android herunterladen pdf von url dann öffnen sie mit einem pdf-reader

Question

Ich versuche eine app zu schreiben pdfs von url herunterladen, speichern sie auf sd, dann öffnen von adobe pdf reader oder andere apps die jemals in der lage, die pdf zu öffnen.

jetzt unbis, ich hatte „erfolgreich heruntergeladen und auf SD-Karte gespeichert“ (aber jedes Mal, wenn ich versuche, das pdf mit einem PDF-Reader, Leser Absturz zu öffnen und zu sagen unerwartete Fehler auftreten), zum Beispiel http://maven.apache.org/maven-1.x/maven.pdf

hier ist der Code für meinen Downloader:

//........code set ui stuff 
//........code set ui stuff 
    new DownloadFile().execute(fileUrl, fileName); 


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

     @Override 
     protected Void doInBackground(String... strings) { 
      String fileUrl = strings[0]; // -> http://maven.apache.org/maven-1.x/maven.pdf 
      String fileName = strings[1]; // -> maven.pdf 
      String extStorageDirectory = Environment.getExternalStorageDirectory().toString(); 
      File folder = new File(extStorageDirectory, "testthreepdf"); 
      folder.mkdir(); 

      File pdfFile = new File(folder, fileName); 

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



public class FileDownloader { 
    private static final int MEGABYTE = 1024 * 1024; 

    public static void downloadFile(String fileUrl, File directory){ 
     try { 

      URL url = new URL(fileUrl); 
      HttpURLConnection urlConnection = (HttpURLConnection)url.openConnection(); 
      urlConnection.setRequestMethod("GET"); 
      urlConnection.setDoOutput(true); 
      urlConnection.connect(); 

      InputStream inputStream = urlConnection.getInputStream(); 
      FileOutputStream fileOutputStream = new FileOutputStream(directory); 
      int totalSize = urlConnection.getContentLength(); 

      byte[] buffer = new byte[MEGABYTE]; 
      int bufferLength = 0; 
      while((bufferLength = inputStream.read(buffer))>0){ 
       fileOutputStream.write(buffer, 0, bufferLength); 
      } 
      fileOutputStream.close(); 
     } catch (FileNotFoundException e) { 
      e.printStackTrace(); 
     } catch (MalformedURLException e) { 
      e.printStackTrace(); 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
    } 
} 

im Debug-Modus, kann ich die App es heruntergeladen und speichere diese pdf auf /storage/sdcard/testpdf/maven.pdf aber ich denke, die Datei kann während des Herunterladens irgendwie beschädigt werden, so öffnet es sich nicht richtig ...

hier ist der Code, wie ich beabsichtigt, sie mit anderen Reader-App zu öffnen:

File pdfFile = new File(Environment.getExternalStorageDirectory() + "/testthreepdf/" + fileName); // -> filename = maven.pdf 
        Uri path = Uri.fromFile(pdfFile); 
        Intent pdfIntent = new Intent(Intent.ACTION_VIEW); 
        pdfIntent.setDataAndType(path, "application/pdf"); 
        pdfIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); 

        try{ 
         startActivity(pdfIntent); 
        }catch(ActivityNotFoundException e){ 
         Toast.makeText(documentActivity, "No Application available to view PDF", Toast.LENGTH_SHORT).show(); 
        } 

Answer 1

Hallo das Problem ist in Filedownloader Klasse

urlConnection.setRequestMethod("GET"); 
    urlConnection.setDoOutput(true); 

Sie müssen die beiden oben genannten Linien entfernen und alles funktioniert fein. Bitte markieren Sie die Frage als beantwortet, wenn sie wie erwartet funktioniert.

Den Arbeitscode mit Screenshots anhängen.

