我正在创建一个类似Uber的应用程序，但它突然崩溃，并出现预期的错误BEGIN_ARRAY，但在第1行第1列路径$ STRING

Question

I am trying to create an app like Uber and I am parsing geolocation and UID of the customer for the Driver. I used Map array to get customerUID and List array for getting the latitude and longitude respectively. But as I tried to compile and run it showed an error:

 Expected BEGIN_ARRAY but was STRING at line 1 column 1 path $.

Previously it was working very well but now I can't even undo the changes I have made because I closed the project and restarted it thinking maybe it would solve the problem but it led me to not being able to undo any step.

Below is given my project code that might help you to help me in solving the error.

package com.matt.dumate;

import com.directions.route.AbstractRouting;
import com.directions.route.Route;
import com.directions.route.RouteException;
import com.directions.route.Routing;
import com.directions.route.RoutingListener;
import com.firebase.geofire.GeoFire;
import com.firebase.geofire.GeoLocation;
import com.firebase.geofire.GeoQuery;
import com.firebase.geofire.GeoQueryEventListener;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;

import android.Manifest;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationManager;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import android.support.v4.content.ContextCompat;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.LocationRequest;
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.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

public class Welcome extends FragmentActivity implements OnMapReadyCallback,
        GoogleApiClient.ConnectionCallbacks,
        GoogleApiClient.OnConnectionFailedListener,
        LocationListener, RoutingListener{

SupportMapFragment mapFragment;

private Button btnBooking;
private Location lastLocation;
private GoogleApiClient.OnConnectionFailedListener onConnectionFailedListener;
private LocationRequest locationRequest;
private LocationListener locationListener;
private LocationManager locationManager;
private Marker marker, driverMarker;
private GoogleMap mMap;
private GoogleApiClient googleApiClient;
private final int RequestCode = 10;
private final int ResourceCode = 11;
private DatabaseReference userLastLocation, customersUnderServiceRef, userRequest, driversOnDuty,workingDrivers, driverRef1, driverWorkingRef ;
GeoFire location, request, onDuty, customersUnderService;
private Boolean clicked = false;
private String driverID = "";
private ValueEventListener driverListener;
private GeoQuery geoQuery;
private String myId = "";
private Double driverLat, driverLng;


@Override
protected void onCreate(Bundle savedInstanceState)
{

    checkLocationPermission();
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_welcome);
    mapFragment = (SupportMapFragment)
            getSupportFragmentManager()
            .findFragmentById(R.id.map);
    mapFragment.getMapAsync(this);
    locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);

    userLastLocation = FirebaseDatabase.getInstance().getReference("User LastLocation");
    location = new GeoFire(userLastLocation);
    setupLocation();

    userRequest = FirebaseDatabase.getInstance().getReference("User Request");
    request = new GeoFire(userRequest);

    driversOnDuty = FirebaseDatabase.getInstance().getReference("DriversOnDuty");
    onDuty = new GeoFire(driversOnDuty);



    driverRef1 = FirebaseDatabase.getInstance().getReference().child("Driver").child(driverID);

    driverWorkingRef = FirebaseDatabase.getInstance().getReference().child("DriversWorking");

    customersUnderServiceRef = FirebaseDatabase.getInstance().getReference().child("CustomersUnderService");
    customersUnderService = new GeoFire(customersUnderServiceRef);
    workingDrivers = FirebaseDatabase.getInstance().getReference().child("DriversWorking").child(driverID);
}

@Override
public void onMapReady(GoogleMap googleMap)
{
    myId = FirebaseAuth.getInstance().getCurrentUser().getUid();
    setupUiViews();
    mMap = googleMap;
    displayLocation();
}

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults)
{
    switch (requestCode) {
        case RequestCode:
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                if (checkPlayServices()){
                    buildGoogleApiClient();
                    createLocationRequest();
                        displayLocation();
                }
            }
            break;
    }
}

@Override
public void onConnected(@Nullable Bundle bundle)
{
    if (ContextCompat.checkSelfPermission(this,
            Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED)
    {
        locationRequest = LocationRequest
                .create()
                .setInterval(1000)
                .setFastestInterval(500)
                .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);

        startLocationUpdates();
        displayLocation();

    }else {
        checkLocationPermission();
    }

}

@Override
public void onConnectionSuspended(int i)

