Illegal State exception example

[Veena Pointi]

Hello,

In HFSJ it says you will get IllegalStateException if we try to forward request after committing response.I tried following code ,it works fine

   
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;

public class RequestDispatch207 extends HttpServlet{

public void doGet(HttpServletRequest request,HttpServletResponse response)
	throws IOException,ServletException{

response.setContentType("application/jar");

ServletContext ctx = getServletContext();
InputStream is = ctx.getResourceAsStream("/jspapi.jar");

int read=0;
byte[] bytes = new byte[1024];

OutputStream os = response.getOutputStream();
while((read = is.read(bytes)) != -1) {
os.write(bytes,0,read);
}

os.flush();

RequestDispatcher view = request.getRequestDispatcher("results.jsp");
view.forward(request,response);
os.close();

}

}

Can anyone please explain what specs is trying to say?

Thanks
Veena

[Walid Abd Elsalam]

Can you try it again after replacing OutputStream with ServletOutputStream. I'm just wondering if it would make a difference as the api documentatio for OutuptStream.flush() says it does nothing.

[Frits Walraven]

I have tried your example on tomcat5.5 and I am getting the IllegalStateException: Cannot forward after response has been committed

what server are you using?
Regards,
Frits

[Veena Pointi]

Hello,

Thank you for replying.I am using Tomcat 5.5 .

[Veena Pointi]

Walid Abd Elsalam wrote:Can you try it again after replacing OutputStream with ServletOutputStream. I'm just wondering if it would make a difference as the api documentatio for OutuptStream.flush() says it does nothing.

Doesn't matter weather OutputStream or ServletOutputStream right?Because spec says

forward should be called before the response has been committed to the client
(before response body output has been flushed). If the response already
has been committed, this method throws an IllegalStateException.

I wonder how my code is working!!!

Thanks
Veena

[Veena Pointi]

I checked the logs.It is showing the IllegalStateException . What I thought was it will throw exception on the browser itself without even processing the page .

Thank you .

Veena