面向对象－Java对象序列化

下面是一个典型的例子，java.awt.geom包中的Point2D.Double类就是不可序列化的，因为该类没有实现Serializable接口，在我的例子中将把它当作LabeledPoint类中的一个数据字段，并演示如何将其序列化！

import java.io.*;

import java.awt.geom.*;

public class TransientTest

{

public static void main(String[] args)

{

LabeledPoint label = new LabeledPoint("Book", 5.00, 5.00);

try

{

System.out.println(label);//写入前

ObjectOutputStream out = new ObjectOutputStream(new

FileOutputStream("Label.txt"));

out.writeObject(label);

out.close();


System.out.println(label);//写入后


ObjectInputStream in = new ObjectInputStream(new

FileInputStream("Label.txt"));

LabeledPoint label1 = (LabeledPoint)in.readObject();

in.close();

System.out.println(label1);//读出并加1.0后

}

catch (Exception e)

{

e.printStackTrace();

}

}


}

class LabeledPoint implements Serializable

{

public LabeledPoint(String str, double x, double y)

{

label = str;

point = new Point2D.Double(x, y);

}


private void writeObject(ObjectOutputStream out) throws IOException

{

/**

*必须通过调用defaultWriteObject()方法来写入

*对象的描述以及那些可以被序列化的字段

*/

out.defaultWriteObject();

out.writeDouble(point.getX());

out.writeDouble(point.getY());

}


private void readObject(ObjectInputStream in)

throws IOException, ClassNotFoundException

{

/**

*必须调用defaultReadObject()方法

*/

in.defaultReadObject();

double x = in.readDouble() + 1.0;

double y = in.readDouble() + 1.0;

point = new Point2D.Double(x, y);

}


public String toString()

{

return getClass().getName()

+ "[label = "+ label

+ ", point.getX() = "+ point.getX()

+ ", point.getY() = "+ point.getY()

+ "]";

}


private  String label;

transient private Point2D.Double point;

}

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