Pass Data from Java Servlet to Jsp

Pass variables from servlet to jsp

You could set all the values into the response object before forwaring the request to the jsp. Or you can put your values into a session bean and access it in the jsp.

how to send parameter from servlet to jsp page

You can not pass hidden params while using request.sendRedirect. You have following options to pass parameters to the JSP from servlet.

1. Set request params in the url itself as

response.sendRedirect(redirectURL + "index.jsp?errorMessage=", dbMessage);

and then in JSP change code to

String errorMsg = request.getParameter("errorMessage")

Error message will be visible in URL on the browser side.

2. Use server-side forwarding as mentioned in the answer by Jaydip as shown below.

request.setAttribute("errorMessage", dbMessage);
RequestDispatcher dispatcher = serveltContext().getRequestDispatcher("/index.jsp");
dispatcher.forward(request, response);


3. Using session

   request.getSession().setAttribute("errorMessage", dbMessage);

   on the JSP, change code to

   String error_msg=(String)request.getSession().getAttribute("errorMessage");

4. Using cookie

   Cookie errorCookie = new Cookie("errorMessage", dbMessage);
errorCookie.setPath(request.getContextPath());
response.addCookie(errorCookie);

On browser side you can read cookie via js or from the request itself

String error_msg = null;
Cookie [] cookies = request.getCookies();
for (Cookie cookie : cookies) {
    if ("errorMessage".equals(cookie.getName())) {
        error_msg =  cookie.getValue();
    }
}

Passing variable from servlet to JSP

This might be a typo, $(item) should be ${item} in the following -

<c:forEach var="column" items="$(item)" >

Update

http://localhost:8080/DataExtractor/ that doesn't map to the servlet, while http://localhost:8080/DataExtractor/DataGetterServlet does. If the servlet isn't invoked then it's obvious that data is not going to be the request. In other words, the first url is not invoking the servlet, but directly talking you to the page. (You probably have as welcome-page in web.xml)

Pass data from Java Servlet to JSP?

You will need to set the data retrieved in the servlet in request scope so that the data is available in JSP

You will have following line in your servlets.

List<Account> accounts = getAccounts();  
request.setAttribute("accountList",accounts);

Then in JSP you can access this data using the expression language like below

${accountList}

I would use request dispatches instead of the sendRedirect as follows

  RequestDispatcher rd = sc.getRequestDispatcher(url);
  rd.forward(req, res);

If you can use RequestDispatcher then you can store these values in request or session object and get in other JSP.

Is there any specific purpose of using request.sendRedirect?. If not use RequestDispatcher.

See this link for more details.

public class AccountServlet extends HttpServlet {

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

    List<Account> accounts = getAccountListFromSomewhere();

    String url="..."; //relative url for display jsp page
    ServletContext sc = getServletContext();
    RequestDispatcher rd = sc.getRequestDispatcher(url);

    request.setAttribute("accountList", accounts );
    rd.forward(request, response);
  }
}

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