exception while running code

[Megha Singhal]

through the following code i am extracting values from database for edit purpose and the following code is calling when i am click on the edit button that is along with every row of table of jsp page

import java.io.*;   
import java.sql.*;   
import javax.servlet.*;   
import javax.servlet.http.*;   
import java.util.*;   
import java.lang.String;   
import java.sql.Connection;
import javax.servlet.RequestDispatcher;  
import java.sql.Statement;   
import java.sql.ResultSet;   
import javax.naming.*;   
import javax.naming.directory.*;   
import oracle.jdbc.pool.OracleDataSource;  


public class UserServlet extends HttpServlet{ 
 
   			public void doPost(HttpServletRequest request, HttpServletResponse response)
                                   throws ServletException,IOException{
			response.setContentType("text/html");
			PrintWriter out = response.getWriter();
			String str[] = request.getRequestURI().toString().split("/");
out.println("connect");
         		int P_ID = Integer.parseInt(str[3]);
			Connection con = null;   
    			Statement st1 = null;   
    		
    			ResultSet rs = null;   
     			
   		 try {   
       
     			 Context initContext = new InitialContext();                     
      			 Context envContext = (Context) initContext.lookup("java:/comp/env");                     
      			OracleDataSource ds = (OracleDataSource) envContext.lookup("jdbc/abc");                      
     			 if (envContext == null)throw new Exception("Error: No Context");                   
      			if (ds == null) throw new Exception("Error: No DataSource");                    
      			if (ds != null)                           
     			 con = ds.getConnection();   
      
      			st1 = con.createStatement();  
				
				ArrayList userList=null;
				String query = "select * from LTCINFO.PERSONS where P_ID="+P_ID;
				
				st1 = con.createStatement();
				  rs = st1.executeQuery(query);


				while(rs.next())
				{
				  
				  userList =new ArrayList();
				  userList.add(rs.getInt(1));
				  userList.add(rs.getString(2));
				  userList.add(rs.getString(3));
				  userList.add(rs.getString(4));
				  userList.add(rs.getString(5));
				  
				}

				request.setAttribute("userList",userList);
				
                String nextJSP = "/catintra/nhtml/LTCHtml/jsp/editUser.jsp";

				RequestDispatcher dispatcher = request.getRequestDispatcher(nextJSP);
				dispatcher.forward(request,response);
				 rs.close();   
                    st1.close(); 
				 con.close();   
  
        } catch (SQLException se) {   
            out.println("An Error Had occurred while accessing the database");   
            out.println("<HR>");   
  
            out.println(se.getMessage());   
        }   
           
        catch (Exception e) {   
            e.printStackTrace();   
            
        } finally {   
            try {   
                if (rs != null)   
                    rs.close();   
                if (st1 != null)   
                    st1.close();  
 
                if (con != null)   
                    con.close();   
            } catch (Exception e) {   
                out.println(e);   
            }   
        }   
   
 

			
  }
}

but it is giving following error

HTTP Status 500 -

--------------------------------------------------------------------------------

type Exception report

message

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

exception

java.lang.NumberFormatException: For input string: "UserServlet"
java.lang.NumberFormatException.forInputString(Unknown Source)
java.lang.Integer.parseInt(Unknown Source)
java.lang.Integer.parseInt(Unknown Source)
UserServlet.doPost(UserServlet.java:24)
javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.catalina.servlets.InvokerServlet.serveRequest(InvokerServlet.java:402)
org.apache.catalina.servlets.InvokerServlet.doPost(InvokerServlet.java:170)
javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
InfonetFilter.doFilter(InfonetFilter.java:43)


note The full stack trace of the root cause is available in the Apache Tomcat/6.0.18 logs.


--------------------------------------------------------------------------------

Apache Tomcat/6.0.18

i don't understand why this error is coming

[Maneesh Godbole]

java.lang.NumberFormatException: For input string: "UserServlet"

Is "UserServlet" a number?

[Megha Singhal]

Maneesh Godbole wrote:

java.lang.NumberFormatException: For input string: "UserServlet"

Is "UserServlet" a number?

no its a class name

[Maneesh Godbole]

Ok. What I meant was do you now figure out what is going wrong?

[Megha Singhal]

Maneesh Godbole wrote:Ok. What I meant was do you now figure out what is going wrong?

no.. not yet

[Rsudha Ramasamy]

the following line causes this exception

Integer.parseInt(str[3]);

try printing str[3]
i guess it's something thats not an integer

[Megha Singhal]

Rsudha Ramasamy wrote:the following line causes this exception

Integer.parseInt(str[3]);

try printing str[3]
i guess it's something thats not an integer

i'm trying to edit particular record on the basis of P_ID and it is a integer type.
i provide that in the database

[Maneesh Godbole]

Maybe.
But what you are getting from

String str[] = request.getRequestURI().toString().split("/");
int P_ID = Integer.parseInt(str[3]);

is not an integer.

