/* * IvyHttpGatewayServlet.java */ package fr.dgac.ivy.tools; import java.io.*; import java.net.*; import java.util.*; import javax.servlet.*; import javax.servlet.http.*; import fr.dgac.ivy.*; /** * Simple gateway between HTTP and Ivy software bus protocols. *

* The gateway enables remote clients to manage Ivy clients via * HTTP protocol. It aims at solving Ivy limitations to local networks. * Features are limited to Ivy bus start(), stop() and sendMsg() methods. * The Ivy HTTP gateway considers two Ivy instances as identical if their * buses names, buses domains and clients IP names equals pair-by-pair. *

* Ivy main web page: * * http://www.tls.cena.fr/products/ivy/ *
* Author home page: * * http://www-clips.imag.fr/multicom/User/francis.jambon/index-en.html *

* * Requests examples: *
 * - start bus: http://host/IvyHttpGatewayServlet?cmd=start&name=test&domain=228.1.2.4:5678
 * - start bus (with message): http://host/IvyHttpGatewayServlet?cmd=start&name=test&domain=228.1.2.4:5678&msg=ready
 * - stop bus: http://host/IvyHttpGatewayServlet?cmd=stop&name=test&domain=228.1.2.4:5678
 * - send message: http://host/IvyHttpGatewayServlet?cmd=sendmsg&name=test&domain=228.1.2.4:5678&msg=hello
 * - interactive webpage: http://host/IvyHttpGatewayServlet
 * - status information: http://host/IvyHttpGatewayServlet?cmd=status
 * - kill all buses managed by the servlet: http://host/IvyHttpGatewayServlet?cmd=killall
 * 
* * Versions history: *
 * - 1.1: new package structure, default address and documentation
 *        non-regression tests with new Ivy 1.2.8-rc2 library
 * - 1.0.5: correction of the form encoding attribute incompatibility with IE
 * - 1.0.4: correction of the button element incompatibility with IE
 * - 1.0.3: correction of the remote host identification bug
 * - 1.0.2: start command can be invoked without message
 * - 1.0.1: licence and some name modifications
 * - 1.0: first working release
 * 
* * Bugs: *
 * - the POST method does not work in the interactive webpage
 *   (the parameters are not transmitted)
 * 
* * License: *
*           * GNU Lesser General Public License, see http://www.gnu.org/copyleft/lesser.html * * @see fr.dgac.ivy * @author Francis JAMBON - CLIPS-IMAG/MultiCom * @version 1.1 */ public class IvyHttpGatewayServlet extends HttpServlet { // Ivy bus(es) list private Hashtable buses; // Valid name, domain and msg regexps private static final String NAME_REGEXP="[^(\\r)]+"; private static final String DOMAIN_REGEXP="(\\d){1,3}+(\\.)(\\d){1,3}+(\\.)(\\d){1,3}+(\\.)(\\d){1,3}+(\\:)(\\d){1,5}+"; private static final String MSG_REGEXP="[^(\\r)]*"; // Default values for the interactive webpage private static final String DEFAULT_NAME="test"; private static final String DEFAULT_DOMAIN="228.1.2.4:5678"; private static final String DEFAULT_MSG="hello"; /** * Initializes the servlet. */ public void init(ServletConfig config) throws ServletException { super.init(config); this.buses = new Hashtable(); } /** * Destroys the servlet. */ public void destroy() { Enumeration eb = this.buses.elements(); while (eb.hasMoreElements()) { ((Ivy)eb.nextElement()).stop(); } // wait 100ms to prevent ugly Ivy bus(es) disconnection try { Thread.sleep(100); } catch (InterruptedException ie) {} this.buses.clear(); this.buses=null; } /** * Processes requests for both HTTP GET and POST methods. * @param request servlet request * @param response servlet response */ protected synchronized void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { if (request.getQueryString()!=null) { if (request.getParameter("cmd").equals("start")) processRequestStart(request,response); else if (request.getParameter("cmd").equals("stop")) processRequestStop(request,response); else if (request.getParameter("cmd").equals("sendmsg")) processRequestSendMsg(request,response); else if (request.getParameter("cmd").equals("status")) processRequestStatus(request,response); else if (request.getParameter("cmd").equals("killall")) processRequestKillAll(request,response); else processRequestError(request, response); } else processRequestWebpage(request,response); } /** * Starts an Ivy bus and adds it to the list. */ private void processRequestStart(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); out.println(""); out.println(""); out.println("Ivy HTTP Gateway"); out.println(""); out.println(""); out.println("
"); out.println("
");

