Comparing values using JSTL

[Vic Hood]

Hi All ,
Im trying to set a value for a dropdown using JSTL, I want to set the value for the dropdown based on the value selected in the previous screen , however it should load the "-1" defualt value when the screen loads for the first time .

	<TD>Domain Type <SELECT NAME="dropdown" SIZE="1" ID="d-down"
		ONCHANGE="changeHiddenInput()">
			
	<c:set value="${domainType_Oid }" var="dt_id" />
	<c:when test="${domainType_Oid>-1 }"> 
		<OPTION  VALUE="-1" label="--Select--">
		</c:when>
		<c:otherwise>
		<OPTION  VALUE="-1" label="--Select--" selected="selected"></OPTION>// to be set when there is no value selected.
		<c:forEach items="${dao.dtList}" var="dt">// looping through the items in dropdown
		<c:when test="${dt.objid==domainType_Oid}">// when a match is found between the value in the list and value stored from previous screen (domainT00ype_Oid).
		<OPTION  VALUE="${dt.objid}"   selected="selected"><c:out value="${dt.description}"  /></OPTION>
		</c:when>
		<c:otherwise>
			<OPTION  VALUE="${dt.objid}"><c:out value="${dt.description}"  /></OPTION>
		</c:otherwise>
		</c:forEach>
		</c:otherwise>
		

When I try running this , I get the error as below .

org.apache.jasper.JasperException: javax.servlet.ServletException: javax.servlet.jsp.JspTagException: Illegal use of <when>-style tag without <choose> as its direct parent
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:491)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:401)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)


Any ideas on how I could implement my logic?
Thanks a lot .

[Dieter Quickfend]

First of all, putting logic in your JSP is discouraged. It is not proper design.

Secondly, you need to do exactly what the error message says. when and otherwise tags need to be in a choose parent tag. Like this:

<c:choose> <c:when test="someBoolean"> <!-- some html content --> </c:when> <c:otherwise> <!-- some html content --> </c:otherwise> </c:choose>

[Vic Hood]

I got rid of the error , but its not serving my purpose , Im trying to set the value of the dropdown to retain. However that is not happening , its being set to default value of -1, when the page submits . Any clues as to where I could be going wrong?

[Dieter Quickfend]

Are you putting all when/otherwise combo's in their own choose tags?

[Vic Hood]

Yes Dieter ,
Thanks a lot for your reply !
My code doesnt show any runtime errors and this is the corrected version,

<TD>Domain Type <SELECT NAME="dropdown" SIZE="1" ID="d-down"
		ONCHANGE="changeHiddenInput()">
			
	<c:set value="${domainType_Oid }" var="dt_id" />
	<c:choose>
	<c:when test="${domainType_Oid>0}"> 
		<OPTION  VALUE="-1">Test</OPTION>
			<c:forEach items="${dao.dtList}" var="dt">
		<c:choose>
		<c:when test="${dt.objid==domainType_Oid}">
		<OPTION  VALUE="${dt.objid}"   selected="selected"><c:out value="${dt.description}"  /></OPTION>
		</c:when>
		<c:otherwise>
			<OPTION  VALUE="${dt.objid}"><c:out value="${dt.description}"  /></OPTION>
		</c:otherwise>
		</c:choose>
		</c:forEach>
		</c:when>
		<c:otherwise>
		<OPTION  VALUE="-1" label="--Select--" selected="selected"></OPTION>
		<c:forEach items="${dao.dtList}" var="dt">
		<c:choose>
		<c:when test="${dt.objid==domainType_Oid}">
		<OPTION  VALUE="${dt.objid}"   selected="selected"><c:out value="${dt.description}"  /></OPTION>
		</c:when>
		<c:otherwise>
			<OPTION  VALUE="${dt.objid}"><c:out value="${dt.description}"  /></OPTION>
		</c:otherwise>
		</c:choose>
		</c:forEach>
		</c:otherwise>
		</c:choose> 

My code above seems to be an overkill of a sort . But my status now is that it works perfectly when the screen loads initially and then when I select a value from the dropdown to populate a list which works fine too , but I have a functionality where Im supposed to be able to edit a particular record from the result set, for which I need to send the value selected from the dropdown to the servlet , when I try this functionality im able to pass the valueselected from the dropdown to the backend , but am not being able to display this value in the jsp(as the page submits) .ie. the drop down value is set to the default "--Select-- " value . Any clue as to what I could be missing?
.
Hope Im being clear.

