file io - javafx and serializability -

in old awt libraries, point class , color class serializable. neither in javafx. save array list of drawables file; here interface

import javafx.scene.canvas.graphicscontext;  public interface drawable {     public void draw(graphicscontext g); } 

when attempt to this, bombarded notserializableexceptons. best alternate course of action? of drawables know color , size.

use custom serializable form , serialize data need. e.g.

import javafx.scene.canvas.graphicscontext ; import javafx.scene.paint.color ; import javafx.geometry.rectangle2d; import java.io.serializable ; import java.io.objectinputstream ; import java.io.objectoutputstream ; import java.io.ioexception ;  public class drawablerect implements drawable, serializable {      private transient color color ;     private transient rectangle2d bounds ;      public drawablerect(color color, rectangle2d bounds) {         this.color = color ;         this.bounds = bounds ;     }      @override     public void draw(graphicscontext g) {         g.setfill(color);         g.fillrect(bounds.getminx(), bounds.getminy(), bounds.getwidth(), bounds.getheight());     }      private void writeobject(objectoutputstream s) throws ioexception {         s.defaultwriteobject();         // write color:         s.writedouble(color.getred());         s.writedouble(color.getgreen());         s.writedouble(color.getblue());         s.writedouble(color.getopacity());          // write bounds:         s.writedouble(bounds.getminx());         s.writedouble(bounds.getminy());         s.writedouble(bounds.getwidth());         s.writedouble(bounds.getheight());     }      private void readobject(objectinputstream s)             throws ioexception, classnotfoundexception {         s.defaultreadobject();         double r = s.readdouble();         double g = s.readdouble();         double b = s.readdouble();         double opacity = s.readdouble();          color = new color(r,g,b,opacity);          double x = s.readdouble();         double y = s.readdouble();         double w = s.readdouble();         double h = s.readdouble();          bounds = new rectangle2d(x,y,w,h);     } } 

if have fields serializable (or primitive types), don't mark them transient, , defaultreadobject , defaultwriteobject handle them. if have fields not serializable, mark them transient , serialize data in form can serialized in example.

obviously, since have multiple implementations of interface may need functionality, might benefit create helper class static methods:

public class drawableio {      public static void writecolor(color color, objectoutputstream s) throws ioexception {         s.writedouble(color.getred());         s.writedouble(color.getgreen());         s.writedouble(color.getblue());         s.writedouble(color.getopacity());     }      public static color readcolor(obectinputstream s) throws ioexception {         double r = s.readdouble();         double g = s.readdouble();         double b = s.readdouble();         double opacity = s.readdouble();          return new color(r,g,b,opacity);     }      public static void writebounds(rectangle2d bounds, objectoutputstream s) throws ioexception {         s.writedouble(bounds.getminx());         s.writedouble(bounds.getminy());         s.writedouble(bounds.getwidth());         s.writedouble(bounds.getheight());     }      public static rectangle2d readbounds(objectinputstream s)  throws ioexception {         double x = s.readdouble();         double y = s.readdouble();         double w = s.readdouble();         double h = s.readdouble();          return new rectangle2d(x,y,w,h);     } } 

and of course methods in drawable implementations reduce like

private void writeobject(objectoutputstream s) throws ioexception {     s.defaultwriteobject();     drawableio.writecolor(color, s);     drawableio.writebounds(bounds, s); }  private void readobject(objectinputstream s)         throws ioexception, classnotfoundexception {     s.defaultreadobject();      color = drawableio.readcolor(s);     bounds = drawableio.readbounds(s); }