MainActivity.java

package com.example.downloadread; 

import java.io.File; 
import java.io.IOException; 

import android.app.Activity; 
import android.content.ActivityNotFoundException; 
import android.content.Intent; 
import android.net.Uri; 
import android.os.AsyncTask; 
import android.os.Bundle; 
import android.os.Environment; 
import android.view.Menu; 
import android.view.View; 
import android.widget.Toast; 

public class MainActivity extends Activity { 

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

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.main, menu); 
     return true; 
    } 

    public void download(View v) 
    { 
     new DownloadFile().execute("http://maven.apache.org/maven-1.x/maven.pdf", "maven.pdf"); 
    } 

    public void view(View v) 
    { 
     File pdfFile = new File(Environment.getExternalStorageDirectory() + "/testthreepdf/" + "maven.pdf"); // -> filename = maven.pdf 
     Uri path = Uri.fromFile(pdfFile); 
     Intent pdfIntent = new Intent(Intent.ACTION_VIEW); 
     pdfIntent.setDataAndType(path, "application/pdf"); 
     pdfIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); 

     try{ 
      startActivity(pdfIntent); 
     }catch(ActivityNotFoundException e){ 
      Toast.makeText(MainActivity.this, "No Application available to view PDF", Toast.LENGTH_SHORT).show(); 
     } 
    } 

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

     @Override 
     protected Void doInBackground(String... strings) { 
      String fileUrl = strings[0]; // -> http://maven.apache.org/maven-1.x/maven.pdf 
      String fileName = strings[1]; // -> maven.pdf 
      String extStorageDirectory = Environment.getExternalStorageDirectory().toString(); 
      File folder = new File(extStorageDirectory, "testthreepdf"); 
      folder.mkdir(); 

      File pdfFile = new File(folder, fileName); 

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


} 

FileDownloader.java

package com.example.downloadread; 

import java.io.File; 
import java.io.FileNotFoundException; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.io.InputStream; 
import java.net.HttpURLConnection; 
import java.net.MalformedURLException; 
import java.net.URL; 

public class FileDownloader { 
    private static final int MEGABYTE = 1024 * 1024; 

    public static void downloadFile(String fileUrl, File directory){ 
     try { 

      URL url = new URL(fileUrl); 
      HttpURLConnection urlConnection = (HttpURLConnection)url.openConnection(); 
      //urlConnection.setRequestMethod("GET"); 
      //urlConnection.setDoOutput(true); 
      urlConnection.connect(); 

      InputStream inputStream = urlConnection.getInputStream(); 
      FileOutputStream fileOutputStream = new FileOutputStream(directory); 
      int totalSize = urlConnection.getContentLength(); 

      byte[] buffer = new byte[MEGABYTE]; 
      int bufferLength = 0; 
      while((bufferLength = inputStream.read(buffer))>0){ 
       fileOutputStream.write(buffer, 0, bufferLength); 
      } 
      fileOutputStream.close(); 
     } catch (FileNotFoundException e) { 
      e.printStackTrace(); 
     } catch (MalformedURLException e) { 
      e.printStackTrace(); 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
    } 
} 

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
    package="com.example.downloadread" 
    android:versionCode="1" 
    android:versionName="1.0" > 

    <uses-sdk 
     android:minSdkVersion="14" 
     android:targetSdkVersion="18" /> 
    <uses-permission android:name="android.permission.INTERNET"></uses-permission> 
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission> 
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission> 
    <uses-permission android:name="android.permission.READ_PHONE_STATE"></uses-permission> 
    <application 
     android:allowBackup="true" 
     android:icon="@drawable/ic_launcher" 
     android:label="@string/app_name" 
     android:theme="@style/AppTheme" > 
     <activity 
      android:name="com.example.downloadread.MainActivity" 
      android:label="@string/app_name" > 
      <intent-filter> 
       <action android:name="android.intent.action.MAIN" /> 

       <category android:name="android.intent.category.LAUNCHER" /> 
      </intent-filter> 
     </activity> 
    </application> 

