我编了一个包Time2,并用TimeTest4来调用,可是在调用的过程中,却出现了点问题,请高手支招.
TimeTest4.java如下:
import javax.swing.*;
import c.czg.Time2;

public class TimeTest4 {
public static void main ( String args[] )
{
Time2 t1,t2,t3,t4,t5,t6;

t1 = new Time2 ();
t2 = new Time2 ( 2 );
t3 = new Time2 ( 21,34 );
t4 = new Time2 ( 12,25,42 );
t5 = new Time2 ( 27,74,99 );
t6 = new Time2 ( t4 );

String output = "Constructed with:" +
"\nt1: all arguments defaluted" +
"\n " + t1.toUniversalString() +
"\n " + t1.toString();

output += "\nt2:hour specified;minute and " +
"second defaluted" +
"\n " + t2.toUniversalString() +
"\n " + t2.toString();

output += "\nt3:hours,minute,and specified" +
"\n " + t3.toUniversalString() +
"\n " + t3.toString();

output += "\nt4:hours,minute,second specified" +
"\n " + t4.toUniversalString() +
"\n " + t4.toString();

output += "\nt5:all invalid values specified" +
"\n " + t5.toUniversalString() +
"\n " + t5.toString();

output += "\nt6:Time2 object t4 specified " +
"\n " + t6.toUniversalString() +
"\n " + t6.toString();

JOptionPane.showMessageDialog( null,output,"Demonstrating Overloaded Contstuctors",
JOptionPane.INFORMATION_MESSAGE );

System.exit(0);
}
}
Time2.java如下:
package c.czg;

import java.text.DecimalFormat;

public class Time2 extends Object {
private int hour ;
private int minute ;
private int second ;

public Time2 ()
{
setTime ( 0, 0, 0);
}

public void setTime ( int h,int m,int s )
{
hour = ( ( h>=0 && h<24 )? h:0 );
minute = ( ( m>=0 && m<60 )? m:0 );
second = ( ( s>=0 && s<60 )? s:0 );
}

public String toUniversalString ()
{
DecimalFormat two = new DecimalFormat ( "00" );

return two.format ( hour ) + ":" +
two.format ( minute ) + ":" +
two.format ( second );
}

public String toString ()
{
DecimalFormat two = new DecimalFormat ( "00" );

return ( ( hour==12 || hour ==0 )? 12:hour%12 ) +
":" + two.format ( minute ) +
":" + two.format ( second ) +
( hour < 12 ? "AM" : "PM" );
}
}