how to fix Cannot call sendRedirect() after the response has been committed? [duplicate]

Question

I am trying to pass values from servlet to jsp page using the code below:

public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {      PrintWriter out = response.getWriter();     try {         System.out.println("try");          String taskid=request.getParameter("id");            convty = new Connectivity();         con = convty.setConnection();         st=con.createStatement();          query="select * from task_table";          rset=convty.getResultSet(query, con);         while(rset.next()) {             System.out.println("while");             lst.add(rset.getString("task_id"));             lst.add(rset.getString("date"));             lst.add(rset.getString("project_name"));             }         rset.close();         System.out.println("after while");      } catch(Exception e) {          RequestDispatcher dd= request.getRequestDispatcher("error.jsp");         dd.forward(request, response);      } finally {         System.out.println("finally1");         HttpSession sessionvar = request.getSession();         sessionvar.setAttribute("TaskData", "lst");          response.sendRedirect("usertaskpage.jsp");          lst.clear();         out.close();                 } } 

when I run my page I am getting:

Error :

java.lang.IllegalStateException: Cannot call sendRedirect() after the response has been committed     org.apache.catalina.connector.ResponseFacade.sendRedirect(ResponseFacade.java:483)     src.Taskservlet.doPost(Taskservlet.java:108)     javax.servlet.http.HttpServlet.service(HttpServlet.java:647)     javax.servlet.http.HttpServlet.service(HttpServlet.java:728)     org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51) 

I tried to use:

RequestDispatcher dd=request.getRequestDispatcher("usertaskpage.jsp"); dd.forward(request, response); 

but I got the same error.

How to fix this error?

Answer 1

you have already forwarded the response in catch block:

RequestDispatcher dd = request.getRequestDispatcher("error.jsp");  dd.forward(request, response); 

so, you can not again call the :

response.sendRedirect("usertaskpage.jsp"); 

because it is already forwarded (committed).

So what you can do is: keep a string to assign where you need to forward the response.

    String page = "";     try {      } catch (Exception e) {       page = "error.jsp";     } finally {       page = "usertaskpage.jsp";     }  RequestDispatcher dd=request.getRequestDispatcher(page); dd.forward(request, response);