Jstl not reflecting values back to servlet

[Vic Hood]

Hi All,
In the following jsp I have a form that where the values of the fields are reflected from beans using EL and jstl as below.

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

<jsp:setProperty property="*" name="domain" />
...

<FORM METHOD="POST" ACTION="ControllerServlet" NAME="crudForm"  ID="Main">
..
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>

however when i try to perform operations after submitting the form in my servlet as below.
Servlet

 System.out.println("Test Print");
									if (objid==0){
										System.out.println("Test Code before insertion"+bean.getCode());// Prints a null value.
									 System.out.println("Insert being called");
										DataObject.InsertionDB(bean);		
										
														 
									domList=DataObject.getDomList();
									}
									
									else{
										System.out.println("Update being called");
										bean=DataObject.updateDB(bean);
										domList=DataObject.getDomList();
									}
 

I get the value of Code printed from the bean.getCode() statement as null. Any clue as to why this may be happening? am i missing something?

[Mike Zal]

Vic Hood wrote:
I get the value of Code printed from the bean.getCode() statement as null. Any clue as to why this may be happening? am i missing something?

You never show where the bean object is instantiated or initialized. Do you call a setCode() somewhere in your code prior to the getCode() call or does it have some default value?

[Vic Hood]

Hi Mike ,
Thanks for replying! You were right about that line however the thing that baffles me is that ,when I tried to retrieve the values after they are being set in the bean it still threw a null. Here is the code that is called through InsertionDB

public void InsertionDB(DomainBean domainBean) throws Exception {
System.out.println("This line prints");
Connection con = null;
PreparedStatement stmt = null;
ResultSet rs = null;
domainBean.setstatusActive(statusActive);
domainBean.setstatusEdit(statusEdit);
domainBean.setCode(code);
domainBean.setDescription(description);
domainBean.setActive(active);
domainBean.setEdit(edit);
domainBean.setDomainTypeOid(domainType_Oid);
domainBean.setObjid(objid); 
System.out.println("The value of code to be inserted is"+domainBean.getCode());// this line prints a null value as well
try {
con= DBConnector.getConnection();
System.out.println("Insertion of Record");
System.out.println(" Description of new record "+domainBean.getDescription());
String query= "INSERT INTO DOMAIN (CODE,DESCRIPTION,ISACTIVE,ISEDITABLE,DOMAINTYPE_OID) VALUES (?,?,?,?,?)" ;
stmt = con.prepareStatement(query);
stmt.setString(1, domainBean.getCode());
stmt.setString(2, domainBean.getDescription());
stmt.setBoolean(3, (domainBean.getActive()));
stmt.setBoolean(4, (domainBean.getEdit()));
stmt.setInt(5,domainBean.getDomainTypeOid());
stmt.executeUpdate();
System.out.println("Insertion Completed Successfully");

}
catch (SQLException sqe) {
	sqe.printStackTrace();
} finally {
	
	DBConnector.closeResultSet(rs);
	DBConnector.closeStatement(stmt);
	DBConnector.closeConnection(con);
}

And the insert query fails throwing a null pointer exception
Also ive placed my bean class below for you to have a look.
File: DomainBean

package com.jspcrud.bean;



import java.io.Serializable;

import java.util.ArrayList;

public class DomainBean implements Serializable  {
/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
private String domainType;
private String  code;
private String description;

private int domainTypeOid;
private boolean active;/*active and edit are meant to be used only in the servlet after obtaining the value of checkbox using statusActive and statusEdit*/
private boolean edit;
@SuppressWarnings("rawtypes")
private ArrayList domList;
private String statusActive;
private String statusEdit;
private String message;
private int  objid;

ArrayList<DomainBean> dtList = new ArrayList<DomainBean>();
	

	public DomainBean(){}
	
	
	public void setDomainType(String domainType) {
		this.domainType = domainType;	}

	public String getDomainType() {
	return domainType;
	}

	public void setCode(String code) {
		this.code = code;
	}

	public String getCode() {
		return code;
	}

	public void setDescription(String description) {
		this.description = description;
	}

	public String getDescription() {
		return description;
	}

	


	@SuppressWarnings("rawtypes")
	public ArrayList getDomList() {
		return domList;
	}

	@SuppressWarnings("rawtypes")
	public void setDomList(ArrayList domList) {
		this.domList = domList;
	}

	public void setDomainTypeOid(int dt_oid) {
		this.domainTypeOid = dt_oid;
	System.out.println(" DomainBean.java--domainTypeOid is "+dt_oid);
	