        String from = request.getRemoteHost();
        String name = request.getParameter("name");
        String domain = request.getParameter("domain");
        String msg = request.getParameter("msg");
        
        out.println("Ivy HTTP Gateway");
        out.println("Request from ["+from+"]");
        out.println();
        out.println("START");
        out.println("- name="+name);
        out.println("- domain="+domain);
        if (msg!=null) out.println("- msg="+msg);
        out.println();
        
        if ( domain!=null && domain.matches(DOMAIN_REGEXP) &&
                name!=null && name.matches(NAME_REGEXP) &&
                ( msg==null || (msg!=null && msg.matches(MSG_REGEXP)) ) )  {
            
            IvyHashKey ihk = new IvyHashKey(from, name, domain);
            if (!this.buses.containsKey(ihk)) {
                try {
                    Ivy bus = new Ivy(name, msg, null);
                    bus.start(domain);
                    this.buses.put(ihk,bus);
                    out.println("Ivy bus started");
                } catch (IvyException ie) {
                    out.println("ERROR while starting Ivy bus: "+ie.getMessage());
                }
            } else {
                out.println("ERROR: Similar Ivy bus already started");
            }
        } else {
            out.println("ERROR: Parameter(s) not valid");
        }
        
        out.println("
"); out.println("
"); out.println(""); out.println(""); out.close(); } /** * Stops an Ivy bus and removes it from the list. */ private void processRequestStop(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); out.println(""); out.println(""); out.println("Ivy HTTP Gateway"); out.println(""); out.println(""); out.println("
"); out.println("
");
        
        String from = request.getRemoteHost();
        String name = request.getParameter("name");
        String domain = request.getParameter("domain");
        
        out.println("Ivy HTTP Gateway");
        out.println("Request from ["+from+"]");
        out.println();
        out.println("STOP");
        out.println("- name="+name);
        out.println("- domain="+domain);
        out.println();
        
        if ( domain!=null && domain.matches(DOMAIN_REGEXP) &&
                name!=null && name.matches(NAME_REGEXP) ) {
            
            IvyHashKey ihk = new IvyHashKey(from, name, domain);
            if (this.buses.containsKey(ihk)) {
                Ivy bus = (Ivy)(this.buses.get(ihk));
                bus.stop();
                // wait 100ms to prevent ugly Ivy bus disconnection
                try { Thread.sleep(100); } catch (InterruptedException ie) {}
                this.buses.remove(ihk);
                bus=null;
                out.println("Ivy bus stopped");
            } else {
                out.println("ERROR: Ivy bus does not exist");
            }
        } else {
            out.println("ERROR: Parameter(s) not valid");
        }
        
        out.println("
"); out.println("
"); out.println(""); out.println(""); out.close(); } /** * Sends a message to an Ivy bus. */ private void processRequestSendMsg(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); out.println(""); out.println(""); out.println("Ivy HTTP Gateway"); out.println(""); out.println(""); out.println("
"); out.println("
");
        
        String from = request.getRemoteHost();
        String name = request.getParameter("name");
        String domain = request.getParameter("domain");
        String msg = request.getParameter("msg");
        
        out.println("Ivy HTTP Gateway");
        out.println("Request from ["+from+"]");
        out.println();
        out.println("SEND MESSAGE");
        out.println("- name="+name);
        out.println("- domain="+domain);
        out.println("- msg="+msg);
        out.println();
        
        if ( domain!=null && domain.matches(DOMAIN_REGEXP) &&
                name!=null && name.matches(NAME_REGEXP) &&
                msg !=null && msg.matches(MSG_REGEXP) ) {
            
            IvyHashKey ihk = new IvyHashKey(from, name, domain);
            if (this.buses.containsKey(ihk)) {
                try {
                    Ivy bus = (Ivy)(this.buses.get(ihk));
                    int count = bus.sendMsg(msg);
                    out.println("Message sent to "+count+" client(s)");
                } catch (IvyException ie) {
                    out.println("ERROR sending message: "+ie.getMessage());
                }
            } else {
                out.println("ERROR: Ivy bus does not exist");
            }
        } else {
            out.println("ERROR: Parameter(s) not valid");
        }
        
        out.println("
"); out.println("
"); out.println(""); out.println(""); out.close(); } /** * Status page. */ private void processRequestStatus(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); out.println(""); out.println(""); out.println("Ivy HTTP Gateway"); out.println(""); out.println(""); out.println("
"); out.println("
");
        
        out.println("Ivy HTTP Gateway");
        out.println("Request from ["+request.getRemoteHost()+"]");
        out.println();
        out.println("STATUS");
        out.println();
        out.println(this.buses.size()+" Ivy bus(es) alive");
        
