An error: java.io.NotSerializableException

Question

I have a class define as follow

public class EvaluationResult implements java.io.Serializable {
    public String ClassName;
    public boolean FeedbackDirected;
    public double HV;
    public double Spread;
    public double PercentageOfCorrectness;
    public double TimeElapsed;
    public ArrayList<double[]> ParetoFront;


}

Doing this

public static void main(String[] args) throws Exception {
         EvaluationResult ae=new EvaluationResult();
         FileOutputStream fileOut =new FileOutputStream("result.txt");
         ObjectOutputStream out = new ObjectOutputStream(fileOut);
         out.writeObject(fileOut);
         out.close();
         fileOut.close();
     }

gives me java.io.NotSerializableException what is the problem?

If you want to dump an object as a sequence of bytes, the class will have to implement the Serializable marker interface. — TheLostMind, Mar 10 '14 at 12:02
Need stacktrace of the exception. Otherwise it is not possible to pin point the issue. — Java_User, Mar 10 '14 at 12:15
http://stackoverflow.com/questions/13895867/java-io-notserializableexception — TheLostMind, Mar 10 '14 at 12:16
No problem now, just that I need to out.writeObject(ae);, thanks — william007, Mar 10 '14 at 12:16

Eugene · Answer 1 · 2014-03-10T12:18:54.493

3

you need to implement Serializable marker interface

 public class EvaluationResult implements Serializable { .... }

You should be writing the object (and not the file stream) :

 out.writeObject(ae);

edited Mar 10 '14 at 12:18

answered Mar 10 '14 at 12:02

Eugene

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score 3 · Answer 2 · answered Mar 10 '14 at 12:02

You must implement Serializable in the class definition:

public class EvaluationResult implements Serializable {
    public String ClassName;
    public boolean FeedbackDirected;
    public double HV;
    public double Spread;
    public double PercentageOfCorrectness;
    public double TimeElapsed;
    public ArrayList<double[]> ParetoFront;

}

score 1 · Answer 3 · answered Mar 10 '14 at 12:06

You must implement the Serializable interface ... this implies implementing the following:

Classes that require special handling during the serialization and deserialization process must implement special methods with these exact signatures:

 private void writeObject(java.io.ObjectOutputStream out) throws IOException
 private void readObject(java.io.ObjectInputStream in) throws IOException, ClassNotFoundException;
 private void readObjectNoData() throws ObjectStreamException;

This tutorial may be of use

An error: java.io.NotSerializableException

3 Answers3