CSDN博客之星投票请移驾：http://vote.blog.csdn.net/blogstaritem/blogstar2013/weidi1989
本文主要介绍本应用的控制层具体实现。如需了解项目结构与框架，请移步之前系列文章：
Android之基于XMPP协议即时通讯软件(一)
Android之基于XMPP协议即时通讯软件(二)
另外，本项目已经升级到V1.0.1，已同步到开源中国代码托管:http://git.oschina.net/way/XMPP
今后更新也只会在此处同步，不会再打包上传到csdn，敬请悉知！
之前给大家介绍过，该小应用采用的是MVC设计模式，所以今天就跟大家分享一下控制层的具体实现。控制层担当一个非常重要的角色，既要处理界面传递过来的任务：点击发送消息、切换在线状态等，又要处理服务器发送过来的消息：有好友上线、收到新消息、保持长连接、掉线自动连接等。概括的说，总共分为以下四步：
①.实例化对象，作一些参数配置。
②.开始连接服务器，实现登陆。
③.注册各种事件监听，比如联系人动态变化、各种消息状态监听、开启长连接任务、掉线自动连接等。
④.用户主动退出，注销登录，断开连接。
第一步很简单，当用户启动该应用时，即启动本应用关健服务，并与界面Activity完成绑定，同时完成xmpp的参数配置，我这里是放在类的静态块里面完成的：
[java] view plaincopyprint?static {
registerSmackProviders();
}
// 做一些基本的配置
static void registerSmackProviders() {
ProviderManager pm = ProviderManager.getInstance();
// add IQ handling
pm.addIQProvider("query", "http://jabber.org/protocol/disco#info",
new DiscoverInfoProvider());
// add delayed delivery notifications
pm.addExtensionProvider("delay", "urn:xmpp:delay",
new DelayInfoProvider());
pm.addExtensionProvider("x", "jabber:x:delay", new DelayInfoProvider());
// add carbons and forwarding
pm.addExtensionProvider("forwarded", Forwarded.NAMESPACE,
new Forwarded.Provider());
pm.addExtensionProvider("sent", Carbon.NAMESPACE, new Carbon.Provider());
pm.addExtensionProvider("received", Carbon.NAMESPACE,
new Carbon.Provider());
// add delivery receipts
pm.addExtensionProvider(DeliveryReceipt.ELEMENT,
DeliveryReceipt.NAMESPACE, new DeliveryReceipt.Provider());
pm.addExtensionProvider(DeliveryReceiptRequest.ELEMENT,
DeliveryReceipt.NAMESPACE,
new DeliveryReceiptRequest.Provider());
// add XMPP Ping (XEP-0199)
pm.addIQProvider("ping", "urn:xmpp:ping", new PingProvider());
ServiceDiscoveryManager.setIdentityName(XMPP_IDENTITY_NAME);
ServiceDiscoveryManager.setIdentityType(XMPP_IDENTITY_TYPE);
}
static {
registerSmackProviders();
}
// 做一些基本的配置
static void registerSmackProviders() {
ProviderManager pm = ProviderManager.getInstance();
// add IQ handling
pm.addIQProvider("query", "http://jabber.org/protocol/disco#info",
new DiscoverInfoProvider());
// add delayed delivery notifications
pm.addExtensionProvider("delay", "urn:xmpp:delay",
new DelayInfoProvider());
pm.addExtensionProvider("x", "jabber:x:delay", new DelayInfoProvider());
// add carbons and forwarding
pm.addExtensionProvider("forwarded", Forwarded.NAMESPACE,
new Forwarded.Provider());
pm.addExtensionProvider("sent", Carbon.NAMESPACE, new Carbon.Provider());
pm.addExtensionProvider("received", Carbon.NAMESPACE,
new Carbon.Provider());
// add delivery receipts
pm.addExtensionProvider(DeliveryReceipt.ELEMENT,
DeliveryReceipt.NAMESPACE, new DeliveryReceipt.Provider());
pm.addExtensionProvider(DeliveryReceiptRequest.ELEMENT,
DeliveryReceipt.NAMESPACE,
new DeliveryReceiptRequest.Provider());
// add XMPP Ping (XEP-0199)
pm.addIQProvider("ping", "urn:xmpp:ping", new PingProvider());
ServiceDiscoveryManager.setIdentityName(XMPP_IDENTITY_NAME);
ServiceDiscoveryManager.setIdentityType(XMPP_IDENTITY_TYPE);
}
第二步，当用户输入账号密码时，在服务中开启新线程启动连接服务器，传入参数信息(服务器、账号密码等)实现登录，同时会将登陆成功与否信息通过回调函数通知界面。也是比较简单的：
[java] view plaincopyprint?public boolean login(String account, String password) throws XXException {// 登陆实现
try {
if (mXMPPConnection.isConnected()) {// 首先判断是否还连接着服务器，需要先断开
try {
mXMPPConnection.disconnect();
} catch (Exception e) {
L.d("conn.disconnect() failed: " + e);
}
}
SmackConfiguration.setPacketReplyTimeout(PACKET_TIMEOUT);// 设置超时时间
SmackConfiguration.setKeepAliveInterval(-1);
SmackConfiguration.setDefaultPingInterval(0);
registerRosterListener();// 监听联系人动态变化
mXMPPConnection.connect();
if (!mXMPPConnection.isConnected()) {
throw new XXException("SMACK connect failed without exception!");
}
mXMPPConnection.addConnectionListener(new ConnectionListener() {
public void connectionClosedOnError(Exception e) {
mService.postConnectionFailed(e.getMessage());// 连接关闭时，动态反馈给服务
}
public void connectionClosed() {
}
public void reconnectingIn(int seconds) {
}
public void reconnectionFailed(Exception e) {
}
public void reconnectionSuccessful() {
}
});
initServiceDiscovery();// 与服务器交互消息监听,发送消息需要回执，判断是否发送成功
// SMACK auto-logins if we were authenticated before
if (!mXMPPConnection.isAuthenticated()) {
String ressource = PreferenceUtils.getPrefString(mService,
PreferenceConstants.RESSOURCE, XMPP_IDENTITY_NAME);
mXMPPConnection.login(account, password, ressource);
}
setStatusFromConfig();// 更新在线状态
} catch (XMPPException e) {
throw new XXException(e.getLocalizedMessage(),
e.getWrappedThrowable());
} catch (Exception e) {
// actually we just care for IllegalState or NullPointer or XMPPEx.
