How to open a pdf stored either in res/raw or assets folder?

You cannot open the pdf file directly from the assets folder.You first have to write the file to sd card from assets folder and then read it from sd card.The code is as follows:-

     @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    File fileBrochure = new File(Environment.getExternalStorageDirectory() + "https://stackoverflow.com/" + "abc.pdf");
    if (!fileBrochure.exists())
    {
         CopyAssetsbrochure();
    } 

    /** PDF reader code */
    File file = new File(Environment.getExternalStorageDirectory() + "https://stackoverflow.com/" + "abc.pdf");      

    Intent intent = new Intent(Intent.ACTION_VIEW);
    intent.setDataAndType(Uri.fromFile(file),"application/pdf");
    intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    try 
    {
        getApplicationContext().startActivity(intent);
    } 
    catch (ActivityNotFoundException e) 
    {
         Toast.makeText(SecondActivity.this, "NO Pdf Viewer", Toast.LENGTH_SHORT).show();
    }
}

//method to write the PDFs file to sd card
    private void CopyAssetsbrochure() {
        AssetManager assetManager = getAssets();
        String[] files = null;
        try 
        {
            files = assetManager.list("");
        } 
        catch (IOException e)
        {
            Log.e("tag", e.getMessage());
        }
        for(int i=0; i<files.length; i++)
        {
            String fStr = files[i];
            if(fStr.equalsIgnoreCase("abc.pdf"))
            {
                InputStream in = null;
                OutputStream out = null;
                try 
                {
                  in = assetManager.open(files[i]);
                  out = new FileOutputStream(Environment.getExternalStorageDirectory() + "https://stackoverflow.com/" + files[i]);
                  copyFile(in, out);
                  in.close();
                  in = null;
                  out.flush();
                  out.close();
                  out = null;
                  break;
                } 
                catch(Exception e)
                {
                    Log.e("tag", e.getMessage());
                } 
            }
        }
    }

 private void copyFile(InputStream in, OutputStream out) throws IOException {
        byte[] buffer = new byte[1024];
        int read;
        while((read = in.read(buffer)) != -1){
          out.write(buffer, 0, read);
        }
    }

Thats all..Enjoy!! and please dont forget to give +1.Thanks