JSP not picking up getAttribute from Servlet

Hello All,

I've been posting my problems here and I am glad it was answered.

I have another assignment. I am halway there, but the last bit is not working.

I have a servlet file which the code looks like this:

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.sql.*;
import java.sql.*;
import java.util.*;

public class Search extends HttpServlet{ 
 
   public void doPost(HttpServletRequest request, HttpServletResponse response)
                                   throws ServletException,IOException{
      response.setContentType("text/html");
      PrintWriter out = response.getWriter();

System.out.println("MySQL Connect Example.");
      Connection conn = null;
      String url = "jdbc:oracle:thin:@server:1521:SID";
      String driver = "oracle.jdbc.driver.OracleDriver";
      String userName = "username"; 
      String password = "password";

Statement st;
      try {
        Class.forName(driver).newInstance();
        conn = DriverManager.getConnection(url,userName,password);
        System.out.println("Connected to the database");
        String  prod_code  = request.getParameter("prod_code");

ArrayList al=null;
        ArrayList emp_list =new ArrayList();
        String query = "select * from POS_DEF_PROD_DEF where prod_code='"+prod_code+"'";
//        String query = "Select * from POS_DEF_PROD_DEF";
        System.out.println("query " + query);
        st = conn.createStatement();
        ResultSet  rs = st.executeQuery(query);

while(rs.next()){
          al  = new ArrayList();
        
          al.add(rs.getString(1));
          al.add(rs.getString(2));
          al.add(rs.getString(3));
          al.add(rs.getString(4));
          al.add(rs.getString(5));
          System.out.println("al :: "+al);
          emp_list.add(al);
        }

request.setAttribute("empList",emp_list);
        
             System.out.println("empList " + emp_list);

//   out.println("emp_list " + emp_list);

String nextJSP = "/viewSearch.jsp";
        RequestDispatcher dispatcher = getServletContext().getRequestDispatcher(nextJSP);
        dispatcher.forward(request,response);
//        conn.close();
//        System.out.println("Disconnected from database");
      } catch (Exception e) {
      e.printStackTrace();
      }
  }
}

When I query, the result came out successfully in the command prompt (where the tomcat server started up and displayed) but in the viewSearch.jsp, there is no result displayed.

My viewSearch.jsp looks like this:

<%@ page import="java.util.*" %> 
<html>
<head>
</head>
<body>
<table width="700px" align="center" style="border:1px solid #000000;">
<tr>
<td colspan=8 align="center" style="background-color:ffeeff">Product Record</td>
</tr>
<tr style="background-color:efefef;">
<td>Product Name</td>
<td>Product Code</td>
<td>Product Desc</td>
</tr>
<%
int count=0;
String color = "#F9EBB3";

if(request.getAttribute("empList")!=null){
	ArrayList al = (ArrayList)request.getAttribute("empList");
	Iterator itr = al.iterator();
	while(itr.hasNext()){
		if((count%2)==0){ 
			color = "#eeffee"; 
		}
		else{
			color = "#F9EBB3";
		}
		count++;
	
	ArrayList empList = (ArrayList)itr.next();
	%>
	<tr style="background-color:<%=color%>;">
		<td><%=empList.get(0)%></td>
		<td><%=empList.get(1)%></td>
		<td><%=empList.get(2)%></td>
	</tr>
	<%
	}
}
%> 
<%
if(count==0){
%>
	<tr>
		<td colspan=8 align="center" style="background-color:eeffee">No Record</td>
	</tr>
<%
}
%>
</table>
</body>
</html>

What's wrong? Is it because of my configuration of web.xml or these codes?

Thanks in advance for helping me.

check the log file to see if some exception has occured

i dont know what is your requirement to display. i dont see any logic (setting values into List and Iterating it in jsp) in your code. Personally i recommend to use TO(Transfer Object)

Your code look fine.

What exactly happens when you hit the link to reach the 'Search' class. I mean do you get the viewSearch.jsp page displayed in the browser with the message No Record or do you end up seeing a blank page or some thing else?

Hi,

we didn't get what's your code logic.

you are trying to add al ArrayList just because color your line.

But i think that will done your only with ArrayList emp_list just iterate your list with status and according to odd or even put your color.

No need to do this complex logic.

Hello All,

thanks for replying. Maybe I didn't clearly explain my program. I have three files:
1)search.jsp (to enter search criteria),
2)search.java, (to connect to DB and query the DB) and
3)viewSearch.jsp (to display the search result).