[Megha Singhal]

Maneesh Godbole wrote:Maybe.
But what you are getting from

String str[] = request.getRequestURI().toString().split("/");
int P_ID = Integer.parseInt(str[3]);

is not an integer.

so can you please tell me what changes i have to make so that it will not show this exception.

[Maneesh Godbole]

Like you were told before, try printing what actual values you are getting.

[Megha Singhal]

Maneesh Godbole wrote:Like you were told before, try printing what actual values you are getting.

but actual values i'm getting in string through session from the previous page but i have to convert it into the integer as in database that is stored in the form of integer and query will work only when i match the field of integer type.

[Maneesh Godbole]

It does not really matter what you wish to do with the value.
Point is the string to int logic is failing because the string cannot be converted to an int.
So do you want to share what it prints?

[Megha Singhal]

Maneesh Godbole wrote:It does not really matter what you wish to do with the value.
Point is the string to int logic is failing because the string cannot be converted to an int.
So do you want to share what it prints?

My first jsp page is following

<%@ page language="java" import="java.util.*;"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
 <HEAD>
  <TITLE>Servlet Application</TITLE>
  
  <script language="javascript">
function editRecord(P_ID){
   
    window.location.href="../edit/UserServlet?"+P_ID; 
  }


  function deleteRecord(P_ID){
   
    window.location.href="../edit/DeleteUser?"+P_ID; 
  }
</script>
 </HEAD>

 <BODY>
 <br>
<table align="center">
  
</table>
<br>
  <table width="600px"  align="center" style="background-color:#EDF6EA;border:1px solid #000000;">
 <tr><td colspan=9 align="center" height="10px"></td></tr>

    <tr><td colspan=9 align="center"><a href="../jsp/addUser.jsp" style="font-weight:bold;color:#cc0000;">Add New User</a></td></tr>
<tr><td colspan=9 align="center" height="10px"></td></tr>
  <tr style="background-color:#7BA88B;font-weight:bold;">
     <td>P_ID</td><td>LastName</td><td>FirstName</td>
	 <td>Address</td><td>City</td>
	 <td>Edit</td><td>Delete</td>
  </tr>
	<%
	String bgcolor="";
	int count=0;
	List viewList = new ArrayList();
	Iterator  viewItr;
	
	if(request.getAttribute("userList")!=null && request.getAttribute("userList")!="")
	{
		List userList =  (ArrayList)request.getAttribute("userList");
		Iterator itr = userList.iterator();
		
		while(itr.hasNext())
		{
			
			if(count%2==0)
			{
			 bgcolor = "#C8E2D1";
			}
			else
			{
				
				bgcolor = "#EAF8EF";
			}
			
			viewList = (ArrayList)itr.next();
			int P_ID = Integer.parseInt(viewList.get(0).toString());
			viewItr = viewList.iterator();
			%>
			<tr style="background-color:<%=bgcolor%>;">
			<%	
			while(viewItr.hasNext())
			{
			
				%>
				<td><%=viewItr.next()%></td>
				
				<%
					
			}
			count++;
			%>
			<td><input type="button" name="edit" value="Edit" style="background-color:#49743D;font-weight:bold;color:#ffffff;" onclick="editRecord(<%=P_ID%>);" ></td>
				<td><input type="button" name="delete" style="background-color:#ff0000;font-weight:bold;;color:#ffffff;" value="Delete" onclick="deleteRecord(<%=P_ID%>);"></td>
			</tr>
			<%
		}
	}
	if(count==0)
	{
		%>
		<tr><td colspan="9" align="center"> </td></tr>
            <tr><td colspan="9" align="center">No Record Avaliable</td></tr>
		<%
	}
	%>
     <tr><td colspan=9 align="center" height="2px"></td></tr>
	<tr><td><input type='text' name='test' value='test'></td></tr>
  </table>	
 </BODY>
</HTML>
 

and when i click on edit button then it should redirect me to follwing servlet

  import java.io.*;   
import java.sql.*;   
import javax.servlet.*;   
import javax.servlet.http.*;   
import java.util.*;   
import java.lang.String;   
import java.sql.Connection;
import javax.servlet.RequestDispatcher;  
import java.sql.Statement;   
import java.sql.ResultSet;   
import javax.naming.*;   
import javax.naming.directory.*;   
import oracle.jdbc.pool.OracleDataSource;  


public class UserServlet extends HttpServlet{ 
 
   			public void doPost(HttpServletRequest request, HttpServletResponse response)
                                   throws ServletException,IOException{
			response.setContentType("text/html");
			PrintWriter out = response.getWriter();
			String str[] = request.getRequestURI().toString().split("/");
int P_ID = Integer.parseInt(str[3]);			
Connection con = null;   
    			Statement st1 = null;   
    		