L.e(SmackImpl.class, "login(): " + Log.getStackTraceString(e));
throw new XXException(e.getLocalizedMessage(), e.getCause());
}
registerAllListener();// 注册监听其他的事件，比如新消息
return mXMPPConnection.isAuthenticated();
}
public boolean login(String account, String password) throws XXException {// 登陆实现
try {
if (mXMPPConnection.isConnected()) {// 首先判断是否还连接着服务器，需要先断开
try {
mXMPPConnection.disconnect();
} catch (Exception e) {
L.d("conn.disconnect() failed: " + e);
}
}
SmackConfiguration.setPacketReplyTimeout(PACKET_TIMEOUT);// 设置超时时间
SmackConfiguration.setKeepAliveInterval(-1);
SmackConfiguration.setDefaultPingInterval(0);
registerRosterListener();// 监听联系人动态变化
mXMPPConnection.connect();
if (!mXMPPConnection.isConnected()) {
throw new XXException("SMACK connect failed without exception!");
}
mXMPPConnection.addConnectionListener(new ConnectionListener() {
public void connectionClosedOnError(Exception e) {
mService.postConnectionFailed(e.getMessage());// 连接关闭时，动态反馈给服务
}
public void connectionClosed() {
}
public void reconnectingIn(int seconds) {
}
public void reconnectionFailed(Exception e) {
}
public void reconnectionSuccessful() {
}
});
initServiceDiscovery();// 与服务器交互消息监听,发送消息需要回执，判断是否发送成功
// SMACK auto-logins if we were authenticated before
if (!mXMPPConnection.isAuthenticated()) {
String ressource = PreferenceUtils.getPrefString(mService,
PreferenceConstants.RESSOURCE, XMPP_IDENTITY_NAME);
mXMPPConnection.login(account, password, ressource);
}
setStatusFromConfig();// 更新在线状态
} catch (XMPPException e) {
throw new XXException(e.getLocalizedMessage(),
e.getWrappedThrowable());
} catch (Exception e) {
// actually we just care for IllegalState or NullPointer or XMPPEx.
L.e(SmackImpl.class, "login(): " + Log.getStackTraceString(e));
throw new XXException(e.getLocalizedMessage(), e.getCause());
}
registerAllListener();// 注册监听其他的事件，比如新消息
return mXMPPConnection.isAuthenticated();
}
第三步比较关健，登陆成功后，我们就必须要监听服务器的各种消息状态变化，以及要维持自身的一个稳定性，即保持长连接和掉线自动重连。下面是注册所有监听的函数：
[java] view plaincopyprint?private void registerAllListener() {
// actually, authenticated must be true now, or an exception must have
// been thrown.
if (isAuthenticated()) {
registerMessageListener();// 注册新消息监听
registerMessageSendFailureListener();// 注册消息发送失败监听
registerPongListener();// 注册服务器回应ping消息监听
sendOfflineMessages();// 发送离线消息
if (mService == null) {
mXMPPConnection.disconnect();
return;
}
// we need to "ping" the service to let it know we are actually
// connected, even when no roster entries will come in
mService.rosterChanged();
}
}
private void registerAllListener() {
// actually, authenticated must be true now, or an exception must have
// been thrown.