When I enter a search criteria at search.jsp, it goes to search.java to find the
record in the database. I can see the search result in the command prompt
but in the viewSearch.jsp, stated "No Record Found" (I can see the table and all).

I can explain more if this is not enough. Really need some lights shed here.

Thanks in advance.

Hi Karthick,
I see the logfile and no exception occured.

Hi Nishan,
I don't really understand what are your explanation. Please share with me your ideas

Hi Emma Aziz,

What i mean first of all you are using scriplet into your jsp page....which is not good for coding....

So, i mean use JSTL <c:forEach tag which gives you iterate your list so no need to write java code and iterate.

That JSTL tag provide you status attribute which gives you odd and even row status what you want. But you use it using division operation and find it is odd or even that gives JSTL. just put your color according to status attribute.

That's what i mean.

>

Emma Aziz - For all the design suggestions that you have got - your code is still correct the way it is. You could try putting a few System.out.println() statements in your JSP to find out how the flow is happening - that would give you some idea of whats going wrong...

Yes I agree with everyone out here that there are lot of design improvements that could be made to the code - it still does not answer the question why the current code is not working? Any thought on that?

i tried this :

<%@ page import="java.util.*"%>
<html>
<body>
<table >
 	<tr>
 		<td >Product
 		Record</td>
 	</tr>
 	<tr >
 		<td>Product Name</td>
 		<td>Product Code</td>
 		<td>Product Desc</td>
 	</tr>
 	<%
 	System.out.println("in scriplet ");
 		int count = 0;
 		String color = "#F9EBB3";
 		List list = new ArrayList();
 		list.add("Aniruddh");
 		list.add("joshi");
 		list.add("SCSL");
 		request.setAttribute("empList", list);
 		System.out.println("empList set to req ");
 		if (request.getAttribute("empList") != null) {
 System.out.println("empList is not null ");
 			ArrayList al = (ArrayList) request.getAttribute("empList");
 			Iterator itr = al.iterator();
 			while (itr.hasNext()) {
 				if ((count % 2) == 0) {
 			color = "#eeffee";
 				} else {
 			color = "#F9EBB3";
 				}
 				count++;
 
 				ArrayList empList = (ArrayList) itr.next();
 	%>
 	<tr >
 		<td><%=empList.get(0)%></td>
 		<td><%=empList.get(1)%></td>
 		<td><%=empList.get(2)%></td>
 	</tr>
 	<%
 		}
 		}
 	%>
 	<%
 	if (count == 0) {
 	%>
 	<tr>
 		<td >No
 		Record</td>
 	</tr>
 	<%
 	}
 	%>
 </table>
</body>
</html>

and got no messages on server console !!
i think the scriplets aren't working ... m looking into why

Aniruddh Joshi wrote:i tried this :
<%@ page import="java.util.*"%> <html> <body> <table > <tr> <td >Product Record</td> </tr> <tr > <td>Product Name</td> <td>Product Code</td> <td>Product Desc</td> </tr> <% System.out.println("in scriplet "); int count = 0; String color = "#F9EBB3"; List list = new ArrayList(); list.add("Aniruddh"); list.add("joshi"); list.add("SCSL"); request.setAttribute("empList", list); System.out.println("empList set to req "); if (request.getAttribute("empList") != null) { System.out.println("empList is not null "); ArrayList al = (ArrayList) request.getAttribute("empList"); Iterator itr = al.iterator(); while (itr.hasNext()) { if ((count % 2) == 0) { color = "#eeffee"; } else { color = "#F9EBB3"; } count++; ArrayList empList = (ArrayList) itr.next(); %> <tr > <td><%=empList.get(0)%></td> <td><%=empList.get(1)%></td> <td><%=empList.get(2)%></td> </tr> <% } } %> <% if (count == 0) { %> <tr> <td >No Record</td> </tr> <% } %> </table> </body> </html>

and got no messages on server console !!
i think the scriplets aren't working ... m looking into why

Your code is incorrect. Its going to throw a class cast exception at line 33 --> ArrayList empList = (ArrayList) itr.next();
That because the itr.next() is going to return the String 'Aniruddh' which is the first element in the ArrayList.

The problem with the original code is on similar lines. Here is the code that works..

Frankly - the code does need a lot of redesign - would have loved to help more but running short of time right now ...