how can i save " PDF " file in RecylerView?

Question

I am creating an offline application for schoolchildren. In this project, a schoolboy clicking a "RecylerView" to upload a book "Pdf" and save it to an external storage. my problem is that it can only view a book using the Internet. If you turn off the Internet, it's simple not to see the pdf file.

please help

implementation 'com.github.kk121:File-Loader:1.1' implementation 'com.karumi:dexter:5.0.0'

My Main Activity

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.RelativeLayout;

import java.util.ArrayList;
import java.util.List;

> public class MainActivity extends AppCompatActivity {
    List<Product> productList;

    //the recyclerview
    RecyclerView recyclerView;

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



        Animation animation = AnimationUtils.loadAnimation(this, R.anim.anim_about_card_show);
        RelativeLayout relativeLayout = findViewById(R.id.rl);
        relativeLayout.startAnimation(animation);
        //getting the recyclerview from xml
        recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));


        //initializing the productlist
        productList = new ArrayList<>();


        //adding some items to our list
        productList.add(
                new Product(
                        1,
                        "TEst 11111 \n",
                        60000,
                        R.drawable.android,
                        "link1"

                ));

        productList.add(
                new Product(
                        1,
                        " More types, Methods, Conditionals \n",

                        60000,
                        R.drawable.android,
                        "link2"
                                            ));

        productList.add(
                new Product(
                        1,
                        "Loops, Arrays ",


                        60000,
                        R.drawable.android,
                        "lin3"
                ));
        productList.add(
                new Product(
                        1,
                        "Strings",
                        60000,
                        R.drawable.android,
                        "https://firebasestorage.googleapis.com/v0/b/firepdf-4c1d6.appspot.com/o/2.intro.pdf?alt=media&token=75731b04-c1e7-42c4-b988-e50a8f7e5f6b    "
                ));


        //creating recyclerview adapter
        ProductAdapter adapter = new ProductAdapter(this, productList);

        //setting adapter to recyclerview
        recyclerView.setAdapter(adapter);
    }

}

Adapter

import android.app.DownloadManager;
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.support.v7.widget.CardView;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.List;


> public class ProductAdapter extends RecyclerView.Adapter<ProductAdapter.ProductViewHolder> {

    //this context we will use to inflate the layout
    private Context mCtx;

    //we are storing all the products in a list
    private List<Product> productList;

    //getting the context and product list with constructor
    public ProductAdapter(Context mCtx, List<Product> productList) {
        this.mCtx = mCtx;
        this.productList = productList;
    }

    @Override
    public ProductViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        //inflating and returning our view holder
        LayoutInflater inflater = LayoutInflater.from(mCtx);
        View view = inflater.inflate(R.layout.layout_products, null);
        return new ProductViewHolder(view);
    }

    @Override
    public void onBindViewHolder(ProductViewHolder holder, final int position) {
        //getting the product of the specified position
        final Product product = productList.get(position);

        //binding the data with the viewholder views

        holder.textViewTitle.setText(product.getTitle());


        holder.imageView.setImageDrawable(mCtx.getResources().getDrawable(product.getImage()));

        holder.cardView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Intent i = new Intent(v.getContext(), pdf.class);
                i.putExtra("title",productList.get(position).getTitle());
                i.putExtra("product",productList.get(position).getTitle());
                i.putExtra("link",productList.get(position).getLink());
                mCtx.startActivity(i);

            }
        });
    }


    @Override
    public int getItemCount() {
        return productList.size();
    }


    class ProductViewHolder extends RecyclerView.ViewHolder {

        TextView textViewTitle;
        ImageView imageView;
        CardView cardView;

        public ProductViewHolder(View itemView) {
            super(itemView);
            cardView = itemView.findViewById(R.id.cardview);// card intial
            textViewTitle = itemView.findViewById(R.id.textViewTitle);
            imageView = itemView.findViewById(R.id.imageView);
        }
    }
}

My Pdf Viewer

import android.app.ProgressDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.MenuItem;
import android.widget.Toast;

import com.github.barteksc.pdfviewer.PDFView;


import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;


public class pdf extends AppCompatActivity {
    String link="",productList="",product="";
    PDFView pdfView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_pdf);
        product =getIntent().getStringExtra("title");
        productList=getIntent().getStringExtra("productList");
        link=getIntent().getStringExtra("link");
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        getSupportActionBar().setDisplayShowHomeEnabled(true);
        getSupportActionBar().setTitle(productList);
        pdfView=findViewById(R.id.pdfv);
        //pdfView.fromAsset(link).load();



        if (isConnected()) {
            Toast.makeText(getApplicationContext(), "Internet Connected", Toast.LENGTH_SHORT).show();


        } else {
            Toast.makeText(getApplicationContext(), "No Internet Connection", Toast.LENGTH_SHORT).show();

            AlertDialog.Builder builder = new AlertDialog.Builder(pdf.this);
            builder.setTitle("NoInternet Connection Alert")
                    .setMessage("GO to Setting ?")
                    .setCancelable(false)
                    .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            startActivity(new Intent(android.provider.Settings.ACTION_WIRELESS_SETTINGS));
                        }
                    })
                    .setNegativeButton("No", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            Toast.makeText(pdf.this,"Go Back TO HomePage!",Toast.LENGTH_SHORT).show();
                        }
                    });
            //Creating dialog box
            AlertDialog dialog  = builder.create();
            dialog.show();
        }




