Wie lese ich eine Textdatei aus Assets in Android Studio?

Question

Ich habe möglicherweise wifi2.txt Datei in meinem Assets Dateiverzeichnis in Android Studio. Ich erhalte jedoch immer eine NULLPointException, wenn ich versuche, darauf zuzugreifen. Mein Code ist unten: (Vielen Dank im Voraus)

   //CSV FILE READING 
    File file = null; 



    try { 



     FileInputStream is = new FileInputStream(file); 

     try { 
      BufferedReader reader = new BufferedReader(new InputStreamReader(getAssets().open("wifi2.txt"))); 
      String line; 
      Log.e("Reader Stuff",reader.readLine()); 
      while ((line = reader.readLine()) != null) { 
       Log.e("code",line); 
       String[] RowData = line.split(","); 
       LatLng centerXY = new LatLng(Double.valueOf(RowData[1]), Double.valueOf(RowData[2])); 
       if (RowData.length == 4) { 
        mMap.addMarker(new MarkerOptions().position(centerXY).title(String.valueOf(RowData[0]) + String.valueOf(RowData[3])).icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN))); 
       } 

      } 

     } catch (IOException ex) { 
      ex.printStackTrace(); 
     } finally { 
      try { 
       is.close(); 
      } catch (IOException e) { 
       e.printStackTrace(); 
      } 
     } 
    } catch (FileNotFoundException e) { 
     e.printStackTrace(); 
    } 


    //Done with CSV File Reading 

Answer 1

File file = null; 
try { 
    FileInputStream is = new FileInputStream(file); 

Eigentlich sind Sie nicht überall mit Fileinputstream. Gerade dieses Stück Code verwenden

try { 
     BufferedReader reader = new BufferedReader(new InputStreamReader(getAssets().open("wifi2.txt"))); 
     String line; 
     Log.e("Reader Stuff",reader.readLine()); 
     while ((line = reader.readLine()) != null) { 
      Log.e("code",line); 
      String[] RowData = line.split(","); 
      LatLng centerXY = new LatLng(Double.valueOf(RowData[1]), Double.valueOf(RowData[2])); 
      if (RowData.length == 4) { 
       mMap.addMarker(new MarkerOptions().position(centerXY).title(String.valueOf(RowData[0]) + String.valueOf(RowData[3])).icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN))); 
      } 

     } 

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

Answer 2

Verbrauch:String yourData = LoadData("wifi2.txt");

Wo wifi2.txt angenommen wird, in assets

public String LoadData(String inFile) { 
     String tContents = ""; 

    try { 
     InputStream stream = getAssets().open(inFile); 

     int size = stream.available(); 
     byte[] buffer = new byte[size]; 
     stream.read(buffer); 
     stream.close(); 
     tContents = new String(buffer); 
    } catch (IOException e) { 
     // Handle exceptions here 
    } 

    return tContents; 

} 

Reference aufzuhalten

Answer 3

Methode eine Datei von Vermögenswerten zu lesen:

public static String readFile(AssetManager mgr, String path) { 
     String contents = ""; 
     InputStream is = null; 
     BufferedReader reader = null; 
     try { 
      is = mgr.open(path); 
      reader = new BufferedReader(new InputStreamReader(is)); 
      contents = reader.readLine(); 
      String line = null; 
      while ((line = reader.readLine()) != null) { 
       contents += '\n' + line; 
      } 
     } catch (final Exception e) { 
      e.printStackTrace(); 
     } finally { 
      if (is != null) { 
       try { 
        is.close(); 
       } catch (IOException ignored) { 
       } 
      } 
      if (reader != null) { 
       try { 
        reader.close(); 
       } catch (IOException ignored) { 
       } 
      } 
     } 
     return contents; 
    }