XMPP通信中的离线消息

╰半橙微兮° 2024-02-17 14:46 22阅读 0赞

ConnectionConfiguration config = new ConnectionConfiguration("192.168.1.100", 5222);
    		config.setSecurityMode(SecurityMode.disabled);
    		config.setDebuggerEnabled(true);
    		config.setSendPresence(false);
    		XMPPConnection con = new XMPPTCPConnection(config);
    		con.setPacketReplyTimeout(5000);
    		con.connect();
    		con.login("admin", "0", "潘迪安");
    		Chat chat = ChatManager.getInstanceFor(con).createChat("yy@192.168.1.100", new MessageListener() {
    			@Override
    			public void processMessage(Chat chat, Message message) {
    				System.out.println("Received message: " + message);
    			}
    		});
    		//离线文件
    		OfflineMessageManager offMM = new OfflineMessageManager(con);
    		System.out.println("离线文件数量 ：" + offMM.getMessageCount());
    		System.out.println("离线文件内容 ：");
    //经测试，当调用getMessages时，会触发chat设置的监听器，从而输出离线消息内容，但是getMessages方法返回的离线消息为空
    		List<Message> listMessage = offMM.getMessages();
    		System.out.println(listMessage.size());
    		for(Message m : offMM.getMessages()) {
    			System.out.println(" 离线  : " + m.getBody() + m.getBodies());
    		}

进入getMessage方法中

<pre name="code" class="java"> public List<Message> getMessages() throws NoResponseException, XMPPErrorException, NotConnectedException {
            List<Message> messages = new ArrayList<Message>();
            OfflineMessageRequest request = new OfflineMessageRequest();
            request.setFetch(true);
            connection.createPacketCollectorAndSend(request).nextResultOrThrow();
    //根据Filter确定要把什么形式的消息放在collector中
            PacketCollector messageCollector = connection.createPacketCollector(packetFilter);
            // Collect the received offline messages

//debug下看到message为空

Message message = (Message) messageCollector.nextResult();
            while (message != null) {
                messages.add(message);
                message = (Message) messageCollector.nextResult();
            }
            // Stop queuing offline messages
            messageCollector.cancel();
            return messages;
        }

public PacketCollector createPacketCollector(PacketFilter packetFilter) {
            PacketCollector collector = new PacketCollector(this, packetFilter);
            // Add the collector to the list of active collectors.
            collectors.add(collector);
            return collector;
        }

protected PacketCollector(XMPPConnection connection, PacketFilter packetFilter) {
            this(connection, packetFilter, SmackConfiguration.getPacketCollectorSize());
        }

protected PacketCollector(XMPPConnection connection, PacketFilter packetFilter, int maxSize) {
            this.connection = connection;
            this.packetFilter = packetFilter;
            this.resultQueue = new ArrayBlockingQueue<Packet>(maxSize);
        }

![Center][]

所以得到的结果是离线消息的数目是实际消息数目，但是通过getMessages得到的list的size为0

离线的消息在chat中的listener中可以看见

每一次执行getMessages，在listener中可以输出一次消息

但是在上述的几个方法中都没有看见回调listener的方法，由此想到回调函数的另一种方式

用while（true）监听一个变量，如果改变则执行回调

[Center]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/30/877c13f8033840218fb175fea6ebe24f.png