java的克隆

Employee.java：

package clone;
import java.util.Date;
import java.util.GregorianCalendar;
public class Employee implements Cloneable{
    private String name;
    private double salary;
    private Date hireDay;

    public Employee(String n,double s){
        name=n;
        salary=s;
        hireDay=new Date();
    }

    public Employee clone() throws CloneNotSupportedException{
        Employee cloned = (Employee)super.clone();
        cloned.hireDay=(Date)hireDay.clone();
        return cloned;
    }

    public void setHireDay(int year,int month,int day){
        Date newHireDay = new GregorianCalendar(year,month-1,day).getTime();
        hireDay.setTime(newHireDay.getTime());
    }

    public void raiseSalary(double byPercent){
        double raise = salary * byPercent / 100;
        salary+=raise;
    }

    public String toString(){
        return "Employee[name="+name+",salary="+salary+",hireDay="+hireDay+"]";
    }
}

cloneTest.java

package clone;
public class cloneTest{
    public static void main(String[] args){
        try {
            Employee original = new Employee("John Q.Public", 50000);
            original.setHireDay(2000, 1, 1);
            Employee copy = original.clone();
            copy.raiseSalary(10);
            copy.setHireDay(2002, 12, 31);
            System.out.println("original="+original);
            System.out.println("copy="+copy);
        } catch (CloneNotSupportedException e) {
            e.printStackTrace();
        }
    }
}

定时器的使用

package timer;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
import javax.swing.Timer;

public class TimerTest {
    public static void main(String[] args) {
        //构造这个类的一个对象将其 传递给Timer构造器
        ActionListener listener = new TimePrinter();
        Timer t = new Timer(10000,listener);
        //第一个参数是发出通告的时间间隔，单位是毫秒
        //第二个参数是监听器对象
        //意思是  每隔10000毫秒通告listener一次 

        t.start();
        //启动定时器，一旦启动成功，当到达指定的时间间隔时，定时器将调用监听器的actionPerformed方法

        JOptionPane.showMessageDialog(null, "Quit program?");
        System.exit(0);
    }
}

//实现java.awt.event包中的ActionListener接口
//到达指定的时间间隔时，定时器就调用actionPerformed方法

class TimePrinter implements ActionListener{
    public void actionPerformed(ActionEvent event){
    Date now = new Date();
    System.out.println("At the tone,the time is"+now);
    Toolkit.getDefaultToolkit().beep();
    //获得默认的工具箱，发出一声玲响
    }
}

内部类的一个例子

package innerClass;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
import javax.swing.Timer;

public class InnnerClassTest {
    public static void main(String[] args) {
        TalkingClock clock = new TalkingClock(1000,true);
        clock.start();

        JOptionPane.showMessageDialog(null, "Quit program?");
        System.exit(0);
    }
}

class TalkingClock{
    private int interval;
    private boolean beep;

    public TalkingClock(int interval,boolean beep){
        this.interval=interval;
        this.beep=beep;
    }

    public void start(){
        ActionListener listener = new TimePrinter();
        Timer t = new Timer(interval, listener);
        t.start();
    }

    public class TimePrinter implements ActionListener{
        public void actionPerformed(ActionEvent event){
            Date now = new Date();
            System.out.println("At the tone,the time is" + now);
            if(beep) Toolkit.getDefaultToolkit().beep();
        }
    }
}