Struts 2 jsp Error.

[Vic Hood]

Hi All,
Im facing an error while trying to run my jsp .Below , is the stacktrace of my error.

Mar 18, 2011 2:42:40 PM org.apache.catalina.core.ApplicationDispatcher invoke
SEVERE: Servlet.service() for servlet jsp threw exception
tag 'select', field 'list', name 'listbean.dt_oid': The requested list key 'dtList' could not be resolved as a collection/array/map/enumeration/iterator type. Example: people or people.{name} - [unknown location]
at org.apache.struts2.components.Component.fieldError(Component.java:231)
at org.apache.struts2.components.Component.findValue(Component.java:293)
at org.apache.struts2.components.ListUIBean.evaluateExtraParams(ListUIBean.java:79)
at org.apache.struts2.components.Select.evaluateExtraParams(Select.java:99)
at org.apache.struts2.components.UIBean.evaluateParams(UIBean.java:780)
at org.apache.struts2.components.UIBean.end(UIBean.java:481)
at org.apache.struts2.views.jsp.ComponentTagSupport.doEndTag(ComponentTagSupport.java:43)
at org.apache.jsp.jsp.interface_jsp._jspx_meth_s_005fselect_005f0(interface_jsp.java:376)
at org.apache.jsp.jsp.interface_jsp._jspx_meth_s_005fform_005f0(interface_jsp.java:265)
at org.apache.jsp.jsp.interface_jsp._jspService(interface_jsp.java:165).

I think its linked to this tag

<s:select 
        headerKey="-1" headerValue="--Select--"
        list="dtList" 
        listValue="description"
        listKey="objid"
        name="listbean.dt_oid" onchange="function1(this)"
         />

.
Please suggest how I could overcome it..
Thanks.

[Rishi Kanth]

"dtList" is not of type ArrayList or List in the Java class. Check the action class which is passing this parameter to the JSP file.

[Vic Hood]

Hi Rishi ,
This is my action class below, and it does contain references to dtList.

package com.vivek.struts2.action;

import java.util.ArrayList;
import java.util.List;

import org.apache.catalina.connector.Request;

import com.opensymphony.xwork2.ActionSupport;
import com.vivek.struts2.*;
import com.vivek.struts2.bean.DomainBean;
import com.vivek.struts2.bean.DomainTypeBean;
import com.vivek.struts2.dao.DomainDAO;

;


public class DomainAction1  extends ActionSupport  {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;



	private DomainBean domainBean;
	
	

	private List<DomainBean> domList;// bean array list for Domain (child).
	private List<DomainTypeBean> dtList; // bean array list for Domain type(parent)
	
	private int domainTypeOid;
	private int objid;
		
	/**
	 * 
	 */
	
	public String loadDomainType(){
		// Class used to get the domain type from domaintype table
		System.out.println("my logging statement"); 
		String result=SUCCESS;
		try {
			System.out.println("Inside loaddomaintype");
			List loadDomainType = DomainDAO.loadDomainType();
			dtList=loadDomainType;
			System.out.println("The value of objid in loaddomaintypeaction class"+objid);
			
			System.out.println("The size of the list is"+dtList.size());
			dtList.iterator();
		
		} catch (Exception e) {
			
			result=ERROR;
			e.printStackTrace();
		}
		
		
		return result;
	}
	
	public String addupDomain(){// Class used to insert a value or execute an update query based on object id from domain table.(Logic in  DAO class)
		String result= SUCCESS;	
		System.out.println("Inside AddDomain");
		domainTypeOid=domainBean.getDomainTypeOid();
		System.out.println("Getting value of domainTypeOid being used for addupDomain"+domainTypeOid);
		if(domainBean!=null){
			try {System.out.println("Inside add try");
				if(DomainDAO.addupDomain(domainBean)){
					result= SUCCESS;
					System.out.println("Adding a tuple");
					
				}
				
					else {System.out.println("Not being able to acesss addupDomain");
						result=ERROR;
					}
				}
			catch (Exception e) {
				System.out.println("Inside add catch");
				result= null;
				
				System.out.println("Adddomain isnt working.");
				
				e.printStackTrace();
			}
		}
		else{
			result=INPUT;
			System.out.println("Unknown else");
			
		}
		listDomain(domainTypeOid);
		return result;
	}

	
	public String listDomain(int dt_oid)
	{										// Used to display records from domain table . Using an iterator tag in the 
		String result= SUCCESS;
			System.out.println("Listing records");
		
		try {
		
			domList=DomainDAO.listDomain(dt_oid);
			System.out.println("Listing domain");
			return result;
			
		
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			result=null;
			return result;
		}
		
	}
	
	public String obtainData(int objid){ // used to obtain a single row from the domain table and repopulate the corresponding fields in drop down and checkboxes.
		
