How to get packageName in companion object?

Question

I want to make a unique key when i send a intent/bundle to new Activity/Fragment in Android.
So, i decided to use packageName.

companion object {
    val MY_UNIQUE_KEY = "${this@Companion::class.java.packageName}MY_KEY"

    fun newInstance(user: User): UserFragment = UserFragment().apply {
        arguments = bundleOf(
            MY_UNIQUE_KEY  to user
        )
    }
}

But, in this case, i couldn't use this@Companion::class.java.packageName because the android system warns me that it requires API 31(mine supports API 21).

How can i make it? or could you tell me another good way?

score 1 · Accepted Answer · answered Jan 06 '23 at 18:15

1

You may use the package field for the same. Like so:

val MY_UNIQUE_KEY = "${this@Companion::class.java.`package`?.name.orEmpty()}MY_KEY"

answered Jan 06 '23 at 18:15

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1

Thank you so much! By the way, i realized that `this@Companion::class.java.name` is much specific and unique than `this@Companion::class.java.`package`?.name.orEmpty()`. – CodingBruceLee Jan 09 '23 at 01:09

score 0 · Answer 2 · answered Jan 06 '23 at 06:33

Try this code

fun newInstance(user: User): UserFragment = UserFragment().apply {
    arguments = bundleOf(
        if (VERSION.SDK_INT >= VERSION_CODES.S) {
            "${javaClass.packageName}MY_KEY" to user
        } else {
            "${javaClass.getPackage()?.name.orEmpty()}MY_KEY" to user
        }
    )
}

OR just create Unique Constant String value for each Fragment/Activity.

How to get packageName in companion object?

2 Answers2