Correct path to save file in Android

Question

I'm trying to write an app for Android and I need to save the resposne from a server, I managed to do it by saving it in a txt file in this path:

String path= "/storage/emulated/0/Android/data/com.example.simone.pizzino/files/response.txt"; final File file = new File(path);

Testing it on my friend's phone he can't see the folder at that path, his path is something like data/data/"packageName", it doesnt work on the emulator in Android Studio either. My phone is a Nexus 5X running 7.1 stock rom. My friend is rooted using 6.1. Is there some way to get a dynamic path to the application folder without having to state it as a constant?

Sorry if this question was already asked but I counldn't find a solution for my problem.

Answer 1

First thing you have to do is to add permission to access external storage in your manifest file

 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

Save a File on Internal Storage

File file = new File(context.getFilesDir(), filename);
String filename = "myfile";
String string = "Hello world!";
FileOutputStream outputStream;

try {
 outputStream = openFileOutput(filename, Context.MODE_PRIVATE);
 outputStream.write(string.getBytes());
 outputStream.close();
} catch (Exception e) {
   e.printStackTrace();
}

public File getTempFile(Context context, String url) {
   File file;
try {
    String fileName = Uri.parse(url).getLastPathSegment();
    file = File.createTempFile(fileName, null, context.getCacheDir());
} catch (IOException e) {
    // Error while creating file
}
return file;
}

Save a File on External Storage

/* Checks if external storage is available for read and write */
public boolean isExternalStorageWritable() {
String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)) {
    return true;
}
return false;
}

/* Checks if external storage is available to at least read */
public boolean isExternalStorageReadable() {
String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state) ||
    Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) {
    return true;
}
return false;
}

public File getAlbumStorageDir(String albumName) {
// Get the directory for the user's public pictures directory.
File file = new File(Environment.getExternalStoragePublicDirectory(
        Environment.DIRECTORY_PICTURES), albumName);
if (!file.mkdirs()) {
    Log.e(LOG_TAG, "Directory not created");
}
return file;
}