我在我的服务中使用了一个 mqtt 服务器连接，它不断地向服务器发出频繁的请求。我的服务突然崩溃，使我的 ui 无响应，活动崩溃但应用程序没有崩溃，并且当服务崩溃时不会调用 ondestroy 方法。这是服务崩溃时的logcat：
10-21 10:34:12.841: W/ActivityThread(10204): ClassLoader.loadClass: The class loader returned by Thread.getContextClassLoader() may fail for processes that host multiple applications. You should explicitly specify a context class loader. For example: Thread.setContextClassLoader(getClass().getClassLoader());
10-21 10:34:13.561: A/libc(10204): Fatal signal 11 (SIGSEGV) at 0x003a003d (code=1)
10-21 10:34:18.061: E/PhonePolicy(10577): Could not preload class for phone policy: com.android.internal.policy.impl.PhoneWindow$ContextMenuCallback
这是我的服务代码：
package com.voltytrack;
public class SubscribeService extends Service implements MqttCallback {
public static final String BROKER_URL = "tcp://27.6.120.57:1883";
String clientId = null;
public static MqttClient mqttClient = null;
final String ROUTEPOINTSTOPIC = "GPS/DATA/ROUTE";
final String BUSLOCTOPIC = "DEMO/CURRENTLOCATION";
final String GETLISTTOPIC = "GPS/DATA/HISTORY/LIST/"+LoginActivity.deviceid;
final String HISTORYTOPIC = "GPS/DATA/HISTORY/"+LoginActivity.deviceid;
String USERNAME = null, PASSWORD = null;
Intent connectedintent;
static Timer conntimer;
public static final String DEBUG_TAG = "MqttService"; // Debug TAG
private static final String MQTT_THREAD_NAME = "MqttService[" + DEBUG_TAG + "]"; // Handler Thread ID
private Handler mConnHandler; // Seperate Handler thread for networking
HandlerThread hthread = new HandlerThread(MQTT_THREAD_NAME);
@Override
public void onCreate() {
super.onCreate();
registerReceiver(businforeceiver, new IntentFilter("SUBSCRIBERECEIVER"));
hthread.start();
}
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
long memory = Runtime.getRuntime().maxMemory() / 1024 / 1024;
Log.i("Memory", String.valueOf(memory));
USERNAME = intent.getStringExtra("username");
PASSWORD = intent.getStringExtra("password");
try {
mConnHandler = new Handler(hthread.getLooper());
mConnHandler.post(new Runnable() {
@Override
public void run() {
try {
connectedintent = new Intent("CONNECTED");
MqttConnectOptions connoptions = new MqttConnectOptions();
connoptions.setCleanSession(false);
connoptions.setUserName(USERNAME);
connoptions.setPassword(PASSWORD.toCharArray());
connoptions.setConnectionTimeout(10);
clientId = "and" + Math.random();
mqttClient = new MqttClient(BROKER_URL, clientId, new MemoryPersistence());
mqttClient.setCallback(SubscribeService.this);
mqttClient.connect(connoptions);
if(mqttClient.isConnected()){
connectedintent.putExtra("CONN_STATUS", "Connection Successful");
}
sendBroadcast(connectedintent);
Toast.makeText(getApplicationContext(), "Contacting Server...", Toast.LENGTH_SHORT).show();
}catch(MqttSecurityException e) {
connectedintent.putExtra("CONN_STATUS", "Invalid credentials");
sendBroadcast(connectedintent);
e.printStackTrace();
}
catch(MqttException e) {
e.printStackTrace();
connectedintent.putExtra("CONN_STATUS", "Connection failed");
sendBroadcast(connectedintent);
// Toast.makeText(getApplicationContext(), "Cannot Connect to Server!", Toast.LENGTH_SHORT).show();
Log.i("not connected", e.getMessage());
}catch (IllegalArgumentException e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(), "Server Error, Try Again!", Toast.LENGTH_SHORT).show();
}
}
});
} catch (Exception e) {
Toast.makeText(getApplicationContext(), "Something went wrong!" + e.getMessage(), Toast.LENGTH_LONG).show();
e.printStackTrace();
}
return Service.START_REDELIVER_INTENT;
}
@Override
public void onDestroy() {
unregisterReceiver(businforeceiver);
try {
// mqttClient.unsubscribe(TOPIC);
if(mqttClient.isConnected()){
mqttClient.disconnect();
}
} catch (MqttException e) {
Toast.makeText(getApplicationContext(), "Something went wrong!" + e.getMessage(), Toast.LENGTH_LONG).show();
e.printStackTrace();
}
super.onDestroy();
}
public BroadcastReceiver businforeceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String PUBLISHTOPIC = intent.getExtras().getString("PUBLISHTOPIC");
String SUBSCRIBETOPIC = intent.getExtras().getString("SUBSCRIBETOPIC");
String DATA = intent.getExtras().getString("TRAVERSE");
try {
if(null!=SUBSCRIBETOPIC){
String[] topic = SUBSCRIBETOPIC.split("@");
mqttClient.subscribe(topic[0]);
mqttClient.subscribe(topic[1]);
}
if(null != PUBLISHTOPIC){
MqttMessage msg1 = new MqttMessage();
msg1.setPayload(DATA.getBytes());
msg1.setQos(0);
mqttClient.getTopic(PUBLISHTOPIC).publish(msg1);
}
} catch (MqttPersistenceException e) {
Log.e("BROADCAST SERVICE", e.getMessage());
} catch (MqttException e) {
Log.e("BROADCAST SERVICE", e.getMessage());
}
}
};
public void connectionLost(Throwable arg0) {
try {
if(null!=conntimer){
conntimer.cancel();
}
MqttConnectOptions connoptions1 = new MqttConnectOptions();
connoptions1.setCleanSession(false);
connoptions1.setUserName(USERNAME);
connoptions1.setPassword(PASSWORD.toCharArray());
mqttClient = new MqttClient(BROKER_URL, clientId, new MemoryPersistence());
mqttClient.setCallback(SubscribeService.this);
mqttClient.connect(connoptions1);
if(mqttClient.isConnected()){
mqttClient.subscribe(BUSLOCTOPIC);
mqttClient.subscribe(HISTORYTOPIC);
Log.i("conn_status", "connected");
}
else{
Log.i("conn_status", "not connected");
}
} catch (MqttSecurityException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (MqttException e) {
// TODO Auto-generated catch block
conntimer = new Timer();
conntimer.scheduleAtFixedRate(new TimerTask() {
@Override
public void run() {
// TODO Auto-generated method stub
connectionLost(null);
}
}, 0, 1000);
e.printStackTrace();
Log.i("not connected", e.getMessage());
}
}
@Override
public void deliveryComplete(MqttDeliveryToken arg0) {
// TODO Auto-generated method stub
}
@Override
public void messageArrived(MqttTopic arg0, MqttMessage arg1)
throws Exception {
if(GETLISTTOPIC.matches(arg0.toString())){
Intent busdataintent = new Intent("BUSLIST");
busdataintent.putExtra("buslist", arg1.toString());
sendBroadcast(busdataintent);
}
else if(HISTORYTOPIC.matches(arg0.toString())){
Intent buspointsintent = new Intent("BUSPOINTS");
buspointsintent.putExtra("buspoints", arg1.toString());
sendBroadcast(buspointsintent);
}
else if(ROUTEPOINTSTOPIC.matches(arg0.toString())){
Intent userbusintent = new Intent("USERBUSDATA");
userbusintent.putExtra("boardingpoints", arg1.toString());
sendBroadcast(userbusintent);
}
}
}
可能是什么原因？