Java.io.NotSerializableException: paint.Main$1

Question

hi everybody this is my problem...
i have this code:
public class Main extends JFrame
class figura implements Serializable
Point x, y;
int tipo;
int rettipo(){ return tipo;}
public Point retx(){ return x;}
public Point rety(){ return y;}
void ponertipo(int a){ tipo = a; }
void ponerpx(Point a){ x = a; }
void ponery(Point a){ y = a;}
JFileChooser archivos = new JFileChooser();
Vector almacen = new Vector(1);
figura temp = new figura();
.... //more code....
i wanna save temp object in a file...
....//more code before this...
archivos.showSaveDialog(Main.this);
File archivo;
FileOutputStream archivo2 = null;
ObjectOutputStream obj = null;
archivo = archivos.getSelectedFile();
try{
archivo2 = new FileOutputStream(archivo.getAbsolutePath());
obj = new ObjectOutputStream(archivo2);
obj.writeObject(temp);
obj.close();
catch(Exception ex)
Throwable tro;
ex.printStackTrace();
tro=ex.getCause();
tro.getMessage();
and this is what i got:
java.io.NotSerializableException: paint.Main$1
and this:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
Any ideas?

Answer 1

why with static the problem is solved?Because a static nested class doesn't have a hidden reference to the outer object.
i understand
that static makes that all instance of the class will
share the same values of their attributesNo it doesn't. It just means the above, and also that the class doesn't have access to instance data members of the enclosing class.
if the class is static i wont be able to save more
than one figure. am i right?No you're not, see above.