if (isAuthenticated()) {
registerMessageListener();// 注册新消息监听
registerMessageSendFailureListener();// 注册消息发送失败监听
registerPongListener();// 注册服务器回应ping消息监听
sendOfflineMessages();// 发送离线消息
if (mService == null) {
mXMPPConnection.disconnect();
return;
}
// we need to "ping" the service to let it know we are actually
// connected, even when no roster entries will come in
mService.rosterChanged();
}
}
①.注册联系人动态变化监听：第一次登陆时要同步本地数据库与服务器数据库的联系人，同时处理连接过程中联系人动态变化，比如说好友切换在线状态、有人申请加好友等。我这里没有将动态变化直接通知到界面线程，而是直接更新联系人数据库Roster.db，因为：我在界面线程监听了联系人数据库的动态变化，这就是ContentProvider的好处，下篇文章细说，这里就只提及一下。下面是关键部分代码：
[java] view plaincopyprint?private void registerRosterListener() {
mRoster = mXMPPConnection.getRoster();
mRosterListener = new RosterListener() {
private boolean isFristRoter;
@Override
public void presenceChanged(Presence presence) {// 联系人状态改变，比如在线或离开、隐身之类
L.i("presenceChanged(" + presence.getFrom() + "): " + presence);
String jabberID = getJabberID(presence.getFrom());
RosterEntry rosterEntry = mRoster.getEntry(jabberID);
updateRosterEntryInDB(rosterEntry);// 更新联系人数据库
mService.rosterChanged();// 回调通知服务，主要是用来判断一下是否掉线
}
@Override
public void entriesUpdated(Collection<String> entries) {// 更新数据库，第一次登陆
// TODO Auto-generated method stub
L.i("entriesUpdated(" + entries + ")");
for (String entry : entries) {
RosterEntry rosterEntry = mRoster.getEntry(entry);
updateRosterEntryInDB(rosterEntry);
}
mService.rosterChanged();// 回调通知服务，主要是用来判断一下是否掉线
}
@Override
public void entriesDeleted(Collection<String> entries) {// 有好友删除时，
L.i("entriesDeleted(" + entries + ")");
for (String entry : entries) {
deleteRosterEntryFromDB(entry);
}
mService.rosterChanged();// 回调通知服务，主要是用来判断一下是否掉线
}
@Override
public void entriesAdded(Collection<String> entries) {// 有人添加好友时，我这里没有弹出对话框确认，直接添加到数据库
L.i("entriesAdded(" + entries + ")");
ContentValues[] cvs = new ContentValues[entries.size()];
int i = 0;
for (String entry : entries) {
RosterEntry rosterEntry = mRoster.getEntry(entry);
cvs[i++] = getContentValuesForRosterEntry(rosterEntry);
}
mContentResolver.bulkInsert(RosterProvider.CONTENT_URI, cvs);
if (isFristRoter) {
isFristRoter = false;
mService.rosterChanged();// 回调通知服务，主要是用来判断一下是否掉线
}
}
};
mRoster.addRosterListener(mRosterListener);
}
private void registerRosterListener() {
mRoster = mXMPPConnection.getRoster();
mRosterListener = new RosterListener() {
private boolean isFristRoter;
@Override
public void presenceChanged(Presence presence) {// 联系人状态改变，比如在线或离开、隐身之类
L.i("presenceChanged(" + presence.getFrom() + "): " + presence);
String jabberID = getJabberID(presence.getFrom());
RosterEntry rosterEntry = mRoster.getEntry(jabberID);
updateRosterEntryInDB(rosterEntry);// 更新联系人数据库
mService.rosterChanged();// 回调通知服务，主要是用来判断一下是否掉线
}
@Override
public void entriesUpdated(Collection<String> entries) {// 更新数据库，第一次登陆
// TODO Auto-generated method stub
L.i("entriesUpdated(" + entries + ")");
for (String entry : entries) {
RosterEntry rosterEntry = mRoster.getEntry(entry);
updateRosterEntryInDB(rosterEntry);
}
mService.rosterChanged();// 回调通知服务，主要是用来判断一下是否掉线
}
@Override
public void entriesDeleted(Collection<String> entries) {// 有好友删除时，
L.i("entriesDeleted(" + entries + ")");
for (String entry : entries) {
deleteRosterEntryFromDB(entry);
}
mService.rosterChanged();// 回调通知服务，主要是用来判断一下是否掉线
}
@Override
public void entriesAdded(Collection<String> entries) {// 有人添加好友时，我这里没有弹出对话框确认，直接添加到数据库
L.i("entriesAdded(" + entries + ")");
ContentValues[] cvs = new ContentValues[entries.size()];
int i = 0;
for (String entry : entries) {
RosterEntry rosterEntry = mRoster.getEntry(entry);
cvs[i++] = getContentValuesForRosterEntry(rosterEntry);
}
mContentResolver.bulkInsert(RosterProvider.CONTENT_URI, cvs);
if (isFristRoter) {
isFristRoter = false;
mService.rosterChanged();// 回调通知服务，主要是用来判断一下是否掉线
}
}
