JSTL+Servlet+beans

[Vas Miriyala]

Here is my question and I need help to develop Servlet,JSTL,Bean..what i am going to do is ,i am developing administrator module for Inventory Management System,in this administrator can see all users in Dropdown menu(this list is coming from database) with in a JSP, .I have written one class file for connecting database and it working properly and I stucked here.. friends please give me ideas how can i do that

[Vijitha Kumara]

srinivas miriyala wrote:.... I have written one class file for connecting database and it working properly and I stucked here..

Where? In JSTL?

[Vas Miriyala]

No saperate...these are my codes
Database1.java

package ims;
import java.sql.*;
public class Database1 {
final String server="localhost:3306";
final String user="root";
final String  password="miriyala";
final String database="NEWIMS";
public Connection con=null;
public ResultSet rs=null;
public Statement stmt=null;

public  Database1()
	{
			try{
					Class.forName("com.mysql.jdbc.Driver");
					con=DriverManager.getConnection("jdbc:mysql://"+server+"/"+database,user,password);
					stmt=con.createStatement();

			   }
			catch(Exception ex)
	 		   {
					System.out.println(ex.toString());
			   }

	}
public void executeUp(String query) throws Exception
{
         	         stmt.executeUpdate(query);
         	         con.close();
}
}

and Method I have written is

public ArrayList<String> displayusers()
{
    Database1 db = new Database1();
    ArrayList<String> al = new ArrayList<String>();
    try{
        String str = "select username from user_details";
                db.rs=db.stmt.executeQuery(str);
        while(db.rs.next())
        {
            al.add(db.rs.getString("username"));
            System.out.print(al);
        }
    }
        catch(Exception e) {
            System.out.println(e);
        }
return al; 

and I have written servlet also comboboxServlet.java

package ims;
import ims.*;
import java.util.*;
import java.io.*;
import java.net.*;

import javax.servlet.*;
import javax.servlet.http.*;


public class comboServlet extends HttpServlet {
   

    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException 
{
 protected void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        processRequest(request, response);
        HttpSession session = request.getSession(true);
         ArrayList list;
        PrintWriter out = response.getWriter();
    Database1 db = new Database1();
    userMain1 um = new userMain1();
    ArrayList ar = new ArrayList();
    adminClass1 ac = new adminClass1();
    list =ac.displayusers();
    if(list!= null)
    {
        list.add(ac);

then how can i use this to call from jsp

[Vijitha Kumara]

srinivas miriyala wrote:then how can i use this to call from jsp

You should set the ArrayList as a scoped attribute (say request) and forward the request to the JSP using RequestDispatcher . Then you might use JSTL to iterate through the ArrayList in the JSP to create the desired HTML.

[Vas Miriyala]

okay let me try with that and i will let you know what happen anyway thanks for the reply

[Vas Miriyala]

I made some changes to the code ,actually i am trying to print the arraylist but nothing it is printing and I am calling my class file from Servlet and I have written loop in my class file to dsiplay content of the arraylist
Here is the files what i have writen
adminclass1.java

public ArrayList<String> displayusers()
{
       Database1 db = new Database1();
    ArrayList<String> al = new ArrayList<String>();
   // ArrayList<String> al1 = new ArrayList<String>();
    try{
        String str = "select username from user_details";
                db.rs=db.stmt.executeQuery(str);
        while(db.rs.next())
        {
            al.add(db.rs.getString("userame"));
                  System.out.println("got the users");           
                       
        }
    }
        catch(Exception e) {
            System.out.println(e);
            System.out.println("error");
        }
   
return al;

Servlet-code

 public void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
   HttpSession session = request.getSession(true);
        doPost(request,response);
    }
    public void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        processRequest(request, response);
     HttpSession session = request.getSession(true);
        ArrayList<String> list;
         
        PrintWriter out = response.getWriter();
         list = new ArrayList<String>();
    adminClass1 ac = new adminClass1();
   list =  ac.displayusers();
        if(list.size()!= 0)
    {
        list.add("username");
        System.out.println("addes users to the list");
    }
    else
    {
        System.out.println("list is empty");
    }
    for(Iterator iter = list.iterator(); iter.hasNext();)
    {
        System.out.println((String)(iter.next()));
    } 
    request.setAttribute("data",list);
    RequestDispatcher dispatcher = request.getRequestDispatcher("user.jsp");
      if (dispatcher != null){
        dispatcher.forward(request, response);
    

    }
}

when i ran this file it need to diplay the users from the araylist in tomcat status window...but nothing it is printing..can somebody tell me what might be the wrong

[Vijitha Kumara]

srinivas miriyala wrote:.. when i ran this file it need to diplay the users from the araylist in tomcat status window...

What do you mean by "tomcat status window"?

[Vas Miriyala]

I am using Netbeans-6.0, I can able to see the output returned by the tomcat in output window,correct me if i am wrong

[Vijitha Kumara]

srinivas miriyala wrote:I am using Netbeans-6.0, I can able to see the output returned by the tomcat in output window,correct me if i am wrong

I'm not sure about the NetBeans but check the server log files inside the Tomcat, you'll find those there.

[Vas Miriyala]

okay ,can you tell me what might be the wrong in my code please