Java关于克隆与“冷藏”和“解冻”方法_Java教程

import Java.awt.Point;
import java.io.IOException;

import com.sun.corba.se.impl.io.OptionalDataException;

/**
* 克隆测试<br>
* 以方形类为例，比较了深克隆(deep clone)与浅克隆(shallow clone)的异同
*
* @see #clone()
* @author 88250
* @version 1.0.0, 2007-8-26
*/
public class CloneTester
{
private Square square = new Square();

private Square cpySquare = null;

    /**
     * 浅克隆操作
     */
    public void shallowClone()
    {
    square.setSideLength(2);
    square.setLocation(new Point(2, 5));
    // 浅克隆
    cpySquare = (Square) square.clone();

}

    /**
     * 深克隆操作
     */
    public void deepClone()
    {
    square.setSideLength(3);
    square.setLocation(new Point(1, 3));
    // 深克隆
    try
    {
        cpySquare = (Square) square.deepClone();
    }
    catch (OptionalDataException e)
    {
        e.printStackTrace();
    }
    catch (IOException e)
    {
        e.printStackTrace();
    }
    catch (ClassNotFoundException e)
    {
        e.printStackTrace();
    }
    }

    /**
     * 克隆结果输出
     */
    public void cloneDisplay()
    {

System.out.println("原始方形长度：" + square.getSideLength());
System.out.println("克隆方形长度：" + cpySquare.getSideLength());

System.out.println("原始方形==克隆方形?" + (square == cpySquare));

    System.out.println("原始方形的位置==克隆方形的位置?"
        + (square.getLocation() == cpySquare.getLocation()));
    }

    public static void main(String[] args)
    {
    CloneTester sm = new CloneTester();
    sm.shallowClone();
    sm.cloneDisplay();

    sm.deepClone();
    sm.cloneDisplay();
    }
}

import java.awt.Point;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

import com.sun.corba.se.impl.io.OptionalDataException;

/**
* 正方形
*
* @author 88250
* @version 1.0.0, 2007-8-26
*/
public class Square implements Cloneable, Serializable
{
private Point location = new Point(0, 0);

private float sideLength = 1F;

    @Override
    public Object clone()
    {
    Square tmp = null;
    try
    {
        tmp = (Square) super.clone();
    }
    catch (CloneNotSupportedException cnse)
    {
        cnse.printStackTrace();
    }
    finally
    {
        return tmp;
    }
    }

    /**
     * 深克隆方法
     * @return
     */
    public Object deepClone()
    throws IOException, OptionalDataException, ClassNotFoundException
    {
    // 首先将对象写到流里
    ByteArrayOutputStream bo = new ByteArrayOutputStream();
    ObjectOutputStream oo = new ObjectOutputStream(bo);
    oo.writeObject(this);

    // 然后将对象从流里读出来
    ByteArrayInputStream bi = new ByteArrayInputStream(bo.toByteArray());
    ObjectInputStream oi = new ObjectInputStream(bi);

    return (oi.readObject());
    }

    /**
     * @return the location
     */
    public Point getLocation()
    {
        return location;
    }

    /**
     * @param location the location to set
     */
    public void setLocation(Point location)
    {
        this.location = location;
    }

    /**
     * @return the sideLength
     */
    public float getSideLength()
    {
        return sideLength;
    }

    /**
     * @param sideLength the sideLength to set

     */
    public void setSideLength(float sideLength)
    {
        this.sideLength = sideLength;
    }

}