</manifest> 

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:paddingBottom="@dimen/activity_vertical_margin" 
    android:paddingLeft="@dimen/activity_horizontal_margin" 
    android:paddingRight="@dimen/activity_horizontal_margin" 
    android:paddingTop="@dimen/activity_vertical_margin" 
    tools:context=".MainActivity" > 

    <Button 
     android:id="@+id/button1" 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:layout_alignParentLeft="true" 
     android:layout_alignParentTop="true" 
     android:layout_marginTop="15dp" 
     android:text="download" 
     android:onClick="download" /> 

    <Button 
     android:id="@+id/button2" 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:layout_alignParentLeft="true" 
     android:layout_alignParentRight="true" 
     android:layout_below="@+id/button1" 
     android:layout_marginTop="38dp" 
     android:text="view" 
     android:onClick="view" /> 

</RelativeLayout> 

Answer 2

Dies ist die beste Methode, wie zum Herunterladen und Anzeigen von PDF-file.You kann es nur von überall anrufen wie

PDFTools.showPDFUrl(context, url);

hier unten den Code setzen . Es wird funktioniert

public class PDFTools { 
private static final String TAG = "PDFTools"; 
private static final String GOOGLE_DRIVE_PDF_READER_PREFIX = "http://drive.google.com/viewer?url="; 
private static final String PDF_MIME_TYPE = "application/pdf"; 
private static final String HTML_MIME_TYPE = "text/html"; 


public static void showPDFUrl(final Context context, final String pdfUrl) { 
    if (isPDFSupported(context)) { 
     downloadAndOpenPDF(context, pdfUrl); 
    } else { 
     askToOpenPDFThroughGoogleDrive(context, pdfUrl); 
    } 
} 


@TargetApi(Build.VERSION_CODES.GINGERBREAD) 
public static void downloadAndOpenPDF(final Context context, final String pdfUrl) { 
    // Get filename 
    //final String filename = pdfUrl.substring(pdfUrl.lastIndexOf("/") + 1); 
    String filename = ""; 
    try { 
     filename = new GetFileInfo().execute(pdfUrl).get(); 
    } catch (InterruptedException e) { 
     e.printStackTrace(); 
    } catch (ExecutionException e) { 
     e.printStackTrace(); 
    } 
    // The place where the downloaded PDF file will be put 
    final File tempFile = new File(context.getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS), filename); 
    Log.e(TAG,"File Path:"+tempFile); 
    if (tempFile.exists()) { 
     // If we have downloaded the file before, just go ahead and show it. 
     openPDF(context, Uri.fromFile(tempFile)); 
     return; 
    } 

    // Show progress dialog while downloading 
    final ProgressDialog progress = ProgressDialog.show(context, context.getString(R.string.pdf_show_local_progress_title), context.getString(R.string.pdf_show_local_progress_content), true); 

    // Create the download request 
    DownloadManager.Request r = new DownloadManager.Request(Uri.parse(pdfUrl)); 
    r.setDestinationInExternalFilesDir(context, Environment.DIRECTORY_DOWNLOADS, filename); 
    final DownloadManager dm = (DownloadManager) context.getSystemService(Context.DOWNLOAD_SERVICE); 
    BroadcastReceiver onComplete = new BroadcastReceiver() { 
     @Override 
     public void onReceive(Context context, Intent intent) { 
      if (!progress.isShowing()) { 
       return; 
      } 
      context.unregisterReceiver(this); 

      progress.dismiss(); 
      long downloadId = intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, -1); 
      Cursor c = dm.query(new DownloadManager.Query().setFilterById(downloadId)); 

      if (c.moveToFirst()) { 
       int status = c.getInt(c.getColumnIndex(DownloadManager.COLUMN_STATUS)); 
       if (status == DownloadManager.STATUS_SUCCESSFUL) { 
        openPDF(context, Uri.fromFile(tempFile)); 
       } 
      } 
      c.close(); 
     } 
    }; 
    context.registerReceiver(onComplete, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE)); 