{
    googleApiClient.connect();
}

@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult)
{
}

@Override
public void onLocationChanged(Location location)
{
    lastLocation = location;
    displayLocation2();

}

public void checkLocationPermission()
{
    if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED)
    {
        if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.ACCESS_FINE_LOCATION))
        {
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, RequestCode);
        } else {
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, RequestCode);
        }
    } else {
        Toast.makeText(this, "Location Permissions Granted", Toast.LENGTH_SHORT).show();
    }
}

protected synchronized void buildGoogleApiClient()
{
    googleApiClient = new GoogleApiClient.Builder(this)
            .addConnectionCallbacks(this)
            .addOnConnectionFailedListener(this)
            .addApi(LocationServices.API)
            .build();
    googleApiClient.connect();
}

private void setupUiViews()

{
    btnBooking = findViewById(R.id.bookingButton);
    btnBooking.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
                if (clicked == false) {
                    startLocationUpdates();
                    displayLocation2();
                    getNearestDriver();
                    Toast.makeText(Welcome.this, "Getting Cab", Toast.LENGTH_SHORT).show();
                    btnBooking.setText("Getting Your Cab..");
                    clicked = true;

                } else
                    {
                        disconnection();


                        try{
                            driverRef1.child("customerRideId").removeValue();
                        }catch (Exception a){
                            return;
                        }
                        stopLocationUpdates();
                        String userId = FirebaseAuth.getInstance().getCurrentUser().getUid();
                        DatabaseReference databaseReference1 = FirebaseDatabase.getInstance().getReference("Customer Request");
                        GeoFire geoFire1 = new GeoFire(databaseReference1);
                        geoFire1.removeLocation(userId);
                        Toast.makeText(Welcome.this, "Canceling Cab", Toast.LENGTH_SHORT).show();
                        btnBooking.setText("Get Cab");
                        if(driverMarker!=null){
                            driverMarker.remove();
                        }
                        clicked = false;
                }
        }
    });
}

private void displayLocation()

{
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED &&
            ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED)
    {
        return;
    }
    lastLocation = LocationServices.FusedLocationApi.getLastLocation(googleApiClient);
    if (lastLocation != null ){
            final Double lat = lastLocation.getLatitude();
            final Double lng = lastLocation.getLongitude();

            location.setLocation(FirebaseAuth.getInstance().getCurrentUser().getUid(), new GeoLocation(lat, lng), new GeoFire.CompletionListener()
            {
                @Override
                public void onComplete(String key, DatabaseError error) {
                    if (marker != null) {
                        marker.remove();
                        marker = mMap.addMarker(new MarkerOptions().position(new LatLng(lat, lng)).icon(BitmapDescriptorFactory.fromResource(R.drawable.locationmarker)).title("You"));

                        mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(lat, lng), 15.0f));
                    }else{
                        marker = mMap.addMarker(new MarkerOptions().position(new LatLng(lat, lng)).icon(BitmapDescriptorFactory.fromResource(R.drawable.locationmarker)).title("You"));

                        mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(lat, lng), 15.0f));
                    }
                }
            });

    }else{
        Log.d("Error", "Cannot Get Your Location");
    }
}

private void displayLocation2()
{
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED &&
            ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED)
    {
        return;
    }
    lastLocation = LocationServices.FusedLocationApi.getLastLocation(googleApiClient);
    if (lastLocation != null ){
        if(clicked == true){
            final Double lat = lastLocation.getLatitude();
            final Double lng = lastLocation.getLongitude();


            request.setLocation(FirebaseAuth.getInstance().getCurrentUser().getUid(), new GeoLocation(lat, lng), new GeoFire.CompletionListener()
            {
                @Override
                public void onComplete(String key, DatabaseError error) {
                    if (marker != null) {
                        marker.remove();
                        marker = mMap.addMarker(new MarkerOptions().position(new LatLng(lat, lng)).icon(BitmapDescriptorFactory.fromResource(R.drawable.locationmarker)).title("You"));