};
mRoster.addRosterListener(mRosterListener);
}
②.注册消息监听，也跟联系人动态监听是一样的处理方式，将消息的动态变化同步到消息数据库Chat.db，并未直接通知界面，界面也是通过监听数据库变化来作出动态变化的。下面是关键代码：
[java] view plaincopyprint?private void registerMessageListener() {
// do not register multiple packet listeners
if (mPacketListener != null)
mXMPPConnection.removePacketListener(mPacketListener);
PacketTypeFilter filter = new PacketTypeFilter(Message.class);
mPacketListener = new PacketListener() {
public void processPacket(Packet packet) {
try {
if (packet instanceof Message) {// 如果是消息类型
Message msg = (Message) packet;
String chatMessage = msg.getBody();
// try to extract a carbon
Carbon cc = CarbonManager.getCarbon(msg);
if (cc != null
&& cc.getDirection() == Carbon.Direction.received) {// 收到的消息
L.d("carbon: " + cc.toXML());
msg = (Message) cc.getForwarded()
.getForwardedPacket();
chatMessage = msg.getBody();
// fall through
} else if (cc != null
&& cc.getDirection() == Carbon.Direction.sent) {// 如果是自己发送的消息，则添加到数据库后直接返回
L.d("carbon: " + cc.toXML());
msg = (Message) cc.getForwarded()
.getForwardedPacket();
chatMessage = msg.getBody();
if (chatMessage == null)
return;
String fromJID = getJabberID(msg.getTo());
addChatMessageToDB(ChatConstants.OUTGOING, fromJID,
chatMessage, ChatConstants.DS_SENT_OR_READ,
System.currentTimeMillis(),
msg.getPacketID());
// always return after adding
return;// 记得要返回
}
if (chatMessage == null) {
return;// 如果消息为空，直接返回了
}
if (msg.getType() == Message.Type.error) {
chatMessage = "<Error> " + chatMessage;// 错误的消息类型
}
long ts;// 消息时间戳
DelayInfo timestamp = (DelayInfo) msg.getExtension(
"delay", "urn:xmpp:delay");
if (timestamp == null)
timestamp = (DelayInfo) msg.getExtension("x",
"jabber:x:delay");
if (timestamp != null)
ts = timestamp.getStamp().getTime();
else
ts = System.currentTimeMillis();
String fromJID = getJabberID(msg.getFrom());// 消息来自对象
addChatMessageToDB(ChatConstants.INCOMING, fromJID,
chatMessage, ChatConstants.DS_NEW, ts,
msg.getPacketID());// 存入数据库，并标记为新消息DS_NEW
mService.newMessage(fromJID, chatMessage);// 通知service，处理是否需要显示通知栏，
}
} catch (Exception e) {
// SMACK silently discards exceptions dropped from
// processPacket :(
L.e("failed to process packet:");
e.printStackTrace();
}
}
};
mXMPPConnection.addPacketListener(mPacketListener, filter);// 这是最关健的了，少了这句，前面的都是白费功夫
}
private void registerMessageListener() {
// do not register multiple packet listeners
if (mPacketListener != null)
mXMPPConnection.removePacketListener(mPacketListener);
PacketTypeFilter filter = new PacketTypeFilter(Message.class);
mPacketListener = new PacketListener() {
public void processPacket(Packet packet) {
try {
if (packet instanceof Message) {// 如果是消息类型
Message msg = (Message) packet;
String chatMessage = msg.getBody();
// try to extract a carbon
Carbon cc = CarbonManager.getCarbon(msg);
if (cc != null
&& cc.getDirection() == Carbon.Direction.received) {// 收到的消息
L.d("carbon: " + cc.toXML());
msg = (Message) cc.getForwarded()
.getForwardedPacket();
chatMessage = msg.getBody();
// fall through
} else if (cc != null
&& cc.getDirection() == Carbon.Direction.sent) {// 如果是自己发送的消息，则添加到数据库后直接返回
L.d("carbon: " + cc.toXML());
msg = (Message) cc.getForwarded()
.getForwardedPacket();
chatMessage = msg.getBody();
if (chatMessage == null)
return;
String fromJID = getJabberID(msg.getTo());
addChatMessageToDB(ChatConstants.OUTGOING, fromJID,
chatMessage, ChatConstants.DS_SENT_OR_READ,
System.currentTimeMillis(),
msg.getPacketID());
// always return after adding
return;// 记得要返回
}
if (chatMessage == null) {
return;// 如果消息为空，直接返回了
}
if (msg.getType() == Message.Type.error) {
chatMessage = "<Error> " + chatMessage;// 错误的消息类型
}
long ts;// 消息时间戳
DelayInfo timestamp = (DelayInfo) msg.getExtension(
"delay", "urn:xmpp:delay");
if (timestamp == null)
timestamp = (DelayInfo) msg.getExtension("x",