    // Enqueue the request 
    dm.enqueue(r); 
} 


public static void askToOpenPDFThroughGoogleDrive(final Context context, final String pdfUrl) { 
    new AlertDialog.Builder(context) 
      .setTitle(R.string.pdf_show_online_dialog_title) 
      .setMessage(R.string.pdf_show_online_dialog_question) 
      .setNegativeButton(R.string.pdf_show_online_dialog_button_no, null) 
      .setPositiveButton(R.string.pdf_show_online_dialog_button_yes, new DialogInterface.OnClickListener() { 
       @Override 
       public void onClick(DialogInterface dialog, int which) { 
        openPDFThroughGoogleDrive(context, pdfUrl); 
       } 
      }) 
      .show(); 
} 

public static void openPDFThroughGoogleDrive(final Context context, final String pdfUrl) { 
    Intent i = new Intent(Intent.ACTION_VIEW); 
    i.setDataAndType(Uri.parse(GOOGLE_DRIVE_PDF_READER_PREFIX + pdfUrl), HTML_MIME_TYPE); 
    context.startActivity(i); 
} 

public static final void openPDF(Context context, Uri localUri) { 
    Intent i = new Intent(Intent.ACTION_VIEW); 
    i.setDataAndType(localUri, PDF_MIME_TYPE); 
    context.startActivity(i); 
} 

public static boolean isPDFSupported(Context context) { 
    Intent i = new Intent(Intent.ACTION_VIEW); 
    final File tempFile = new File(context.getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS), "test.pdf"); 
    i.setDataAndType(Uri.fromFile(tempFile), PDF_MIME_TYPE); 
    return context.getPackageManager().queryIntentActivities(i, PackageManager.MATCH_DEFAULT_ONLY).size() > 0; 
} 

// get File name from url 
static class GetFileInfo extends AsyncTask<String, Integer, String> 
{ 
    protected String doInBackground(String... urls) 
    { 
     URL url; 
     String filename = null; 
     try { 
      url = new URL(urls[0]); 
      HttpURLConnection conn = (HttpURLConnection) url.openConnection(); 
      conn.connect(); 
      conn.setInstanceFollowRedirects(false); 
      if(conn.getHeaderField("Content-Disposition")!=null){ 
       String depo = conn.getHeaderField("Content-Disposition"); 

       String depoSplit[] = depo.split("filename="); 
       filename = depoSplit[1].replace("filename=", "").replace("\"", "").trim(); 
      }else{ 
       filename = "download.pdf"; 
      } 
     } catch (MalformedURLException e1) { 
      e1.printStackTrace(); 
     } catch (IOException e) { 
     } 
     return filename; 
    } 

    @Override 
    protected void onPreExecute() { 
     super.onPreExecute(); 
    } 
    @Override 
    protected void onPostExecute(String result) { 
     super.onPostExecute(result); 
     // use result as file name 
    } 
} 

}

es versuchen. es Werke, genießen

Answer 3

Quellcode downloaden von hier (Open Pdf from url in Android Programmatically)

MainActivity.java

package com.deepshikha.openpdf; 

import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.view.View; 
import android.webkit.WebView; 
import android.webkit.WebViewClient; 
import android.widget.ProgressBar; 

public class MainActivity extends AppCompatActivity { 
    WebView webview; 
    ProgressBar progressbar; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     webview = (WebView)findViewById(R.id.webview); 
     progressbar = (ProgressBar) findViewById(R.id.progressbar); 
     webview.getSettings().setJavaScriptEnabled(true); 
     String filename ="http://www3.nd.edu/~cpoellab/teaching/cse40816/android_tutorial.pdf"; 
     webview.loadUrl("http://docs.google.com/gview?embedded=true&url=" + filename); 

     webview.setWebViewClient(new WebViewClient() { 

      public void onPageFinished(WebView view, String url) { 
       // do your stuff here 
       progressbar.setVisibility(View.GONE); 
      } 
     }); 

    } 
} 

Dank!