How to serialize ObservableList

Question

I am working on a javaFx project where we have to use ObservableList to add Listners. ObservableList includes Model of persons. Bu

Answer 1

ObservableList implementations are not Serializable (Essentially there's no sensible way to define the behavior for serializing the listeners, and not serializing the listeners at all is just the same as serializing a non-observable list with the same data, which I think is what you want to do here.) Assuming your Person class is Serializable (and that instances can actually be serialized), you can do:

 public void write(ObservableList<EmployeeEntity> personObservalble) {
    try {
        // write object to file
        FileOutputStream fos = new FileOutputStream("Objectsavefile.ser");
        ObjectOutputStream oos = new ObjectOutputStream(fos);
        oos.writeObject(new ArrayList<EmployeeEntity>(personsObservable));
        oos.close();


    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

}

To read it back in, you would do:

ObjectInputStream ois = ... ;
List<EmployeeEntity> list = (List<EmployeeEntity>) ois.readObject();
personsObservable = FXCollections.observableList(list);

Here is a complete test. I ran this and it worked (I removed the persistence annotations, as I didn't have javax.persistence on the classpath in my test environment, but that should make no difference).

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.List;

import javafx.collections.FXCollections;
import javafx.collections.ObservableList;

public class SerializeObservableListTest {

    public static void main(String[] args) throws IOException {
        EmployeeEntity bill = new EmployeeEntity("1000", "Seattle, WA", "1000", "Bill", "Gates");
        EmployeeEntity tim = new EmployeeEntity("2000", "Mobile, AL", "2000", "Tim", "Cook");

        ObservableList<EmployeeEntity> staff = FXCollections.observableArrayList(bill, tim);

        Path temp = Files.createTempFile("employees", "ser");
        write(staff, temp);

        ObservableList<EmployeeEntity> listFromFile = read(temp);
        System.out.println("Lists equal? "+listFromFile.equals(staff));
    }

    private static void write(ObservableList<EmployeeEntity> employees, Path file) {
        try {

            // write object to file
            OutputStream fos = Files.newOutputStream(file);
            ObjectOutputStream oos = new ObjectOutputStream(fos);
            oos.writeObject(new ArrayList<EmployeeEntity>(employees));
            oos.close();


        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

    private static ObservableList<EmployeeEntity> read(Path file) {
        try {
            InputStream in = Files.newInputStream(file);
            ObjectInputStream ois = new ObjectInputStream(in);
            List<EmployeeEntity> list = (List<EmployeeEntity>) ois.readObject() ;

            return FXCollections.observableList(list);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return FXCollections.emptyObservableList();
    }
}