"jabber:x:delay");
if (timestamp != null)
ts = timestamp.getStamp().getTime();
else
ts = System.currentTimeMillis();
String fromJID = getJabberID(msg.getFrom());// 消息来自对象
addChatMessageToDB(ChatConstants.INCOMING, fromJID,
chatMessage, ChatConstants.DS_NEW, ts,
msg.getPacketID());// 存入数据库，并标记为新消息DS_NEW
mService.newMessage(fromJID, chatMessage);// 通知service，处理是否需要显示通知栏，
}
} catch (Exception e) {
// SMACK silently discards exceptions dropped from
// processPacket :(
L.e("failed to process packet:");
e.printStackTrace();
}
}
};
mXMPPConnection.addPacketListener(mPacketListener, filter);// 这是最关健的了，少了这句，前面的都是白费功夫
}
③.启动保持长连接任务。我这里与服务器保持长连接，其实是通过每隔一段时间(本应用是15分钟)去ping一次服务器，服务器收到此ping消息，会对应的回复一个pong消息，完成一次ping-pong的过程，我们暂且叫它为心跳。此ping-pong过程有一个唯一的id，用来区分每一次的ping-pong记录。为了保证应用在系统休眠时也能启动ping的任务，我们使用了闹钟服务，而不是定时器，关于闹钟服务具体使用，请参看我之前的博客：Android中的定时器AlarmManager 。具体操作是：
从连上服务器完成登录15分钟后，闹钟响起，开始给服务器发送一条ping消息(随机生成一唯一ID)，同时启动超时闹钟(本应用是30+3秒)，如果服务器在30+3秒内回复了一条pong消息(与之前发送的ping消息ID相同)，代表与服务器任然保持连接，则取消超时闹钟，完成一次ping-pong过程。如果在30+3秒内服务器未响应，或者回复的pong消息与之前发送的ping消息ID不一致，则认为与服务器已经断开。此时，将此消息反馈给界面，同时启动重连任务。实现长连接。
关健代码如下：
[java] view plaincopyprint? / start 处理ping服务器消息 **/
private void registerPongListener() {
// reset ping expectation on new connection
mPingID = null;// 初始化ping的id
if (mPongListener != null)
mXMPPConnection.removePacketListener(mPongListener);// 先移除之前监听对象
mPongListener = new PacketListener() {
@Override
public void processPacket(Packet packet) {
if (packet == null)
return;
if (packet.getPacketID().equals(mPingID)) {// 如果服务器返回的消息为ping服务器时的消息，说明没有掉线
L.i(String.format(
"Ping: server latency %1.3fs",
(System.currentTimeMillis() - mPingTimestamp) / 1000.));
mPingID = null;
((AlarmManager) mService
.getSystemService(Context.ALARM_SERVICE))
.cancel(mPongTimeoutAlarmPendIntent);// 取消超时闹钟
}
}
};
mXMPPConnection.addPacketListener(mPongListener, new PacketTypeFilter(
IQ.class));// 正式开始监听
mPingAlarmPendIntent = PendingIntent.getBroadcast(
mService.getApplicationContext(), 0, mPingAlarmIntent,
PendingIntent.FLAG_UPDATE_CURRENT);// 定时ping服务器，以此来确定是否掉线
mPongTimeoutAlarmPendIntent = PendingIntent.getBroadcast(
mService.getApplicationContext(), 0, mPongTimeoutAlarmIntent,
PendingIntent.FLAG_UPDATE_CURRENT);// 超时闹钟
mService.registerReceiver(mPingAlarmReceiver, new IntentFilter(
PING_ALARM));// 注册定时ping服务器广播接收者
mService.registerReceiver(mPongTimeoutAlarmReceiver, new IntentFilter(
PONG_TIMEOUT_ALARM));// 注册连接超时广播接收者
((AlarmManager) mService.getSystemService(Context.ALARM_SERVICE))
.setInexactRepeating(AlarmManager.RTC_WAKEUP,
System.currentTimeMillis()
+ AlarmManager.INTERVAL_FIFTEEN_MINUTES,
AlarmManager.INTERVAL_FIFTEEN_MINUTES,
mPingAlarmPendIntent);// 15分钟ping以此服务器
}
/**
* BroadcastReceiver to trigger reconnect on pong timeout.
*/
private class PongTimeoutAlarmReceiver extends BroadcastReceiver {
public void onReceive(Context ctx, Intent i) {
L.d("Ping: timeout for " + mPingID);
mService.postConnectionFailed(XXService.PONG_TIMEOUT);
//logout();// 超时就断开连接
}
}
/**
* BroadcastReceiver to trigger sending pings to the server
*/
private class PingAlarmReceiver extends BroadcastReceiver {
public void onReceive(Context ctx, Intent i) {
if (mXMPPConnection.isAuthenticated()) {
sendServerPing();// 收到ping服务器的闹钟，即ping一下服务器
} else
L.d("Ping: alarm received, but not connected to server.");
}
}
public void sendServerPing() {
if (mPingID != null) {// 此时说明上一次ping服务器还未回应，直接返回，直到连接超时
L.d("Ping: requested, but still waiting for " + mPingID);
return; // a ping is still on its way
}
Ping ping = new Ping();
ping.setType(Type.GET);
ping.setTo(PreferenceUtils.getPrefString(mService,
PreferenceConstants.Server, PreferenceConstants.GMAIL_SERVER));
mPingID = ping.getPacketID();// 此id其实是随机生成，但是唯一的
mPingTimestamp = System.currentTimeMillis();
L.d("Ping: sending ping " + mPingID);
