/*
* SimplifiedServletHandler
*
* A gutted version of SUN's ServletHandler.
* Illustrates the basic idea, without any attempts at the fancy stuff.
*/
package com.ora.rmibook.chapter22.tunneler;
import java.io.*;
import java.net.*;
import java.util.*;
import java.rmi.registry.*;
import java.rmi.*;
import java.rmi.server.*;
import javax.servlet.http.*;
import javax.servlet.*;
public class SimplifiedServletHandler extends HttpServlet {
public void init(ServletConfig config) throws ServletException {
super.init(config);
System.out.println("Simplified RMI Servlet Handler loaded sucessfully.");
}
/**
* Execute the command given in the servlet request query string.
* The string before the first '=' in the queryString is
* interpreted as the command name, and the string after the first
* '=' is the parameters to the command.
*
* @param req HTTP servlet request, contains incoming command and
* arguments
* @param res HTTP servlet response
* @exception ServletException and IOException when invoking
* methods of <code>req<code> or <code>res<code>.
*/
public void doPost(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
try {
String queryString = req.getQueryString();
String command, param;
int delim = queryString.indexOf("=");
if (delim == -1) {
command = queryString;
param = "";
} else {
command = queryString.substring(0, delim);
param = queryString.substring(delim + 1);
}
if (command.equalsIgnoreCase("forward")) {
try {
LoggingServletForwardCommand.execute(req, res, param);
} catch (ServletClientException e) {
returnClientError(res, "client error: " + e.getMessage());
e.printStackTrace();
} catch (ServletServerException e) {
returnServerError(res, "internal server error: " + e.getMessage());
e.printStackTrace();
}
} else {
returnClientError(res, "invalid command: " + command);
}
} catch (Exception e) {
returnServerError(res, "internal error: " + e.getMessage());
e.printStackTrace();
}
}
public void doGet(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
returnClientError(res, "GET Operation not supported: " + "Can only forward POST requests.");
}
public void doPut(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
returnClientError(res, "PUT Operation not supported: " + "Can only forward POST requests.");
}
public String getServletInfo() {
return "RMI Call Forwarding Servlet Servlet.<br>\n";
}
private static void returnClientError(HttpServletResponse res, String message)
throws IOException {
res.sendError(HttpServletResponse.SC_BAD_REQUEST,
"<HTML><HEAD>" +
"<TITLE>Java RMI Client Error</TITLE>" +
"</HEAD>" +
"<BODY>" +
"<H1>Java RMI Client Error</H1>" +
message +
"</BODY></HTML>");
System.err.println(HttpServletResponse.SC_BAD_REQUEST +
"Java RMI Client Error" + message);
}
private static void returnServerError(HttpServletResponse res, String message)
throws IOException {
res.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR,
"<HTML><HEAD>" +
"<TITLE>Java RMI Server Error</TITLE>" +
"</HEAD>" +
"<BODY>" +
"<H1>Java RMI Server Error</H1>" +
message +
"</BODY></HTML>");
System.err.println(HttpServletResponse.SC_INTERNAL_SERVER_ERROR +
"Java RMI Server Error: " + message);
}
}
|