	}

	public int getDomainTypeOid() {
		return domainTypeOid;
	}

	public void setObjid(int objid) {
		System.out.println("The value of objid in the bean  "+objid);
		this.objid = objid;
	}

	public int getObjid() {
		return objid;
	}

	public void setstatusActive(String statusActive) {
		this.statusActive = statusActive;
	}

	public String getstatusActive() {
		//System.out.println("Status of active check"+statusActive);
		return statusActive;
		
	}

	public void setstatusEdit(String statusEdit) {
		this.statusEdit = statusEdit;
	}

	public String getstatusEdit() {
		return statusEdit;
	}

	public void setMessage(String message) {
		this.message = message;
	}

	public String getMessage() {
		return message;
	}

	

	
	public ArrayList<DomainBean> getDtList() {
		return dtList;
	}

	public void setDtList(ArrayList<DomainBean> dtList) {
		this.dtList = dtList;
	}


	public void setActive(boolean active) {
		this.active = active;
	}


	public boolean getActive() {
		return active;
	}


	public void setEdit(boolean edit) {
		this.edit = edit;
	}


	public boolean getEdit() {
		return edit;
	}
	
	

}

Thanks for your time.

[Mike Zal]

If an object throws returns null when you call a method (getCode), why would you expect it to return anything other than a null when you call the same method from the same object when passed as a parameter into another method?

[Vic Hood]

Hi Mike ,
I dont know if im thinking on the wrong lines here ,Im trying to pass the values that i get from the form ,into the bean (hence setting the bean variables) within the function InsertionDB, and then use these values for insertion , is my approach correct?

[Mike Zal]

It seems like the instance variables of the DataObject are not initialized. Inside the InsertDB method, put debug statements after each assignment to see that value you are assigning to the DomainBean. I have a feeling that your statement at line 8 [domainBean.setCode(code)] is setting a null value.

[Vic Hood]

Hi Mike,
Hmm .. yes you were right .
The value of code being set is null as inferred from
File: DAO.java

...
domainBean.setstatusActive(statusActive);
domainBean.setstatusEdit(statusEdit);
domainBean.setCode(code);
System.out.println("The INSERTED CODE---"+domainBean.getCode());
domainBean.setDescription(description);
domainBean.setActive(active);
domainBean.setEdit(edit);
domainBean.setDomainTypeOid(domainType_Oid);
domainBean.setObjid(objid); ...

The log generated is

Test Print
Insert being called
This line prints
The INSERTED CODE---null// here
 DomainBean.java--domainTypeOid is 2
The value of objid in the bean  0
The value of code to be inserted isnull

ANy clues on how I could set the values into the bean variables ?Is it becuase im missing something in my jsp?Thanks for your time

[Mike Zal]

How does your code handle the request parameters and attempt to save them into either the DataObject or the bean objects? Can you show your code for the doGet/doPost or handleRequest methods?

[Vic Hood]

Hi Mike,
Okay well heres my servlet code the entire doPost method

public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{

						HttpSession session=request.getSession();
						response.setContentType("text/html");
						PrintWriter pw = response.getWriter();
						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");
						//System.out.println("The ObjID from Main.jsp"+ObjID);	
						if (!"".equalsIgnoreCase(Dtype) && null != Dtype)  {  
				            setDtID = String.valueOf(Dtype);  
				            System.out.println("setting Domain To"+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("the domaintype oid selected is"+domainType_Oid);	
								// End of Dtype.
								
								
		/* The fragment below is intended to ensure that when the page is first submitted for insert ,
		 * the value obtained from the hidden field is blank or "" so a check is made to avoid a NumberException.
		 */
											
									if(ObjID!=""){
										objid=Integer.parseInt(ObjID);	
									}
									else if(ObjID==null || ObjID==""){
										objid=0;
									}
									
						System.out.println("The integer value of objid"+objid);
					
					    active = request.getParameter("statusActive") == null ? false : true;  // The active and edit values here are used
					    edit = request.getParameter("statusEdit") == null ? false : true;      // to convert the status of the checkbox's 
					    															// to 0 or 1 values to perform DB operations.
					    request.setAttribute("setDtID", setDtID);  
					    System.out.println("Set Domain ID"+setDtID);
					    request.setAttribute("domainType_Oid", domainType_Oid);
					    System.out.println("DomainType_oid"+domainType_Oid);
					    request.setAttribute("objid", objid);
					    try {
					        
							if((actcode!=null)&& (actcode.trim().equals("GETDOMLIST"))){
								System.out.println("test block domlist");
								bean.setDomainTypeOid(domainType_Oid);
								domList=DataObject.getDomList();
							
								request.setAttribute("domList", domList);
								RequestDispatcher rd = request.getRequestDispatcher("POC.jsp");
								rd.forward(request, response);
								
