我有一个问题，当我的连接被侵入时，mqtt发布没有重新连接发送，如何解决？我跟着this answer但没有工作
我做了什么：
但是当我重新连接时的结果仍然是我在线时发布的数据＆amp;不发布存储的持久性数据。
这是我的源代码：
package id.trustudio.android.mdm.service;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.net.TrafficStats;
import android.os.Handler;
import android.os.IBinder;
import android.support.annotation.Nullable;
import android.util.Log;
import org.eclipse.paho.android.service.MqttAndroidClient;
import org.eclipse.paho.client.mqttv3.IMqttActionListener;
import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken;
import org.eclipse.paho.client.mqttv3.IMqttToken;
import org.eclipse.paho.client.mqttv3.MqttCallback;
import org.eclipse.paho.client.mqttv3.MqttClient;
import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
import org.eclipse.paho.client.mqttv3.MqttException;
import org.eclipse.paho.client.mqttv3.MqttMessage;
import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;
import java.io.UnsupportedEncodingException;
import id.trustudio.android.mdm.http.DetectConnection;
import id.trustudio.android.mdm.util.Cons;
import id.trustudio.android.mdm.util.Debug;
import id.trustudio.android.mdm.util.GPSTracker;
import id.trustudio.android.mdm.util.GPSTracker2;
public class MqttService extends Service implements MqttCallback {
public static boolean isStarted = false;
private double latitude = 0;
private double longitude = 0;
private GPSTracker mGPSTracker;
private GPSTracker2 mGPSTracker2;
boolean isInternetPresent = false;
private SharedPreferences mPrivatePref;
private SharedPreferences.Editor editor;
private DetectConnection mDetectConnection;
String deviceID,Name;
int totalbyte;
String packages;
MemoryPersistence persistence;
String clientId;
MqttAndroidClient client;
@Nullable
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public void onCreate() {
super.onCreate();
mPrivatePref = this.getSharedPreferences(Cons.PRIVATE_PREF, Context.MODE_PRIVATE);
editor = mPrivatePref.edit();
deviceID = mPrivatePref.getString(Cons.APP_PACKAGE + "deviceid", "");
Name = mPrivatePref.getString(Cons.APP_PACKAGE + "user", "");
clientId = MqttClient.generateClientId();
persistence = new MemoryPersistence();
client =
new MqttAndroidClient(getApplicationContext(), "tcp://broker.administrasi.id:1883",
clientId, persistence);
client.setCallback(this);
try{
MqttConnectOptions connOpts = new MqttConnectOptions();
connOpts.setCleanSession(false);
client.connect(connOpts,null, new IMqttActionListener() {
@Override
public void onSuccess(IMqttToken asyncActionToken) {
}
@Override
public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
}
});
}catch (Exception e){
e.printStackTrace();
}
mHandler.postDelayed(mUpdateTask, 1000);
}
public int onStartCommand(Intent intent, int flags, int startId) {
int res = super.onStartCommand(intent, flags, startId);
//check if your service is already started
if (isStarted){ //yes - do nothing
return Service.START_STICKY;
} else { //no
isStarted = true;
}
return Service.START_STICKY;
}
private Handler mHandler = new Handler();
private Runnable mUpdateTask = new Runnable() {
public void run() {
getLatLng();
if (latitude == 0.0 || longitude == 0.0) getLatLngWifi();
Debug.e("MQTT","Connect");
String topic = "gps/kodeupi/kodeap/kodeup/" + deviceID;
Debug.e("MQTT CLIENT", clientId);
int qos = 1;
try {
IMqttToken subToken = client.subscribe(topic, qos);
subToken.setActionCallback(new IMqttActionListener() {
@Override
public void onSuccess(IMqttToken asyncActionToken) {
// The message was published
String topic = "gps/kodeupi/kodeap/kodeup/" + deviceID;
long CurrentTime = System.currentTimeMillis();
String payload = deviceID + "|" + latitude + "|" + longitude + "|" + CurrentTime;
byte[] encodedPayload = new byte[0];
try {
encodedPayload = payload.getBytes("UTF-8");
MqttMessage message = new MqttMessage(encodedPayload);
client.publish(topic, message);
message.setRetained(true);
// set quality of service
message.setQos(1);
Log.d("TAG", "onSuccess");
} catch (UnsupportedEncodingException | MqttException e) {
e.printStackTrace();
}
}
@Override
public void onFailure(IMqttToken asyncActionToken,
Throwable exception) {
// The subscription could not be performed, maybe the user was not
// authorized to subscribe on the specified topic e.g. using wildcards
}
});
} catch (MqttException e) {
e.printStackTrace();
}
mHandler.postDelayed(this, 20000);
}
};
private void getLatLng() {
mGPSTracker2 = new GPSTracker2(this);
isInternetPresent = mDetectConnection.isConnectingToInternet();
if (isInternetPresent == true) {
if (mGPSTracker2.canGetLocation()) {
latitude = mGPSTracker2.getLatitude();
longitude = mGPSTracker2.getLongitude();
if(latitude != 0.0 && longitude != 0.0) {
editor.putString(Cons.APP_LATITUDE, latitude+"");
editor.putString(Cons.APP_LONGITUDE, longitude+"");
editor.commit();
}
} else {
// getLatLngWifi();
Debug.i(Cons.TAG, "on gps failed, please check");
}
} else {
Debug.i(Cons.TAG, "no connection");
if(mGPSTracker2 != null)
mGPSTracker2.stopUsingGPS();
}
}
private void getLatLngWifi() {
mGPSTracker = new GPSTracker(this);
isInternetPresent = mDetectConnection.isConnectingToInternet();
if (isInternetPresent == true) {
if (mGPSTracker.canGetLocation()) {
latitude = mGPSTracker.getLatitude();
longitude = mGPSTracker.getLongitude();
if(latitude != 0.0 && longitude != 0.0) {
editor.putString(Cons.APP_LATITUDE, latitude+"");
editor.putString(Cons.APP_LONGITUDE, longitude+"");
editor.commit();
}
} else {
Debug.i(Cons.TAG, "wifi " + "on gps failed, please check");
}
} else {
Debug.i(Cons.TAG, "wifi " + "no connection");
if(mGPSTracker != null)
mGPSTracker.stopUsingGPS();
}
}
@Override
public void connectionLost(Throwable cause) {
}
@Override
public void messageArrived(String topic, MqttMessage message) throws Exception {
}
@Override
public void deliveryComplete(IMqttDeliveryToken token) {
}
}
抱歉我的英文不好
答案 0 :(得分：1)
正如评论中所述。
这是您必须自己编写的代码，不支持存储由于客户端在框架中断开连接而未发送的消息。 MQTT持久性仅用于确保在QOS握手完成之前与代理的连接断开时，QOS 1/2的消息不会丢失。
如果您尝试在断开连接时发布消息，client.publish(topic, message)调用将引发异常，则需要捕获此异常，然后安排在重新建立连接时存储消息内容。一旦连接恢复并运行，您需要迭代存储的详细信息并再次尝试发送。