A DESCRIPTION OF THE PROBLEM :
In Java's Calendar.Builder API, when setting an invalid ERA (e.g., ERA = 6) for a Japanese calendar (setCalendarType("japanese")), the build() method throws ArrayIndexOutOfBoundsException instead of the expected IllegalArgumentException.


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
throw IllegalArgumentException.
ACTUAL -
throw ArrayIndexOutOfBoundsException

---------- BEGIN SOURCE ----------
import java.util.Calendar;
class Main {
    public static void main(String[] args) {
        try {
            new Calendar.Builder()
                .setCalendarType("japanese")
                .setFields(Calendar.ERA, 6, Calendar.YEAR, 1, Calendar.MONTH, Calendar.MAY, Calendar.DAY_OF_MONTH, 1)
                .build();
            System.out.println("Test failed: Expected IllegalArgumentException but none was thrown.");
        } catch (IllegalArgumentException e) {
            System.out.println("Test passed: Caught expected IllegalArgumentException.");
        } catch (Exception e) {
            System.err.println("Test failed: Unexpected exception - " + e);
        }
    }
}
---------- END SOURCE ----------