android: SharedPreferences speichert keine Daten

Question

Ich habe eine kleine Android-App, die aus einer Listview, öffnet eine Google Maps-Aktivität und wenn Sie auf der Karte lang drücken, speichert es die Adresse dieser Position in einem ArrayList und fügt es dann zu Auf diese Weise werden auch die Listenansicht und die Standortnummer gespeichert, und dann speichere ich diese Informationen über SharedPreferences. Mein Problem ist, dass, obwohl der Listenansicht aktualisiert wird, wenn die App läuft, ich alle Daten verlieren, wenn ich die App neu starte, im Grunde bedeutet, dass die Informationen nie an erster Stelle gespeichert wird. Das Speichern von Daten erfolgt über die Methode onMapLongClick in MapsActivity, und das Laden der Daten erfolgt über die Methode OnCreate in der MainActivity.

MainActivity:

package com.rapha.favoriteplaces; 

import android.content.Context; 
import android.content.Intent; 
import android.content.SharedPreferences; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.AdapterView; 
import android.widget.ArrayAdapter; 
import android.widget.ListView; 
import java.io.IOException; 
import java.util.ArrayList; 

public class MainActivity extends AppCompatActivity { 
    static ArrayList<String> places = new ArrayList<>(); 
    static ArrayList<String> lats = new ArrayList<>(); 
    static ArrayList<String> lngs = new ArrayList<>(); 
    static ArrayAdapter arrayAdapter; 

    @Override 
    public void onBackPressed() 
    { 

    } 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     ListView listView = (ListView)findViewById(R.id.list); 

     places.add("Add a location..."); 

     final Intent intent = new Intent(getApplicationContext(), MapsActivity.class); 

     SharedPreferences sharedPreferences = this.getSharedPreferences("package com.rapha.favoriteplaces", Context.MODE_PRIVATE); 

     try { 
      places = (ArrayList<String>) ObjectSerializer.deserialize(sharedPreferences.getString("places", ObjectSerializer.serialize(new ArrayList<String>()))); 

      lats = (ArrayList<String>)ObjectSerializer.deserialize(sharedPreferences.getString("lats", ObjectSerializer.serialize(new ArrayList<String>()))); 
      lngs = (ArrayList<String>)ObjectSerializer.deserialize(sharedPreferences.getString("lngs", ObjectSerializer.serialize(new ArrayList<String>()))); 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } 

     if(places.size() > 0 && lats.size() > 0 && lngs.size() > 0) 
     { 
      System.out.println("load data sucessfully check"); 
     } 

     arrayAdapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, places); 
     listView.setAdapter(arrayAdapter); 

     listView.setOnItemClickListener(new AdapterView.OnItemClickListener() { 

      @Override 
      public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 

       if(position == 0) 
       { 
        intent.putExtra("coisa", position); 
        startActivity(intent); 
       } 
       else 
       { 
        intent.putExtra("coisa", position); 
        String lat = ((lats.get(position - 1))); 
        String lon = ((lngs.get(position - 1))); 
        intent.putExtra("lat", lat); 
        intent.putExtra("lon", lon); 
        intent.putExtra("ad", places.get(position)); 

        startActivity(intent); 
       } 
      } 
     }); 
    } 
} 

MapsActivity:

package com.rapha.favoriteplaces; 

import android.*; 
import android.Manifest; 
import android.app.Activity; 
import android.content.Context; 
import android.content.Intent; 
import android.content.SharedPreferences; 
import android.content.pm.PackageManager; 
import android.location.Address; 
import android.location.Geocoder; 
import android.location.Location; 
import android.location.LocationListener; 
import android.location.LocationManager; 
import android.net.Uri; 
import android.os.Build; 
import android.os.Handler; 
import android.support.annotation.NonNull; 
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.GestureDetector; 
import android.view.MotionEvent; 
import android.widget.Toast; 
import com.google.android.gms.appindexing.Action; 
import com.google.android.gms.appindexing.AppIndex; 
import com.google.android.gms.appindexing.Thing; 
import com.google.android.gms.common.api.GoogleApiClient; 
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.IOException; 
import java.util.List; 
import java.util.Locale; 

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback, GoogleMap.OnMapLongClickListener { 

    private GoogleMap mMap; 
    LocationManager locationManager; 
    LocationListener locationListener; 
    String address; 

    @Override 
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) { 
     super.onRequestPermissionsResult(requestCode, permissions, grantResults); 

     if (grantResults.length > 0 && grantResults[0] != PackageManager.PERMISSION_GRANTED) { 
      if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) { 
       locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 5, 100000, locationListener); 
      } 
     } 
    } 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     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); 
    } 
    /** 
    * Manipulates the map once available. 
    * This callback is triggered when the map is ready to be used. 
    * This is where we can add markers or lines, add listeners or move the camera. In this case, 
    * we just add a marker near Sydney, Australia. 
    * If Google Play services is not installed on the device, the user will be prompted to install 
    * it inside the SupportMapFragment. This method will only be triggered once the user has 
    * installed Google Play services and returned to the app. 
    */ 
    @Override 
    public void onMapReady(GoogleMap googleMap) { 
     mMap = googleMap; 

     Intent intent = getIntent(); 

     mMap.setOnMapLongClickListener(this); 
     int coisa = intent.getIntExtra("coisa", 0); 

     if(coisa == 0) 
     { 
      locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE); 

      locationListener = new LocationListener() { 
       @Override 
       public void onLocationChanged(Location location) { 