[Dieter Quickfend]

Well... the selected attribute of your --Select-- option is unchanged, is it?

[Vic Hood]

Uhh I understand , the well.. Hope I wasnt confusing you completely
. When I click on the edit hyperlink associated to a particular row , the page submits and it is expected to populate the values corresponding to the selected row in the fields . ie . set the value in the dropdown and also populate the fields .
However when I click this edit hyper link, all I see now is a blank form and the dropdown being set to "--Select". Am I being clear enough or should I re- explain . ? .

[Dieter Quickfend]

Well I can't really know why without seeing your servlet code, and the resulting JSP... Show your code, and make sure you use XML/java code tags and use correct indentation as well, because your XML is quite annoying to read.

[Vic Hood]

Thanks for replying Dieter!
"your xml is quite annoying" Im sorry , I didnt quite get that .
Any ways , these are my jsp and servlet files.
Servlet .

package com.jspcrud.dao;

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

import javax.servlet.RequestDispatcher;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.jspcrud.bean.DomainBean;

public class ControlServlet extends HttpServlet {


	DAO dataObject=new DAO();
	public ArrayList dtList;// List to store the domaintype beans.
	public List<DomainBean>domList;
	int domainType_Oid;
	int objid;
	String setDtID;
	String code=null;
	String description=null;
	String ObjID=null;
	String Dtype=null;
	String statusActive=null;
	String statusEdit=null;
	String actcode=null;
	boolean active;
	boolean edit;


	public void doPost(HttpServletRequest request,HttpServletResponse response){
		DomainBean bean=new DomainBean();
		Dtype=request.getParameter("selectedval");
		ObjID = request.getParameter("selectedID");
		code = request.getParameter("code");
		description = request.getParameter("description");
		statusActive = request.getParameter("statusActive");
		statusEdit = request.getParameter("statusEdit");
		actcode = request.getParameter("actcode");
		active = request.getParameter("statusActive") == null ? false : true;
		edit = request.getParameter("statusEdit") == null ? false : true;
		dtList=dataObject.dtList;
		if(ObjID!=""){
			int objid1=Integer.parseInt(ObjID);
		}
		else{
			System.out.println("Initial Screen Load");
		}

		try{
			if ((actcode != null) && (actcode.trim().equals("GETDOMLIST"))) {
				if (!"".equalsIgnoreCase(Dtype) && null != Dtype)  {  
					setDtID = String.valueOf(Dtype);  
					System.out.println("setting Domain To-- List Servlet"+setDtID);
				} else {  
					setDtID = "-1";  
					System.out.println("Setting Domain to undefined value"+setDtID);
				}
				domainType_Oid=Integer.parseInt(setDtID);
				dataObject.domainType_Oid=domainType_Oid;
				System.out.println("test block domlist");
				bean.setDomainTypeOid(domainType_Oid);
				domList=dataObject.getDomList();
				request.setAttribute("setDtID", setDtID);  
				request.setAttribute("domainType_Oid", domainType_Oid);

			}
			if ((actcode != null) && (actcode.trim().equals("OBTAINDATA"))) {
				System.out.println(actcode);
				Dtype=request.getParameter("selectedval");
				if (!"".equalsIgnoreCase(Dtype) && null != Dtype)  {  
					setDtID = String.valueOf(Dtype);  
					System.out.println("setting Domain To-- ObtainData"+setDtID);
				} else {  
					setDtID = "-1";  
					System.out.println("Setting Domain to undefined value"+setDtID);
				}
				domainType_Oid=Integer.parseInt(setDtID);
				dataObject.domainType_Oid=domainType_Oid;
				bean.setDomainTypeOid(domainType_Oid);
				if (ObjID != "") {
					objid = Integer.parseInt(ObjID);
				} else if (ObjID == null || ObjID == "") {
					objid = 0;
				}

				if(objid!=0){
					bean.setObjid(objid);
					System.out.println("Objid of row selected"+objid);
					//objid=bean.getObjid();//stupid statement but just trying.
					ObjID=String.valueOf(objid);
					System.out.println("String value of objid "+ObjID);
					request.setAttribute("ObjID",ObjID );
					System.out.println("Domain Of the record"+bean.getDomainTypeOid());

