kann nicht Datei im Dateimanager mit OkHttp3 wählen

Question

Ich versuche, eine Anwendung zu erstellen, wo ich jede Datei nicht mehr als 16-20 MB hochladen muss. Ich benutze OkHttpClient3, aber mein Hauptproblem wird es Datei mit einfachen Namen wie a.mp4, b.jpg etc. usw. aber es kann nicht Datei wie hello world 12.mp4 wählen, welche Code in RequestBody file_body = RequestBody.create(MediaType.parse(content_type),f). Code eingefügt werden soll.

public void enable_button(){ 
     choosefile.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View view) { 
       new MaterialFilePicker() 
         .withActivity(ShowStudent.this) 
         .withRequestCode(10) 
         .start(); 
      } 
     }); 
    } 
    @Override 
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) { 
     if(requestCode == 100 && (grantResults[0] == PackageManager.PERMISSION_GRANTED)){ 
      enable_button(); 
     }else { 
      if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) { 
       requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},100); 
      } 
     } 
    } 
    @Override 
    protected void onActivityResult(int requestCode, int resultCode, final Intent data) { 
     if(requestCode == 10 && resultCode == RESULT_OK){ 
      progress = new ProgressDialog(ShowStudent.this); 
      progress.setTitle("Uploading"); 
      progress.setMessage("Please wait..."); 
      progress.show(); 

      Thread t = new Thread(new Runnable() { 
       @Override 
       public void run() { 
        File f = new File(data.getStringExtra(FilePickerActivity.RESULT_FILE_PATH)); 
        String content_type = getMimeType(f.getPath()); 
        String file_path = f.getAbsolutePath(); 
        OkHttpClient client = new OkHttpClient(); 
        RequestBody file_body = RequestBody.create(MediaType.parse(content_type),f); 
        RequestBody request_body = new MultipartBody.Builder() 
          .setType(MultipartBody.FORM) 
          .addFormDataPart("type",content_type) 
          .addFormDataPart("uploaded_file",file_path.substring(file_path.lastIndexOf("/")+1), file_body) 
          .build(); 
        Request request = new Request.Builder() 
          .url("http://onsitesupport.info/diary/uploadproject.php") 
          .post(request_body) 
          .build(); 
        try { 
         Response response = client.newCall(request).execute(); 
         if(!response.isSuccessful()){ 
          throw new IOException("Error : "+response); 
         } 
         progress.dismiss(); 
        } catch (IOException e) { 
         e.printStackTrace(); 
        } 
       } 
      }); 
      t.start(); 
     } 
    } 
    private String getMimeType(String path) { 
     String extension = MimeTypeMap.getFileExtensionFromUrl(path); 
     return MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension); 
    } 

und ich bekommen ths Ausnahme

E/AndroidRuntime: FATAL EXCEPTION: Thread-3122 
       Process: com.kliff.studentteacherportal, PID: 29436 
       java.lang.NullPointerException: Attempt to invoke interface method 'int java.lang.CharSequence.length()' on a null object reference 
        at java.util.regex.Matcher.reset(Matcher.java:177) 
        at java.util.regex.Matcher.<init>(Matcher.java:90) 
        at java.util.regex.Pattern.matcher(Pattern.java:297) 
        at okhttp3.MediaType.parse(MediaType.java:51) 
        at com.kliff.studentteacherportal.ShowStudent$2.run(ShowStudent.java:100) 
        at java.lang.Thread.run(Thread.java:818) 
E/WindowManager: android.view.WindowLeaked: Activity com.kliff.studentteacherportal.ShowStudent has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{26acab10 V.E..... R......D 0,0-684,322} that was originally added here 
       at android.view.ViewRootImpl.<init>(ViewRootImpl.java:458) 
       at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:278) 
       at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:85) 
       at android.app.Dialog.show(Dialog.java:311) 
       at com.kliff.studentteacherportal.ShowStudent.onActivityResult(ShowStudent.java:91) 
       at android.app.Activity.dispatchActivityResult(Activity.java:6294) 
       at android.app.ActivityThread.deliverResults(ActivityThread.java:3873) 
       at android.app.ActivityThread.handleSendResult(ActivityThread.java:3920) 
       at android.app.ActivityThread.access$1300(ActivityThread.java:182) 
       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1523) 
       at android.os.Handler.dispatchMessage(Handler.java:111) 
       at android.os.Looper.loop(Looper.java:194) 
       at android.app.ActivityThread.main(ActivityThread.java:5706) 
       at java.lang.reflect.Method.invoke(Native Method) 
       at java.lang.reflect.Method.invoke(Method.java:372) 
       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1033) 
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:828) 
W/MALI: glDrawArrays:714: [MALI] glDrawArrays takes more than 5ms here. Total elapse time(us): 5659 

Answer 1

Ok ich herausfinden, es kann nicht Datei mit Platz wählen, aber ich mein Problem gelöst durch

String mimeType= URLConnection.guessContentTypeFromName(f.getName()); 
RequestBody file_body = RequestBody.create(MediaType.parse(mimeType),f);`