产生异常的原因?
import java.io.*;
import java.util.*;
class Blip1 implements Externalizable
{
public Blip1()
{
System.out.println("Blip1 Constructor");
}
public void writeExternal(ObjectOutput out) throws IOException
{
System.out.println("Blip1.writeExternal");
}
public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException
{
System.out.println("Blip1.readExternal");
}
}
class Blip2 implements Externalizable
{
Blip2()
{
System.out.println("Blip2 Constructor");
}
public void writeExternal(ObjectOutput out) throws IOException
{
System.out.println("Blip2.writeExternal");
}
public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException
{
System.out.println("Blip2.readExternal");
}
}
public class Blips
{
public static void main(String[] args)
{
System.out.println("Constructing objects:");
Blip1 b1 = new Blip1();
Blip2 b2 = new Blip2();
try
{
ObjectOutputStream o = new ObjectOutputStream( new FileOutputStream("Blips.out"));
System.out.println("Saving objects:");
o.writeObject(b1);
o.writeObject(b2);
o.close();
// Now get them back:
ObjectInputStream in = new ObjectInputStream(new FileInputStream("Blips.out"));
System.out.println("Recovering b1:");
b1 = (Blip1)in.readObject();
System.out.println("Recovering b2:");
b2 = (Blip2)in.readObject(); //为何在此处发生异常????
}
catch(Exception e)
{
e.printStackTrace();
}
}
} ///:~