'firebase Data Snapshot is not working in android Studio?
I have spent Hours on this...pls help
Here i have provided the code of the activity which uses firebase, googlesdk api. Basically i wanted to make uber for ambulances but due to many errors or no responses the code dosent seem to work despite thw logic being right. It would be great if this is solved. Thank you
CustomerMapActivity '
public class CustomerMapActivity extends FragmentActivity implements OnMapReadyCallback {
private GoogleMap mMap;
Location mLastLocation;
LocationRequest mLocationRequest;
private FusedLocationProviderClient mFusedLocationClient;
private Button mLogout,mRequest,mSettings,mHistory;
private LatLng pickupLocation;
private Boolean requestBol = false;
private Marker pickupMarker;
private SupportMapFragment mapFragment;
private String destination;
private LatLng destinationLatlng;
private RatingBar mRatingBar;
private LinearLayout mDriverInfo;
private TextView mDriverName, mDriverPhone, mDriverCar;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_customer_map);
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
mFusedLocationClient = LocationServices.getFusedLocationProviderClient(this);
mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
destinationLatlng = new LatLng(0.0, 0.0);
mDriverInfo = (LinearLayout) findViewById(R.id.driverInfo);
mDriverName = (TextView) findViewById(R.id.driverName);
mDriverPhone = (TextView) findViewById(R.id.driverPhone);
mDriverCar = (TextView) findViewById(R.id.driverCar);
mRequest = (Button) findViewById(R.id.request);
mSettings = (Button) findViewById(R.id.settings);
mRatingBar = (RatingBar) findViewById(R.id.ratingBar);
mHistory = (Button) findViewById(R.id.history);
mLogout = (Button) findViewById(R.id.logout);
mLogout.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
FirebaseAuth.getInstance().signOut();
Intent intent = new Intent(CustomerMapActivity.this, Welcome_Activity.class);
startActivity(intent);
finish();
return;
}
});
mRequest.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(requestBol){
endRide();
}else {
}
requestBol = true;
String userId=FirebaseAuth.getInstance().getCurrentUser().getUid();
DatabaseReference ref = FirebaseDatabase.getInstance().getReference("customerRequest");
GeoFire geoFire = new GeoFire(ref);
geoFire.setLocation(userId, new GeoLocation(mLastLocation.getLatitude(),mLastLocation.getLongitude()));
pickupLocation = new LatLng(mLastLocation.getLatitude(),mLastLocation.getLongitude());
pickupMarker = mMap.addMarker(new MarkerOptions().position(pickupLocation).title("Pickup Here").icon(BitmapDescriptorFactory.fromResource(R.mipmap.patient)));
mRequest.setText("Getting Your Ambulance...");
getClosestDriver();
}
});
mSettings.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent=new Intent(CustomerMapActivity.this,CustomerSettingsActivity.class);
startActivity(intent);
return;
}
});
mHistory.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent=new Intent(CustomerMapActivity.this,HistoryActivity.class);
intent.putExtra("customerOrDriver","Customers");
startActivity(intent);
return;
}
});
}
private int radius=1;
private Boolean driverFound = false;
private String driverFoundID;
GeoQuery geoQuery;
private void getClosestDriver(){
DatabaseReference driverLocation = FirebaseDatabase.getInstance().getReference().child("driversAvailable");
GeoFire geoFire = new GeoFire(driverLocation);
geoQuery = geoFire.queryAtLocation(new GeoLocation(pickupLocation.latitude, pickupLocation.longitude), radius);
geoQuery.removeAllListeners();
geoQuery.addGeoQueryEventListener(new GeoQueryEventListener() {
@Override
public void onKeyEntered(String key, GeoLocation location) {
if (!driverFound && requestBol){
DatabaseReference mCustomerDatabase = FirebaseDatabase.getInstance().getReference().child("Users").child("Drivers").child(key);
mCustomerDatabase.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
if (dataSnapshot.exists() && dataSnapshot.getChildrenCount()>0){
// Map<String, Object> driverMap = (Map<String, Object>) dataSnapshot.getValue();
if (driverFound){
return;
}
driverFound = true;
driverFoundID = dataSnapshot.getKey();
DatabaseReference driverRef = FirebaseDatabase.getInstance().getReference().child("Users").child("Drivers").child(driverFoundID).child("customerRequest");
String customerId = FirebaseAuth.getInstance().getCurrentUser().getUid();
HashMap map = new HashMap();
map.put("customerRideId", customerId);
map.put("destination", destination);
map.put("destinationLat", destinationLatlng.latitude);
map.put("destinationLng", destinationLatlng.longitude);
driverRef.updateChildren(map);
getDriverLocation();
getDriverInfo();
getHasRideEnded();
mRequest.setText("Looking for Driver's Location....");
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
}
@Override
