src/dolda/jsvc/util/ErrorHandler.java

   1 package dolda.jsvc.util;
   2
   3 import dolda.jsvc.*;
   4 import java.net.*;
   5 import java.io.*;
   6 import java.util.logging.*;
   7
   8 public class ErrorHandler implements Responder {
   9     private Responder next;
  10     private static Logger logger = Logger.getLogger("dolda.jsvc.context");
  11
  12     public ErrorHandler(Responder next) {
  13         this.next = next;
  14     }
  15
  16     protected void log(Request req, Throwable t) {
  17         logger.log(Level.SEVERE, "Unhandled error in responder", t);
  18     }
  19
  20     protected void respdebug(Request req, Throwable t) {
  21         req.status(500);
  22         req.outheaders().put("content-type", "text/plain; charset=utf-8");
  23         PrintWriter out;
  24         try {
  25             out = new PrintWriter(new OutputStreamWriter(req.output(), "UTF-8"));
  26         } catch(UnsupportedEncodingException e) {
  27             throw(new Error(e));
  28         }
  29         t.printStackTrace(out);
  30         out.flush();
  31     }
  32
  33     protected void resperr(Request req, Throwable t) {
  34         req.status(500);
  35         req.outheaders().put("content-type", "text/html; charset=us-ascii");
  36         PrintWriter out;
  37         try {
  38             out = new PrintWriter(new OutputStreamWriter(req.output(), "US-ASCII"));
  39         } catch(UnsupportedEncodingException e) {
  40             throw(new Error(e));
  41         }
  42         out.println("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
  43         out.println("<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.1//EN\" \"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd\">");
  44         out.println("<html xmlns=\"http://www.w3.org/1999/xhtml\" xml:lang=\"en-US\">");
  45         out.println("<head><title>Internal error</title></head>");
  46         out.println("<body>");
  47         out.println("<h1>Internal error</h1>");
  48         out.println("An error occurred on the server processing your request.");
  49         out.println("</body>");
  50         out.println("</html>");
  51         out.flush();
  52     }
  53
  54     protected boolean debug(Request req, Throwable t) {
  55         SocketAddress rem = req.remoteaddr();
  56         return((rem instanceof InetSocketAddress) && ((InetSocketAddress)rem).getAddress().isLoopbackAddress());
  57     }
  58
  59     protected void handle(Request req, Throwable t) {
  60         log(req, t);
  61         if(req instanceof ResettableRequest) {
  62             ResettableRequest rr = (ResettableRequest)req;
  63             if(rr.canreset())
  64                 rr.reset();
  65         }
  66         if(debug(req, t))
  67             respdebug(req, t);
  68         else
  69             resperr(req, t);
  70     }
  71
  72     public void respond(Request req) {
  73         try {
  74             next.respond(req);
  75         } catch(Throwable t) {
  76             handle(req, t);
  77         }
  78     }
  79 }