Answer:
public class AmericanTimeFormatting {
public static String convertTime(String amerFormat)
{
if(amerFormat.length()<8) {
System.out.println("Length of the input string should be 8");
return null;
}
else if(!Character.isDigit(amerFormat.charAt(0)) && !Character.isDigit(amerFormat.charAt(1)) && !Character.isDigit(amerFormat.charAt(3)) && Character.isDigit(amerFormat.charAt(4))) {
System.out.println("Digit is requird");
return null;
}
else if(amerFormat.charAt(2)!=':'|| amerFormat.charAt(7)!='.') {
System.out.println("Punctuation required");
return null;
}
//Am or Pm specification check
else if(!amerFormat.substring(5,7).equals("PM") && !amerFormat.substring(5,7).equals("AM")){
System.out.println("Required PM or AM");
return null;
}
else {
//For PM
if(amerFormat.substring(5,7).equals("PM")) {
String time="";
int hour=Integer.parseInt(amerFormat.substring(0,2));
hour=24-(12-hour);
time+=String.valueOf(hour)+":";
int minute=Integer.parseInt(amerFormat.substring(3,5));
time+=minute;
return time;
}
//For AM
else {
return amerFormat.substring(0,5);
}
}
}
public static void main(String[] args) {
String time=convertTime("06:12PM.");
if(!time.equals(null)) {
System.out.println("Time is "+time);
}
}
}
