Android 无法理解 kotlin 函数

Question

I am not very well versed with Kotlin and I am preferring Java over Kotlin while learning Android. But I am stuck at a piece of code which is as follows:

private fun getOutputDirectory(): File {
       val mediaDir = externalMediaDirs.firstOrNull()?.let {
           File(it, resources.getString(R.string.app_name)).apply { mkdirs() } }
       return if (mediaDir != null && mediaDir.exists())
           mediaDir else filesDir
}

The following function is called in onCreate method as var outputDirectory: File = getOutputDirectory();

Can you please help me convert the code into Java and in understanding it? Thank you.

Answer 1

here is the process on how to convert Kotlin code to Java code. https://www.geeksforgeeks.org/how-to-convert-kotlin-code-to-java-code-in-android-studio/

But I suggest you to learn Kotlin as it is faster and preffered for Android app development.

Answer 2

    private File getOutputDirectory() {
        File mediaDir = null;
        if (getExternalMediaDirs().size > 0) {
            mediaDir = new File(getExternalMediaDirs()[0], getResources().getString(R.string.app_name));
            mediaDir.mkdirs();
        }
        
        return if (mediaDir != null && mediaDir.exists())
         mediaDir
        else 
        filesDir
        
    }