An alternative to DateTimeFormatter in Android API-21

Question

My app is crashing when I run it. It worked the first time I built and compile it but now it doesn't. I think this is due to the "DateTimeFormatter" not being able to be used in my current api level 21. Is there a workaround this?

Here is the error:

java.lang.NoClassDefFoundError: Failed resolution of: Ljava/time/format/DateTimeFormatter;

Here is the code that is affected:

@RequiresApi(api = Build.VERSION_CODES.O)
public boolean checkTimeAgainstCurrentTime(String time) throws ParseException {
    boolean isTime = false;
    DateTimeFormatter parser = DateTimeFormatter.ofPattern("h:mma", Locale.ENGLISH);
    DateTimeFormatter formatter = DateTimeFormatter.ofPattern("HH:mm");
    LocalTime theTime = LocalTime.parse(time, parser);
    Date time1 = new Date(System.currentTimeMillis());
    Date time2 = new SimpleDateFormat("HH:mm:ss").parse(theTime + ":00");
    time1.setHours(time2.getHours());
    time1.setMinutes(time2.getMinutes());
    SimpleDateFormat dateFormat = new SimpleDateFormat("HH:mm:ss");
    dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
    Date today = Calendar.getInstance().getTime();
    today.setHours(today.getHours()+8);
    if (today.after(time1)) {
        isTime = true;
    }
    // If true, means expired.
    return isTime;
}

Answer 1

You can enable API Desugaring for backwards compatibility, here https://developer.android.com/studio/write/java8-support#library-desugaring are the instructions for it but essentially you will have to add one line of code, as shown below in the app level build.gradle.

android {
  compileOptions {
    coreLibraryDesugaringEnabled true
  }
}

and you need a dependency

dependencies {
  coreLibraryDesugaring 'com.android.tools:desugar_jdk_libs:1.0.9'
}