[英]How to store data mqtt when offline and send them when online
我有一個問題，當我的連接中斷時，mqtt發布在重新連接時不發送，該如何解決？ 我按照這個答案，但不起作用
我所做的 ：
但是當我重新聯機並不發布存儲的持久性數據時，重新連接的結果仍會發布數據。
這是我的源代碼：
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) {
}
}
對不起，我的英語不好
如評論中所述。
這是您必須自己編寫的代碼，不支持存儲由於客戶端在框架中斷開連接而尚未發送的消息。 MQTT持久性僅用於確保在QOS握手完成之前與代理的連接斷開時，具有QOS 1/2的消息不會在傳輸中丟失。
如果您嘗試在斷開客戶端連接的情況下發布消息client.publish(topic, message)調用將引發異常，則需要捕獲此異常，然后安排重新建立連接時存儲消息的內容。 連接恢復並運行后，您需要遍歷存儲的詳細信息並再次嘗試發送。
因此，這里的示例作為hardillb的答案，我將自己制作為將數據存儲到本地數據庫並在重新建立的連接中發送所有數據的工具。
這是我的源代碼
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
mList = getLocationAll();//call all data stored on sqlite
Debug.e("MQTT","Connected. Size list = "+mList.size());
if(mList.size() > 0){//if data found then send in looping
for (int i = 0; i < mList.size() ; i++) {
final String Latitude = mList.get(i).latitude;
final String Longitude = mList.get(i).longitude;
final String timestamps = mList.get(i).CurrentTimes;
String payload = deviceID + "|" + timestamps + "|" + Name + "|" + Latitude + "|" + Longitude;
byte[] encodedPayload = new byte[0];
try {
encodedPayload = payload.getBytes("UTF-8");
MqttMessage message = new MqttMessage(encodedPayload);
// set quality of service
client.publish(topic, message);
} catch (UnsupportedEncodingException | MqttException e) {
e.printStackTrace();
}
}
DeleteAllLocation();
}
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
long CurrentTime = System.currentTimeMillis();
addLocation(deviceID, CurrentTime+"", Name, latitude+"" , longitude+""); //add data to sqlite when offline
Debug.e("MQTT","Failure");
}
});
} catch (MqttException e) {
e.printStackTrace();
}
mHandler.postDelayed(this, 20000);
}
};
這是我的sqlite來存儲和刪除數據
public void addLocation( String device_id, String timestamp, String user_id, String latitude, String longitude) {
if (sqLite == null) {
Debug.i(Cons.TAG, "null database");
return;
}
ContentValues values = new ContentValues();
values.put("device_id", device_id);
values.put("timestamp", timestamp);
values.put("user_id", user_id);
values.put("latitude", latitude);
values.put("longitude", longitude);
Debug.i(Cons.TAG, "Insert location : title = " + device_id);
sqLite.insert("tbl_location", null, values);
}
public ArrayList<LocationModel> getLocationAll() {
ArrayList<LocationModel> result = new ArrayList<LocationModel>();
if (sqLite == null || result == null) {
return result;
}
String sql = "SELECT * FROM tbl_location ORDER BY timestamp ASC";
Cursor c = sqLite.rawQuery(sql, null);
int device_id = c.getColumnIndex("device_id");
int timestamp = c.getColumnIndex("timestamp");
int userid = c.getColumnIndex("user_id");
int latitude = c.getColumnIndex("latitude");
int longitude = c.getColumnIndex("longitude");
if (c != null) {
if (c.moveToFirst()) {
while (c.isAfterLast() == false) {
LocationModel mApps = new LocationModel();
mApps.DeviceId = c.getInt(device_id);
mApps.CurrentTimes = c.getString(timestamp);
mApps.UserId = c.getString(userid);
mApps.latitude = c.getString(latitude);
mApps.longitude = c.getString(longitude);
result.add(mApps);
c.moveToNext();
}
c.close();
}
}
return result;
}
public void DeleteAllLocation() {
if (sqLite == null)
return;
sqLite.delete("tbl_location", null, null);
}
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