java/src/main/com/google/appengine/api/channel/ChannelPresenceParser.java

   1 // Copyright 2011 Google Inc. All Rights Reserved.
   2
   3 package com.google.appengine.api.channel;
   4
   5 import com.google.appengine.api.utils.HttpRequestParser;
   6
   7 import java.io.IOException;
   8
   9 import javax.servlet.http.HttpServletRequest;
  10 import javax.mail.BodyPart;
  11 import javax.mail.internet.MimeMultipart;
  12 import javax.mail.MessagingException;
  13
  14 /**
  15  * {@code ChannelPresenceParser} encapsulates the use of the {@code
  16  * javax.mail} package to parse an incoming {@code
  17  * multipart/form-data} HTTP request and to convert it to a {@link
  18  * Presence} object.
  19  *
  20  *
  21  */
  22 class ChannelPresenceParser extends HttpRequestParser {
  23   static ChannelPresence parsePresence(HttpServletRequest request) throws IOException {
  24     try {
  25       MimeMultipart multipart = parseMultipartRequest(request);
  26       if (multipart == null) {
  27         throw new IllegalArgumentException(
  28             "No arguments provided in request.");
  29       }
  30
  31       boolean isConnected;
  32       if (request.getRequestURI().endsWith("/channel/connected/")) {
  33         isConnected = true;
  34       } else if (request.getRequestURI().endsWith("/channel/disconnected/")) {
  35         isConnected = false;
  36       } else {
  37         throw new IllegalArgumentException(
  38             "Can't determine the type of channel presence from the path: " +
  39             request.getRequestURI());
  40       }
  41
  42       int parts = multipart.getCount();
  43       for (int i = 0; i < parts; i++) {
  44         BodyPart part = multipart.getBodyPart(i);
  45         if ("from".equals(getFieldName(part))) {
  46           return new ChannelPresence(isConnected, getTextContent(part));
  47         }
  48       }
  49
  50       throw new IllegalArgumentException(
  51           "Can't determine clientId from request body: " + multipart.toString());
  52     } catch (MessagingException ex) {
  53       IOException ex2 = new IOException("Could not parse incoming request.");
  54       ex2.initCause(ex);
  55       throw ex2;
  56     }
  57   }
  58 }