//Fig. 8.1: Time1java
//Time1 class declaration maintains the time in 24-hour format.
public class Time1
{
int hour;
int minute;
int second;
public void setTime( int h, int m, int s)
{
if ( ( h >= 0 && h < 24 ) && ( m >= 0 && m < 60 ) &&
( s >= 0 && s < 60 ) )
{
hour = h;
minute = m;
second = s;
}
else
throw new IllegalArgumentException(
"hour, minute and/our second was out of range");
}
public String toUniversalString()
{
return String.format("%02d:02d:%02d", hour,minute,second);
}
public String toString()
{
return String.format("%d:%d02:%d02 %s",
( ( hour == 0 || hour == 12 ) ? 12 : hour % 12 ),
minute, second, (hour < 12 ? "AM" : "PM" ) ) ;
}
}
// Fig.8.2: Time1Test.java
// Time1 object used in a application.
public class Time1Test
{
public static void main( String[] args )
{
Time1 time = new Time1();
System.out.print( "The initial universal time is: ");
System.out.println(time.toUniversalString() );
System.out.print( "The initial standard time is: ");
System.out.println(time.toString() );
System.out.println();
time.setTime( 13, 27, 6);
System.out.print( "Universal time after setTime is: ");
System.out.println(time.toUniversalString() );
System.out.print("Standard time after setTime is: ");
System.out.println( time.toString() );
System.out.println();
try
{
time.setTime( 99, 99 , 99 );
}
catch ( IllegalArgumentException e )
{
System.out.printf( "Exception: %s\n\n", e.getMessage() );
}
System.out.println( "After attempting invalid settings:");
System.out.print( "Universal time: ");
System.out.println(time.toUniversalString() );
System.out.print("Standard time: ");
System.out.println( time.toString() );
}
}
Output :
// Fig. 8.3: MemberAccsessTest.java
// Private members of class Time1 are not accessible.
public class MemberAccsessTest
{
public static void main(String[] args)
{
Time1 time = new Time1();
time.hour = 7;
time.minute = 15;
time.second = 30;
}
}
// Fig. 8.4: ThisTest.java
// this used implicity and explicitly to refer
to members of an object.
public class ThisTest
{
public static void main( String[] args )
{
SimpleTime time = new SimpleTime( 15, 30, 19);
System.out.println( time.buildString() );
}
}
class SimpleTime
{
private int hour;
private int minute;
private int second;
public SimpleTime( int hour, int minute, int second)
{
this.hour = hour;
this.minute = minute;
this.second = second;
}
public String buildString()
{
return String.format( "%24s: %s\n%24s: %s",
"this.toUniversalString()",this.toUniversalString(),
"toUniversalString()",toUniversalString() );
}
public String toUniversalString()
{
return String.format("%02d:%02d:%02d",
this.hour, this.minute, this.second );
}
}
Output :
// Fig. 8.5: Time2.java
//Time2 class delcaration with overloaded constructions.
public class Time2
{
private int hour;
private int minute;
private int second;
public Time2()
{
this( 0, 0, 0 );
}
public Time2( int h )
{
this( h, 0, 0 );
}
public Time2( int h, int m )
{
this( h, m, 0 );
}
public Time2( int h, int m, int s )
{
setTime( h, m, s );
}
public Time2( Time2 time )
{
this( time.getHour(), time.getMinute(), time.getSecond() );
}
public void setTime( int h, int m, int s )
{
setHour( h );
setMinute( m );
setSecond( s );
}
public void setHour( int h )
{
if ( h>= 0 && h < 24 )
hour = h;
else
throw new IllegalArgumentException("hour must be 0-23");
}
public void setMinute( int m )
{
if (m >= 0 && m < 60)
minute = m;
else
throw new IllegalArgumentException("minute must be 0-59");
}
public void setSecond( int s )
{
if (s >= 0 && s < 60 )
second = ( ( s >= 0 && s < 60 ) ? s : 0 );
else
throw new IllegalArgumentException("second must be 0-59");
}
public int getHour()
{
return hour;
}
public int getMinute()
{
return minute;
}
public int getSecond()
{
return second;
}
public String toUniversalString()
{
return String.format(
"%02d:%02d:%02d", getHour(), getMinute(), getSecond() );
}
public String toString()
{
return String.format("%d:%02d:%02d %s",
( (getHour() == 0 || getHour() == 12) ? 12 : getHour() % 12),
getMinute(), getSecond(), ( getHour() < 12 ? "AM" : "PM" ) );
}
}
// Fig. 8.6: Time2Test.java
// Overloaded constructors used to initialize Time2 object.
public class Time2Test
{
public static void main( String[] args )
{
Time2 t1 = new Time2();
Time2 t2 = new Time2( 2 );
Time2 t3 = new Time2( 21, 34 );
Time2 t4 = new Time2( 12, 25, 42 );
Time2 t5 = new Time2( t4 );
System.out.println( "Constructed with: " );
System.out.println( "t1: all argument defaulted" );
System.out.printf( " %s\n", t1.toUniversalString() );
System.out.printf( " %s\n", t1.toString() );
System.out.println(
"t2: hour specified; minute and second defaulted" );
System.out.printf( " %s\n", t2.toUniversalString() );
System.out.printf( " %s\n", t2.toString() );
System.out.println(
"t3: hour and minute specified; second defaulted" );
System.out.printf( " %s\n", t3.toUniversalString() );
System.out.printf( " %s\n", t3.toString() );
System.out.println( "t4: hour, minute and second specified" );
System.out.printf( " %s\n", t4.toUniversalString() );
System.out.printf( " %s\n", t4.toString() );
System.out.println( "t5: Time2 object t4 specified" );
System.out.printf( " %s\n", t5.toUniversalString() );
System.out.printf( " %s\n", t5.toString() );
try
{
Time2 t6 = new Time2( 27, 74, 99 );
}
catch ( IllegalArgumentException e )
{
System.out.printf( "\nException while initializing t6: %s\n",
e.getMessage() );
}
}
}
Output :
