Kann nicht auf externe Speicher schreiben Android

Question

Ich bin nicht in der Lage, eine PDF-Datei von einer URL in Android-Speicher heruntergeladen zu schreiben. Ich habe alle verwandten Fragen auf dieser Website gelesen, kann aber immer noch nicht herausfinden, was mit meinem Code nicht stimmt.

Fehler ist in pdfFile.createNewFile(); drinnen versuche {} block.

private class DownloadFile extends AsyncTask<String, Void, Void> { 

     @Override 
     protected Void doInBackground(String... strings) { 
      String fileUrl = strings[0]; 
      String fileName = strings[1]; 
      String extStorageDirectory = Environment.getExternalStorageDirectory().toString(); 
      File folder = new File(extStorageDirectory, "/test/"); 
      folder.mkdirs(); 

      File pdfFile = new File(folder, fileName); 

      try{ 
       pdfFile.getParentFile().mkdirs(); 
       pdfFile.createNewFile(); 
      }catch (IOException e){ 
       e.printStackTrace(); 
      } 
      FileDownloader.downloadFile(fileUrl, pdfFile); 
      return null; 
     } 

Mein Logcat

06-24 19:11:26.886 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err: java.io.IOException: open failed: ENOENT (No such file or directory) 
06-24 19:11:26.886 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at java.io.File.createNewFile(File.java:939) 
06-24 19:11:26.886 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at in.ac.iitd.bsw.iitdapp.VolleyDownload$DownloadFile.doInBackground(VolleyDownload.java:112) 
06-24 19:11:26.888 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at in.ac.iitd.bsw.iitdapp.VolleyDownload$DownloadFile.doInBackground(VolleyDownload.java:96) 
06-24 19:11:26.888 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at android.os.AsyncTask$2.call(AsyncTask.java:295) 
06-24 19:11:26.888 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at java.util.concurrent.FutureTask.run(FutureTask.java:237) 
06-24 19:11:26.889 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234) 
06-24 19:11:26.889 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113) 
06-24 19:11:26.889 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588) 
06-24 19:11:26.889 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at java.lang.Thread.run(Thread.java:818) 
06-24 19:11:26.889 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err: Caused by: android.system.ErrnoException: open failed: ENOENT (No such file or directory) 
06-24 19:11:26.889 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at libcore.io.Posix.open(Native Method) 
06-24 19:11:26.890 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at libcore.io.BlockGuardOs.open(BlockGuardOs.java:186) 
06-24 19:11:26.890 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at java.io.File.createNewFile(File.java:932) 
06-24 19:11:26.890 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  ... 8 more 
06-24 19:11:26.890 22920-22999/in.ac.iitd.bsw.iitdapp W/System: ClassLoader referenced unknown path: /system/framework/tcmclient.jar 
06-24 19:11:27.040 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err: java.io.FileNotFoundException: /storage/emulated/0/test/maven.pdf: open failed: ENOENT (No such file or directory) 
06-24 19:11:27.041 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at libcore.io.IoBridge.open(IoBridge.java:452) 
06-24 19:11:27.041 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at java.io.FileOutputStream.<init>(FileOutputStream.java:87) 
06-24 19:11:27.041 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at java.io.FileOutputStream.<init>(FileOutputStream.java:72) 
06-24 19:11:27.041 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at in.ac.iitd.bsw.iitdapp.FileDownloader.downloadFile(FileDownloader.java:27) 
06-24 19:11:27.041 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at in.ac.iitd.bsw.iitdapp.VolleyDownload$DownloadFile.doInBackground(VolleyDownload.java:116) 
06-24 19:11:27.041 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at in.ac.iitd.bsw.iitdapp.VolleyDownload$DownloadFile.doInBackground(VolleyDownload.java:96) 
06-24 19:11:27.041 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at android.os.AsyncTask$2.call(AsyncTask.java:295) 
06-24 19:11:27.041 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at java.util.concurrent.FutureTask.run(FutureTask.java:237) 
06-24 19:11:27.041 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234) 
06-24 19:11:27.041 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113) 
06-24 19:11:27.041 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588) 
06-24 19:11:27.042 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at java.lang.Thread.run(Thread.java:818) 
06-24 19:11:27.042 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err: Caused by: android.system.ErrnoException: open failed: ENOENT (No such file or directory) 
06-24 19:11:27.043 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at libcore.io.Posix.open(Native Method) 
06-24 19:11:27.043 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at libcore.io.BlockGuardOs.open(BlockGuardOs.java:186) 
06-24 19:11:27.043 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  at libcore.io.IoBridge.open(IoBridge.java:438) 
06-24 19:11:27.043 22920-22999/in.ac.iitd.bsw.iitdapp W/System.err:  ... 11 more 

ich die Erlaubnis, in Android Manifest richtig eingestellt haben

Answer 1

ich es auf meinem Gerät testete mit Android 6.0 Eibisch, die zusätzliche Berechtigungen erfordert sensible Daten zuzugreifen.

Kredit - @CommonsWare Android permission doesn't work even if I have declared it

Dieses Verfahren verwendet werden können Benutzer-Berechtigungen zu fragen. Ursprüngliche Antwort - https://stackoverflow.com/a/33162451/4420961

public boolean isStoragePermissionGranted() { 
    if (Build.VERSION.SDK_INT >= 23) { 
     if (checkSelfPermission(android.Manifest.permission.WRITE_EXTERNAL_STORAGE) 
       == PackageManager.PERMISSION_GRANTED) { 
      Log.v(TAG,"Permission is granted"); 
      return true; 
     } else { 

      Log.v(TAG,"Permission is revoked"); 
      ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1); 
      return false; 
     } 
    } 
    else { //permission is automatically granted on sdk<23 upon installation 
     Log.v(TAG,"Permission is granted"); 
     return true; 
    } 


} 

Answer 2

Bitte versuchen Sie dies.

private class DownloadFile extends AsyncTask<String, Void, Void> { 
    @Override 
    protected Void doInBackground(String... strings) { 
     String fileUrl = strings[0]; 
     String fileName = strings[1]; 
     String extStorageDirectory = Environment.getExternalStorageDirectory().getPath() + "/test/"; 
     File folder = new File(extStorageDirectory); 
     if (!folder.exists()) { 
      folder.mkdirs(); 
     } 
     fileName = extStorageDirectory + fileName; 
     File pdfFile = new File(fileName); 

     try{ 
      pdfFile.createNewFile(); 
     }catch (IOException e){ 
      e.printStackTrace(); 
     } 
     FileDownloader.downloadFile(fileUrl, pdfFile); 
     return null; 
    }