentario"/></td>
                    </tr>
                </logic:iterate>
            </logic:notEmpty>    
        </table>
        </html:form>
        <html:link forward="agregar">Agregar Link</html:link>
    </body>
</html>

linkListAction(with several comments of the things I tried)

package com.myapp.struts;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.Action;

public class linkListAction extends Action {

    /**
     * This is the action called from the Struts framework.
     * @param mapping The ActionMapping used to select this instance.
     * @param form The optional ActionForm bean for this request.
     * @param request The HTTP Request we are processing.
     * @param response The HTTP Response we are processing.
     * @throws java.lang.Exception
     * @return
     */
    
    @Override
    public ActionForward execute(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response)
            throws Exception {
        
        LinkListForm linklistform= (LinkListForm) form;
        
        //listaLinks listal=new listaLinks();
        //listal.saveLink("aaa", "l", 0); 
        // HttpSession session=request.getSession(true);
        //linklistform.setLinks(lista.lista(session));
        //session.setAttribute("linkList", linklistform.getLinks());
        //linklistform.setLinks(listal.lista());
        request.setAttribute("LinkListForm", linklistform.getLinks());
        return mapping.findForward("mostrarlista");
    }
}

listaLink.java (again, a lot of comments, also, im not sure of the path for the file, that is, to keep and load the links)

package com.myapp.struts;

import java.io.*;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;

public class listaLinks {

    private Collection links;

    public listaLinks(){
        links=new ArrayList();
        //links.add(new link("Http","hola",1));
    }
    
    public void saveLink(String d, String c, int i) {
        link aux = new link(d, c, i);
        links.add(aux);
        backupinarchive();
    }

    public void deleteLink(String d) {
        int i = 0;
        Collection aux=new ArrayList();
        //while (!esta && i <= links.size() - 1) 
        Iterator it=links.iterator();
        while (it.hasNext()){
            link l=(link) it.next();
            if (!l.getDir().equals(d)) aux.add(l);
        }
        links=aux;
        backupinarchive();
        //aca tambien podria haber un error, por si no lo encuentra. Revisar!
    }

    private void reload() {
        File f = new File("/com/myapp/struts/listal.lnk");
        try {
            RandomAccessFile raf = new RandomAccessFile(f, "r");
            char aux = raf.readChar();
            while (aux != -1) {
                String direccion = "";
                String comentario = "";
                int icono = 0;
                while (aux != '*') {
                    direccion = direccion + aux;
                    aux = raf.readChar();
                }
                aux = raf.readChar();
                while (aux != '*') {
                    comentario = comentario + aux;
                    aux = raf.readChar();
                }
                aux = raf.readChar();
                while (aux != '#') {
                    icono = aux;
                    aux = raf.readChar();
                }
                links.add(new link(direccion, comentario, icono));
                aux = raf.readChar();
            }
            raf.close();
        } catch (Exception e) {}
        //Aca deberia haber un error por si no puede leer.
    }

    private void backupinarchive() {
        File f2 = new File("/com/myapp/struts/listal.lnk");
        if (f2.delete()) {
            try {
                File f = new File("/com/myapp/struts/listal.lnk");
                RandomAccessFile raf = new RandomAccessFile(f, "rw");
                Iterator it=links.iterator();
                while (it.hasNext()){
                    link l=(link) it.next();
                    raf.writeChars(l.getDir());
                    raf.writeChar('*');
                    raf.writeChars(l.getComentario());
                    raf.writeChar('*');
                    raf.writeInt(l.getIco());
                    raf.writeChar('#');
                }
                raf.close();
            } catch (Exception e) {
            }
        }
    }
    
    public Collection lista(){
       //reload();
       return links;
    }
}

Thanks a lot!

[Shankar Tanikella]

Are you sure that execute method is not being called? anyways, try this piece of code in your action just to very what is happening

    public ActionForward execute(ActionMapping mapping, ActionForm form,   
            HttpServletRequest request, HttpServletResponse response) throws Exception {   
        LinkListForm linklistform= (LinkListForm) form;   
        Collection links = new ArrayList();   
        links.add(new link("Http","hola",1));   
		linklistform.setLinks(links);
        request.setAttribute("LinkListForm", linklistform.getLinks());   
        return mapping.findForward("mostrarlista");   
    }

And to see the list size in your JSP add some text within the iterate tag and see if it is entering the loop(just in case)

[Juan Matias Lopez]

Shankar Tanikella wrote:Are you sure that execute method is not being called? anyways, try this piece of code in your action just to very what is happening

    public ActionForward execute(ActionMapping mapping, ActionForm form,   
            HttpServletRequest request, HttpServletResponse response) throws Exception {   
        LinkListForm linklistform= (LinkListForm) form;   
        Collection links = new ArrayList();   
        links.add(new link("Http","hola",1));   
		linklistform.setLinks(links);
        request.setAttribute("LinkListForm", linklistform.getLinks());   
        return mapping.findForward("mostrarlista");   
    }

And to see the list size in your JSP add some text within the iterate tag and see if it is entering the loop(just in case)

Just tested it, the list is still "size=0".

