I am trying to learn abt servlets. I am getting a IllegalStateException when i call forward(). The error occurs in the LoginBean.do if block at the point where i call forward.
process(request,response);
}
private void process(HttpServletRequest request, HttpServletResponse response) {
// TODO Auto-generated method stub
String uri = request.getRequestURI();
RequestDispatcher rd = null;
CAppModel model = new CAppModel();
System.out.println("Inside process ()");
try{
if(uri.contains("/Login"))
{
System.out.println("Inside Login.do");
rd = request.getRequestDispatcher("Login.jsp");
rd.forward(request,response);
}
if(uri.contains("/Register.do"))
{
System.out.println("inside Register.do");
}
if(uri.contains("/LoginBean.do"))
{
System.out.println("Inside LoginBean.do");
LoginBean lb = (LoginBean)request.getAttribute("login");
System.out.println("toString(): "+lb.toString());
String result = model.authenticate(lb);
System.out.println("CS: result of auth "+result);
if(result.equals("Success"))
{
System.out.println("Inside if Success of loginbean");
HttpSession session = request.getSession(true);
session.setAttribute("user", lb.getEmail());
rd = request.getRequestDispatcher("Menu.jsp");
rd.forward(request, response);
}
else
{
System.out.println("failed auth "+result);
request.setAttribute("errorMsg", result);
rd = request.getRequestDispatcher("Login.jsp");
rd.forward(request,response);
}
}
}
catch(Exception e)
{
e.printStackTrace();
}
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
process(request,response);
}
}
I am getting the following error
java.lang.IllegalStateException: Cannot forward after response has been committed
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:328)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:318)
at com.aditya.CApp.ControllerServlet.process(ControllerServlet.java:69)
at com.aditya.CApp.ControllerServlet.doGet(ControllerServlet.java:31)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:721)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:466)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:391)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:318)
at org.apache.jasper.runtime.PageContextImpl.doForward(PageContextImpl.java:741)
at org.apache.jasper.runtime.PageContextImpl.forward(PageContextImpl.java:711)
at org.apache.jsp.LoginInt_jsp._jspService(LoginInt_jsp.java:104)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:438)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:396)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:340)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:617)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:668)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1527)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1484)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
A request containing /LoginBean.do will trigger 2 if blocks causing 2 forwards to be invoked causing the error after the 2nd forward. While you could re-arrange the the if statements as
if (uri.contains("/LoginBean.do")) {
...
else if (uri.contains("/LoginBean")) {
...
Generally its simpler to use an individual servlet per if block functionality.