Documentation Comments
Use this form to comment on this topic. You can also provide any general observations about the Online Documentation, or request that additional information be added in a future release.
Reality V15.0 ()
Example Servlet Code (JReal) (exampleservlet.htm)
/* @(#) rwdemo.java ver 22.4 00/08/21 14:43:49
* ???.java, initial version May 2000
*
* Copyright (c) 2000 Northgate Information Solutions Plc.
* All Rights Reserved.
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
import com.northgateis.reality.rsc.*;
import com.northgateis.realweb.*;
/**
* Sample servlet demonstrating access to a Reality database.
*
* @author Kevin Wright
*/
public class rwdemo extends HttpServlet
{
private static String NL = "<BR>";
public void init(ServletConfig config) throws ServletException {
super.init(config);
/* Must initialise the RealWeb connection timer */
RealWeb.init();
}
/**
* Handle post requests by by calling doGet()
*/
public void doPost(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
doGet(req, res);
} /**
* This is the main entry point for a servlet and handles get requests
* from a browser
*/
public void doGet(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
PrintWriter out;
RealWebUrl URL;
RealWeb connection = null;
// set content type
res.setContentType("text/html");
// Get an output stream
out = res.getWriter();
// Create an HTML page header
out.println("<HTML>");
out.println("<HEAD>");
out.println("<TITLE>RealWeb Demo Servlet</TITLE>");
out.println("</HEAD>");
out.println("<BODY>");
out.println("<H1>RealWeb Demo Servlet</H1>");
try {
// Generate a RealWebUrl object to extract the required
information from the URL
URL = new RealWebUrl(req);
// Get a connection (new or current)
connection = RealWeb.getConnection(req, res, URL);
// Run the BASIC program
self.execute(req, res, connection, URL, out);
}
catch (IOException e) {
// Handle exceptions by just printing a message
out.println(e.toString());
}
finally {
// Must always make the connection available again
if (connection != null)
connection.setAvailable();
}
// Finish the HTML page
out.println("</BODY>");
out.println("</HTML>");
} public String getServletInfo() {
return "Sample RealWeb servlet";
}
/**
* Execute a Remote Basic subroutine and send the results
* back to the browser
*
* Create, compile and catalog the following subroutine
* The subroutine just returns its input parameters.
*
SUBROUTINE RW.SAMPLE(PARAM1, PARAM2)
PARAM1 = "First parameter is ":PARAM1
PARAM2 = "Second parameter is ":PARAM2
RETURN
*
* Don't forget to enable the subroutine by creating a V entry in the
* Remote Basic security file (RBASIC by default)
*
* Use the following URL to access the subroutine
* /host/servlet/rwdemo/section/RW.SAMPLE?a query
*
* Where host is the host running the web server
* and section is a section name generated by the rwconfig servlet
*/
private void execute(HttpServletRequest req,
HttpServletResponse res,
RealWeb con,
RealWebUrl URL,
PrintWriter out)
throws RSCException, IOException
{
// Attempt to run the Remote Basic program
try
{
//Get the subroutine name from the processed URL
String subName = URL.command;
//Create a subroutine handle
RSC sub = new RSC(con, subName);
String query = req.getQueryString();
if (query == null)
query = "none";
RSCParam p1, p2;
// Get references to the parameters
p1=sub.getParam(1);
p2=sub.getParam(2);
// Set the parameters
p1.setValue(query);
p2.setValue(req.getServletPath());
// Run the Remote Basic program
sub.execute();
// Print the returned parameters, one per line
out.println(p1.getString());
out.println("<BR>");
out.println(p2.getString());
}
catch (RSCException e) {
// catch any RSC exceptions and convert them to HTML
throw new RealWebException(NL+RealWeb.AMtoNL(e.toString())+NL);
}
}
public void destroy() }
RealWeb.destroy ();
super.destroy
}
}