public void onKeyExited(String key) {
}
@Override
public void onKeyMoved(String key, GeoLocation location) {
}
@Override
public void onGeoQueryReady() {
if (!driverFound)
{
radius++;
getClosestDriver();
}
}
@Override
public void onGeoQueryError(DatabaseError error) {
}
});
}
/*private void getClosestDriver(){
DatabaseReference driverLocation = FirebaseDatabase.getInstance().getReference().child("driversAvailable");
GeoFire geoFire=new GeoFire(driverLocation);
geoQuery= geoFire.queryAtLocation(new GeoLocation(pickupLocation.latitude,pickupLocation.longitude), radius);
geoQuery.removeAllListeners();
geoQuery.addGeoQueryEventListener(new GeoQueryEventListener() {
@Override
public void onKeyEntered(String key, GeoLocation location) {
if(!driverFound && requestBol) {
driverFound = true;
driverFoundID = key;
DatabaseReference driverRef = FirebaseDatabase.getInstance().getReference().child("Users").child("Drivers").child(driverFoundID).child("customerRequest");
String customerId = FirebaseAuth.getInstance().getCurrentUser().getUid();
HashMap map = new HashMap();
map.put("customerRideId",customerId);
map.put("destination",destination);
map.put("destinationLat",destinationLatlng.latitude);
map.put("destinationLng",destinationLatlng.longitude);
driverRef.updateChildren(map);
getDriverLocation();
getHasRideEnded();
mRequest.setText("Looking for Ambulance Location...");
}
}
@Override
public void onKeyExited(String key) {
}
@Override
public void onKeyMoved(String key, GeoLocation location) {
}
@Override
public void onGeoQueryReady() {
if (!driverFound)
{
radius++;
getClosestDriver();
}
}
@Override
public void onGeoQueryError(DatabaseError error) {
}
});
}*/
private Marker mDriverMarker;
private DatabaseReference driverLocationRef;
private ValueEventListener driverLocationRefListener;
private void getDriverLocation(){
driverLocationRef = FirebaseDatabase.getInstance().getReference().child("driversWorking").child(driverFoundID).child("l");
driverLocationRefListener=driverLocationRef.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
if(dataSnapshot.exists() && requestBol){
List<Object> map=(List<Object>) dataSnapshot.getValue();
double LocationLat = 0;
double LocationLng = 0;
// mRequest.setText("Ambulance Found");
if(map.get(0)!= null){
LocationLat = Double.parseDouble(map.get(0).toString());
}
if(map.get(1)!= null){
LocationLng = Double.parseDouble(map.get(1).toString());
}
LatLng driverLatLng = new LatLng(LocationLat, LocationLng);
if(mDriverMarker!=null){
mDriverMarker.remove();
}
Location loc1 = new Location("");
loc1.setLatitude(pickupLocation.latitude);
loc1.setLongitude(pickupLocation.longitude);
Location loc2 = new Location("");
loc2.setLatitude(driverLatLng.latitude);
loc2.setLongitude(driverLatLng.longitude);
float distance = loc1.distanceTo(loc2);
if(distance<100){
mRequest.setText("Ambulance Arrived");
}else{
int dis = (int)distance/1000;
mRequest.setText("Ambulance Found: "+ String.valueOf(dis)+ " Kms away...");
}
mDriverMarker = mMap.addMarker(new MarkerOptions().position(driverLatLng).title("Your Ambulance").icon(BitmapDescriptorFactory.fromResource(R.mipmap.ambulance)));
}
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
}
private void getDriverInfo(){
mDriverInfo.setVisibility(View.VISIBLE);
DatabaseReference mCustomerDatabase = FirebaseDatabase.getInstance().getReference().child("Users").child("Drivers").child(driverFoundID);
mCustomerDatabase.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
if(dataSnapshot.exists() && dataSnapshot.getChildrenCount()>0){
if(dataSnapshot.child("Name")!=null){
mDriverName.setText(Objects.requireNonNull(dataSnapshot.child("Name").getValue()).toString());
}
if(dataSnapshot.child("Phone")!=null){
mDriverPhone.setText(Objects.requireNonNull(dataSnapshot.child("Phone").getValue()).toString());
}
if(dataSnapshot.child("Car")!=null){
mDriverCar.setText(Objects.requireNonNull(dataSnapshot.child("Car").getValue()).toString());
}
int ratingSum = 0;
float ratingsTotal = 0;
float ratingsAvg = 0;
for (DataSnapshot child : dataSnapshot.child("rating").getChildren()){
ratingSum = ratingSum + Integer.parseInt(Objects.requireNonNull(child.getValue()).toString());
ratingsTotal++;
}
if(ratingsTotal!= 0){
ratingsAvg = ratingSum/ratingsTotal;
mRatingBar.setRating(ratingsAvg);
}
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
mLocationRequest = new LocationRequest();
mLocationRequest.setInterval(1000);
mLocationRequest.setFastestInterval(1000);
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
if(android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M){
if(ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED){
}else{
checkLocationPermission();
}
}
mFusedLocationClient.requestLocationUpdates(mLocationRequest, mLocationCallback, Looper.myLooper());
mMap.setMyLocationEnabled(true);
}
