Paho Mqtt Android 客户端错误：无效的客户端句柄，非法参数异常（应用程序运行时随时随机出现）
使用 PahoAndroidMqtt 客户端库 连接代码：
@Override
public IMqttToken connect(MqttConnectOptions options, Object userContext,
IMqttActionListener callback) throws MqttException {
IMqttToken token = new MqttTokenAndroid(this, userContext,
callback);
connectOptions = options;
connectToken = token;
/*
* The actual connection depends on the service, which we start and bind
* to here, but which we can't actually use until the serviceConnection
* onServiceConnected() method has run (asynchronously), so the
* connection itself takes place in the onServiceConnected() method
*/
if (mqttService == null) { // First time - must bind to the service
Intent serviceStartIntent = new Intent();
serviceStartIntent.setClassName(myContext, SERVICE_NAME);
Object service = myContext.startService(serviceStartIntent);
if (service == null) {
IMqttActionListener listener = token.getActionCallback();
if (listener != null) {
listener.onFailure(token, new RuntimeException(
"cannot start service " + SERVICE_NAME));
}
}
// We bind with BIND_SERVICE_FLAG (0), leaving us the manage the lifecycle
// until the last time it is stopped by a call to stopService()
myContext.bindService(serviceStartIntent, serviceConnection,
Context.BIND_AUTO_CREATE);
if (!receiverRegistered) registerReceiver(this);
}
else {
pool.execute(new Runnable() {
@Override
public void run() {
doConnect();
//Register receiver to show shoulder tap.
if (!receiverRegistered) registerReceiver(MqttAndroidClient.this);
}
});
}
return token;
}
private void registerReceiver(BroadcastReceiver receiver) {
IntentFilter filter = new IntentFilter();
filter.addAction(MqttServiceConstants.CALLBACK_TO_ACTIVITY);
LocalBroadcastManager.getInstance(myContext).registerReceiver(receiver, filter);
receiverRegistered = true;
}
/**
* Actually do the mqtt connect operation
*/
private void doConnect() {
if (clientHandle == null) {
clientHandle = mqttService.getClient(serverURI, clientId,myContext.getApplicationInfo().packageName,
persistence);
}
mqttService.setTraceEnabled(traceEnabled);
mqttService.setTraceCallbackId(clientHandle);
String activityToken = storeToken(connectToken);
try {
mqttService.connect(clientHandle, connectOptions, null,
activityToken);
}
catch (MqttException e) {
IMqttActionListener listener = connectToken.getActionCallback();
if (listener != null) {
listener.onFailure(connectToken, e);
}
}
}
抛出错误的 Mqtt 服务类代码是：
/**
* Get an MqttConnection object to represent a connection to a server
*
* @param serverURI specifies the protocol, host name and port to be used to connect to an MQTT server
* @param clientId specifies the name by which this connection should be identified to the server
* @param contextId specifies the app conext info to make a difference between apps
* @param persistence specifies the persistence layer to be used with this client
* @return a string to be used by the Activity as a "handle" for this
* MqttConnection
*/
public String getClient(String serverURI, String clientId, String contextId, MqttClientPersistence persistence) {
String clientHandle = serverURI + ":" + clientId+":"+contextId;
if (!connections.containsKey(clientHandle)) {
MqttConnection client = new MqttConnection(this, serverURI,
clientId, persistence, clientHandle);
connections.put(clientHandle, client);
}
return clientHandle;
}
/**
* Get the MqttConnection identified by this client handle
*
* @param clientHandle identifies the MqttConnection
* @return the MqttConnection identified by this handle
*/
private MqttConnection getConnection(String clientHandle) {
MqttConnection client = connections.get(clientHandle);
if (client == null) {
throw new IllegalArgumentException("Invalid ClientHandle");
}
return client;
}
StackTrace 是：
Fatal Exception: java.lang.IllegalArgumentException: Invalid ClientHandle
at org.eclipse.paho.android.service.MqttService.getConnection(MqttService.java:588)
at org.eclipse.paho.android.service.MqttService.connect(MqttService.java:328)
at org.eclipse.paho.android.service.MqttAndroidClient.doConnect(MqttAndroidClient.java:467)
at org.eclipse.paho.android.service.MqttAndroidClient.access$200(MqttAndroidClient.java:76)
at org.eclipse.paho.android.service.MqttAndroidClient$1.run(MqttAndroidClient.java:435)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818)
我认为您的问题是您使用的客户端与发布 IMqttToken 的客户端不同。
尝试通过以下方式获得正确的客户参考：
科特林：
val currentClient = asyncActionToken!!.client
爪哇：
IMqttAsyncClient currentClient = asyncActionToken.getClient()
我也面临同样的问题，所以我定制了方法，以便每次我们都得到布尔值的响应。
public boolean isAlreadyConnected() {
if(myMqttAndroidClient != null){
try{
boolean result = myMqttAndroidClient.isConnected();
if(result){
return true;
}
else {
return false;
}
}
catch (Exception e){
e.printStackTrace();
return false;
}
}
else {
return false;
}
}
我建议你使用hiveMQ库，它支持很好地处理重连和连接等。 一开始用的是paho，后来用的是这个库，就没再遇到这样的问题了