mXMPPConnection.sendPacket(ping);// 发送ping消息
// register ping timeout handler: PACKET_TIMEOUT(30s) + 3s
((AlarmManager) mService.getSystemService(Context.ALARM_SERVICE)).set(
AlarmManager.RTC_WAKEUP, System.currentTimeMillis()
+ PACKET_TIMEOUT + 3000, mPongTimeoutAlarmPendIntent);// 此时需要启动超时判断的闹钟了，时间间隔为30+3秒
}
/***************** start 处理ping服务器消息 ***********************/
private void registerPongListener() {
// reset ping expectation on new connection
mPingID = null;// 初始化ping的id
if (mPongListener != null)
mXMPPConnection.removePacketListener(mPongListener);// 先移除之前监听对象
mPongListener = new PacketListener() {
@Override
public void processPacket(Packet packet) {
if (packet == null)
return;
if (packet.getPacketID().equals(mPingID)) {// 如果服务器返回的消息为ping服务器时的消息，说明没有掉线
L.i(String.format(
"Ping: server latency %1.3fs",
(System.currentTimeMillis() - mPingTimestamp) / 1000.));
mPingID = null;
((AlarmManager) mService
.getSystemService(Context.ALARM_SERVICE))
.cancel(mPongTimeoutAlarmPendIntent);// 取消超时闹钟
}
}
};
mXMPPConnection.addPacketListener(mPongListener, new PacketTypeFilter(
IQ.class));// 正式开始监听
mPingAlarmPendIntent = PendingIntent.getBroadcast(
mService.getApplicationContext(), 0, mPingAlarmIntent,
PendingIntent.FLAG_UPDATE_CURRENT);// 定时ping服务器，以此来确定是否掉线
mPongTimeoutAlarmPendIntent = PendingIntent.getBroadcast(
mService.getApplicationContext(), 0, mPongTimeoutAlarmIntent,
PendingIntent.FLAG_UPDATE_CURRENT);// 超时闹钟
mService.registerReceiver(mPingAlarmReceiver, new IntentFilter(
PING_ALARM));// 注册定时ping服务器广播接收者
mService.registerReceiver(mPongTimeoutAlarmReceiver, new IntentFilter(
PONG_TIMEOUT_ALARM));// 注册连接超时广播接收者
((AlarmManager) mService.getSystemService(Context.ALARM_SERVICE))
.setInexactRepeating(AlarmManager.RTC_WAKEUP,
System.currentTimeMillis()
+ AlarmManager.INTERVAL_FIFTEEN_MINUTES,
AlarmManager.INTERVAL_FIFTEEN_MINUTES,
mPingAlarmPendIntent);// 15分钟ping以此服务器
}
/**
* BroadcastReceiver to trigger reconnect on pong timeout.
*/
private class PongTimeoutAlarmReceiver extends BroadcastReceiver {
public void onReceive(Context ctx, Intent i) {
L.d("Ping: timeout for " + mPingID);
mService.postConnectionFailed(XXService.PONG_TIMEOUT);
//logout();// 超时就断开连接
}
}
/**
* BroadcastReceiver to trigger sending pings to the server
*/
private class PingAlarmReceiver extends BroadcastReceiver {
public void onReceive(Context ctx, Intent i) {
if (mXMPPConnection.isAuthenticated()) {
sendServerPing();// 收到ping服务器的闹钟，即ping一下服务器
} else
L.d("Ping: alarm received, but not connected to server.");
}
}
public void sendServerPing() {
if (mPingID != null) {// 此时说明上一次ping服务器还未回应，直接返回，直到连接超时
L.d("Ping: requested, but still waiting for " + mPingID);
return; // a ping is still on its way
}
Ping ping = new Ping();
ping.setType(Type.GET);
ping.setTo(PreferenceUtils.getPrefString(mService,
PreferenceConstants.Server, PreferenceConstants.GMAIL_SERVER));
mPingID = ping.getPacketID();// 此id其实是随机生成，但是唯一的
mPingTimestamp = System.currentTimeMillis();
L.d("Ping: sending ping " + mPingID);
mXMPPConnection.sendPacket(ping);// 发送ping消息
// register ping timeout handler: PACKET_TIMEOUT(30s) + 3s
((AlarmManager) mService.getSystemService(Context.ALARM_SERVICE)).set(
AlarmManager.RTC_WAKEUP, System.currentTimeMillis()
+ PACKET_TIMEOUT + 3000, mPongTimeoutAlarmPendIntent);// 此时需要启动超时判断的闹钟了，时间间隔为30+3秒
}
④.如果与服务器连接超时，则进入了我们掉线重连的任务了，因为mService.postConnectionFailed(XXService.PONG_TIMEOUT);回反馈到服务中，此时，我们会判断使用是否开启了掉线重连，关健代码如下，首先将消息由子线程发送到界面线程，文章开头说了，我们的连接是在新的线程中执行的：
[java] view plaincopyprint?public void postConnectionFailed(final String reason) {
mMainHandler.post(new Runnable() {
public void run() {
connectionFailed(reason);
}
});
}
private void connectionFailed(String reason) {
L.i(XXService.class, "connectionFailed: " + reason);
mConnectedState = DISCONNECTED;// 更新当前连接状态
