openfire+spark+smack 即时通讯（问题篇一）离线消息获取不到

即时通信功能已经开发完毕，现在还木有时间整理，打算后期抽时间整理后发一下源码跟教程。现在记录一下遇到的问题，首先是获取离线消息。

OfflineMessageManager是官方获取离线消息的，但是直接获取，是获取不到任何消息的，需要先设置离线，然后获取后，再上线。功能代码如下。

1、离线

// 初始化
	public XMPPConnection init(LoginConfig loginConfig) {
		Connection.DEBUG_ENABLED = false;
		ProviderManager pm = ProviderManager.getInstance();
		configure(pm);

		connectionConfig = new ConnectionConfiguration(
				loginConfig.getXmppHost(), loginConfig.getXmppPort(),
				loginConfig.getXmppServiceName());
		connectionConfig.setSASLAuthenticationEnabled(false);// 不使用SASL验证，设置为false
		connectionConfig
				.setSecurityMode(ConnectionConfiguration.SecurityMode.enabled);
		// 允许自动连接
		connectionConfig.setReconnectionAllowed(false);
		connectionConfig.setSendPresence(false);// 设置离线
		// 收到好友邀请后manual表示需要经过同意,accept_all表示不经同意自动为好友
		Roster.setDefaultSubscriptionMode(Roster.SubscriptionMode.manual);
		connection = new XMPPConnection(connectionConfig);
		return connection;
	}

OfflineMessageManager offlineManager = new OfflineMessageManager(connection);
		try {
			Log.i("离线消息数量: ", "" + offlineManager.getMessageCount());
			Iterator<org.jivesoftware.smack.packet.Message> it = offlineManager.getMessages();
			
			while (it.hasNext()) {
				org.jivesoftware.smack.packet.Message message = it.next();
				Log.i("收到离线消息", "Received from 【" + message.getFrom()
						+ "】 message: " + message.getBody());
				if (message != null && message.getBody() != null
						&& !message.getBody().equals("null")) {
					IMMessage msg = new IMMessage();
					String time = (String) message
							.getProperty(IMMessage.KEY_TIME);
					msg.setTime(time == null ? DateUtil.getCurDateStr() : time);
					msg.setContent(message.getBody());
					if (Message.Type.error == message.getType()) {
						msg.setType(IMMessage.ERROR);
					} else {
						msg.setType(IMMessage.SUCCESS);
					}
					String from = message.getFrom().split("/")[0];
					msg.setFromSubJid(from);

					// 生成通知
					NoticeManager noticeManager = NoticeManager
							.getInstance(context);
					Notice notice = new Notice();
					notice.setTitle("新信息");
					notice.setNoticeType(Notice.CHAT_MSG);
					notice.setContent(message.getBody());
					notice.setFrom(from);
					notice.setStatus(Notice.UNREAD);
					notice.setNoticeTime(time == null ? DateUtil
							.getCurDateStr() : time);

					// 历史记录
					IMMessage newMessage = new IMMessage();
					newMessage.setMsgType(0);
					newMessage.setFromSubJid(from);
					newMessage.setContent(message.getBody());
					newMessage.setTime(time == null ? DateUtil.getCurDateStr()
							: time);
					MessageManager.getInstance(context).saveIMMessage(
							newMessage);

					long noticeId = noticeManager.saveNotice(notice);
					if (noticeId != -1) {
						Intent intent = new Intent(Constant.NEW_MESSAGE_ACTION);
						intent.putExtra(IMMessage.IMMESSAGE_KEY, msg);
						intent.putExtra("noticeId", noticeId);
						context.sendBroadcast(intent);
						activitySupport.setNotiType(
								R.drawable.ic_launcher,
								context.getResources().getString(
										R.string.new_message),
								notice.getContent(), ChatActivity.class, from);
					}
				}
			}

			offlineManager.deleteMessages();// 通知服务器删除离线消息
		} catch (Exception e) {
			e.printStackTrace();
		}

3、设置上线：

Presence presence = new Presence(Presence.Type.available);
        connection.sendPacket(presence);