    			ResultSet rs = null;   
     			
   		 try {   
       
     			 Context initContext = new InitialContext();                     
      			 Context envContext = (Context) initContext.lookup("java:/comp/env");                     
      			OracleDataSource ds = (OracleDataSource) envContext.lookup("jdbc/abc");                      
     			 if (envContext == null)throw new Exception("Error: No Context");                   
      			if (ds == null) throw new Exception("Error: No DataSource");                    
      			if (ds != null)                           
     			 con = ds.getConnection();   
      
      			st1 = con.createStatement();  
				
				ArrayList userList=null;
				String query = "select * from LTCINFO.PERSONS where P_ID="+P_ID;
				
				st1 = con.createStatement();
				  rs = st1.executeQuery(query);

				while(rs.next())
				{
				  
				  userList =new ArrayList();
				  userList.add(rs.getInt(1));
				  userList.add(rs.getString(2));
				  userList.add(rs.getString(3));

				  userList.add(rs.getString(4));
				  userList.add(rs.getString(5));
				  
				}


				request.setAttribute("userList",userList);
				
                String nextJSP = "../jsp/editUser.jsp";

				RequestDispatcher dispatcher = request.getRequestDispatcher(nextJSP);
				dispatcher.forward(request,response);
				 rs.close();   
                    st1.close(); 
				 con.close();   
  
        } catch (SQLException se) {   
            out.println("An Error Had occurred while accessing the database");   
            out.println("<HR>");   
  
            out.println(se.getMessage());   
        }   
           
        catch (Exception e) {   
            e.printStackTrace();   
            
        } finally {   
            try {   
                if (rs != null)   
                    rs.close();   
                if (st1 != null)   
                    st1.close();  
 
                if (con != null)   
                    con.close();   
            } catch (Exception e) {   
                out.println(e);   
            }   
        }   
   
 

			
  }
}

and after it should take me to following jsp page

</head>
<body>
<%!
int P_ID;
String LASTNAME="";
String FIRSTNAME="";
String ADDRESS="";
String CITY="";
List  userList=null;
%>

<%

if(request.getAttribute("userList")!=null && request.getAttribute("userList")!="")
{
		userList = (ArrayList)request.getAttribute("userList");
		P_ID=Integer.parseInt(userList.get(0).toString());
		LASTNAME=userList.get(1).toString();
		FIRSTNAME=userList.get(2).toString();
		ADDRESS=userList.get(3).toString();
		CITY=userList.get(4).toString();
		
}
%>

<form name="userform" method="post" action="EditUser">
<br><br><br>
<table align="center" width="300px" style="background-color:#EDF6EA;border:1px solid #000000;">
<input type="hidden" name="P_ID" value="<%=P_ID%>">
<tr><td colspan=2 style="font-weight:bold;" align="center">Edit User</td></tr>
<tr><td colspan=2 align="center" height="10px"></td></tr>
	
	<tr>
		<td>LASTNAME</td>
		<td><input type="text" name="LASTNAME" value="<%=LASTNAME%>"></td>
	</tr>
	<tr>
		<td>FIRSTNAME</td>
		<td><input type="text" name="FIRSTNAME" value="<%=FIRSTNAME%>"></td>
	</tr>
	<tr>
		<td>ADDRESS</td>
		<td><input type="text" name="ADDRESS" value="<%=ADDRESS%>"></td>
	</tr>
	<tr>
		<td>CITY</td>
		<td><input type="text" name="CITY" value="<%=CITY%>"></td>
	</tr>
	
	
	
	<tr>
		<td></td>
		<td><input type="submit" name="Submit" value="Edit" style="background-color:#49743D;font-weight:bold;color:#ffffff;"></td>
	</tr>
	<tr><td colspan=2 align="center" height="10px"></td></tr>
</table>
</form>
</body>
</html>

on this page fetched value should be shown

[Maneesh Godbole]

Maneesh Godbole wrote:
So do you want to share what it prints?

