CODEWITHSUNDEEP
androidkotlin
Sajid Anam
Sajid Anam

Reputation: 139

file.exists() returns different value for same file in different activity

My app downloads PDF files. So in some activities I need to check which files are available to do some operation. I am using the below code to check if the file is available -

val file = File(getDir(book))

if (file.exists()) {
   // do some stuff
} else {
   // do other stuff
}

Here is the code for getDir function -

fun getDir(book: Book): String {
  return Environment.getExternalStorageDirectory().toString() + File.separator +
      "PDF FOLDER/${book.layer_name}/${book.class_name}/${book.name}.pdf"
}

This piece of code is working perfectly in Activity 1 where the file is downloaded from. But When I go to Activity 2 this method says the file does not exist.

I logged getDir(book) from both activities and they are 100% same. The logs are below - 

E/loggg: /storage/emulated/0/PDF FOLDER/Primary/Class1/my_book.pdf
E/loggg: /storage/emulated/0/PDF FOLDER/Primary/Class1/my_book.pdf

And when I download files from Activity 2 the codes works perfectly again.

What could be the reason behind this problem? I can't see any problem in my code. Any help would be appreciated. Thanks.

Upvotes: 0

Views: 114

Answers (2)

Sajid Anam
Sajid Anam

Reputation: 139

SOLUTION

After a while I found the problem. Still don't know the exact reason.

After downloading the PDF I was opening another activity from Activity 1(from where the file is downloaded) to read the PDF file without finishing Activity 1. Then when I went back to Activity 2(Bookmark activity) file.exist() was returning false.

But if I finish Activity 1 after downloading the file and head back to Activity 2 file.exist() is returning true.

Upvotes: 1

Abner Escócio
Abner Escócio

Reputation: 2785

For a job safe, try use a interface where this code is shared, this avoid duplicate codes and this diminishes the cases like this (where the same code block not work)

Try

open class ActivityBase: AppCompatActivity {
    protected fun getDir(book: Book): String {
        return Environment.getExternalStorageDirectory().toString() + File.separator + 
        "PDF FOLDER/${book.layer_name}/${book.class_name}/${book.name}.pdf"
    }
}

class Activity1: ActivityBase

class Activity2: ActivityBase

Maybe this above code be helpfull to you

Upvotes: 2

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