if (mSmackable != null)
mSmackable.setStatusOffline();// 将所有联系人标记为离线
if (TextUtils.equals(reason, LOGOUT)) {// 如果是手动退出
((AlarmManager) getSystemService(Context.ALARM_SERVICE))
.cancel(mPAlarmIntent);
return;
}
// 回调
if (mConnectionStatusCallback != null) {
mConnectionStatusCallback.connectionStatusChanged(mConnectedState,
reason);
if (mIsFirstLoginAction)// 如果是第一次登录,就算登录失败也不需要继续
return;
}
// 无网络连接时,直接返回
if (NetUtil.getNetworkState(this) == NetUtil.NETWORN_NONE) {
((AlarmManager) getSystemService(Context.ALARM_SERVICE))
.cancel(mPAlarmIntent);
return;
}
String account = PreferenceUtils.getPrefString(XXService.this,
PreferenceConstants.ACCOUNT, "");
String password = PreferenceUtils.getPrefString(XXService.this,
PreferenceConstants.PASSWORD, "");
// 无保存的帐号密码时，也直接返回
if (TextUtils.isEmpty(account) || TextUtils.isEmpty(password)) {
L.d("account = null || password = null");
return;
}
// 如果不是手动退出并且需要重新连接，则开启重连闹钟
if (PreferenceUtils.getPrefBoolean(this,
PreferenceConstants.AUTO_RECONNECT, true)) {
L.d("connectionFailed(): registering reconnect in "
+ mReconnectTimeout + "s");
((AlarmManager) getSystemService(Context.ALARM_SERVICE)).set(
AlarmManager.RTC_WAKEUP, System.currentTimeMillis()
+ mReconnectTimeout * 1000, mPAlarmIntent);
mReconnectTimeout = mReconnectTimeout * 2;
if (mReconnectTimeout > RECONNECT_MAXIMUM)
mReconnectTimeout = RECONNECT_MAXIMUM;
} else {
((AlarmManager) getSystemService(Context.ALARM_SERVICE))
.cancel(mPAlarmIntent);
}
}
public void postConnectionFailed(final String reason) {
mMainHandler.post(new Runnable() {
public void run() {
connectionFailed(reason);
}
});
}
private void connectionFailed(String reason) {
L.i(XXService.class, "connectionFailed: " + reason);
mConnectedState = DISCONNECTED;// 更新当前连接状态
if (mSmackable != null)
mSmackable.setStatusOffline();// 将所有联系人标记为离线
if (TextUtils.equals(reason, LOGOUT)) {// 如果是手动退出
((AlarmManager) getSystemService(Context.ALARM_SERVICE))
.cancel(mPAlarmIntent);
return;
}
// 回调
if (mConnectionStatusCallback != null) {
mConnectionStatusCallback.connectionStatusChanged(mConnectedState,
reason);
if (mIsFirstLoginAction)// 如果是第一次登录,就算登录失败也不需要继续
return;
}
// 无网络连接时,直接返回
if (NetUtil.getNetworkState(this) == NetUtil.NETWORN_NONE) {
((AlarmManager) getSystemService(Context.ALARM_SERVICE))
.cancel(mPAlarmIntent);
return;
}
String account = PreferenceUtils.getPrefString(XXService.this,
PreferenceConstants.ACCOUNT, "");
String password = PreferenceUtils.getPrefString(XXService.this,
PreferenceConstants.PASSWORD, "");
// 无保存的帐号密码时，也直接返回
if (TextUtils.isEmpty(account) || TextUtils.isEmpty(password)) {
L.d("account = null || password = null");
return;
}
// 如果不是手动退出并且需要重新连接，则开启重连闹钟
if (PreferenceUtils.getPrefBoolean(this,
PreferenceConstants.AUTO_RECONNECT, true)) {
L.d("connectionFailed(): registering reconnect in "
+ mReconnectTimeout + "s");
((AlarmManager) getSystemService(Context.ALARM_SERVICE)).set(
AlarmManager.RTC_WAKEUP, System.currentTimeMillis()
+ mReconnectTimeout * 1000, mPAlarmIntent);
mReconnectTimeout = mReconnectTimeout * 2;
if (mReconnectTimeout > RECONNECT_MAXIMUM)
mReconnectTimeout = RECONNECT_MAXIMUM;
} else {
((AlarmManager) getSystemService(Context.ALARM_SERVICE))
.cancel(mPAlarmIntent);
}
}
从上述代码中可以看出，在connectionFailed函数中，我们除了将此消息通知界面，同时会根据不同的reason来判断是否需要重连，如果是用户手动退出reason=LOGOUT，则直接返回咯，否则也是开启一个闹钟，启动重新连接任务，下面是该闹钟的接收处理：
[java] view plaincopyprint?// 自动重连广播接收者
private class ReconnectAlarmReceiver extends BroadcastReceiver {
public void onReceive(Context ctx, Intent i) {
L.d("Alarm received.");
if (!PreferenceUtils.getPrefBoolean(XXService.this,
PreferenceConstants.AUTO_RECONNECT, true)) {
return;
}
if (mConnectedState != DISCONNECTED) {
L.d("Reconnect attempt aborted: we are connected again!");
return;
}
String account = PreferenceUtils.getPrefString(XXService.this,
