source: trunk/gsdl3/src/java/org/greenstone/gsdl3/LibraryServlet.java@ 3346

package org.greenstone.gsdl3;

import org.greenstone.gsdl3.core.*;
import org.greenstone.gsdl3.util.*;

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.util.Enumeration;
import java.io.File;

/** a servlet to serve the greenstone library - using servlets instead
 * of cgi
 * the init method is called only once - the first time the servlet classes
 * are loaded. Each time a request comes in to the servlet, the session()
 * method is called in a new thread (calls doGet/doPut etc)
 * takes the a=p&p=home type args and builds a simple request to send to 
 * its receptionist, which returns the result in html, cos output=html
 * is set in the request
 * @see Receptionist
 */
public class LibraryServlet extends HttpServlet {
    
    private ConfigVars config_=null; // holds all teh system set up vars
    private Receptionist recept_=null;
    private ModuleInterface message_router_=null;
    /** initialise the servlet
     */
    public void init(ServletConfig config) throws ServletException {
    // always call super.init;
    super.init(config);

    config_ = new ConfigVars();
    String sites_home_ = config.getInitParameter("siteshome");
    String site_name_ = config.getInitParameter("sitename");
    String interfaces_home_ = config.getInitParameter("interfaceshome");
    String interface_name_ = config.getInitParameter("interfacename");
    if (sites_home_ == null || site_name_==null || interfaces_home_ ==null || interface_name_==null) {
        // must have this
        System.err.println("initialisation parameters not all set!");
        System.err.println(" you must have siteshome, sitename, interfaceshome, interfacename");
        System.exit(1);
    }

    config_.sites_home_ = sites_home_;
    config_.site_name_ = site_name_;
    config_.interfaces_home_ = interfaces_home_;
    config_.interface_name_ =interface_name_;

    config_.createXML();
    
    // new message router - create it and pass a handle to recept.
    // the servlet wont use this directly
    MessageRouter mr = new MessageRouter();
    mr.setSiteHome(config_.sites_home_+File.separatorChar
               +config_.site_name_);
    mr.configure();
    // new receptionist
    recept_ = new Receptionist();
    recept_.setConfigVars(config_);
    recept_.setMessageRouter(mr);
    recept_.configure();

    }
    
    public void doGet(HttpServletRequest request,
              HttpServletResponse response)
    throws ServletException, IOException {
    
    response.setContentType("text/html");
    PrintWriter out = response.getWriter();

    String lang = request.getParameter("l");
    if (lang==null || lang.equals("")) {
        lang = "en"; // the default
    }
    // the request to the receptionist  
    String xml_request="<message lang='"+lang+"'>";

    String action = request.getParameter("a");
    if (action==null || action.equals("")) {
        // display the home page
        // a=p&p=home
        xml_request +="<request type='action' output='html' info='p/home'/>";
    } else {
        String subaction = request.getParameter("sa");
        xml_request += "<request type='action' info='"+action;
        if (subaction != null) {
        xml_request += "/"+subaction;
        }
        xml_request += "'><paramList>";
        Enumeration params = request.getParameterNames();
        while(params.hasMoreElements()) {
        String name = (String)params.nextElement();
        if (!name.equals("a") && !name.equals("sa")) {
            String value = request.getParameter(name);
        // for now, just add value as attribute - should un-url 
            // encode them etc and so some might need to be text not atts
            // or is that done already?
            xml_request += "<param name='"+name+"' value='"+value+"'/>";
        }
        }
        xml_request += "</paramList></request>";
    }
    xml_request += "</message>";

    System.out.println("request="+xml_request);

    String result = recept_.process(xml_request);
    out.println(result);


    
    }
}