java中对象之间的交互

1.对象之间的联系紧密程度叫耦合，耦合度越高，说明两个对象之间依赖性很强，相互牵扯的。我们理想的模型是对象与对象之间的耦合要尽可能的松，平行的对象要尽量减少直接联系，让更高的对象提供它们之间的通信服务。

2.

public class Main1 {public static void main(String[] args) {java.util.Scanner in = new java.util.Scanner(System.in);Clock clock = new Clock(in.nextInt(), in.nextInt(), in.nextInt());clock.tick();System.out.println(clock);in.close();}}class Clock{private Display hour;private Display minute;private Display second;public Clock(int hour,int minute,int second){this.hour = new Display(24, hour);this.minute = new Display(60, minute);this.second = new Display(60, second);}public void tick(){if(second.increase()){if(minute.increase())hour.increase();}}public String toString(){String s = String.format("%02d:%02d:%02d", hour.getValue(),minute.getValue(),second.getValue());return s;}}class Display{private int value = 0;private int limit = 0;public Display(int limit,int value){this.limit=limit;this.value=value;}public boolean increase(){boolean k = false;value++;if(value==limit){value=0;k = true;}return k;}public int getValue(){return value;}}

这是一个有秒计时的数字时钟。每调用tick()函数，秒钟都会加1。