android studio télécharger le fichier pdf et enregistrez-le dans sharedpreferences

Question

J'ai un problème en essayant de télécharger le fichier PDF et enregistrez-le dans le stockage interne ou les préférences partagées et le lire. Est-il possible de le télécharger en mémoire interne? J'ai suivi plusieurs tutoriels d'internet mais ça ne marche pas. quelqu'un pourrait-il me guider comment le faire? Merci beaucoup.

package com.icul.downloadinternal; 

import android.content.SharedPreferences; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.preference.PreferenceManager; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.util.Base64; 
import android.view.View; 
import android.widget.Button; 
import android.widget.ImageView; 
import android.widget.Toast; 

import java.io.IOException; 

import okhttp3.OkHttpClient; 
import okhttp3.Request; 
import okhttp3.Response; 

public class MainActivity extends AppCompatActivity { 

    Button download, read; 
    ImageView pdf; 
    String url = "https://www.cdc.gov/eval/guide/cdcevalmanual.pdf"; 

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

     download = (Button) findViewById(R.id.button); 
     read = (Button) findViewById(R.id.button2); 
     pdf = (ImageView) findViewById(R.id.image); 

     download.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       try { 
        downloadFileSync(url); 
       } catch (Exception e) { 
        e.printStackTrace(); 
       } 
      } 
     }); 

     read.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       SharedPreferences shre = PreferenceManager.getDefaultSharedPreferences(getApplicationContext()); 
       String previouslyEncodedImage = shre.getString("pdf_data", ""); 

       if(!previouslyEncodedImage.equalsIgnoreCase("")){ 
        byte[] b = Base64.decode(previouslyEncodedImage, Base64.DEFAULT); 
        Bitmap bitmap = BitmapFactory.decodeByteArray(b, 0 , b.length); 
        pdf.setImageBitmap(bitmap); 
       } 
       else { 
        Toast.makeText(getApplicationContext(),"No File", Toast.LENGTH_LONG).show(); 
       } 
      } 
     }); 

    } 
    public void downloadFileSync(String downloadUrl) throws Exception { 

     OkHttpClient client = new OkHttpClient(); 
     Request request = new Request.Builder().url(downloadUrl).build(); 
     Response response = client.newCall(request).execute(); 
     if (!response.isSuccessful()) { 
      throw new IOException("Failed to download file: " + response); 
     } 

     String encodedImage = Base64.encodeToString(response.body().bytes(), Base64.DEFAULT); 
     SharedPreferences shre = PreferenceManager.getDefaultSharedPreferences(this); 
     SharedPreferences.Editor edit = shre.edit(); 
     edit.putString("pdf_data", encodedImage); 
     edit.commit(); 
    } 
} 

Answer 1

Gradle

compile 'com.squareup.okhttp3:okhttp:3.8.0' 

Ecrire:

public void downloadFileSync(String downloadUrl) throws Exception { 

    OkHttpClient client = new OkHttpClient(); 
    Request request = new Request.Builder().url(downloadUrl).build(); 
    Response response = client.newCall(request).execute(); 
    if (!response.isSuccessful()) { 
     throw new IOException("Failed to download file: " + response); 
    } 
    String encodedImage = Base64.encodeToString(response.body().bytes(), Base64.DEFAULT); 

    SharedPreferences shre = 
    PreferenceManager.getDefaultSharedPreferences(this); 
    Editor edit=shre.edit(); 
    edit.putString("pdf_data",encodedImage); 
    edit.commit(); 
} 

Pour lire:

SharedPreferences shre = PreferenceManager.getDefaultSharedPreferences(this); 
String previouslyEncodedImage = shre.getString("pdf_data", ""); 

if(!previouslyEncodedImage.equalsIgnoreCase("")){ 
    byte[] b = Base64.decode(previouslyEncodedImage, Base64.DEFAULT); 
    // ..... 
} 

Answer 2

S'il vous plaît ajouter des fichiers suivant/méthode pour votre projet

1. PdfDownloader.java
2. PDFDownloaderAsyncTask.java

, puis en utilisant la méthode suivante handleViewPdf pour afficher pdf:

private void handleViewPdf() { 

    File folder = getAppDirectory(context); 
    String fileName = "test.pdf";// getPdfFileName(pdfUrl); 
    File pdfFile = new File(folder, fileName); 

    if(pdfFile.exists() && pdfFile.length() > 0) { 
     openPDFFile(context, Uri.fromFile(pdfFile)); 
    } 
    else { 
     if(pdfFile.length() == 0) { 
      pdfFile.delete(); 
     } 
     try { 
      pdfFile.createNewFile(); 
     } 
     catch(IOException e) { 
      e.printStackTrace(); 
     } 
     ArrayList<String> fileNameAndURL = new ArrayList<>(); 
     fileNameAndURL.add(pdfFile.toString()); 
     fileNameAndURL.add(pdfUrl); 
     fileNameAndURL.add(fileName); 
     if(pdfDownloaderAsyncTask == null) { 
      pdfDownloaderAsyncTask = new PDFDownloaderAsyncTask(context, pdfFile); 
     } 
     if(hasInternetConnection(context)) { 
      if(!pdfDownloaderAsyncTask.isDownloadingPdf()) { 
       pdfDownloaderAsyncTask = new PDFDownloaderAsyncTask(context, pdfFile); 
       pdfDownloaderAsyncTask.execute(fileNameAndURL); 
      } 
     } 
     else { 
      //show error 
     } 
    } 
} 