							}
							
							else if((actcode!=null)&& actcode.equalsIgnoreCase("INSUPDATE")){
									System.out.println("Test Print");
									if (objid==0){
									//	System.out.println("Test Code before insertion"+bean.getCode());
									 System.out.println("Insert being called");
										DataObject.InsertionDB(bean);		
										
														 
									domList=DataObject.getDomList();
									}
									
									else{
										System.out.println("Update being called");
										bean=DataObject.updateDB(bean);
										domList=DataObject.getDomList();
									}
								 
								request.setAttribute("domList", domList);		 
								// Check the below three lines which defines where it should be forwarded to . 
								RequestDispatcher rd = request.getRequestDispatcher("POC.jsp");
								rd.forward(request, response);
								bean.setDomainTypeOid(domainType_Oid);
							}
							

Im trying to obtain the values from the jsp, using EL and set it to the bean , so that the values are set automatically . And then i try to retreive those values through the request parameters as said above and set them into the bean . Ive pasted my jsp in the first post on this thread.I have a feeling im making a silly mistake here. Any pointers could be helpful.
Thanks.

[Mike Zal]

So looking at your Servlet code, it looks like you are using instance variables to handle request parameters. That is a VERY bad idea because that means that those values are not thread save. If you have multiple people sending requests to the Servlet, they will overwrite each other.

On line 9 of the doPost method, you are saving the request parameter to the Servlet's instance variable named code. In the InsertionDB method, you are trying to save the DataObject's instance variable named code. Somewhere in your code, your doPost you need to set the DataObject's code variable similar to the way that you did it on line 24 of the doPost:

DataObject.domainType_Oid=domainType_Oid;

Minor note on that code: you should not have public instance variables. You should make those private and create public getters and setters.

[Vic Hood]

HI Mike ,
Thanks for your reply.
Just to quickly clarify your suggestion . You are saying that . I manually set the values obtained from ym servlet into the DAO like i do here

DataObject.domainType_Oid=domainType_Oid;  
DataObject.code=code// something like this?

Also in addition I was against the idea of using instance variables for the fields altogether ,from my very limited knowledge of beans I was hoping that while doing something like this in my jsp

<jsp:useBean id="domain" scope="request" class="com.jspcrud.bean.DomainBean"/>  
  
<jsp:setProperty property="*" name="domain" />  
...
 <TD>Description<INPUT TYPE="TEXT" NAME="description" SIZE="20" VALUE="${domain.description}"><BR>  
....// other values omitted

would set the values onto the bean(Ive just used one field for example sakes)
and then use the values from the form when they are submitted as they are automatically set onto the bean through set Bean and then manipulate them for further use.
But are instance variables in the servlet needed to get these values? Shouldnt they be set to the bean directly?And there would be no need of any instance variables in that case?
It would be great if anyone could correct my code as Iv e been stuck here for days now .
Im sorry if my post is confusing . its just that im relatively very new to coding and trying to get a hang of how this would work

[Mike Zal]

Vic Hood wrote:HI Mike ,
Just to quickly clarify your suggestion . You are saying that . I manually set the values obtained from ym servlet into the DAO like i do here

DataObject.domainType_Oid=domainType_Oid;  
DataObject.code=code// something like this?

Yes that is something that I was suggesting, but you should do it for all the request parameters and not just those two.

Also in addition I was against the idea of using instance variables for the fields altogether ,from my very limited knowledge of beans I was hoping that while doing something like this in my jsp

<jsp:useBean id="domain" scope="request" class="com.jspcrud.bean.DomainBean"/>  
  
<jsp:setProperty property="*" name="domain" />  
...
 <TD>Description<INPUT TYPE="TEXT" NAME="description" SIZE="20" VALUE="${domain.description}"><BR>  
....// other values omitted

You have a Servlet so there is no need to use the useBean or setProperty tags. You should set the values of your domain bean in Servlet and set it as a request attribute. i.e. request.setAttribute("domain",bean).

