Hello everyone I am new to Android development and. I am currently working on an Android app that fetches changing location coordinates from a SQL database, and plots on a Map view at regular intervals. But I think this code can be made more efficient, as I am unable to fetch locations after a certain time and can't figure out how to solve it.
I am attaching the code of which contains 2 classes. The first is MapsActivity.javaMapsActivity.java that displays the locations on maps, and the second is BGTaskBGTask.java.java that's It is inside MapsActivity.javaMapsActivity.java and extended from AsyncTask for fetching data from the database and. There is a thread also for regular fetching of data from database and plotting on maps.
Here is MapsActivity.javamy MapsActivity.java:
package com.maps.saury.mybus_demo;
import android.Manifest;
import android.content.pm.PackageManager;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.FragmentActivity;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {
private GoogleMap mMap;
String DATA_STRING;
String lat,lng;
Double d_lat,d_lng;
public static Handler handler;
public static Thread thread1;
public static Boolean status=false;
public static Button button;
public static LatLng latlng,latlng_currentloc;
public static byte count=0;
public static Marker now;
@Override
protected void onCreate(Bundle savedInstanceState) {
button=(Button)findViewById(R.id.button2);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
startAct();
}
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return;
}
mMap.setMyLocationEnabled(true);
}
public void showLoc(View v){
mMap.moveCamera(CameraUpdateFactory.newLatLng(latlng));
mMap.animateCamera(CameraUpdateFactory.zoomTo(16));
}
public void exitMap(View v){
status=false;
finish();
}
public void startAct(){
count=0;
status=true;
thread1=new Thread(new Loopclass());
thread1.start();
handler=new Handler(){
@Override
public void handleMessage(Message msg) {
Toast.makeText(getApplicationContext(),"count= "+count,Toast.LENGTH_SHORT).show();
new BGTask().execute();
}
};
}
class BGTask extends AsyncTask<Void, Void, String> {
@Override
protected void onPreExecute() {}
@Override
protected String doInBackground(Void... params) {
String locurl = "http://krazydomain.in/test.php";
try {
URL url = new URL(locurl);
HttpURLConnection http = (HttpURLConnection) url.openConnection();
InputStream is = http.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(is));
StringBuilder sb = new StringBuilder();
while ((DATA_STRING = br.readLine()) != null) {
sb.append(DATA_STRING + "\n");
}
br.close();
is.close();
http.disconnect();
return sb.toString().trim();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(String s) {
int i=0;
while(s.charAt(i)!=' '){i++;}
lat=s.substring(0,i-1);
lng=s.substring(i+1);
d_lat= Double.parseDouble(lat);
d_lng= Double.parseDouble(lng);
latlng = new LatLng(d_lat,d_lng);
if(now!=null)
now.remove();
if(count==0)
{
mMap.animateCamera(CameraUpdateFactory.newLatLng(latlng));
count++;
}
else
{
now=mMap.addMarker(new MarkerOptions().position(latlng).icon(BitmapDescriptorFactory.fromResource(R.drawable.bus)).title("My loc"));
}
}
}
class Loopclass implements Runnable{
@Override
public void run() {
while(true){
if(status==false)break;
Message msg=Message.obtain();
msg.arg1=8;
handler.sendMessage(msg);
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}}
}
}
}
