How do I cast a String to an int ? HELP !

Question

Dear Java People,
If I have a program that outputs a String of the time ie
09:25
How do I code in Java to check this String to see if it is greater than 12 o'clock and if so tack on a String of "PM'.....
I tried
if ((int) hours.getDisplayValue()> 12 )
to attempt to add "PM" at the end of the String
The error message says:
"ClockDisplay.java": Error cannot cast java.lang.String to int at line 88, column 12
below is the program
Thank you in advance
Stan
* The ClockDisplay class implements a digital clock display for a
* European-style 24 hour clock. The clock shows hours and minutes. The
* range of the clock is 00:00 (midnight) to 23:59 (one minute before
* midnight).
* The clock display receives "ticks" (via the timeTick method) every minute
* and reacts by incrementing the display. This is done in the usual clock
* fashion: the hour increments when the minutes roll over to zero.
* @author Michael Kolling and David J. Barnes
* @version 2001.05.26
public class ClockDisplay
private NumberDisplay hours;
private NumberDisplay minutes;
private String displayString; // simulates the actual display
* Constructor for ClockDisplay objects. This constructor
* creates a new clock set at 00:00.
public ClockDisplay()
hours = new NumberDisplay(24);
minutes = new NumberDisplay(60);
updateDisplay();
* Constructor for ClockDisplay objects. This constructor
* creates a new clock set at the time specified by the
* parameters.
public ClockDisplay(int hour, int minute)
hours = new NumberDisplay(24);
minutes = new NumberDisplay(60);
setTime(hour, minute);
* This method should get called once every minute - it makes
* the clock display go one minute forward.
public void timeTick()
minutes.increment();
if(minutes.getValue() == 0) { // it just rolled over!
hours.increment();
updateDisplay();
* Set the time of the display to the specified hour and
* minute.
public void setTime(int hour, int minute)
//Exercise 3.19 This condition will insure that it will be a 12 hour clock
if(hour > 12)
hour = hour - 12;
hours.setValue(hour);
minutes.setValue(minute);
updateDisplay();
* Return the current time of this display in the format HH:MM.
public String getTime()
return displayString;
* Update the internal string that represents the display.
private void updateDisplay()
if ((int) hours.getDisplayValue() > 12 )
displayString = hours.getDisplayValue() + ":" +
minutes.getDisplayValue() ;
* The NumberDisplay class represents a digital number display that can hold
* values from zero to a given limit. The limit can be specified when creating
* the display. The values range from zero (inclusive) to limit-1. If used,
* for example, for the seconds on a digital clock, the limit would be 60,
* resulting in display values from 0 to 59. When incremented, the display
* automatically rolls over to zero when reaching the limit.
* @author Michael Kolling and David J. Barnes
* @version 2001.05.26
public class NumberDisplay
private int limit;
private int value;
* Constructor for objects of class Display
public NumberDisplay(int rollOverLimit)
limit = rollOverLimit;
value = 0;
* Return the current value.
public int getValue()
return value;
* Return the display value (that is, the current value as a two-digit
* String. If the value is less than ten, it will be padded with a leading
* zero).
public String getDisplayValue()
if(value < 10)
return "0" + value;
else
return "" + value;
* Set the value of the display to the new specified value. If the new
* value is less than zero or over the limit, do nothing.
public void setValue(int replacementValue)
if((replacementValue >= 0) && (replacementValue < limit))
value = replacementValue;
* Increment the display value by one, rolling over to zero if the
* limit is reached.
public void increment()
value = (value + 1) % limit;
public class TryClockDisplay
public static void main(String[] args)
ClockDisplay clockDisplay_1 = new ClockDisplay();
clockDisplay_1.setTime(17,40);
System.out.println("\nThe time now is " + clockDisplay_1.getTime());
clockDisplay_1.timeTick();
clockDisplay_1.timeTick();
clockDisplay_1.timeTick();
clockDisplay_1.timeTick();
clockDisplay_1.timeTick();
clockDisplay_1.timeTick();
clockDisplay_1.timeTick();
System.out.println("\nThe time now is " + clockDisplay_1.getTime());

Answer 1

String time = "09:25";
String hrs = time.substring(0,2);
int hrsInt = Integer.parseInt(hrs);
if(hrsInt>12){
    time += "PM";
System.out.println(time);