Serialization problem

[Ivan Demin]

Hi there!

Here's my class:

public class SBufferedImage extends BufferedImage implements Serializable{

    public SBufferedImage(int width, int height, int type){
        super(width, height, type);
    }

    public  SBufferedImage(){
        super(512, 480, SBufferedImage.TYPE_INT_RGB);
    }

}

I successfully serialize SBufferedImage object, but then i try this to deserialize:

            ByteArrayInputStream bais = new ByteArrayInputStream(this.img);
            ObjectInputStream in = new ObjectInputStream(bais);
            img = (SBufferedImage)in.readObject();

and I receive this error: "java.io.InvalidClassException: SBufferedImage; SBufferedImage; no valid constructor"

I know that it is required for deserialized object to have default constructor but it has one. What am i doing wrong?

[Ivan Demin]

I've forgot to tell this is an applet, but I guess it doesn't matter.

[Paul Clapham]

Ivan Demin wrote:I've forgot to tell this is an applet, but I guess it doesn't matter.

No, I don't think it matters either. So let's move the thread...

[Rob Spoor]

For a class to be serializable, its super class must a) be serializable too, or b) it must have a no-argument constructor. Unfortunately for you, BufferedImage does not meet these criteria. Therefore, you can't (easily) serialize / deserialize your class.

There is good news though. Class ImageIO allows you to read a BufferedImage from any InputStream, and write a BufferedImage with a specific type (e.g. JPG, PNG) to any OutputStream. Maybe you can use that for the "serialization" / "deserialization".

[Ivan Demin]

Rob Prime wrote:For a class to be serializable, its super class must a) be serializable too, or b) it must have a no-argument constructor. Unfortunately for you, BufferedImage does not meet these criteria. Therefore, you can't (easily) serialize / deserialize your class.

There is good news though. Class ImageIO allows you to read a BufferedImage from any InputStream, and write a BufferedImage with a specific type (e.g. JPG, PNG) to any OutputStream. Maybe you can use that for the "serialization" / "deserialization".

Thanks, i'll try that.

[Ivan Demin]

Rob Prime, it works! Thanks a lot!

[Rob Spoor]

You're welcome