But are instance variables in the servlet needed to get these values? Shouldnt they be set to the bean directly?And there would be no need of any instance variables in that case?

Yes, that was what I was implying. you should be doing something like DataObject.code = request.getParameter("code");

It would be great if anyone could correct my code as Iv e been stuck here for days now .
Im sorry if my post is confusing . its just that im relatively very new to coding and trying to get a hang of how this would work

I cannot do that because this site is NotACodeMill. I would highly suggest buying the Head First Servlets and JSP book. It is well worth the cost and will vastly improve your knowledge of Servlets/JSP.

[Vic Hood]

Thanks a lot for your reply Mike!
It helped in my solving my current problem , I wasnt setting the values obtained from the jsp into the DAO object, thanks for helping me with that.
However now when i try to insert a row , there are are two records added as in duplicate entries , any clue as to why this could be happening ?


And I wasnt asking for code , only for corrections, thats thwe way it works here
,right?And also I do have Head First Servlets and JSP , an awesome book , and am reading through it , however im being pressurised to finish this work much faster than I could progress through the book.

[Vijitha Kumara]

...when i try to insert a row , there are are two records added as in duplicate entries , any clue as to why this could be happening ?

What gets printed (to console by your System.out.. statements) when your "InsertionDB" method executes? Are there any duplicates?

[Vic Hood]

Hi Vijitha,
Thank you fore replying and sorry for the delay ,the entire set of statements is printed twice
For example this is what happens from loading the page , to the insertion of record.
1. The dropdown content is accessed.
2.The list according to the dropdown is presented (upon selecting a value in the dropdown)
3.Upon entering values in to the fields and hitting submit , the whole page reloads ,and the insert query is executed twice (from the log) and then the whole list is redisplayed .
Any clue on where I could be going wrong?
And Ive rechecked there is only one explicit call to InsertionDB in my code so im baffled as to how its printed twice :\

[Vijitha Kumara]

Looks like the form get refreshes again (I haven't gone through your complete code though) unless done by the user, which results in the same request submitted again. If that's the case try using a redirect from the servlet upon a successful insertion. So that you will be redirected to a different page once the insertion happens. Sample here. (You may implement the Java stuff in your servlet)

EDIT: You may also log in your doPost() method to see whether it gets called twice...

[Vic Hood]

Hi Vijitha,
Thanks a lot for replying . I did perform logging in the doPost (). and Using logging , I think you were right , the page refreshes again performing a double submit , I tried looking at why this was happening , but no use . Could you please provide an example of redirecting to another servlet?
EDIT: I tried doing something like this in my jsp , so that (I hoped(dont know if im right ) to work around the double submit problem.I wrote another servlet that was only responsible for listing the records and one to insert/update data.
I modified my jsp like this :
File:POC.jsp

<FORM METHOD="GET" ACTION="ListServlet" NAME="crudForm"  ID="List">
<FORM METHOD="POST" ACTION="ControllerServlet" 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()">
		<OPTION  VALUE="-1" label="--Select--" >
		<c:forEach items="${dao.dtList}" var="dt">
					<OPTION  VALUE="${dt.objid}" ><c:out value="${dt.description}"  /></OPTION>
		</c:forEach>
	</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="SUBMIT" VALUE="Submit" onclick="test()">
<INPUT TYPE="HIDDEN" NAME="actcode" id ="actcode"/>
</FORM>
</FORM>

I encapsulated the post method with a get method and used the List form to just display values and the other form to submit values for insert/update
File:ListServlet.java

public class ListServlet extends HttpServlet{
	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;
	int domainType_Oid;
	DAO DataObject=new DAO();
	public List<DomainBean>domList;
	

 @Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
		throws ServletException, IOException {
	 		
	 response.setContentType("text/html");
		PrintWriter pw = response.getWriter();
		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");
		DataObject.domainType_Oid=domainType_Oid;
		DataObject.code=code;
		DataObject.description=description;
		DataObject.statusActive=statusActive;
		DataObject.statusEdit=statusEdit;
		active = request.getParameter("statusActive") == null ? false : true;  // The active and edit values here are used
		edit = request.getParameter("statusEdit") == null ? false : true;      // to convert the status of the checkbox's 
		    															// to 0 or 1 values to perform DB operations.
			