        Bundle bundle = getIntent().getExtras();
        if (bundle != null) {
            link = getIntent().getStringExtra("link");
        }
        new pdf.RetrievePDFStream().execute(link);
    }


    public boolean isConnected() {
        boolean connected = false;
        try {
            ConnectivityManager cm = (ConnectivityManager)getApplicationContext().getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo nInfo = cm.getActiveNetworkInfo();
            connected = nInfo != null && nInfo.isAvailable() && nInfo.isConnected();
            return connected;
        } catch (Exception e) {
            Log.e("Connectivity Exception", e.getMessage());
        }
        return connected;
    }


    class RetrievePDFStream extends AsyncTask<String, Void, InputStream> {

        ProgressDialog progressDialog;
        protected void onPreExecute()
        {
            progressDialog = new ProgressDialog(pdf.this);
            progressDialog.setTitle("getting the book content...");
            progressDialog.setMessage("Please wait...");
            progressDialog.setCanceledOnTouchOutside(false);
            progressDialog.show();



        }
        @Override
        protected InputStream doInBackground(String... strings) {
            InputStream inputStream = null;

            try {

                URL urlx = new URL(strings[0]);
                HttpURLConnection urlConnection = (HttpURLConnection) urlx.openConnection();
                if (urlConnection.getResponseCode() == 200) {
                    inputStream = new BufferedInputStream(urlConnection.getInputStream());

                }
            } catch (IOException e) {
                return null;
            }
            return inputStream;

        }

        @Override
        protected void onPostExecute(InputStream inputStream) {
            pdfView.fromStream(inputStream).load();
            progressDialog.dismiss();
        }
    }
    @Override public boolean onOptionsItemSelected(MenuItem item)
    {
        if (item.getItemId() == android.R.id.home)//means home default hai kya yesok
        {
            onBackPressed();
            return true;
        }
        return false;
    }
}

And LAst Product

public class Product {
    private int id;
    private String title;
    private int image;
    private String link;


    public Product(int id, String title,  double price, int image, String link) {
        this.id = id;
        this.title = title;
        this.image = image;
        this.link=link;


    }

    public int getId() {
        return id;
    }

    public String getTitle() {
        return title;
    }


    public int getImage() {
        return image;
    }

    public String getLink() {
        return link;
    }

I just skimmed your code after reading your title so what u want to do is download the file and store it somwhere right? To easily do that I recommend okhttp because that is what I use. See this https://stackoverflow.com/questions/25893030/download-binary-file-from-okhttp and see the answer with 159 upvotes that is what I use. Save the file path to your local db and show it to the user using some pdf viewing library like https://github.com/barteksc/AndroidPdfViewer — Pemba Tamang, Aug 12 '19 at 11:08
I would suggest using an interface to pass the arraylist position in from the adapter to the activity and show an alert if they want to download it or not just to avoid any wanted transitions https://www.youtube.com/watch?v=69C1ljfDvl0 or atleast set the onclick listener to a maybe a download button rather than the entire cardview — Pemba Tamang, Aug 12 '19 at 11:10
`File downloadedFile = new File(context.getCacheDir(), filename)` is what I am referring to. The 3 lines of code after that will save the pdf in the `downloadFile` path. You can use `getFilesDir()` instead of `context.getCacheDir()`and it will give you the internal storage where u do not need to ask permissions and the pdf will be visible only within the app. However if you want it to be visible in the file manager get the external storage permission and give the `downloadFile` object an external path. — Pemba Tamang, Aug 12 '19 at 11:35
I'm sorry I'm pretty newbie, but where should I use File downloadedFile = new File (context.getCacheDir (), filename) — Samat Zhusup, Aug 12 '19 at 11:48
see the comment with 159 upvotes (as of now). Okhttp has an `onResponse(Call call, Response response)` use it there, like the comment says. — Pemba Tamang, Aug 12 '19 at 11:49
bro, I still can’t do it, can you edit my code? to keep it simple save the file privately — Samat Zhusup, Aug 12 '19 at 13:39

score 0 · Answer 1 · answered Aug 12 '19 at 11:08

0

After application download the PDF file to local device, need to update link in your list. Create some database with book information.

answered Aug 12 '19 at 11:08

Александр Волошиновский

1,123
8
21

I think that the database is not needed, I want that when I clicked the button I downloaded the file via "url" + I saved the device to memory, ... – Samat Zhusup Aug 12 '19 at 11:34
ok, you will download the file every time when you open the application, you need to store local path and remote url – Александр Волошиновский Aug 12 '19 at 12:37
https://www.youtube.com/watch?v=rcE4zUiwwbo I want to do 16:21 min until the end of the same method but with place buttons use "RecylerView" – Samat Zhusup Aug 12 '19 at 13:22

how can i save " PDF " file in RecylerView?

My Main Activity

Adapter

My Pdf Viewer

And LAst Product

1 Answers1