                    }else{
                        marker = mMap.addMarker(new MarkerOptions().position(new LatLng(lat, lng)).icon(BitmapDescriptorFactory.fromResource(R.drawable.locationmarker)).title("You"));
                        }
                }
            });
        }
    }else{
        Log.d("Error", "Cannot Get Your Location");
    }
}

private void setupLocation()
{
    if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED)
    {
        if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.ACCESS_FINE_LOCATION))
        {
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, RequestCode);
        } else {
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, RequestCode);
        }
    }else{
        if (checkPlayServices())
        {
            buildGoogleApiClient();
            createLocationRequest();

        }
    }
}

private void createLocationRequest()
{
    locationRequest = LocationRequest.create()
            .setInterval(1500)
            .setFastestInterval(500)
            .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY)
            .setSmallestDisplacement(0);
}

private boolean checkPlayServices()
{
    int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
    if (resultCode != ConnectionResult.SUCCESS)
    {
        if (GooglePlayServicesUtil.isUserRecoverableError(resultCode))
            GooglePlayServicesUtil.getErrorDialog(resultCode, this, ResourceCode).show();
        else {
            Toast.makeText(this, "This Device Is Not Supported", Toast.LENGTH_SHORT).show();
            finish();
        }return false;
    }
    return true;
}

private void stopLocationUpdates()
{
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED)
    {
        return;
    }
    LocationServices.FusedLocationApi.removeLocationUpdates(googleApiClient, this);
}

private void startLocationUpdates()
{
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED)
    {
        return;
    }
    LocationServices.FusedLocationApi.requestLocationUpdates(googleApiClient, locationRequest, this);
}

private int radius = 1;
private Boolean driverFound = false;

private void getNearestDriver()
{

    geoQuery = location.queryAtLocation(new GeoLocation(lastLocation.getLatitude(), lastLocation.getLongitude()), radius);
    geoQuery.removeAllListeners();

    geoQuery.addGeoQueryEventListener(new GeoQueryEventListener() {
        @Override
        public void onKeyEntered(String key, GeoLocation location) {

             String driverId = key;
            if(!driverFound){
                driverFound = true;
                driverID = key;
                DatabaseReference driverRef = FirebaseDatabase.getInstance().getReference().child("Driver").child(driverId);

                String customerId = FirebaseAuth.getInstance().getCurrentUser().getUid();

                HashMap map = new HashMap();
                map.put("customerRideId", customerId);
                driverRef.updateChildren(map);

                driverID = key;
                btnBooking.setText("Getting Driver Location");

                customersUnderService.setLocation(FirebaseAuth.getInstance().getCurrentUser().getUid(), new GeoLocation(lastLocation.getLatitude(), lastLocation.getLongitude()));

                getDriverLocation();


            }

        }

        @Override
        public void onKeyExited(String key) {
            disconnection();

        }

        @Override
        public void onKeyMoved(String key, GeoLocation location) { }

        @Override
        public void onGeoQueryReady() {
            if(!driverFound){
                radius++;
                getNearestDriver();
            }
        }

        @Override
        public void onGeoQueryError(DatabaseError error) {
            disconnection();
            Toast.makeText(Welcome.this, "GeoQuery Error", Toast.LENGTH_SHORT);
        }
    });
}

private void getDriverLocation()
{
    driverWorkingRef = driverWorkingRef.child(driverID).child("l");
    driverListener = driverWorkingRef.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            if (dataSnapshot.exists()){
                List<Object> map = (List<Object>) dataSnapshot.getValue();
                double locationLat = 0;
                double locationLng = 0;

                btnBooking.setText("Driver Found");

                if (map.get(0) != null)
                {
                    locationLat = Double.parseDouble(map.get(0).toString());
                    driverLat = locationLat;
                }

                if (map.get(1) != null)
                {
                    locationLng = Double.parseDouble(map.get(1).toString());
                    driverLng = locationLng;
                }

                LatLng driverLatLng = new LatLng(locationLat, locationLng);

                if (driverMarker != null) {
                    driverMarker.remove();
                }
                    driverMarker = mMap.addMarker(new MarkerOptions().position(driverLatLng).icon(BitmapDescriptorFactory.fromResource(R.drawable.carmarker)).title("You"));
                    mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(driverLatLng, 15.0f));

                    Location myLoc = new Location("");
                    Location driverLoc = new Location("");

                    myLoc.setLatitude(lastLocation.getLatitude());
                    myLoc.setLongitude(lastLocation.getLongitude());

                    driverLoc.setLatitude(locationLat);
                    driverLoc.setLongitude(locationLng);

                    float distance = myLoc.distanceTo(driverLoc);
                    ;
                    if (distance<100){
                        btnBooking.setText("Driver Reached");

