src/java/org/opensrf/net/xmpp/XMPPReader.java

   1 package org.opensrf.net.xmpp;
   2
   3 import javax.xml.stream.*;
   4 import javax.xml.stream.events.* ;
   5 import javax.xml.namespace.QName;
   6 import java.util.Queue;
   7 import java.io.InputStream;
   8 import java.util.concurrent.ConcurrentLinkedQueue;
   9 import java.util.Date;
  10
  11
  12 /**
  13  * Slim XMPP Stream reader.  This reader only understands enough XMPP
  14  * to handle logins and recv messages.  It's implemented as a StAX parser.
  15  * @author Bill Erickson, Georgia Public Library Systems
  16  */
  17 public class XMPPReader implements Runnable {
  18
  19     /** Queue of received messages. */
  20     private Queue<XMPPMessage> msgQueue;
  21     /** Incoming XMPP XML stream */
  22     private InputStream inStream;
  23     /** Current message body */
  24     private StringBuffer msgBody;
  25     /** Current message thread */
  26     private StringBuffer msgThread;
  27     /** Current message status */
  28     private StringBuffer msgStatus;
  29     /** Current message error type */
  30     private StringBuffer msgErrType;
  31     /** Current message sender */
  32     private String msgFrom;
  33     /** Current message recipient */
  34     private String msgTo;
  35     /** Current message error code */
  36     private int msgErrCode;
  37
  38     /** Where this reader currently is in the document */
  39     private XMLState xmlState;
  40
  41     /** The current connect state to the XMPP server */
  42     private XMPPStreamState streamState;
  43
  44
  45     /** Used to represent out connection state to the XMPP server */
  46     public static enum XMPPStreamState {
  47         DISCONNECTED,   /* not connected to the server */
  48         CONNECT_SENT,   /* we've sent the initial connect message */
  49         CONNECT_RECV,   /* we've received a response to our connect message */
  50         AUTH_SENT,      /* we've sent an authentication request */
  51         CONNECTED       /* authentication is complete */
  52     };
  53
  54
  55     /** Used to represents where we are in the XML document stream. */
  56     public static enum XMLState {
  57         IN_NOTHING,
  58         IN_BODY,
  59         IN_THREAD,
  60         IN_STATUS
  61     };
  62
  63
  64     /**
  65      * Creates a new reader. Initializes the message queue.
  66      * Sets the stream state to disconnected, and the xml
  67      * state to in_nothing.
  68      * @param inStream the inbound XML stream
  69      */
  70     public XMPPReader(InputStream inStream) {
  71         msgQueue = new ConcurrentLinkedQueue<XMPPMessage>();
  72         this.inStream = inStream;
  73         resetBuffers();
  74         xmlState = XMLState.IN_NOTHING;
  75         streamState = XMPPStreamState.DISCONNECTED;
  76     }
  77
  78     /**
  79      * Change the connect state and notify that a core
  80      * event has occurred.
  81      */
  82     protected void setXMPPStreamState(XMPPStreamState state) {
  83         streamState = state;
  84         notifyCoreEvent();
  85     }
  86
  87     /**
  88      * @return The current stream state of the reader
  89      */
  90     public XMPPStreamState getXMPPStreamState() {
  91         return streamState;
  92     }
  93
  94
  95     /**
  96      * @return The next message in the queue, or null
  97      */
  98     public XMPPMessage popMessageQueue() {
  99         return (XMPPMessage) msgQueue.poll();
 100     }
 101
 102
 103     /**
 104      * Initializes the message buffers
 105      */
 106     private void resetBuffers() {
 107         msgBody = new StringBuffer();
 108         msgThread = new StringBuffer();
 109         msgStatus = new StringBuffer();
 110         msgErrType = new StringBuffer();
 111         msgFrom = "";
 112         msgTo = "";
 113     }
 114
 115
 116     /**
 117      * Notifies the waiting thread that a core event has occurred.
 118      * Each reader should have exactly one dependent session thread.
 119      */
 120     private synchronized void notifyCoreEvent() {
 121         notify();
 122     }
 123
 124
 125     /**
 126      * Waits up to timeout milliseconds for a core event to occur.
 127      * Also, having a message already waiting in the queue
 128      * constitutes a core event.
 129      * @param timeout The number of milliseconds to wait.  If
 130      * timeout is negative, waits potentially forever.
 131      * @return The number of milliseconds in wait
 132      */
 133     public synchronized long waitCoreEvent(long timeout) {
 134
 135         if(msgQueue.peek() != null || timeout == 0) return 0;
 136
 137         long start = new Date().getTime();
 138         try{
 139             if(timeout < 0) wait();
 140             else wait(timeout);
 141         } catch(InterruptedException ie) {}
 142
 143         return new Date().getTime() - start;
 144     }
 145
 146
 147
 148     /** Kickoff the thread */
 149     public void run() {
 150         read();
 151     }
 152
 153
 154     /**
 155      * Parses XML data from the provided XMPP stream.
