if(android.os.Build.VERSION.SDK_INT ==  android.os.Build.VERSION_CODES.LOLLIPOP){
    // Code For Android Version higher equal to LOLLIPOP(21)
} else if(android.os.Build.VERSION.SDK_INT > 21){
    // Code For Android Version higher than LOLLIPOP(21)
} else{
    // Code For Android Version lower than LOLLIPOP(21)
}