				}
				request.setAttribute("setDtID", setDtID);  
				request.setAttribute("domainType_Oid", domainType_Oid);
			}


			if ((actcode != null) && (actcode.trim().equals("INSUPDATE"))) {
				System.out.println(actcode);
				if (!"".equalsIgnoreCase(Dtype) && null != Dtype)  {  
					setDtID = String.valueOf(Dtype);  
					System.out.println("setting Domain To-- INSUPDATE"+setDtID);
				} else {  
					setDtID = "-1";  
					System.out.println("Setting Domain to undefined value"+setDtID);
				}


				domainType_Oid=Integer.parseInt(setDtID);
				dataObject.domainType_Oid=domainType_Oid;
				bean.setDomainTypeOid(domainType_Oid);
				dataObject.code = code;
				dataObject.description = description;
				dataObject.statusActive = statusActive;
				dataObject.statusEdit = statusEdit;
				dataObject.active = active;
				dataObject.edit = edit;
				dataObject.objid = objid;

				if (objid == 0) {
					bean.setDomainTypeOid(domainType_Oid);
					System.out.println("Insert being called");
					dataObject.InsertionDB(bean);
					dataObject.domainType_Oid=domainType_Oid;
					domList = dataObject.getDomList();
				}
				else if(objid!=0) {
					System.out.println("Update being called");
					System.out.println("Record Belongs to Domain Number:" + setDtID);
					System.out.println("Objid for update"+objid);
					dataObject.updateDB(bean);
					domList = dataObject.getDomList();
				}	
			}
			
		}

		catch(Exception e){
			e.printStackTrace();

		}
		request.setAttribute("domList", domList);
		//request.setAttribute("setDtID", setDtID);  
		request.setAttribute("dtList",dtList);
		request.setAttribute("domainType_Oid", domainType_Oid);
		RequestDispatcher rd = request.getRequestDispatcher("POC.jsp");
		try{
			rd.forward(request, response);
		}
		catch (Exception e) {
			e.printStackTrace();
		}
		}

	}

My Jsp ..POC.jsp

<%@ taglib uri="http://displaytag.sf.net" prefix="display"%> 
<%@ page import="java.util.*"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>

<%@page import="com.jspcrud.bean.DomainBean"%>
<HTML>
<HEAD>
<TITLE>Domain database</TITLE>
</HEAD>
<BODY>


<SCRIPT TYPE="text/javascript">

	function changeHiddenInput() {
		alert('changeHidden');
		var objDropDown=document.getElementById("d-down");
		var DTobjid=objDropDown.options[objDropDown.selectedIndex].value;	
		document.getElementById('selectedval').value=DTobjid;
		alert(DTobjid);
		document.getElementById('actcode').value="GETDOMLIST";
		document.getElementById('Main').submit();
		}

	function selectobjID(objid){
		alert('objid');
	 	document.getElementById('selectedID').value=objid;
	 	alert(document.getElementById('selectedID').value);
		document.getElementById('actcode').value="OBTAINDATA";
	 	document.getElementById('Main').submit();	 
 }
 function test(){
	 	alert('check');
		document.getElementById('actcode').value="INSUPDATE";
	 	document.getElementById('Main').submit();	 

	
 }


</SCRIPT>
<p>The header is ${header.host}</p> 


<jsp:useBean id="dao" scope="request" class="com.jspcrud.dao.DAO" />
<jsp:useBean id="domain" scope="request" class="com.jspcrud.bean.DomainBean" />

<FORM METHOD="POST" ACTION="ControlServlet" NAME="crudForm"  ID="Main">
<INPUT	TYPE="HIDDEN" NAME="selectedval" ID="selectedval" value="${setDtID}"><!-- Hidden variable to store selected domaintype -->
<INPUT TYPE="HIDDEN" NAME="selectedID" ID="selectedID">
<TD>
<TR>

	<TD>Domain Type <SELECT NAME="dropdown" SIZE="1" ID="d-down"
		ONCHANGE="changeHiddenInput()">
			