 156      */
 157     public void read() {
 158
 159         try {
 160
 161             XMLInputFactory factory = XMLInputFactory.newInstance();
 162
 163             /** disable as many unused features as possible to speed up the parsing */
 164             factory.setProperty(XMLInputFactory.IS_REPLACING_ENTITY_REFERENCES, Boolean.FALSE);
 165             factory.setProperty(XMLInputFactory.IS_SUPPORTING_EXTERNAL_ENTITIES, Boolean.FALSE);
 166             factory.setProperty(XMLInputFactory.IS_NAMESPACE_AWARE, Boolean.FALSE);
 167             factory.setProperty(XMLInputFactory.IS_COALESCING, Boolean.FALSE);
 168             factory.setProperty(XMLInputFactory.SUPPORT_DTD, Boolean.FALSE);
 169
 170             /** create the stream reader */
 171             XMLStreamReader reader = factory.createXMLStreamReader(inStream);
 172             int eventType;
 173
 174             while(reader.hasNext()) {
 175                 /** cycle through the XML events */
 176
 177                 eventType = reader.next();
 178
 179                 switch(eventType) {
 180
 181                     case XMLEvent.START_ELEMENT:
 182                         handleStartElement(reader);
 183                         break;
 184
 185                     case XMLEvent.CHARACTERS:
 186                         switch(xmlState) {
 187                             case IN_BODY:
 188                                 msgBody.append(reader.getText());
 189                                 break;
 190                             case IN_THREAD:
 191                                 msgThread.append(reader.getText());
 192                                 break;
 193                             case IN_STATUS:
 194                                 msgStatus.append(reader.getText());
 195                                 break;
 196                         }
 197                         break;
 198
 199                     case XMLEvent.END_ELEMENT:
 200                         xmlState = XMLState.IN_NOTHING;
 201                         if("message".equals(reader.getName().toString())) {
 202
 203                            /** build a message and add it to the message queue */
 204                            XMPPMessage msg = new XMPPMessage();
 205                            msg.setFrom(msgFrom);
 206                            msg.setTo(msgTo);
 207                            msg.setBody(msgBody.toString());
 208                            msg.setThread(msgThread.toString());
 209
 210                            msgQueue.offer(msg);
 211                            resetBuffers();
 212                            notifyCoreEvent();
 213                         }
 214                         break;
 215                 }
 216             }
 217
 218         } catch(javax.xml.stream.XMLStreamException se) {
 219             /* XXX log an error */
 220             xmlState = XMLState.IN_NOTHING;
 221             streamState = XMPPStreamState.DISCONNECTED;
 222             notifyCoreEvent();
 223         }
 224     }
 225
 226
 227     /**
 228      * Handles the start_element event.
 229      */
 230     private void handleStartElement(XMLStreamReader reader) {
 231
 232         String name = reader.getName().toString();
 233
 234         if("message".equals(name)) {
 235             xmlState = XMLState.IN_BODY;
 236
 237             /** add a special case for the opensrf "router_from" attribute */
 238             String rf = reader.getAttributeValue(null, "router_from");
 239             if( rf != null )
 240                 msgFrom = rf;
 241             else
 242                 msgFrom = reader.getAttributeValue(null, "from");
 243             msgTo = reader.getAttributeValue(null, "to");
 244             return;
 245         }
 246
 247         if("body".equals(name)) {
 248             xmlState = XMLState.IN_BODY;
 249             return;
 250         }
 251
 252         if("thread".equals(name)) {
 253             xmlState = XMLState.IN_THREAD;
 254             return;
 255         }
 256
 257         if("stream:stream".equals(name)) {
 258             setXMPPStreamState(XMPPStreamState.CONNECT_RECV);
 259             return;
 260         }
 261
 262         if("iq".equals(name)) {
 263             if("result".equals(reader.getAttributeValue(null, "type")))
 264                 setXMPPStreamState(XMPPStreamState.CONNECTED);
 265             return;
 266         }
 267
 268         if("status".equals(name)) {
 269             xmlState = XMLState.IN_STATUS;
 270             return;
 271         }
 272
 273         if("stream:error".equals(name)) {
 274             setXMPPStreamState(XMPPStreamState.DISCONNECTED);
 275             return;
 276         }
 277
 278         if("error".equals(name)) {
 279             msgErrType.append(reader.getAttributeValue(null, "type"));
 280             msgErrCode = Integer.parseInt(reader.getAttributeValue(null, "code"));
 281             setXMPPStreamState(XMPPStreamState.DISCONNECTED);
 282             return;
 283         }
 284     }
 285 }
 286
 287
 288
 289