Servlets - An Introduction to Network Programming with Java - page 255

+ "User Preferences</FONT>");
out.println("<BR>");
out.println("<TABLE>");
out.println("<TR>");
out.println("<TD>First name</TD>");
out.println("<TD><INPUT TYPE='Text' "
+ "NAME='Name' VALUE='' SIZE=15></TD>");
out.println("</TR>");
out.println("<TR>");
out.println("<TD>Foreground colour</TD>");
out.println("<TD><INPUT TYPE='Text' "
+ "NAME='ForeColour' VALUE=''"
+ "SIZE=10></TD>");
out.println("</TR>");
out.println("<TR>");
out.println("<TD>Background colour</TD>");
out.println("<TD><INPUT TYPE='Text' "
+ "NAME='BackColour' VALUE=''"
+ "SIZE=10></TD>");
out.println("</TR>");
out.println("</TABLE>");
out.println("<BR><BR>");
out.println("<INPUT TYPE='Submit' "
+ "VALUE = 'Submit'>");
out.println("<INPUT TYPE='Reset' "
+ "VALUE='Clear'>");
out.println("</CENTER>");
out.println("</BODY>");
out.println("</HTML>");
out.fl ush();
}
}
Note the setting of session variable fi rstVisit to 'Yes', for subsequent checking by
the ShowSum servlet. Figure 8.10 shows the output generated by the GetPreferences
servlet and some example user entry:
Servlet ShowSum may be called from either GetPreferences or CookieAdder . Since
the former passes on form data and the latter doesn't, ShowSum implements neither
doPost nor doGet , but method service . Before attempting to transmit the result page,
the servlet checks the value of session variable fi rstVisit . If this variable has been set
to 'Yes', the servlet retrieves the user's preferences (via the HttpServletRequest
object), creates the appropriate cookies and updates the session variables (including
the setting of the fi rstVisit cookie variable and session variable to 'No').