@RequiresApi() and @ChecksSdkIntAtLeast() Annotations

@RequiresApi() and @ChecksSdkIntAtLeast() Annotations are used by lint tool in Android Studio to provide proper warning/error messages

One of the things I am confused about in Android development is these lint tool annotations. These annotations do not sound like lint tool annotations to me, but they are.

So, I call them lint tool annotations because it makes them clear to me on their purposes which provides you with the proper lint warning/error messages to you in Android Studio.

@RequiresAPI()

Let’s say you have a function that calls an Android API that requires min SDK 23, anything below 23 won’t work. You annotate @RequiresAPI(23) in your function to let the caller knows that it won't work if the Android device is running below SDK 23.

@RequiresApi(23)
fun callFunctionThatRequiresAPI23() {
   /* code here only applicable for SDK API 23 and above */
}

So, you call it from another function.

fun callerFunction(){
   callFunctionThatRequiresAPI23()
}

You will get this lint error if you’re running on minSdk below 23. This error message is coming from the @RequiresApi(23) annotation that I have in the previous function.

Call requires API level 23 (current min is 21): callFunctionThatRequiresAPI23

If you’re on minSdk 23, you won’t get this error message, and this makes sense because SDK 23 has no problem running the code. Please note that there isn’t any build error here, it is a lint error.

Based on the suggested fix, you annotate the function with @RequiresApi(23) to get rid of the error message.

@RequiresApi(23)
fun callerFunction(){
   callFunctionThatRequiresAPI23()
}

Well, this is wrong! You shouldn’t do this because calling this function on a device that running below 23 won’t work. It defeats the original purpose of the error message.

Instead, you should implement the code for SDK < 23. Without the need to add @RequiresApi(23), the error message goes…