                    }else{
                        btnBooking.setText("Driver at " + distance);

                    }
            }getDriverLocation();

        }

        @Override
        public void onCancelled(DatabaseError databaseError) {
            disconnection();
        }
    });
}

@Override
public void onRoutingFailure(RouteException e)
{}
@Override
public void onRoutingStart()
{}
@Override
public void onRoutingSuccess(ArrayList<Route> arrayList, int i)
{}

@Override
public void onRoutingCancelled()
{}
private void disconnection(){

    try {
        customersUnderService.removeLocation(myId);
    }catch(Exception b){ }

    try {
        driverWorkingRef.removeEventListener(driverListener);
    }catch(Exception c){

    }
    try {
        onDuty.setLocation(driverID,new GeoLocation(driverLat, driverLng));
    }catch(Exception d){ }

    try {
        geoQuery.removeAllListeners();
    }catch(Exception f){ }

    try {
        request.removeLocation(myId);
    }catch(Exception g){ }

    try
    {
    driverRef1.child("customerRideId").removeValue();

    } catch(Exception h) { }


    try
    {
        onDuty.setLocation(driverID,new GeoLocation(driverLat, driverLng));
    } catch(Exception h) { }

    driverFound = false;
    if (driverMarker != null){
        driverMarker.remove();
    }
    btnBooking.setText("Get Cab");
    clicked = false;

}
@Override
protected void onStop()
{
    super.onStop();
    //disconnection();
}
private void getDirection(LatLng latLng)
{

    Routing routing = new Routing.Builder()
            .travelMode(AbstractRouting.TravelMode.DRIVING)
            .withListener(this)
            .alternativeRoutes(true)
            .waypoints(new LatLng(lastLocation.getLatitude(), lastLocation.getLongitude()), latLng)
            .build();
    routing.execute();

}

@Override
protected void onPause() {
    super.onPause();
}
}

The Error Codes are as

Caused by: com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: Expected BEGIN_ARRAY but was STRING at line 1 column 1 path $
at com.google.gson.Gson.fromJson(Gson.java:899)
at com.google.gson.Gson.fromJson(Gson.java:852)
at com.android.build.gradle.internal.pipeline.SubStream.loadSubStreams(SubStream.java:129)
at com.android.build.gradle.internal.pipeline.IntermediateFolderUtils.<init>(IntermediateFolderUtils.java:66)
at com.android.build.gradle.internal.pipeline.IntermediateStream.init(IntermediateStream.java:191)
at com.android.build.gradle.internal.pipeline.IntermediateStream.asOutput(IntermediateStream.java:135)
at com.android.build.gradle.internal.pipeline.TransformTask$2.call(TransformTask.java:228)
at com.android.build.gradle.internal.pipeline.TransformTask$2.call(TransformTask.java:217)
at com.android.builder.profile.ThreadRecorder.record(ThreadRecorder.java:102)
at com.android.build.gradle.internal.pipeline.TransformTask.transform(TransformTask.java:212)
at sun.reflect.GeneratedMethodAccessor568.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:73)
at org.gradle.api.internal.project.taskfactory.IncrementalTaskAction.doExecute(IncrementalTaskAction.java:46)
at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:39)
at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:26)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$1.run(ExecuteActionsTaskExecuter.java:121)
at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:336)
at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:328)
at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:199)
at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:110)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:110)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:92)
... 107 more
Caused by: java.lang.IllegalStateException: Expected BEGIN_ARRAY but was STRING at line 1 column 1 path $
at com.google.gson.stream.JsonReader.beginArray(JsonReader.java:350)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:80)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:61)
at com.google.gson.Gson.fromJson(Gson.java:887)
... 130 more

This is my database structure Database Structure Of App

Answer 1

This is a bug in android studio. But you can recover your project by copying the codes that you have in different activities and other files which you have created yourself. Don't try to copy the whole project as that would again crash the app. There seems to be a wrong entry by Android Studio in some of your automatically generated files. So only copy files which you have creates or have made changes to. I would try to file a bug report to android studio for the error. Anyways if it helps you please let me know.. Thanks...