Class TimeOfDay

java.lang.Object

TimeOfDay

public class TimeOfDay
extends Object

A class that represents the time of day in hours and minutes such as might be used on a digital alarm clock. Times before noon (AM) are different from times from noon onwards (PM).

Times start at 12:00 AM (midnight) and go up to 11:59 PM.

Constructor Summary

Constructors

Constructor	Description
TimeOfDay()	Initializes this time to 12:00 AM (midnight).
TimeOfDay(int hour, int minute, boolean isAM)	Initializes this time to the specified hours and minutes.
TimeOfDay(TimeOfDay other)	Initializes this time by copying the hour, minute, and AM/PM indicator form another TimeOfDay instance.

Method Summary

Modifier and Type	Method	Description
TimeOfDay	advance(int minutes)	Advances the time forward by the specified number of minutes, or winds back the time by the specified number of minutes if minutes is negative.
int	getHour()	Returns the hour of this time.
int	getMinute()	Returns the minute of this time.
boolean	isAM()	Returns true if the time is before noon, and false otherwise.
TimeOfDay	setHour(int hour)	Sets the hour of this time to the specified hour.
TimeOfDay	setMinute(int minute)	Sets the minute of this time to the specified minute.
String	toString()	Returns a string representation of this time.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

TimeOfDay

public TimeOfDay()

Initializes this time to 12:00 AM (midnight).

TimeOfDay

public TimeOfDay(int hour,
                 int minute,
                 boolean isAM)

Initializes this time to the specified hours and minutes. If isAM is true then the time is before noon, otherwise the time is from noon onwards.

Parameters:

hour - the hour of this time

minute - the minute of this time

isAM - if true then the time is before noon, otherwise the time is from noon onwards

Throws:

IllegalArgumentException - if hour is not between 1 and 12, inclusive

IllegalArgumentException - if minute is not between 0 and 59, inclusive

TimeOfDay

public TimeOfDay(TimeOfDay other)

Initializes this time by copying the hour, minute, and AM/PM indicator form another TimeOfDay instance.

Parameters:

other - the time to copy

Method Detail

getHour

public int getHour()

Returns the hour of this time. The returned value is between 1 and 12, inclusive.

Returns:

the hour of this time

getMinute

public int getMinute()

Returns the minute of this time. The returned value is between 0 and 59, inclusive.

Returns:

the minute of this time

setHour

public TimeOfDay setHour(int hour)

Sets the hour of this time to the specified hour.

Parameters:

hour - the new hour of this time

Returns:

a reference to this object

Throws:

IllegalArgumentException - if hour is not between 1 and 12, inclusive

setMinute

public TimeOfDay setMinute(int minute)

Sets the minute of this time to the specified minute.

Parameters:

minute - the new minute of this time

Returns:

a reference to this object

Throws:

IllegalArgumentException - if minute is not between 0 and 59, inclusive

isAM

public boolean isAM()

Returns true if the time is before noon, and false otherwise.

Returns:

true if the time is before noon, and false otherwise

advance

public TimeOfDay advance(int minutes)

Advances the time forward by the specified number of minutes, or winds back the time by the specified number of minutes if minutes is negative. For example, if the current time is 10:15 AM then advancing the time by +3 minutes changes the time to 10:18 AM. If the current time is 10:15 AM then advancing the time by -3 minutes changes the time to 10:12 AM.

The time can be advanced past the end of the day in which case the time wraps around towards the start of the day. For example, if the current time is 11:59 PM then advancing the time by +2 minutes changes the time to 12:01 AM.

Similarly, the time can be wound back past the start of the day, in which case the time wraps around towards the end of the day. For example, if the current time is 12:01 AM then advancing the time by -2 minutes changes the time to 11:59 PM.

Parameters:

minutes - the number of minutes to advance the time

Returns:

a reference to this object

toString

public String toString()

Returns a string representation of this time. The string representation is the hour followed by a colon followed by the minutes followed by a space followed by the string "AM" or "PM". For example the string representation of the time five minutes after three in the afternoon is the string equal to "3:05 PM".

Overrides:

toString in class Object

Returns:

a string representation of this time