Re: serialize on SWT class
Red Orchid wrote:
As far as I know, To de/serialize SWT widgets requires different
mechanism from Sun's de/serialization one, because SWT widgets
cannot exist without a parent.
For instance, typical constructors of them are:
Widget w = new Widget(Widget parent, ...);
And the mechanism of Sun's de/serialization is typically:
ObjectInputStream in = ...;
T obj = (T) in.readObject();
That is, the mechanism of Sun's de/serialization do not have
a way to pass "parent" to her.
At the present time, SWT don't support de/serialization of SWT
widgets. Probably, you should implement your own mechanism.
This is not true! The serialization process has no problems with these
type of constructors. The parent is just another reference and as long
as this reference is Serializable the serializer has no problems with
it. See test below. More reasonable is that due to the fact an Widget
is bound to a certain Device/Display it would make it hard to serialize
and deserialize these two since they are directly connected to
Hardware.
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.io.Serializable;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
try {
Parent p = new Parent();
ByteArrayOutputStream boas = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(boas);
oos.writeObject(p);
oos.flush();
oos.close();
System.out.println("no Exception occured");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
static class Parent implements Serializable {
public final Child child;
public Parent() {
child = new Child(this);
}
}
static class Child implements Serializable {
public final Parent parent;
public Child(Parent parent) {
this.parent = parent;
}
}
}