		    DataObject.active=active;
		    DataObject.edit=edit;
	
		if (!"".equalsIgnoreCase(Dtype) && null != Dtype)  {  
            setDtID = String.valueOf(Dtype);  
            System.out.println("setting Domain To"+setDtID);
        } else {  
            setDtID = "-1";  
            System.out.println("Setting Domain to undefined value"+setDtID);
        }
		
		domainType_Oid=Integer.parseInt(setDtID);
		DataObject.domainType_Oid=domainType_Oid;
		if((actcode!=null)&& (actcode.trim().equals("GETDOMLIST"))){
		try{
			System.out.println("test block domlist");
		
			bean.setDomainTypeOid(domainType_Oid);
			domList=DataObject.getDomList();
		}
		catch (Exception e) {
			// TODO: handle exception
		}
			request.setAttribute("domList", domList);
			RequestDispatcher rd = request.getRequestDispatcher("POC.jsp");
			request.setAttribute("setDtID", setDtID);  
			request.setAttribute("domainType_Oid", domainType_Oid);
			rd.forward(request, response);
			System.out.println("Actcode"+actcode);
			System.out.println("This belongs to domain number--"+domainType_Oid);
		}			
		else
	super.doGet(request, response);
}
}

And the earlier ControllerServlet as below.

public class ControllerServlet extends HttpServlet {
DAO DataObject=new DAO();
		@SuppressWarnings("rawtypes")
		public ArrayList dtList;// List to store the domaintype beans.
		@SuppressWarnings("rawtypes")
		public List<DomainBean>domList;
		int domainType_Oid;
		@SuppressWarnings("rawtypes")
		//public List domList1;
		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 List<Integer> chkList=new ArrayList();
	
		public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{

						HttpSession session=request.getSession();
						response.setContentType("text/html");
						PrintWriter pw = response.getWriter();
						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");
						//System.out.println("The ObjID from Main.jsp"+ObjID);	
						if (!"".equalsIgnoreCase(Dtype) && null != Dtype)  {  
				            setDtID = String.valueOf(Dtype);  
				            System.out.println("setting Domain To"+setDtID);
				        } else {  
				            setDtID = "-1";  
				            System.out.println("Setting Domain to undefined value"+setDtID);
				        }  
	
					domainType_Oid=Integer.parseInt(setDtID);
					DataObject.domainType_Oid=domainType_Oid;
					DataObject.code=code;
					DataObject.description=description;
					DataObject.statusActive=statusActive;
					DataObject.statusEdit=statusEdit;
					active = request.getParameter("statusActive") == null ? false : true;  // The active and edit values here are used
					edit = request.getParameter("statusEdit") == null ? false : true;      // to convert the status of the checkbox's 
					    															// to 0 or 1 values to perform DB operations.
						
					    DataObject.active=active;
					    DataObject.edit=edit;
					
					System.out.println("the domaintype oid selected is"+domainType_Oid);	
								// End of Dtype.
							
											
									if(ObjID!=""){
										objid=Integer.parseInt(ObjID);	
									}
									else if(ObjID==null || ObjID==""){
										objid=0;
									}
									
						System.out.println("The integer value of objid"+objid);
					
					    active = request.getParameter("statusActive") == null ? false : true;
					    edit = request.getParameter("statusEdit") == null ? false : true; 
					    request.setAttribute("setDtID", setDtID);  
					    System.out.println("Set Domain ID"+setDtID);
					    request.setAttribute("domainType_Oid", domainType_Oid);
					    System.out.println("DomainType_oid"+domainType_Oid);
					    request.setAttribute("objid", objid);
					    try {
					        
							 if((actcode!=null)&& (actcode.trim().equals("INSUPDATE"))) {
									System.out.println("Test Print");
									if (objid==0){
									//	System.out.println("Test Code before insertion"+bean.getCode());
									 System.out.println("Insert being called");
										DataObject.InsertionDB(bean);		
										
														 
									domList=DataObject.getDomList();
									}
									
									else{
										System.out.println("Update being called");
										bean=DataObject.updateDB(bean);
										domList=DataObject.getDomList();
									}
								 
								request.setAttribute("domList", domList);		 
								// Check the below three lines which defines where it should be forwarded to . 
								RequestDispatcher rd = request.getRequestDispatcher("POC.jsp");
								request.setAttribute("actcode", "GETDOMLIST");
								rd.forward(request, response);
								bean.setDomainTypeOid(domainType_Oid);
								bean =null;
							}

Now im able to display the list by transferring control to the list servlet
However , now when i try to submit the form to perform an insert I get an error saying

HTTP Status 405 - HTTP method GET is not supported by this URL

What should I be doing to work around this?