[Neeraj Dhiman]

what i think. In code:

int P_ID = Integer.parseInt(str[3]);

str[3] is null. so check these by printing the value of str[3]. if it is null or not.

[Prasad Krishnegowda]

The exception clearly tells, that it cannot convert the String value to an Integer. That means check what is been passed to Integer.parseInt, it is not an number.
As suggested earlier by Maneesh and Rsudha, why can't you just print that value and show us what it prints?

[Megha Singhal]

Prasad Krishnegowda wrote:The exception clearly tells, that it cannot convert the String value to an Integer. That means check what is been passed to Integer.parseInt, it is not an number.
As suggested earlier by Maneesh and Rsudha, why can't you just print that value and show us what it prints?

now i change the code but stll it is not redirecting me to jsp

import java.io.*;   
import java.sql.*;   
import javax.servlet.*;   
import javax.servlet.http.*;   
import java.util.*;   
import java.lang.String;   
import java.sql.Connection;
import javax.servlet.RequestDispatcher;  
import java.sql.Statement;   
import java.sql.ResultSet;   
import javax.naming.*;   
import javax.naming.directory.*;   
import oracle.jdbc.pool.OracleDataSource;  


public class UserServlet extends HttpServlet{ 

public void doGet(HttpServletRequest request, HttpServletResponse response)
                                   throws ServletException,IOException{
		doPost(request,response);
	}
 
   			public void doPost(HttpServletRequest request, HttpServletResponse response)
                                   throws ServletException,IOException{
			response.setContentType("text/html");
			PrintWriter out = response.getWriter();
//changes i made
			[b]String str = request.getQueryString();

			int P_ID = Integer.parseInt(str); [/b]			
Connection con = null;   
    			Statement st1 = null;   
    		
    			ResultSet rs = null;   
     			
   		 try {   
       
     			 Context initContext = new InitialContext();                     
      			 Context envContext = (Context) initContext.lookup("java:/comp/env");                     
      			OracleDataSource ds = (OracleDataSource) envContext.lookup("jdbc/abc");                      
     			 if (envContext == null)throw new Exception("Error: No Context");                   
      			if (ds == null) throw new Exception("Error: No DataSource");                    
      			if (ds != null)                           
     			 con = ds.getConnection();   
      
      			st1 = con.createStatement();  
				
				ArrayList userList=null;
				String query = "select * from LTCINFO.PERSONS where P_ID="+P_ID;
				
				st1 = con.createStatement();
				  rs = st1.executeQuery(query);

				while(rs.next())
				{
				  
				  userList =new ArrayList();
				  userList.add(rs.getInt(1));
				  userList.add(rs.getString(2));
				  userList.add(rs.getString(3));

				  userList.add(rs.getString(4));
				  userList.add(rs.getString(5));
				  
				}


				request.setAttribute("userList",userList);
				
                String nextJSP = "../jsp/editUser.jsp";

				RequestDispatcher dispatcher = request.getRequestDispatcher(nextJSP);
				dispatcher.forward(request,response);
				 rs.close();   
                    st1.close(); 
				 con.close();   
  
        } catch (SQLException se) {   
            out.println("An Error Had occurred while accessing the database");   
            out.println("<HR>");   
  
            out.println(se.getMessage());   
        }   
           
        catch (Exception e) {   
            e.printStackTrace();   
            
        } finally {   
            try {   
                if (rs != null)   
                    rs.close();   
                if (st1 != null)   
                    st1.close();  
 
                if (con != null)   
                    con.close();   
            } catch (Exception e) {   
                out.println(e);   
            }   
        }   
   
 

			
  }
}

and my below code that is for delete that is working which is following and redirecting me to other page

import java.io.*;   
import java.sql.*;   
import javax.servlet.*;   
import javax.servlet.http.*;   
import java.util.*;   
import java.lang.String;   
import java.sql.Connection;
import javax.servlet.RequestDispatcher;   
import java.sql.Statement;   
import java.sql.ResultSet;   
import javax.naming.*;   
import javax.naming.directory.*;   
import oracle.jdbc.pool.OracleDataSource;  

public class DeleteUser extends HttpServlet{ 

 public void doGet(HttpServletRequest request, HttpServletResponse response)
                                   throws ServletException,IOException{
		doPost(request,response);
	}
 
   public void doPost(HttpServletRequest request, HttpServletResponse response)
                                   throws ServletException,IOException{
			response.setContentType("text/html");
			PrintWriter out = response.getWriter();
Connection con = null;   
    			Statement st1 = null;   
    		
