Question

When I compile this code by compiler compliance level 6.0 in eclipse then it compile fine but when I change compiler level 4.0 then this code shows error that Incompatible Conditional operand types String and Integer. What is the problem and changes this code need to get the same result

Calendar cal = Calendar.getInstance();
String timeStr = (calendar.get(Calendar.HOUR_OF_DAY) < 10 ?    
    "0" + Integer.valueOf(calendar.get(Calendar.HOUR_OF_DAY)) :       
    Integer.valueOf(calendar.get(Calendar.HOUR_OF_DAY))) + ":" + 
        (calendar.get(Calendar.MINUTE) < 10 ? 
        "0" + Integer.valueOf(calendar.get(Calendar.MINUTE)) : 
        Integer.valueOf(calendar.get(Calendar.MINUTE)));

Answer 1

Why not just use SimpleDateFormat to get the same result, like this:

Calendar cal = Calendar.getInstance();
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm");
String timeStr = sdf.format(cal.getTime());

It works with the compiler compliance level set to 1.4.

Edit: for reference if SimpleDateFormat didn’t exist, I’d recommend writing it something like this:

int hour = calendar.get(Calendar.HOUR_OF_DAY);
int minute = calendar.get(Calendar.MINUTE);
String timeStr = (hour < 10 ? "0" : "") + hour + ":"
        + (minute < 10 ? "0" : "") + minute;