PDFDownloaderAsyncTask.java

import java.io.File; 
    import java.util.ArrayList; 

    import android.content.Context; 
    import android.net.Uri; 
    import android.os.AsyncTask; 
    import android.os.Handler; 
    import android.text.TextUtils; 
    import android.widget.Toast; 


    public class PDFDownloaderAsyncTask extends AsyncTask<ArrayList<String>, Void, String> { 

     private boolean isDownloadingPdf = false; 

     private File file; 
     private Context context; 

     public PDFDownloaderAsyncTask(Context context, File file) { 

      this.file = file; 
      this.context = context; 
      this.isDownloadingPdf = false; 
     } 

     public boolean isDownloadingPdf() { 

      return this.isDownloadingPdf; 
     } 

     @Override 
     protected void onPreExecute() { 

      super.onPreExecute(); 
      //show loader etc 
     } 

     @Override 
     protected String doInBackground(ArrayList<String>... params) { 

      isDownloadingPdf = true; 
      File file = new File(params[0].get(0)); 
      String fileStatus = PdfDownloader.downloadFile(params[0].get(1), file); 
      return fileStatus; 
     } 

     @Override 
     protected void onPostExecute(String result) { 

      super.onPostExecute(result); 
      Loader.hideLoader(); 
      if(!TextUtils.isEmpty(result) && result.equalsIgnoreCase(context.getString(R.string.txt_success))) { 
       showPdf(); 
      } 
      else { 
       isDownloadingPdf = false; 
       Toast.makeText(context, context.getString(R.string.error_could_not_download_pdf), Toast.LENGTH_LONG).show(); 
       file.delete(); 
      } 
     } 

     @Override 
     protected void onCancelled() { 

      isDownloadingPdf = false; 
      super.onCancelled(); 
      //Loader.hideLoader(); 
     } 

     @Override 
     protected void onCancelled(String s) { 

      isDownloadingPdf = false; 
      super.onCancelled(s); 
      //Loader.hideLoader(); 
     } 

     private void showPdf() { 

      new Handler().postDelayed(new Runnable() { 
       @Override 
       public void run() { 

        isDownloadingPdf = false; 
        openPDFFile(context, Uri.fromFile(file)); 
       } 
      }, 1000); 
     } 
    } 

PdfDownloader.java

package com.pdf; 

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 PdfDownloader { 
    private static final int MEGABYTE = 1024 * 1024; 

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

     String downloadStatus; 
     try { 

      URL url = new URL(fileUrl); 
      HttpURLConnection urlConnection =(HttpURLConnection) url.openConnection(); 
      urlConnection.connect(); 

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

      Log.d("PDF", "Total size: " + totalSize); 
      byte[] buffer = new byte[MEGABYTE]; 
      int bufferLength = 0; 
      while((bufferLength = inputStream.read(buffer)) > 0) { 
       fileOutputStream.write(buffer, 0, bufferLength); 
      } 
      downloadStatus = "success"; 
      fileOutputStream.close(); 
     } 
     catch(FileNotFoundException e) { 
      downloadStatus = "FileNotFoundException"; 
      e.printStackTrace(); 
     } 
     catch(MalformedURLException e) { 
      downloadStatus = "MalformedURLException"; 
      e.printStackTrace(); 
     } 
     catch(IOException e) { 
      downloadStatus = "IOException"; 
      e.printStackTrace(); 
     } 
     Log.d("PDF", "Download Status: " + downloadStatus); 
     return downloadStatus; 
    } 


    public static void openPDFFile(Context context, Uri path) { 

     Intent intent = new Intent(Intent.ACTION_VIEW); 
     intent.setDataAndType(path, "application/pdf"); 
     intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); 
     try { 
      context.startActivity(intent); 
     } 
     catch(ActivityNotFoundException e) { 
      Toast.makeText(context, context.getString(R.string.txt_no_pdf_available), Toast.LENGTH_SHORT).show(); 
     } 
     Loader.hideLoader(); 
    } 

    public static File getAppDirectory(Context context) { 

     String extStorageDirectory = Environment.getExternalStorageDirectory().toString(); 
     File folder = new File(extStorageDirectory, context.getString(R.string.app_folder_name).trim()); 
     if(!folder.exists()) { 
      boolean success = folder.mkdirs(); 
      Log.d("Directory", "mkdirs():" + success); 
     } 
     return folder; 
    } 

}