    			ResultSet rs = null; 
	String str = request.getQueryString();

			int P_ID = Integer.parseInt(str);  
     			
   		 try {   
       
     			 Context initContext = new InitialContext();                     
      			 Context envContext = (Context) initContext.lookup("java:/comp/env");                     
      			OracleDataSource ds = (OracleDataSource) envContext.lookup("jdbc/abc");                      
     			 if (envContext == null)throw new Exception("Error: No Context");                   
      			if (ds == null) throw new Exception("Error: No DataSource");                    
      			if (ds != null)                           
     			 con = ds.getConnection();   
      
      			st1 = con.createStatement();   
				
				ArrayList al=null;
				ArrayList userList =new ArrayList();
				String query = "delete from LTCINFO.PERSONS  where P_ID="+P_ID;
				            
			    int i = st1.executeUpdate(query);
				if(i>0)
				{
					response.sendRedirect("ServletRecord");
				}
				 rs.close();   
                    st1.close(); 
				 con.close();   
  
        } catch (SQLException se) {   
            out.println("An Error Had occurred while accessing the database");   
            out.println("<HR>");   
  
            out.println(se.getMessage());   
        }   
           
        catch (Exception e) {   
            e.printStackTrace();   
            
        } finally {   
            try {   
                if (rs != null)   
                    rs.close();   
                if (st1 != null)   
                    st1.close();  
 
                if (con != null)   
                    con.close();   
            } catch (Exception e) {   
                out.println(e);   
            }   
        }   
   
 

			
  }
}

[Prasad Krishnegowda]

I am just wondering, is it so difficult to do what we all suggested here (just printing one value and posting here the result..)

I request for the last time. Please post the value of the variable been passed to Integer.parseInt() as suggested by Maneesh,Rsudha and Neeraj already.

If you just keep on posting code, without doing what's suggested, its of no use.
Also, posting things like, below code is working and below is not working, will not help. You are expecting us to keep on guessing what changes you did?
You need to TellTheDetails, such as what changes you did, what you expected and what came..

[Ankit Garg]

If the value is coming as a query string, you can simply use request.getParameter to get its value...

[Megha Singhal]

Ankit Garg wrote:If the value is coming as a query string, you can simply use request.getParameter to get its value...

when i am passing the the value below like this and disable to bring variable from the previous page then it is giving below output that is what i want

import java.io.*;   
import java.sql.*;   
import javax.servlet.*;   
import javax.servlet.http.*;   
import java.util.*;   
import java.lang.String;   
import java.sql.Connection;
import javax.servlet.RequestDispatcher;  
import java.sql.Statement;   
import java.sql.ResultSet;   
import javax.naming.*;   
import javax.naming.directory.*;   
import oracle.jdbc.pool.OracleDataSource;  


public class UserServlet extends HttpServlet{ 

public void doGet(HttpServletRequest request, HttpServletResponse response)
                                   throws ServletException,IOException{
		doPost(request,response);
	}
 
   			public void doPost(HttpServletRequest request, HttpServletResponse response)
                                   throws ServletException,IOException{
			response.setContentType("text/html");
			PrintWriter out = response.getWriter();
			/*String str = request.getQueryString();

			int P_ID = Integer.parseInt(str);*/

			Connection con = null;   
    			Statement st1 = null;   
    		
    			ResultSet rs = null;   
     			
   		 try {   
       
     			 Context initContext = new InitialContext();                     
      			 Context envContext = (Context) initContext.lookup("java:/comp/env");                     
      			OracleDataSource ds = (OracleDataSource) envContext.lookup("jdbc/abc");                      
     			 if (envContext == null)throw new Exception("Error: No Context");                   
      			if (ds == null) throw new Exception("Error: No DataSource");                    
      			if (ds != null)                           
     			 con = ds.getConnection();   
      
      			st1 = con.createStatement();  
				
				ArrayList userList=null;
				[u]String query = "select * from LTCINFO.PERSONS where P_ID=35";[/u]				
				st1 = con.createStatement();
				  rs = st1.executeQuery(query);

				while(rs.next())
				{
				  
				  userList =new ArrayList();
				  userList.add(rs.getInt(1));
				  userList.add(rs.getString(2));
				  userList.add(rs.getString(3));

				  userList.add(rs.getString(4));
				  userList.add(rs.getString(5));
				  
				}


				request.setAttribute("userList",userList);
				
                String nextJSP = "/nhtml/LTCHtml/jsp/editUser.jsp";

				RequestDispatcher dispatcher = request.getRequestDispatcher(nextJSP);
				dispatcher.forward(request,response);
				 rs.close();   

but i have to work generaly on that it is not working

i have attached the output screen shot that is based on fix value.

and following is syntax for calling from the previous page to this servlet page , the event which has to be performed on button click

function editRecord(P_ID){

window.location.href="../edit/UserServlet?"+P_ID;
}

[Swastik Dey]

Are you sure that the following path is correct?