PreferenceConstants.ACCOUNT, "");
String password = PreferenceUtils.getPrefString(XXService.this,
PreferenceConstants.PASSWORD, "");
if (TextUtils.isEmpty(account) || TextUtils.isEmpty(password)) {
L.d("account = null || password = null");
return;
}
Login(account, password);
}
}
// 自动重连广播接收者
private class ReconnectAlarmReceiver extends BroadcastReceiver {
public void onReceive(Context ctx, Intent i) {
L.d("Alarm received.");
if (!PreferenceUtils.getPrefBoolean(XXService.this,
PreferenceConstants.AUTO_RECONNECT, true)) {
return;
}
if (mConnectedState != DISCONNECTED) {
L.d("Reconnect attempt aborted: we are connected again!");
return;
}
String account = PreferenceUtils.getPrefString(XXService.this,
PreferenceConstants.ACCOUNT, "");
String password = PreferenceUtils.getPrefString(XXService.this,
PreferenceConstants.PASSWORD, "");
if (TextUtils.isEmpty(account) || TextUtils.isEmpty(password)) {
L.d("account = null || password = null");
return;
}
Login(account, password);
}
}
是不是这样就实现了长连接呢？也许高兴得太早了，我们还有一个重要的因素没有考虑到，对了，就是手机网络，因为很多手机在系统休眠的时候是会断开网络连接的(应该是为了省电吧)，所以，我们必须要动态监听网络变化，来做出处理,以下是关键代码：
[java] view plaincopyprint?public void onNetChange() {
if (NetUtil.getNetworkState(this) == NetUtil.NETWORN_NONE) {// 如果是网络断开，不作处理
connectionFailed(NETWORK_ERROR);
return;
}
if (isAuthenticated())// 如果已经连接上，直接返回
return;
String account = PreferenceUtils.getPrefString(XXService.this,
PreferenceConstants.ACCOUNT, "");
String password = PreferenceUtils.getPrefString(XXService.this,
PreferenceConstants.PASSWORD, "");
if (TextUtils.isEmpty(account) || TextUtils.isEmpty(password))// 如果没有帐号，也直接返回
return;
if (!PreferenceUtils.getPrefBoolean(this,
PreferenceConstants.AUTO_RECONNECT, true))// 不需要重连
return;
Login(account, password);// 重连
}
public void onNetChange() {
if (NetUtil.getNetworkState(this) == NetUtil.NETWORN_NONE) {// 如果是网络断开，不作处理
connectionFailed(NETWORK_ERROR);
return;
}
if (isAuthenticated())// 如果已经连接上，直接返回
return;
String account = PreferenceUtils.getPrefString(XXService.this,
PreferenceConstants.ACCOUNT, "");
String password = PreferenceUtils.getPrefString(XXService.this,
PreferenceConstants.PASSWORD, "");
if (TextUtils.isEmpty(account) || TextUtils.isEmpty(password))// 如果没有帐号，也直接返回
return;
if (!PreferenceUtils.getPrefBoolean(this,
PreferenceConstants.AUTO_RECONNECT, true))// 不需要重连
return;
Login(account, password);// 重连
}
OK，与服务器保持长连接，基本上就是这样了，其实还有一些问题没有考虑到，比如说内存过低，服务被系统回收，我们是没有考虑到的，这个就留个读者一个思考吧，我的想法是：在用户唤醒系统时也启动一次服务，接收此广播：
⑤.实现服务在前台运行：这个我在之前的文章中有介绍过：Android之后台服务判断本应用Activity是否处于栈顶，这里就不在赘述了。
第四步是用户主动退出，注销登陆，这个好像没有多少需要介绍的，无法是释放掉一些资源，关闭一些服务等等，也无需多说。看看代码即可：
[java] view plaincopyprint?// 退出
public boolean logout() {
// mIsNeedReConnection = false;// 手动退出就不需要重连闹钟了
boolean isLogout = false;
if (mConnectingThread != null) {
synchronized (mConnectingThread) {
try {
mConnectingThread.interrupt();
mConnectingThread.join(50);
} catch (InterruptedException e) {
L.e("doDisconnect: failed catching connecting thread");
} finally {
mConnectingThread = null;
}
}
}
if (mSmackable != null) {
isLogout = mSmackable.logout();
mSmackable = null;
}
connectionFailed(LOGOUT);// 手动退出
return isLogout;
}
// 退出
public boolean logout() {
// mIsNeedReConnection = false;// 手动退出就不需要重连闹钟了
boolean isLogout = false;
if (mConnectingThread != null) {
synchronized (mConnectingThread) {
try {
mConnectingThread.interrupt();
mConnectingThread.join(50);
} catch (InterruptedException e) {
L.e("doDisconnect: failed catching connecting thread");
} finally {
mConnectingThread = null;
}
}
}
if (mSmackable != null) {
isLogout = mSmackable.logout();
mSmackable = null;
}
connectionFailed(LOGOUT);// 手动退出
return isLogout;
}
好了，整个控制层大概就讲到这里，总结一下：
重要的是第三步：注册监听和长连接的处理，其中长连接处理也是最为关键和麻烦的。
文章比较长，其实也花了我几个小时的时间，首先感谢你看到了文章末尾，由于个人水平限制，难免会有一些失误或者不准确的地方，欢迎大家批评指出。
时间： 2025-01-03 16:26:27