Understanding the interaction of Java objects: Clock display program

Realize:

Structure:

Object: Clock-object: Hour

-Object: Minutes

• Hours and minutes have the same attribute (value, upper limit), and you can define both objects with a class display.
• But there is a connection between the two (when the minute reaches the upper limit, the hour will add 1), then another class clock to manage them;
• First, the clock class is used to define a clock object, which is used to manage two display type objects, which is the member variable of Clock (min,hour), to manage the relationship between them, and then do the display;
• Summary: There are two objects inside an object.

Package Clock:

• >>class dispaly
• >>class Clock

1  Packageclock;2 3  Public classDisplay {4     intValue = 0;5     intLimit = 0;6     7Display (intlimit) {8          This. Limit =limit;9     }Ten  One     voidIncrease () { A++value; -         if(Value = =limit) { -Value = 0; the         } -     } -      -     intGetValue () { +         returnvalue; -     } +      A      Public Static voidMain (string[] args) {//Test atDisplay min =NewDisplay (60); -          for(;;) { - min.increase (); - System.out.println (Min.getvalue ()); -         } -     } in      -}

Display.java

1  Packageclock;2 3  Public classClock {4Display min =NewDisplay (60);5Display hour =NewDisplay (24);6     7     voidstart () {8 min.increase ();9         if(Min.getvalue () ==0) {Ten hour.increase (); One         } A     } -      -      Public Static voidMain (string[] args) { theClock Clock =NewClock (); -          for(;;) { - Clock.start (); -System.out.printf ("%02d:%02d\n", Clock.hour.getvalue (), Clock.min.getvalue ()); +         } -     } +  A}

Clock.java

Understanding the interaction of Java objects: Clock display program