String nextJSP = "../jsp/editUser.jsp";

[Megha Singhal]

Swastik Dey wrote:Are you sure that the following path is correct?

String nextJSP = "../jsp/editUser.jsp";

as i told it is working on fix value but not on query string and the screen shot i attached that is coming because i have given the proper path.
that's for sure prob is not in the path there is something in the query string

[Swastik Dey]

Does exception stack trace say something?

[Piyush Mangal]

Hi,

Why can't you use query parameter instead of query string.
You can try with following code changes.
JavaScript

function editRecord(P_ID){
 alert('Value of PID is ' + P_ID)
 window.location.href="../edit/UserServlet?userId="+P_ID;} 

Java Code

 /*String str = request.getQueryString(); 
                    int P_ID = Integer.parseInt(str);*/ 
                   String str = request.getRequestParameter("userId"); 

 [u]String query = "select * from LTCINFO.PERSONS where P_ID=" +str ;[/u]     

[Megha Singhal]

Swastik Dey wrote:Does exception stack trace say something?

No

[Megha Singhal]

Piyush Mangal wrote:Hi,

Why can't you use query parameter instead of query string.
You can try with following code changes.
JavaScript

function editRecord(P_ID){
 alert('Value of PID is ' + P_ID)
 window.location.href="../edit/UserServlet?userId="+P_ID;} 

Java Code

 /*String str = request.getQueryString(); 
                    int P_ID = Integer.parseInt(str);*/ 
                   String str = request.getRequestParameter("userId"); 

 [u]String query = "select * from LTCINFO.PERSONS where P_ID=" +str ;[/u]     

ok then where should i declare userId?

[Piyush Mangal]

You are already defining userId in your js function (see below). What we are doing here is P_ID will be passed as a request parameter with the name "userId" which we get by using request.getParameter("userId") in servlet.

window.location.href="../edit/UserServlet?userId="+P_ID;} 

[Megha Singhal]

Megha Singhal wrote:

Piyush Mangal wrote:Hi,

Why can't you use query parameter instead of query string.
You can try with following code changes.
JavaScript

function editRecord(P_ID){
 alert('Value of PID is ' + P_ID)
 window.location.href="../edit/UserServlet?userId="+P_ID;} 

Java Code

 /*String str = request.getQueryString(); 
                    int P_ID = Integer.parseInt(str);*/ 
                   String str = request.getRequestParameter("userId"); 

 [u]String query = "select * from LTCINFO.PERSONS where P_ID=" +str ;[/u]     

ok then where should i declare userId?

now this is giving following error

UserServlet.java:27: cannot find symbol
symbol : method getRequestParameter(java.lang.String)
location: interface javax.servlet.http.HttpServletRequest
String str = request.getRequestParameter("userId");
^

[Piyush Mangal]

My Apologies for typo.

It should be String str = request.getParameter("userId");

[Megha Singhal]

Piyush Mangal wrote:My Apologies for typo.

It should be String str = request.getParameter("userId");

but the problem still same .
i'm still not able to redirect to jsp page actualy this servlet will run only when i connect it with previous jsp page as query string is passing from jsp to servlet page and then i am redirecting it to the next jsp page so the problem is still same i'm not able to redirect to next jsp page.
my main problem is this only that it is not going on next page and there is no error in the path as this path is working on another but i'm not understanding why it is not working on this page.

[Piyush Mangal]

Can you describe the structure of your web application including jsp folder.

Please also share the source code for
1. JSP from where you are taking user to Servlet.
2. The servlet which will forward the request to Jsp

[Megha Singhal]

Piyush Mangal wrote:Can you describe the structure of your web application including jsp folder.

