I'm on android and I'm trying to save a list of objects into a file but I always get this exception: java.io.NotSerializableException: android.app.Application.
I've tried to find what could cause this but all I found is that this error is thrown when trying to serialize a Context object but I'm not even trying to serialize anything related to Application or Context.
DataFileManager.java
public class DataFileManager implements Serializable {
public static final String FILE_NAME = "circles.dat";
private transient final Context ctxt;
private Set<Save> saves;
public DataFileManager(Context ctxt) {
this.ctxt = ctxt;
this.saves = new HashSet<>();
reloadSaves();
}
public void reloadSaves() {
File file = file();
if(file.exists()) {
try (ObjectInputStream reader = new ObjectInputStream(
new BufferedInputStream(ctxt.openFileInput(FILE_NAME)))) {
saves.clear();
try {
while (true) {
Save save = (Save) reader.readObject();
saves.add(save);
}
} catch(EOFException e) {
} finally {
reader.close();
}
} catch (IOException | ClassNotFoundException e) {
Log.e(e.getClass().getName(), "", e);
}
} else
Log.e("load", "file does not exist");
}
private void save() {
try {
file().createNewFile();
} catch (IOException e) {
e.printStackTrace();
Log.e(e.getClass().getName(), "", e);
}
try (ObjectOutputStream writer = new ObjectOutputStream(new BufferedOutputStream(ctxt.openFileOutput(FILE_NAME, Context.MODE_PRIVATE)))) {
Iterator<Save> iter = saves.iterator();
while(iter.hasNext()) {
Save save = iter.next();
writer.writeObject(save);
}
writer.flush();
writer.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
Log.e(e.getClass().getName(), "", e);
} catch (IOException e) {
Log.e(e.getClass().getName(), "", e);
}
}
private File file() {
return ctxt.getFileStreamPath(FILE_NAME);
}
public Save save(String saveName, Set<Circle> circles) throws SaveAlreadyExistsException {
if(exists(saveName))
throw new SaveAlreadyExistsException();
Save save = createSave(saveName, circles);
if(!saves.add(save))
throw new SaveAlreadyExistsException();
return save;
}
public Save forceSave(String saveName, Set<Circle> circles) throws UnknownSaveException {
Save save;
if(exists(saveName))
(save = find(saveName)).overwrite(circles);
else {
save = createSave(saveName, circles);
if(!saves.add(save)) {
saves.remove(save);
if(!saves.add(save))
throw new UnknownSaveException("Couldn't add Save object to the list");
}
save();
}
return save;
}
private Save createSave(String name, Set<Circle> circles) {
Save save = new Save(name);
save.circles.addAll(circles);
return save;
}
public boolean exists(String saveName) {
return saves.stream().anyMatch(s -> s.getName().equals(saveName));
}
public boolean existsIgnoreCase(String saveName) {
return saves.stream().anyMatch(s -> s.getName().equalsIgnoreCase(saveName));
}
public Save find(String saveName) {
return saves.stream().filter(s -> s.getName().equals(saveName)).findFirst().orElse(null);
}
public List<Save> search(String query) {
return saves.stream().filter(s -> s.getName().toLowerCase().contains(query.toLowerCase()))
.collect(Collectors.toList());
}
public Set<Save> getSaves() {
return Collections.unmodifiableSet(saves);
}
public class Save implements Serializable {
private final String name;
private final Set<Circle> circles;
private Save(String name) {
this.name = name;
circles = new HashSet<>();
}
public boolean overwrite(Set<Circle> circles) {
if (circles != null && circles.size() > 0) {
this.circles.clear();
this.circles.addAll(circles);
save();
return true;
}
return false;
}
public Set<Circle> getCircles() {
return circles.stream().map(Circle::clone).collect(Collectors.toSet());
}
public String getName() {
return name;
}
@Override
public boolean equals(Object obj) {
return obj != null && obj instanceof Save && ((Save)obj).name.equals(this.name);
}
}
public static class SaveAlreadyExistsException extends UnknownSaveException {
public SaveAlreadyExistsException() {
super("save already exists");
}
}
public static class UnknownSaveException extends Exception {
private static final String DFLT_MSG = "An unknown error occured";
public UnknownSaveException() {
super(DFLT_MSG);
}
public UnknownSaveException(String message) {
super(message);
}
public UnknownSaveException(String message, Throwable cause) {
super(message, cause);
}
public UnknownSaveException(Throwable cause) {
super(DFLT_MSG, cause);
}
}
}
Circle.java
public class Circle implements Cloneable, Serializable {
private static long nextID = 0;
private float radius, centerX, centerY;
private final long id;
public Circle(float centerX, float centerY) {
this(centerX, centerY, nextID++);
}
private Circle(float centerX, float centerY, long id) {
this.radius = 0;
this.centerX = centerX;
this.centerY = centerY;
this.id = id;
}
public float getRadius() {
return radius;
}
public void setRadius(float radius) {
this.radius = radius;
}
public float getCenterX() {
return centerX;
}
public void setCenterX(float centerX) {
this.centerX = centerX;
}
public float getCenterY() {
return centerY;
}
public void setCenterY(float centerY) {
this.centerY = centerY;
}
@Override public Circle clone() {
return new Circle(getCenterX(), getCenterY(), id);
}
public boolean isCloneOf(Circle circle) {
return circle != null && circle != this && this.id == circle.id;
}
@Override
public boolean equals(Object obj) {
return obj != null && obj instanceof Circle && !isCloneOf((Circle)obj);
}
}
StackTrace
E/java.io.NotSerializableException: java.io.NotSerializableException: android.app.Application at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1224) at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1584) at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1549) at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1472) at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1218) at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1584) at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1549) at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1472) at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1218) at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:346) at com.multimedia.tp3.model.files.DataFileManager.save(DataFileManager.java:77) at com.multimedia.tp3.model.files.DataFileManager.forceSave(DataFileManager.java:116) at com.multimedia.tp3.DrawSurface.save(DrawSurface.java:131) at com.multimedia.tp3.MainActivity.onActivityResult(MainActivity.java:95) at android.app.Activity.dispatchActivityResult(Activity.java:6996) at android.app.ActivityThread.deliverResults(ActivityThread.java:4069) at android.app.ActivityThread.handleSendResult(ActivityThread.java:4116) at android.app.ActivityThread.-wrap20(ActivityThread.java) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1516) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:159) at android.app.ActivityThread.main(ActivityThread.java:6097) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
Circlea standalone Java class, or is it an inner class inside something else? – CommonsWareCircleis an inner class ofDataFileManager– Elie G.file().createNewFile();is pointless here, and does not throw exceptions. You don't need to iterate the set: you can save the whole thing in one go. – user207421