SD 카드에 파일을 다운로드하지 못했습니다.

Question

왜 이것이 작동하지 않는지에 대한 통찰력이 있는지 궁금합니다. 먼저 모든 코드가 웹 사이트에서 pdf로 연결되는 링크를 얻습니다. pdf에 대한 링크는 다음과 같습니다. 확실히 올바른,하지만 내 SD 카드에 그것을 다운로드하지 않는 것 같습니다. 확실하지 않은 경우 그것은 내 장치에서 안드로이드 스튜디오에서 그것을 실행하는 방식으로 완료되면? 링크는 그냥 컨테이너 개체입니다 나는 URL을 가지고 단지 파일 이름, 전체 URL을주는 몇 가지 방법과 PDF, 등 내 매니페스트

<uses-permission android:name="android.permission.INTERNET"/> 
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/> 

,369에서

public class MainActivity extends AppCompatActivity { 



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

    Button btnFetchData = (Button) findViewById(R.id.buttonTest); 
    btnFetchData.setOnClickListener(new View.OnClickListener() { 

     @Override 
     public void onClick(View v) { 
      new FetchWebsiteData().execute(); 


     } 
    }); 

} 
private class FetchWebsiteData extends AsyncTask<Void, Void, Void> { 

    private String pdfLink = "didnt work"; 
    private Link foundLink = new Link(""); 
    String fileLocation= ""; 

    @Override 
    protected void onPreExecute() { 
     super.onPreExecute(); 


    } 

    @Override 
    protected Void doInBackground(Void... params) { 
     int count; 
     try { 

      Document doc = Jsoup.connect("http://www.dunnesstores.com/offer20/food-wine/fcp-category/home").userAgent("Mozilla/5.0 (Windows NT 6.1; WOW64; rv:5.0) Gecko/20100101 Firefox/5.0").get(); 
      //Elements links = doc.select("a[title=\"Download offers in store\"]"); 
      Element links = doc.select("a[title=\"Download offers in store\"]").first(); 
      foundLink = new Link(links.attr("href")); 

      URL url = new URL(foundLink.getUrlWithDomain()); 

      //create the new connection 
      HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection(); 

      //set up some things on the connection 
      urlConnection.setRequestMethod("GET"); 
      urlConnection.setDoOutput(true); 

      //and connect! 
      urlConnection.connect(); 

      //set the path where we want to save the file 
      //in this case, going to save it on the root directory of the 
      //sd card. 
      File SDCardRoot = Environment.getExternalStorageDirectory(); 
      //create a new file, specifying the path, and the filename 
      //which we want to save the file as. 
      File file = new File(SDCardRoot,foundLink.getFileNameOnly()); 
      fileLocation = file.toString(); 
      //this will be used to write the downloaded data into the file we created 
      FileOutputStream fileOutput = new FileOutputStream(file); 

      //this will be used in reading the data from the internet 
      InputStream inputStream = urlConnection.getInputStream(); 

      //this is the total size of the file 
      int totalSize = urlConnection.getContentLength(); 
      //variable to store total downloaded bytes 
      int downloadedSize = 0; 

      //create a buffer... 
      byte[] buffer = new byte[1024]; 
      int bufferLength = 0; //used to store a temporary size of the buffer 

      //now, read through the input buffer and write the contents to the file 
      while ((bufferLength = inputStream.read(buffer)) > 0) { 
       //add the data in the buffer to the file in the file output stream (the file on the sd card 
       fileOutput.write(buffer, 0, bufferLength); 
       //add up the size so we know how much is downloaded 
       downloadedSize += bufferLength; 
       //this is where you would do something to report the progress, like this maybe 


      } 
      //close the output stream when done 
      fileOutput.close(); 





     } catch (IOException e) { 
      //e.printStackTrace(); 
     } 
     return null; 
    } 

    @Override 
    protected void onPostExecute(Void result) { 
     TextView txttitle = (TextView) findViewById(R.id.resultTextView); 
     //testing the file location 
     txttitle.setText(fileLocation); 

    } 

} 

권한

편집 : java.io.FileNotFoundException 도움이 될 예외 스택 추적에서 다음을 찾았습니다. /storage/emulated/0/29-11-16.pdf : 열기 실패 : EACCES (사용 권한이 거부 됨)

Answer 1

Android 6+ 런타임 권한을 요청해야합니다. 여기에 예를

private void checkPermission() { 
    final String permissionWrite = Manifest.permission.WRITE_EXTERNAL_STORAGE; 
    final String permissionRead = Manifest.permission.READ_EXTERNAL_STORAGE; 

    if (ContextCompat.checkSelfPermission(getActivity(), permissionWrite) != PermissionChecker.PERMISSION_GRANTED 
      || ContextCompat.checkSelfPermission(getActivity(), permissionRead) != PermissionChecker.PERMISSION_GRANTED) { 
     requestPermissions(new String[]{permissionWrite, permissionRead}, 0); 
     return; 
    } 
    new FetchWebsiteData().execute(); 
} 

@Override 
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) { 
    if (requestCode != 0) return; 
    if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED 
      && grantResults[1] == PackageManager.PERMISSION_GRANTED) { 
     new FetchWebsiteData().execute(); 
    } else { 
     // well no permission granted 
    } 
} 

그리고 당신이 어떤 오류 메시지를 받으셨어요이

btnFetchData.setOnClickListener(new View.OnClickListener() { 

    @Override 
    public void onClick(View v) { 
     checkPermission(); 
    } 
});