        LatLng userLocation = new LatLng(location.getLatitude(), location.getLongitude()); 

        mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(userLocation, 15)); 
       } 

       @Override 
       public void onStatusChanged(String provider, int status, Bundle extras) { 

       } 

       @Override 
       public void onProviderEnabled(String provider) { 

       } 

       @Override 
       public void onProviderDisabled(String provider) { 

       } 
      }; 
      if (Build.VERSION.SDK_INT < 23) { 
       locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 100, locationListener); 
      } else { 
       if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) { 
        ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 1); 
       } else { 
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 100, locationListener); 
        mMap.clear(); 
        Location lastKnownLocation = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER); 
        LatLng userLocation = new LatLng(lastKnownLocation.getLatitude(), lastKnownLocation.getLongitude()); 
        mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(userLocation, 15)); 
       } 
      } 
     } 
     else 
     { 
      double lat = Double.parseDouble(intent.getStringExtra("lat")); 
      double lon = Double.parseDouble(intent.getStringExtra("lon")); 
      LatLng location = new LatLng(lat, lon); 

      mMap.addMarker(new MarkerOptions().position(location).title(intent.getStringExtra("ad"))); 
      mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(location, 15)); 
     } 
    } 
    @Override 
    public void onMapLongClick(LatLng latLng) { 

     Geocoder geocoder = new Geocoder(getApplicationContext(), Locale.getDefault()); 
     try { 
      List<Address> addresses = geocoder.getFromLocation(latLng.latitude, latLng.longitude, 1); 

      if (addresses != null && addresses.size() > 0) { 

       address = addresses.get(0).getAddressLine(0); 
      } 

     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
     mMap.addMarker(new MarkerOptions().position(latLng).title(address)); 
     MainActivity.lats.add(String.valueOf(latLng.latitude)); 
     MainActivity.lngs.add(String.valueOf(latLng.longitude)); 
     MainActivity.places.add(address); 
     MainActivity.arrayAdapter.notifyDataSetChanged(); 

     SharedPreferences sharedPreferences = getSharedPreferences("com.rapha.favoriteplaces",Context.MODE_PRIVATE); 

     try { 

      sharedPreferences.edit().putString("lats", ObjectSerializer.serialize(MainActivity.lats)).apply(); 
      sharedPreferences.edit().putString("lngs", ObjectSerializer.serialize(MainActivity.lngs)).apply(); 

      sharedPreferences.edit().putString("places", ObjectSerializer.serialize(MainActivity.places)).apply(); 

     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
    } 
} 

Die Object Serializer Klasse:

import java.io.ByteArrayInputStream; 
import java.io.ByteArrayOutputStream; 
import java.io.IOException; 
import java.io.ObjectInputStream; 
import java.io.ObjectOutputStream; 
import java.io.Serializable; 

public class ObjectSerializer { 

    public static String serialize(Serializable obj) throws IOException { 
     if (obj == null) return ""; 
     try { 
      ByteArrayOutputStream serialObj = new ByteArrayOutputStream(); 
      ObjectOutputStream objStream = new ObjectOutputStream(serialObj); 
      objStream.writeObject(obj); 
      objStream.close(); 
      return encodeBytes(serialObj.toByteArray()); 
     } catch (Exception e) { 
      throw new RuntimeException(e); 
     } 
    } 

    public static Object deserialize(String str) throws IOException { 
     if (str == null || str.length() == 0) return null; 
     try { 
      ByteArrayInputStream serialObj = new ByteArrayInputStream(decodeBytes(str)); 
      ObjectInputStream objStream = new ObjectInputStream(serialObj); 
      return objStream.readObject(); 
     } catch (Exception e) { 
      throw new RuntimeException(e); 
     } 
    } 

    public static String encodeBytes(byte[] bytes) { 
     StringBuffer strBuf = new StringBuffer(); 

     for (int i = 0; i < bytes.length; i++) { 
      strBuf.append((char) (((bytes[i] >> 4) & 0xF) + ((int) 'a'))); 
      strBuf.append((char) (((bytes[i]) & 0xF) + ((int) 'a'))); 
     } 

     return strBuf.toString(); 
    } 

    public static byte[] decodeBytes(String str) { 
     byte[] bytes = new byte[str.length()/2]; 
     for (int i = 0; i < str.length(); i += 2) { 
      char c = str.charAt(i); 
      bytes[i/2] = (byte) ((c - 'a') << 4); 
      c = str.charAt(i + 1); 
      bytes[i/2] += (c - 'a'); 
     } 
     return bytes; 
    } 
} 

Answer 1

Sie scheinen Indienststellung und aus zwei unterschiedlichen Vorlieben bekommen zu sein.

Wenn aus Präferenz holen, verwenden Sie package com.rapha.favoriteplaces:

SharedPreferences sharedPreferences = getSharedPreferences("com.rapha.favoriteplaces",Context.MODE_PRIVATE); 
sharedPreferences.edit().putString("lats", ObjectSerializer.serialize(MainActivity.lats)).apply(); 

Machen beide gleich und dann versuchen:

SharedPreferences sharedPreferences = this.getSharedPreferences("package com.rapha.favoriteplaces", Context.MODE_PRIVATE); 
try { 
    places = (ArrayList<String>) ObjectSerializer.deserialize(sharedPreferences.getString("places", ObjectSerializer.serialize(new ArrayList<String>()))); 
    // ... 

Wenn die Werte, die Sie com.rapha.favoriteplaces verwenden zu speichern.