[Shankar Tanikella]

Interesting, Could you share the latest code snippets for
1. the method in action class
2. the form bean (if it is changed to the earlier)
3. the JSP code used to display
There is some small and silly thing that we are missing, we shall dig it this time

[Juan Matias Lopez]

Shankar Tanikella wrote:Interesting, Could you share the latest code snippets for
1. the method in action class
2. the form bean (if it is changed to the earlier)
3. the JSP code used to display
There is some small and silly thing that we are missing, we shall dig it this time

linkListAction:

package com.myapp.struts;

import java.util.ArrayList;
import java.util.Collection;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.Action;

public class linkListAction extends Action {
    
    @Override
    public ActionForward execute(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response)
            throws Exception {
        
        //LinkListForm linklistform= (LinkListForm) form;
        
        //listaLinks listal=new listaLinks();
        //listal.saveLink("aaa", "l", 0); 
        // HttpSession session=request.getSession(true);
        //linklistform.setLinks(lista.lista(session));
        //session.setAttribute("linkList", linklistform.getLinks());
        //linklistform.setLinks(listal.lista());
        //request.setAttribute("LinkListForm", linklistform.getLinks());
        LinkListForm linklistform= (LinkListForm) form;     
        Collection links = new ArrayList();     
        links.add(new link("Http","hola",1));     
        linklistform.setLinks(links);  
        request.setAttribute("LinkListForm", linklistform.getLinks());     
        
        return mapping.findForward("mostrarlista");
    }
}

linkListForm:

package com.myapp.struts;

import java.util.Collection;
import java.util.ArrayList;
import javax.servlet.http.HttpServletRequest;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionForm;

public class LinkListForm extends ActionForm {
    
    private Collection links;

    public Collection getLinks() {
        return links;
    }

    public void setLinks(Collection links) {
        this.links = links;
    }
    
    @Override
    public void reset(ActionMapping arg0, HttpServletRequest arg1) {
        links = new ArrayList();
    }
    
}

listalink.jsp:

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@taglib uri="/WEB-INF/fmt.tld" prefix="fmt"%>
<%@taglib uri="/WEB-INF/struts-html.tld" prefix="html"%>
<%@taglib uri="/WEB-INF/struts-logic.tld" prefix="logic"%>
<%@taglib uri="/WEB-INF/struts-bean.tld" prefix="bean"%>

<!DOCTYPE html>

<html>
    <head>
        <link rel="stylesheet" href="http://netbeans.org/netbeans.css" type="text/css">
	<fmt:setBundle basename="com.myapp.struts.ApplicationResource" />
	<title><fmt:message key="login.title"/></title>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    </head>
    <body>
        <html:form action="/linkList.do">
        <table>
            <logic:empty name="linkListForm" property="links">
                <tr>
                    <td colspan="5">No Hay Links Ingresados. Por que no agregas uno?</td>
                </tr>
            </logic:empty>
            <logic:notEmpty name="linkListForm" property="links">
                <logic:iterate name="linkListForm" property="links" id="link">
                    <tr>
                        <td colspan="2"><bean:write name="link" property="dir"/></td>
                        <td colspan="3"><bean:write name="link" property="comentario"/></td>
                    </tr>
                </logic:iterate>
            </logic:notEmpty>    
        </table>
        </html:form>
        <html:link forward="agregar">Agregar Link</html:link>
    </body>
</html>

Testing some things, we noticed that in a similar jsp/form/action (the one used to simulate a login) the execute() method is accesed after posting a <html:submit>. So, we are looking for a way to do this automatically, I think.

[Shankar Tanikella]

Good, 1. try changing the method name in the action class from 'execute' to something else and call this method in the input JSP.
2. extend DispatchAction instead of Action (not really sure, just give a try)

[Juan Matias Lopez]

The second option didnt work. The first one... Im not really sure who to call that renamed method. Anyway, I dont really think thats the good way to go XD Thanks for the ideas.

[Shankar Tanikella]

One point to note is that the form reset method is called upon the request submission.

Anyways, just to add up, let us look into this scenario
1. You logged into the application (execute method is invoked),welcome screen is displayed with several links
2. you click on one of the links (a) or button (b)
(a) link: you would provide some URL for redirection, say for example: http://mysite.com/SecondPage.do
(b) button: you would handle the destination of submit in a JS(?). For this you would provide form.action=http://mysite.com/SecondPage.do
3. (in both the scenarios a,b you would execute using 'execute' method itself) The destination page (say your links page) is displayed after processing

now we shall change this using parameter,
in the struts config you have posted earlier we also have an option to add "parameter" attribute in the action mapping section. normally we use the parameter as method. we can give any name for that matter(even my name), for example

<action type="com.myapp.struts.linkListAction" name="linkListForm" parameter="method" validate="false" input="/linkList.jsp" scope="request" path="/linkList">  

this makes you to call several methods in the same action class, how?
Going back to the 2.b you provide the action for form submission form.action=http://mysite.com/SecondPage.do?method=someMethodNameInSameAction
So then it would verify the "/SecondPage" action path and execute the method named 'someMethodNameInSameAction'. However, if you feel that using methods is not the good way to go, then, we would end up creating a separate action class for each functionality we have, isn't it?

[Juan Matias Lopez]

On a second thought, im running out of ideas XD
I tried your suggestion, same result.

<action type="com.myapp.struts.linkListAction" name="linkListForm" validate="false" input="/linkList.jsp" scope="request" path="/linkList" parameter="method">

public ActionForward empezar(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response)
            throws Exception {
       
        LinkListForm linklistform= (LinkListForm) form;     
        Collection links = new ArrayList();     
        links.add(new link("Http","hola",1));     
        linklistform.setLinks(links);  
        request.setAttribute("LinkListForm", linklistform.getLinks());     
        
        return mapping.findForward("mostrarlista");
    }

<html:form action="/linkList.do?method=empezar">

However, im not sure if the syntax is right.
Anyway, this is not working either. You said something about making addicional Action classes, what for? Anyway, thanks for the help! (again)