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.
  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();
  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(int 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     /** Thread kickoff point */
 148     public void run() {
 149         read();
 150     }
 151
 152
 153     /**
 154      * Parses XML data from the provided XMPP stream.
 155      * @param inStream The stream to parse.
 156      */
 157     public void read() {
 158
 159         try {
 160             XMLInputFactory factory = XMLInputFactory.newInstance();
 161
 162             /** disable as many features as possible to speed up the parsing */
 163             factory.setProperty(XMLInputFactory.IS_REPLACING_ENTITY_REFERENCES, Boolean.FALSE);
 164             factory.setProperty(XMLInputFactory.IS_SUPPORTING_EXTERNAL_ENTITIES, Boolean.FALSE);
 165             factory.setProperty(XMLInputFactory.IS_NAMESPACE_AWARE, Boolean.FALSE);
 166             factory.setProperty(XMLInputFactory.IS_COALESCING, Boolean.FALSE);
 167             factory.setProperty(XMLInputFactory.SUPPORT_DTD, Boolean.FALSE);
 168
 169             /** create the stream reader */
 170             XMLStreamReader reader = factory.createXMLStreamReader(inStream);
 171             int eventType;
 172
 173             while(reader.hasNext()) {
 174                 /** cycle through the XML events */
 175
 176                 eventType = reader.next();
 177
 178                 switch(eventType) {
 179
 180                     case XMLEvent.START_ELEMENT:
 181                         handleStartElement(reader);
 182                         break;
 183
 184                     case XMLEvent.CHARACTERS:
 185                         switch(xmlState) {
 186                             case IN_BODY:
 187                                 msgBody.append(reader.getText());
 188                                 break;
 189                             case IN_THREAD:
 190                                 msgThread.append(reader.getText());
 191                                 break;
 192                             case IN_STATUS:
 193                                 msgStatus.append(reader.getText());
 194                                 break;
 195                         }
 196                         break;
 197
 198                     case XMLEvent.END_ELEMENT:
 199                         xmlState = XMLState.IN_NOTHING;
 200                         if("message".equals(reader.getName().toString())) {
 201
 202                            /** build a message and add it to the message queue */
 203                            XMPPMessage msg = new XMPPMessage();
 204                            msg.setFrom(msgFrom);
 205                            msg.setTo(msgTo);
 206                            msg.setBody(msgBody.toString());
 207                            msg.setThread(msgThread.toString());
 208
 209                            msgQueue.offer(msg);
 210                            resetBuffers();
 211                            notifyCoreEvent();
 212                         }
 213                         break;
 214                 }
 215             }
 216
 217         } catch(javax.xml.stream.XMLStreamException se) {
 218             /* XXX log an error, set a state, and notify */
 219         }
 220     }
 221
 222
 223     /**
 224      * Handles the start_element event.
 225      */
 226     private void handleStartElement(XMLStreamReader reader) {
 227
 228         String name = reader.getName().toString();
 229
 230         if("stream:stream".equals(name)) {
 231             setXMPPStreamState(XMPPStreamState.CONNECT_RECV);
 232             return;
 233         }
 234
 235         if("iq".equals(name)) {
 236             if("result".equals(reader.getAttributeValue(null, "type")))
 237                 setXMPPStreamState(XMPPStreamState.CONNECTED);
 238             return;
 239         }
 240
 241         if("message".equals(name)) {
 242             xmlState = XMLState.IN_BODY;
 243             /** add a special case for the opensrf "router_from" attribute */
 244             String rf = reader.getAttributeValue(null, "router_from");
 245             if( rf != null )
 246                 msgFrom = rf;
 247             else
 248                 msgFrom = reader.getAttributeValue(null, "from");
 249             msgTo = reader.getAttributeValue(null, "to");
 250             return;
 251         }
 252
 253         if("thread".equals(name)) {
 254             xmlState = XMLState.IN_THREAD;
 255             return;
 256         }
 257
 258         if("status".equals(name)) {
 259             xmlState = XMLState.IN_STATUS;
 260             return;
 261         }
 262
 263         if("stream:error".equals(name)) {
 264             setXMPPStreamState(XMPPStreamState.DISCONNECTED);
 265             return;
 266         }
 267
 268         if("error".equals(name)) {
 269             msgErrType.append(reader.getAttributeValue(null, "type"));
 270             msgErrCode = Integer.parseInt(reader.getAttributeValue(null, "code"));
 271             setXMPPStreamState(XMPPStreamState.DISCONNECTED);
 272             return;
 273         }
 274     }
 275 }
 276
 277
 278
 279