[Mike Zal]

You should NEVER use nested forms. It is not supported by any standards and you cannot guarantee the result. I think the best course of action would be to replace your forEach loop with a custom tag. Read chapter 9 of the Head First Book. They have any example of how to custom select elements.

[Vijitha Kumara]

...Could you please provide an example of redirecting to another servlet?

As shown in the link I provided you may use the sendRedirect() method of the response object to do this.
And also don't try to make things complex, just create two pages (one for the input and other for the display) to see whether it works in the first place.

[Vic Hood]

Hey everyone!
I solved the double insert issue , it was just that the submit button at the end of the page was causing it to submit again ! So I changed it to button and it worked!
However , Im trying to edit the values in the list generated below now by using the edit hyperlink
.
The jsp code of that fragment is as below.

//JS fragment
function selectobjID(objid){
		alert('objid');
	 	document.getElementById('selectedID').value=objid;
	 	alert(document.getElementById('selectedID').value);
		document.getElementById('actcode').value="OBTAINDATA";// Control value to ControllerServlet.java
	 	document.getElementById('Main').submit();	 
 }


 <display:table name="${domList}" pagesize="100" id ="dl" export="true" >     
       <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>   // The edit link here
    	</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" /> 

Fragment of ControllerServlet.java

	if ((actcode != null) && (actcode.trim().equals("INSUPDATE"))) {
				//Code for Insertion/update
			}

			else if ((actcode != null) && (actcode.trim().equals("OBTAINDATA"))) {

				if(objid!=0){
					bean=DataObject.obtainData(objid);
					domList = DataObject.getDomList();
					request.setAttribute("setDtID", setDtID);
					System.out.println("Set Domain ID" + setDtID);
					request.setAttribute("domainType_Oid", domainType_Oid);
					System.out.println("DomainType_oid" + domainType_Oid);
					domList = DataObject.getDomList();
				}
			}
		} catch (Exception e1) {
			e1.printStackTrace();
		}
		request.setAttribute("domList", domList);
		RequestDispatcher rd = request.getRequestDispatcher("POC.jsp");
		rd.forward(request, response);
		bean.setDomainTypeOid(domainType_Oid);
		System.out.println("Actcode" + actcode);
		System.out.println("This belongs to domain number--" + domainType_Oid);

	}
}

What im trying to do is get the values from the bean through obtainData(which is happening through the backend)and be able to set the values in the jsp typically here
JSP code

<FORM METHOD="POST" ACTION="ControllerServlet" 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()">
		<OPTION  VALUE="-1" label="--Select--" >
		<c:forEach items="${dao.dtList}" var="dt">
					<OPTION  VALUE="${dt.objid}" ><c:out value="${dt.description}"  /></OPTION>
		</c:forEach>
	</SELECT> <BR />
	</TD>
</TR>
</TD>

<TR>
	<TD>Code<INPUT TYPE="TEXT" NAME="code" SIZE="20" VALUE="${domain.code}"><BR>// As in set the value of code obtained here 
	</TD>
	<TD>Description<INPUT TYPE="TEXT" NAME="description" SIZE="20"	VALUE="${domain.description}"><BR>//description of the row obtained here
	</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>

Any clues on how I could go about doing that?
Thanks to all of you for taking the time to help

[Mike Zal]

Your code is getting so complicated that I can't follow the logic properly anymore. It seems that your biggest problem is that you have circular dependencies between your View and Controller code. Your Controller (Servlet code) is expecting to have request parameters (It looks like it will fail to produce attributes if it will not work). Your View (JSP code) is trying to generate request parameters based on the attributes from the Controller, but those values were not assigned because the View did not provide request parameters.

Can you go through a simple Use Case. What happens when the a user tries to access your JSP/Servlet for the first time.
1) User performs a Get to access the Servlet with no request parameters
2) What data is generated when no request parameters (It looks like it returns null)
3) The JSP page tries to assign value from the attributes but those values were null
4) Then the page loads with no information

I have no clue what is going on with your obtainData method. It takes the variable objid but you do not show where it is declared or how it is set. What does the method do when a null value is passed in. In general, how does your code react if any value is null or not initalized. You also call the getDomList method twice in the same block of code, which makes no sense.

The get the data from the obtainData method is easy

//Inside Servlet
request.setAttribute("bean",bean");

//Inside JSP
${bean.code}