Please also share the source code for
1. JSP from where you are taking user to Servlet.
2. The servlet which will forward the request to Jsp

i already mentioned those servlet and jsp above but i am mentioning again.

below is the first jsp page

<%@ page language="java" import="java.util.*;"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
 <HEAD>
  <TITLE>Servlet Application</TITLE>
  
  <script language="javascript">
function editRecord(P_ID){   
   
 window.location.href="../edit/UserServlet?P_ID="+P_ID;
}   



  function deleteRecord(P_ID){
   
    window.location.href="../edit/DeleteUser?"+P_ID; 
  }
</script>
 </HEAD>

 <BODY>
 <br>
<table >
  
</table>
<br>
  <table    >
 <tr><td   ></td></tr>

    <tr><td  ><a   rel="nofollow">Add New User</a></td></tr>
<tr><td   ></td></tr>
  <tr >
     <td>P_ID</td><td>LastName</td><td>FirstName</td>
	 <td>Address</td><td>City</td>
	 <td>Edit</td><td>Delete</td>
  </tr>
	<%
	String bgcolor="";
	int count=0;
	List viewList = new ArrayList();
	Iterator  viewItr;
	
	if(request.getAttribute("userList")!=null && request.getAttribute("userList")!="")
	{
		List userList =  (ArrayList)request.getAttribute("userList");
		Iterator itr = userList.iterator();
		
		while(itr.hasNext())
		{
			
			if(count%2==0)
			{
			 bgcolor = "#C8E2D1";
			}
			else
			{
				
				bgcolor = "#EAF8EF";
			}
			
			viewList = (ArrayList)itr.next();
			int P_ID = Integer.parseInt(viewList.get(0).toString());
			viewItr = viewList.iterator();
			%>
			<tr style="background-color:<%=bgcolor%>;">
			<%	
			while(viewItr.hasNext())
			{
			
				%>
				<td><%=viewItr.next()%></td>
				
				<%
					
			}
			count++;
			%>
			<td><input type="button" name="edit" value="Edit" style="background-color:#49743D;font-weight:bold;color:#ffffff;" onclick="editRecord(<%=P_ID%>);" ></td>
				<td><input type="button" name="delete" style="background-color:#ff0000;font-weight:bold;;color:#ffffff;" value="Delete" onclick="deleteRecord(<%=P_ID%>);"></td>
			</tr>
			<%
		}
	}
	if(count==0)
	{
		%>
		<tr><td  > </td></tr>
            <tr><td  >No Record Avaliable</td></tr>
		<%
	}
	%>
     <tr><td   ></td></tr>
	<tr><td><input type='text' name='test' value='test'></td></tr>
  </table>	
 </BODY>
</HTML>
 

below is the servlet on which the jsp page will redirect on edit button click

import java.io.*;   
import java.sql.*;   
import javax.servlet.*;   
import javax.servlet.http.*;   
import java.util.*;   
import java.lang.String;   
import java.sql.Connection;
import javax.servlet.RequestDispatcher;  
import java.sql.Statement;   
import java.sql.ResultSet;   
import javax.naming.*;   
import javax.naming.directory.*;   
import oracle.jdbc.pool.OracleDataSource;  


public class UserServlet extends HttpServlet{ 

public void doGet(HttpServletRequest request, HttpServletResponse response)
                                   throws ServletException,IOException{
		doPost(request,response);
	}
 
   			public void doPost(HttpServletRequest request, HttpServletResponse response)
                                   throws ServletException,IOException{
			response.setContentType("text/html");
			PrintWriter out = response.getWriter();
			String str = request.getParameter("userId");   

			  

			Connection con = null;   
    			Statement st1 = null;   
    		
    			ResultSet rs = null;   
     			
   		 try {   
       
     			 Context initContext = new InitialContext();                     
      			 Context envContext = (Context) initContext.lookup("java:/comp/env");                     
      			OracleDataSource ds = (OracleDataSource) envContext.lookup("jdbc/abc");                      
     			 if (envContext == null)throw new Exception("Error: No Context");                   
      			if (ds == null) throw new Exception("Error: No DataSource");                    
      			if (ds != null)                           
     			 con = ds.getConnection();   
      
      			st1 = con.createStatement();  
				
				ArrayList userList=null;
				String query = "select * from LTCINFO.PERSONS where P_ID="+str;
				
				st1 = con.createStatement();
				  rs = st1.executeQuery(query);

				while(rs.next())
				{
				  
				  userList =new ArrayList();
				  userList.add(rs.getInt(1));
				  userList.add(rs.getString(2));
				  userList.add(rs.getString(3));

				  userList.add(rs.getString(4));
				  userList.add(rs.getString(5));
				  
				}


				request.setAttribute("userList",userList);
				
                String nextJSP = "/editUser.jsp";

				RequestDispatcher dispatcher = request.getRequestDispatcher(nextJSP);
				dispatcher.forward(request,response);
				 rs.close();   
                    st1.close(); 
				 con.close();   
  
        } catch (SQLException se) {   
            out.println("An Error Had occurred while accessing the database");   
            out.println("<HR>");   
  
            out.println(se.getMessage());   
        }   
           
        catch (Exception e) {   
            e.printStackTrace();   
            