		String result= ERROR;
		if(domainBean!=null){
			try {
				result= SUCCESS;
				domainBean =DomainDAO.obtainData(objid);
			} catch (Exception e) {
				result=ERROR;
				domainBean=null;

				e.printStackTrace();
			}
		}
		
		return result;
		
	}
	
	
	public DomainBean getDomainBean() {
		return domainBean;
	}

	public void setDomainBean(DomainBean domainBean) {
		this.domainBean = domainBean;
	}

	public void setDomList(List<DomainBean> domList) {
		this.domList = domList;
	}

	public List<DomainBean> getDomList() {
		return domList;
	}

	/*public int getDt_oid() {
		return domainTypeOid;
	}

	public void setDt_oid(int domainTypeOid) {
	
		this.dt_oid = domainTypeOid;
		System.out.println("Dtoid is"+domainTypeOid);
	}*/

	public void setDtList(List<DomainTypeBean> dtList) {
		this.dtList = dtList;
	}

	public List<DomainTypeBean> getDtList() {
		return dtList;
	}

	public void setObjid(int objid) {
		this.objid = objid;
		

	}

	public int getObjid() {
		return objid;
	}
	
	
}

So what Am I doing wrong here? Please help

[sri ramvaithiyanathan]

check this Link.

Initialize your arraylist ie dtList inside your action class and add the values to arraylist.
Before moving to jsp page,check the size of the arraylist inside your action class.

Hope it will clear your doubt.
waiting for your reply

[Vic Hood]

sri ramvaithiyanathan wrote:check this Link.
Hope it will clear your doubt.
waiting for your reply

Hi ,
I did check that link and think Ive already done whats been mentioned in the link.IVe used getters and setters of the bean list array dtList in the action class and my select tag in the jsp also fetches that particular array list an populates into the name attribute . So please advise what Im missing here > Thanks.

[Raza Mohd]

Hi vic,

This error might occur if your page is having validation error and you are not navigation your Error to the most appropriate JSP.
Validation errors are encountered before calling
For example ..define result name in your struts.xml as 'ERROR' or 'INPUT' and corresponding jsp for validation error.

thanks and Regards
Raza

[Vic Hood]

Hi Raza ,
Im not using much of validation here . im just using the struts.xml for redirecting my pages.Ive attached a copy of the same .

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">
 
<struts>
	<constant name="struts.enable.DynamicMethodInvocation"
		value="false" />
	<constant name="struts.devMode" value="true" />
 
	<constant name="struts.custom.i18n.resources"
		value="ApplicationResources" />
 
	<package name="default" extends="struts-default" >

		
		<action name="loadDomainType"  class="com.vivek.struts2.action.DomainAction1" method="loadDomainType">
		<result name="success">/jsp/interface.jsp</result>
        </action>        
		<action name="listDomain" class="com.vivek.struts2.action.DomainAction1" method="listDomain">
				<result name="success">/jsp/interface.jsp</result>
				
	    </action>
	    <action name="addupDomain" class="com.vivek.struts2.action.DomainAction1" method="addupDomain">
	    			<result name="success">/jsp/interface.jsp</result>
	    		<result name="error">/jsp/header.jsp</result><!-- Pages placed just to help in detecting that the flow of logic is incorrect -->
	    		<result name="input">/jsp/footer.jsp</result><!-- Pages placed just to help in detecting that the flow of logic is incorrect -->
	    </action>
	    <action name="obtainData" class="com.vivek.struts2.action.DomainAction1" method="obtainData" >	
	    				    <result name="success">/jsp/interface.jsp</result>
	    </action>
	    
	    		
	</package>
</struts>

[Raza Mohd]

Hi vic,

Look at your code.might be, your method is getting exception and in the catch you assign Error to result parameter.
That might causing the page to navigate to Error which is not defined in struts.xml

Thanks and regards
Mohd Raza.

[sri ramvaithiyanathan]

you have declared your arralist as

private List<DomainTypeBean> dtList;

and inside action class you used as

dtList=loadDomainType;

what I am saying is initialize inside your action class like this

dtList=new List<DomainTypeBean>();
dtList=loadDomainType;

I am not sure whether it will work but give one try.

Regards,
Sriram.V