Java关于克隆与“冷藏”和“解冻”方法

文章作者 100test 发表时间 2007:09:29 12:42:42
来源 100Test.Com百考试题网

import java.awt.Point. import java.io.IOException. import com.sun.corba.se.impl.io.OptionalDataException. /** * 克隆测试 * 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. } }