Should the URL path be "servlets" or "servlet" ?
The directory for your code is "servlets":
c:\sambar43\servlets\Hello.class
Whereas, the URL path uses "servlet" as the default alias for identifying
servlets:
http://localhost/servlet/Hello
How can I get the name of the currently executing script ?
Use req.getRequestURI() or req.getServletPath().
The former returns the path to the script including any extra path
information following the name of the servlet; the latter strips the
extra path info.
How can I debug my servlet ?
A few IDEs support servlet debugging (such as Symantec Cafe). Beyond
these, the most important thing you can do is to always catch your
exceptions. An uncaught exception can terminate your servlet, and
write a minimal error the the server.log file.
The following code sets up a catch block that will trap
any exception, and print its value to standard error output and to the
ServletOutputStream so that the exception shows up on the
browser. (Note: If you see "Compiled Code" instead
of line numbers in the exception stack trace, then turn off the JIT in
the server.)
res.setContentType("text/html");
ServletOutputStream out = res.getOutputStream();
try
{
// do your thing here
...
}
catch (Exception e)
{
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
e.printStackTrace(pw);
out.println("<pre>");
out.print(sw.toString());
out.println("</pre>");
}
|