servlet to jsp pass value
Question
I want to simple pass value servlet to jsp page. I want to run jsp file and onload data is display from getting servlet
But I got null : "Servlet communicated message to JSP: null "
below is my code.
java code
package api;
public class ServletToJSP extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//communicating a simple String message.
String message = "Example source code of Servlet to JSP communication.";
request.setAttribute("message", message);
RequestDispatcher reqDispatcher = getServletConfig().getServletContext().getRequestDispatcher("javaPapers.jsp");
reqDispatcher.forward(request,response);
}
}
jsp file
<%@ page import="api.ServletToJSP" language="java" %>
<html>
<body>
<%
String message = (String) request.getAttribute("message");
out.println("Servlet communicated message to JSP: "+ message);
// Vector vecObj = (Vector) request.getAttribute("vecBean");
// out.println("Servlet to JSP communication of an object: "+vecObj.get(0));
%>
</body>
</html>
web.xml
<servlet>
<servlet-name>ServletToJSP</servlet-name>
<servlet-class>api.ServletToJSP</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>ServletToJSP</servlet-name>
<url-pattern>/ServletToJSP/*</url-pattern>
</servlet-mapping>
4 answers
solution1
2
There are few things to change:
In servlet
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//communicating a simple String message.
String message = "Example source code of Servlet to JSP communication.";
request.setAttribute("message", message);
request.getRequestDispatcher("javaPapers.jsp").forward(request,response);
}
In jsp
<html>
<body>
Servlet communicated message to JSP: ${message}
</body>
</html>
Changes made:
- In servlet, used request.getRequestDispatcher(String url)
- In jsp, removed servlet import.
- In jsp, used EL to get attribute value.
solution2
0 2013-09-03 07:05:52
replace
RequestDispatcher reqDispatcher = getServletConfig().getServletContext().getRequestDispatcher("javaPapers.jsp");
with
RequestDispatcher reqDispatcher = request.getRequestDispatcher("javaPapers.jsp");
solution3
0 2013-09-03 09:48:07
Passing the param using the request.setAttribute("message", message); should work using this code:
RequestDispatcher rd = getServletContext().getRequestDispatcher("yourPage.jsp");
rd.forward(request,response);
You can also pass the attribute using the URL in dispatcher :
RequestDispatcher rd = getServletContext().getRequestDispatcher("yourPage.jsp?message=some message");
rd.forward(request,response);
Also you can share info using session object.
session.setAttribute("message","your message");
And then retrieve it in jsp using:
String message=(String)session.getAttribute("message");
solution4
-1 2015-08-02 08:59:52
You have to use context path to get message from servlet to jsp. This will definitely work I have done it.
String msg = "Message from servlet to jsp";
response.sendRedirect(response.encodeRedirectURL(contextPath+"/report/test.jsp?msg="+msg));
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