	<c:set value="${domainType_Oid }" var="dt_id" />
	<c:choose>
	<c:when test="${domainType_Oid>0}"> 
		<OPTION  VALUE="-1">Test</OPTION>
			<c:forEach items="${dao.dtList}" var="dt">
		<c:choose>
		<c:when test="${dt.objid==domainType_Oid}">
		<OPTION  VALUE="${dt.objid}"   selected="selected"><c:out value="${dt.description}"  /></OPTION>
		</c:when>
		<c:otherwise>
			<OPTION  VALUE="${dt.objid}"><c:out value="${dt.description}"  /></OPTION>
		</c:otherwise>
		</c:choose>
		</c:forEach>
		</c:when>
		<c:otherwise>
		<OPTION  VALUE="-1" label="--Select--" selected="selected"></OPTION>
		<c:forEach items="${dao.dtList}" var="dt">
		<c:choose>
		<c:when test="${dt.objid==domainType_Oid}">
		<OPTION  VALUE="${dt.objid}"   selected="selected"><c:out value="${dt.description}"  /></OPTION>
		</c:when>
		<c:otherwise>
			<OPTION  VALUE="${dt.objid}"><c:out value="${dt.description}"  /></OPTION>
		</c:otherwise>
		</c:choose>
		</c:forEach>
		</c:otherwise>
		</c:choose> 
		
	</SELECT> <BR />
	</TD>
</TR>
</TD>

<TR>
	<TD>Code<INPUT TYPE="TEXT" NAME="code" SIZE="20" VALUE="${domain.code}"><BR>
	</TD>
	<TD>Description<INPUT TYPE="TEXT" NAME="description" SIZE="20"	VALUE="${domain.description}"><BR>
	</TD>
</TR>
<TR>
	<TD>Active<INPUT TYPE="CHECKBOX" NAME="statusActive" VALUE="${domain.statusActive}"  /></TD>
	<TD>Editable<INPUT TYPE="CHECKBOX" NAME="statusEdit"VALUE="${domain.statusEdit}" ></TD>
	<BR />
</TR>

<HR>
<INPUT TYPE="BUTTON" VALUE="Submit" onclick="test()">
<INPUT TYPE="HIDDEN" NAME="actcode" id ="actcode"/>
</FORM>


<BR>

	
<%System.out.println("I think domList is being accessed");
%>
		
  <display:table name="${domList}" pagesize="100" id ="dl" export="true" class="" >     
       <display:column property="code" sortable="true"/>     
       <display:column property="description" sortable="true" />    
       <display:column  property="statusActive" sortable="true" title="IsActive?"/>   
       <display:column  property="statusEdit" title="IsEdit?" sortable="true"/>  
      
       	<display:column title="Edit" media="html">  
       <c:set var="id" value="${dl.objid}" />  
        <a href="POC.jsp?${id}" onclick="selectobjID(${id})">Edit </a>   
    	</display:column>  
 	 <display:setProperty name="export.pdf.filename" value="POC.pdf"/>
	<display:setProperty name="export.excel.filename" value="POC.xls"/>
	<display:setProperty name="export.csv.filename" value="POC.txt"/>
	<display:setProperty name="export.pdf" value="true" /> 
	<display:setProperty name="export.excel" value="true" /> 
	<display:setProperty name="export.xml" value="false" /> 
	<display:setProperty name="export.csv" value="true" /> 

          </display:table> 
         <c:set var="id" value="${objid}"/>
</BODY>
        <script>  
       var idd = ${setDtID};  
    document.getElementById("d-down").options.selectedIndex=idd;  
    </script>  
</HTML>

[Dieter Quickfend]

Alright. I think you're gonna have to go back to the drawing board for your application.

You've got no separation of concerns in your servlet, which means spaghetti code. One giant method in your servlet, one small setback for the human mind.
You're using instance variables in your servlet, which means none of it's thread safe.

It's time to learn object oriented programming.

And it's also time to learn about the scopes.

Also, don't use DAO's as value objects.

[Vic Hood]

Dieter Quickfend wrote:Alright. I think you're gonna have to go back to the drawing board for your application.

You've got no separation of concerns in your servlet, which means spaghetti code. One giant method in your servlet, one small setback for the human mind.
You're using instance variables in your servlet, which means none of it's thread safe.

It's time to learn object oriented programming.

And it's also time to learn about the scopes.

Also, don't use DAO's as value objects.

Ow! .
Well , I need to solve this app to be working asap .Could you suggest anything I should correct/implement in my code ?