        Enumeration ek = this.buses.keys();
        while (ek.hasMoreElements()) {
            IvyHashKey ihk = (IvyHashKey)(ek.nextElement());
            out.println("- Ivy bus ["+ihk.getName()+
                    "] on domain ["+ihk.getDomain()+
                    "] managed by ["+ihk.getFrom()+"]");
        }
        
        out.println("
"); out.println("
"); out.println(""); out.println(""); out.close(); } /** * Stops all Ivy buses. */ private void processRequestKillAll(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); out.println(""); out.println(""); out.println("Ivy HTTP Gateway"); out.println(""); out.println(""); out.println("
"); out.println("
");
        
        out.println("Ivy HTTP Gateway");
        out.println("Request from ["+request.getRemoteHost()+"]");
        out.println();
        out.println("KILL ALL");
        out.println();
        
        if (this.buses.size()!=0) {
            
            Enumeration eb = this.buses.elements();
            while (eb.hasMoreElements()) {
                ((Ivy)eb.nextElement()).stop();
            }
            Enumeration ek = this.buses.keys();
            while (ek.hasMoreElements()) {
                IvyHashKey ihk = (IvyHashKey)(ek.nextElement());
                out.println("Ivy bus ["+ihk.getName()+
                        "] on domain ["+ihk.getDomain()+
                        "] managed by ["+ihk.getFrom()+
                        "] stopped");
            }
            // wait 100ms to prevent ugly Ivy bus(es) disconnection
            try { Thread.sleep(100); } catch (InterruptedException ie) {}
            this.buses.clear();
        } else {
            out.println("NOTHING TO DO: no alive Ivy bus");
        }
        
        out.println("
"); out.println("
"); out.println(""); out.println(""); out.close(); } /** * Error (request not understood). */ private void processRequestError(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); out.println(""); out.println(""); out.println("Ivy HTTP Gateway"); out.println(""); out.println(""); out.println("
"); out.println("
");
        
        out.println("Ivy HTTP Gateway");
        out.println("Request from ["+request.getRemoteHost()+"]");
        out.println();
        out.println("ERROR: request not understood");
        out.println();
        out.println("Parameters string readed: "+request.getQueryString());
        
        out.println("
"); out.println("
"); out.println(""); out.println(""); out.close(); } /** * Interactive webpage (request without parameter). */ private void processRequestWebpage(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); out.println(""); out.println(" "); out.println(" Ivy HTTP Gateway"); out.println(" "); out.println(" "); out.println("

Ivy HTTP Gateway Servlet Interactive Webpage

"); out.println("
"); out.println("

Global Commands

"); out.println("
"); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println("
Ivy bus(es) status:
Kill all (warning!):
"); out.println("
"); out.println("
"); out.println("

Bus Commands

"); out.println("
"); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println("
(name of the Ivy agent - required)
(IP address and port - required)
(message to be sent)
"); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println(" "); out.println("
Commands:
"); out.println("
"); out.println("
"); out.println(" Request from ["+request.getRemoteHost()+"]"); out.println("
"); out.println(" CLIPS-IMAG/MultiCom"); out.println(" "); out.println(""); out.close(); } /** * Handles the HTTP GET method. * @param request servlet request * @param response servlet response */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { processRequest(request, response); } /** * Handles the HTTP POST method. * @param request servlet request * @param response servlet response */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { processRequest(request, response); } /** * Returns a short description of the servlet. * @return the short description */ public String getServletInfo() { return "Ivy HTTP Gateway"; } /** * Internal class for Ivy bus hashkey definition. */ private class IvyHashKey { private String from; private String name; private String domain; public IvyHashKey(String from, String name, String domain) { this.from=from; this.name=name; this.domain=domain; } public String getFrom() { return this.from; } public String getName() { return this.name; } public String getDomain() { return this.domain; } public boolean equals(Object o) { if (o!=null && o instanceof IvyHashKey) { IvyHashKey ihk = (IvyHashKey)o; return (this.from.equals(ihk.from) && this.name.equals(ihk.name) && this.domain.equals(ihk.domain) ); } else return false; } public int hashCode() { return this.name.hashCode(); } } }