        } finally {   
            try {   
                if (rs != null)   
                    rs.close();   
                if (st1 != null)   
                    st1.close();  
 
                if (con != null)   
                    con.close();   
            } catch (Exception e) {   
                out.println(e);   
            }   
        }   
   


			
  }
}                                                                                                                                                                                                                                                                                                                                                                                                                                                                              

below is the jsp code on which servlet should redirect

<%@ page language="java" import="java.util.*;"%>
</head>
<body>
<%!
int P_ID;
String LASTNAME="";
String FIRSTNAME="";
String ADDRESS="";
String CITY="";
List  userList=null;
%>

<%

if(request.getAttribute("userList")!=null && request.getAttribute("userList")!="")
{
		userList = (ArrayList)request.getAttribute("userList");
		P_ID=Integer.parseInt(userList.get(0).toString());
		LASTNAME=userList.get(1).toString();
		FIRSTNAME=userList.get(2).toString();
		ADDRESS=userList.get(3).toString();
		CITY=userList.get(4).toString();
		
}
%>

<form name="userform" method="post" action="EditUser">
<br><br><br>
<table   >
<input type="hidden" name="P_ID" value="<%=P_ID%>">
<tr><td   >Edit User</td></tr>
<tr><td   ></td></tr>
	
	<tr>
		<td>LASTNAME</td>
		<td><input type="text" name="LASTNAME" value="<%=LASTNAME%>"></td>
	</tr>
	<tr>
		<td>FIRSTNAME</td>
		<td><input type="text" name="FIRSTNAME" value="<%=FIRSTNAME%>"></td>
	</tr>
	<tr>
		<td>ADDRESS</td>
		<td><input type="text" name="ADDRESS" value="<%=ADDRESS%>"></td>
	</tr>
	<tr>
		<td>CITY</td>
		<td><input type="text" name="CITY" value="<%=CITY%>"></td>
	</tr>
	
	
	
	<tr>
		<td></td>
		<td><input type="submit" name="Submit" value="Edit" style="background-color:#49743D;font-weight:bold;color:#ffffff;"></td>
	</tr>
	<tr><td   ></td></tr>
</table>
</form>
</body>
</html>

so above are the required servlet and jsps

[Neeraj Dhiman]

ok. so you are not redirecting to another page then what is the error message or in which error page you are redirecting or something else.
is there any exception?

[Megha Singhal]

Neeraj Dhiman wrote:ok. so you are not redirecting to another page then what is the error message or in which error page you are redirecting or something else.
is there any exception?

yes this is redirecting to my college main page.
it is in our server if there is any error in code then it will redirect to college main page without showing any exception or error

[Neeraj Dhiman]

it mean there is errors in your code. have you checked your console for exception? your are using e.printStackTrace();
try to find in which segment of code you got exception which will caused to redirect to another page.

[Swastik Dey]

In you jsp you have something like. What does this mean?
request.getAttribute("userList")!=""

You probably want to make sure that the list not empty?

if(arrrayList!=null && arrayList.size()>0){
  //do something
}

Problem 2, you are initializing the arraylist inside the loop

while(rs.next())  
                {  
                    
                  userList =new ArrayList();  
                  userList.add(rs.getInt(1));  
                  userList.add(rs.getString(2));  
                  userList.add(rs.getString(3));  
  
                  userList.add(rs.getString(4));  
                  userList.add(rs.getString(5));  
                    
                }  

So what happens in the above code, every time the loop executes a new arraylist object is created, means it will always store only the last record in the array list. Initialize it before you start the loop.

[Piyush Mangal]

Hi,

Why are you using ?P_ID="+P_ID and not ?userId="+P_ID in your javascript?

#   <script language="javascript">  
# function editRecord(P_ID){     
#      
#  window.location.href="../edit/UserServlet?P_ID="+P_ID;  
# }     
#   

If you want to use ?P_ID="+P_ID , then in your code also , you will need to change request parameter name accordingly.

[Megha Singhal]

Piyush Mangal wrote:Hi,

Why are you using ?P_ID="+P_ID and not ?userId="+P_ID in your javascript?

#   <script language="javascript">  
# function editRecord(P_ID){     
#      
#  window.location.href="../edit/UserServlet?P_ID="+P_ID;  
# }     
#   

If you want to use ?P_ID="+P_ID , then in your code also , you will need to change request parameter name accordingly.

in my jsp P_ID is defined so i have to use P_ID and i alraedy made changes in req.getparameter but still problem is coming