LocationCallback mLocationCallback = new LocationCallback() {
@Override
public void onLocationResult(LocationResult locationResult) {
for (Location location : locationResult.getLocations()) {
mLastLocation = location;
LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude());
mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
mMap.animateCamera(CameraUpdateFactory.zoomTo(11));
if(!getDriversAroundStarted)
getDriversAround();
}
}
};
boolean getDriversAroundStarted = false;
List<Marker> markers = new ArrayList<Marker>();
private void getDriversAround(){
getDriversAroundStarted = true;
DatabaseReference driverLocation = FirebaseDatabase.getInstance().getReference().child("driversAvailable");
GeoFire geoFire = new GeoFire(driverLocation);
GeoQuery geoQuery = geoFire.queryAtLocation(new GeoLocation(mLastLocation.getLongitude(), mLastLocation.getLatitude()), 999999999);
geoQuery.addGeoQueryEventListener(new GeoQueryEventListener() {
@Override
public void onKeyEntered(String key, GeoLocation location) {
LatLng driverLocation = new LatLng(location.latitude, location.longitude);
Marker mDriverMarker = mMap.addMarker(new MarkerOptions().position(driverLocation).title(key).icon(BitmapDescriptorFactory.fromResource(R.mipmap.ambulance)));
mDriverMarker.setTag(key);
markers.add(mDriverMarker);
for(Marker markerIt : markers){
if(markerIt.getTag().equals(key))
return;
}
}
@Override
public void onKeyExited(String key) {
for(Marker markerIt : markers){
if(markerIt.getTag().equals(key)){
markerIt.remove();
}
}
}
@Override
public void onKeyMoved(String key, GeoLocation location) {
for(Marker markerIt : markers){
if(markerIt.getTag().equals(key)){
markerIt.setPosition(new LatLng(location.latitude, location.longitude));
}
}
}
@Override
public void onGeoQueryReady() {
}
@Override
public void onGeoQueryError(DatabaseError error) {
}
});
}
private void checkLocationPermission() {
if(ContextCompat.checkSelfPermission(this,Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED){
if(ActivityCompat.shouldShowRequestPermissionRationale(this,Manifest.permission.ACCESS_FINE_LOCATION)){
new android.app.AlertDialog.Builder(this)
.setTitle("Please give permission...")
.setMessage("Please give permission...")
.setPositiveButton("OK", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
ActivityCompat.requestPermissions(CustomerMapActivity.this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION},1);
}
})
.create()
.show();
}
else{
ActivityCompat.requestPermissions(CustomerMapActivity.this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION},1);
}
}
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
switch (requestCode) {
case 1: {
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
if(ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)==PackageManager.PERMISSION_GRANTED){
mFusedLocationClient.requestLocationUpdates(mLocationRequest,mLocationCallback, Looper.myLooper());
mMap.setMyLocationEnabled(true);
}
} else {
Toast.makeText(getApplicationContext(), "Please provide the permission...", Toast.LENGTH_LONG).show();
}
break;
}
}}
private DatabaseReference driveHasEndedRef;
private ValueEventListener driveHasEndedRefListener;
private void getHasRideEnded(){
// String driverId = FirebaseAuth.getInstance().getCurrentUser().getUid();
driveHasEndedRef = FirebaseDatabase.getInstance().getReference().child("Users").child("Drivers").child(driverFoundID).child("customerRequest").child("customerRideId");
driveHasEndedRefListener = driveHasEndedRef.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
if(dataSnapshot.exists()){
}else{
endRide();
}
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
}
private void endRide()
{
requestBol = false;
if(geoQuery != null){
geoQuery.removeAllListeners();
}
if(driverLocationRefListener != null&& driveHasEndedRefListener != null){
driverLocationRef.removeEventListener(driverLocationRefListener);
driveHasEndedRef.removeEventListener(driveHasEndedRefListener);
}
if(driverFoundID!=null){
DatabaseReference driverRef = FirebaseDatabase.getInstance().getReference().child("Users").child("Drivers").child(driverFoundID).child("customerRequest");
driverRef.removeValue();
driverFoundID = null;
}
driverFound = false;
radius = 1;
String userId=FirebaseAuth.getInstance().getCurrentUser().getUid();
DatabaseReference ref = FirebaseDatabase.getInstance().getReference("customerRequest");
GeoFire geoFire = new GeoFire(ref);
geoFire.removeLocation(userId);
if( pickupMarker!=null){
pickupMarker.remove();
}
if (mDriverMarker != null){
mDriverMarker.remove();
}
mRequest.setText("Request An Ambulance");
mDriverInfo.setVisibility(View.GONE);
mDriverName.setText("");
mDriverPhone.setText("");
}
}`
Sources
This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.
Source: Stack Overflow
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