Check if global file exists on internal storage

Question

Im trying to create a file with one app, and check if it exists with another app. What im tryin to achieve is global file in cache, which can be accessed by any app on the device. I've read this: this and this one. But seems I am lost. I'm getting new file created every time I check from another app, did first app created a file.

private boolean doesFileExist() {
        File file = new File(this.getCacheDir().toString() + "myfile");
        if(file.exists()) {
            return true;
        }
        else return false;
    }

    private void createFileForMe() {
        File file = new File(this.getCacheDir().toString() + "myfile", "myfile");
        file.setReadable(true, false);
        Log.v("FILE", "created file");
    }

public void onCreate() {
        super.onCreate();
            if (!doesFileExist()) {
                Log.v("FILE", "FILE DOESnt EXIST");
                createFileForMe();
            } else Log.v("FILE", "FILE DOES EXIST");
    }

Answer 1

Android Javadoc of the getCacheDir() says:

Returns the absolute path to the application specific cache directory on the filesystem.

It means that it's available ONLY to single app. The same method returns different location for your second application. These apps can't share cache using mentioned method.

You have to pick another location for sharing your data. Please note that most of the space of internal storage is restricted. Maybe it's better to use built in external storage (logically external, not sdcard).

Update

I see 2 options:

• Store data on external storage in public location, you can read about it here
• Use ContentProvider to share your private data on internal storage to the other app,you can read about it here