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Difference between getRequestDispatcher () of ServletContext and ServletRequest

What is the difference between getRequestDispatcher () of ServletContext and ServletRequest

Please explain in easy to understand language and explain with a simple working example.

Please explain from latest J2EE version.

I want to understand when to use ServletContext and when to use ServletRequest's dispatcher call

SOLUTION

girionis

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sudhakar_koundinya

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sudhakar_koundinya

ServletA
doPost{}{
RequestDispatcher showDispatcher = req.getRequestDispatcher("fwdinclude");
resp.setContentType("text/html");
PrintWriter out = resp.getWriter();
showDispatcher.forward(req,resp);
}

Final url on your browser is http://localhost:8080/servlet/A

ServletA
doPost{}{
RequestDispatcher showDispatcher = req.getRequestDispatcher("fwdinclude");
resp.setContentType("text/html");
PrintWriter out = resp.getWriter();
showDispatcher.include(req,resp);
}

Final url on your browser is http://localhost:8080/servlet/A

ServletA
doPost{}{

resp.setContentType("text/html");
PrintWriter out = resp.getWriter();
res.sendRedirect("fwdinclude");
}

Final url is http://localhost:8080/servlet/fwdinclude

sudhakar_koundinya

From the javadoc of ServletRequest.getRequestDispatcher(String):

'The pathname specified may be relative, although it cannot extend
outside the current servlet context. If the path begins with a "/" it is
interpreted as relative to the current context root. This method returns
null if the servlet container cannot return a RequestDispatcher.

The difference between this method and
ServletContext.getRequestDispatcher(String) is that this method can take
a relative path.'

So, if you get your RequestDispatcher from the request, you don't need
the leading "/".

sudhakar_koundinya

thanks