Serializing a class variable which does not implement serializable

Question

I have a class which implements Serializable. There is an other class object in the class which does not implement serializable. What should be done to serialize the member of the class.

My class is something like this

public class Employee implements Serializable{
    private String name;
    private Address address;
}


public class Address{
    private String street; 
    private String area;   
    private String city;
}

Here, I dont have access to the Address class to make it implement Serializable. Please help. Thanks in advance

Do you have to use Java's serialization? – Sotirios Delimanolis Sep 05 '13 at 18:08 — Sotirios Delimanolis, Sep 05 '13 at 18:08

score 6 · Answer 1 · edited Dec 18 '17 at 20:13

6

Well of course there's the obvious solution to put Serializable on it. I understand that's not always an option.

Perhaps you can extend the Address and put Serializable on the child you make. Then you make it so Employee has a Child field instead of an Address field.

Here are some other things to consider:

You can keep the Employee.address field as an Address type. You can serialize if you call the Employee.setAddress(new SerializableAddress())
If Address is null, you can serialize the whole employee even if Address's type is not serializable.
If you mark Address as transient, it will skip trying to serialize Address. This may solve your problem.

Then there are other "serialization" frameworks like XStream that don't require the marker interface to work. It depends on your requirements whether that's an option though.

edited Dec 18 '17 at 20:13

scraymer

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answered Sep 05 '13 at 18:07

Daniel Kaplan

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I would **not** extend it. The members are private anyway. Create a class `SerializeableAdress` which should be an exact copy of `Adress` and make it serializeable (of course...). – mike Sep 05 '13 at 18:09
@mike They're private, but they're already `Serializable`. Won't that be a non-issue? – Daniel Kaplan Sep 05 '13 at 18:09
Can we any other way except extending the address class?? – user2047302 Sep 05 '13 at 18:12
You don't have access to private members if you extend a class. – mike Sep 05 '13 at 18:12
@mike if it has getters and setters, it'll still work. If it doesn't... how are you supposed to get data in there anyway? And if you can't get data in there, then extending and using the child will serialize the same thing as if it originally implemented `Serializable ` – Daniel Kaplan Sep 05 '13 at 18:16
Tried extending the address class but the private members!!!, I ll not be able to do that. Any other options please? – user2047302 Sep 05 '13 at 18:18
@user2047302 how do you set the data in there on a normal `Address`? – Daniel Kaplan Sep 05 '13 at 18:20
Could you please show some more code and more error messages. – mike Sep 05 '13 at 18:23
@user2047302 then call the setters. What's the problem? – Daniel Kaplan Sep 05 '13 at 18:23
And why are you not "able to do that" please show the error messages you get. – mike Sep 05 '13 at 18:25

score 1 · Answer 2 · edited May 23 '17 at 12:30

1

You caanot directly make this Address class serializable as you do not have access to modify it.

There are few options :

Create a subclass of Address class and use it. You can mark this class as serializable.
Mark the Address as transient.

Please take a look at this stackoverflow link

edited May 23 '17 at 12:30

Community

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answered Sep 05 '13 at 18:12

Ankur Shanbhag

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Also this class is being used in many others logics. If I have to create a new class that is exactly same I ll have to rewrite so many parts of the app. – user2047302 Sep 05 '13 at 18:20
You can simply inherit this class without overriding any of the methods in it. It will be as good as base class. – Ankur Shanbhag Sep 05 '13 at 18:26

score 0 · Answer 3 · edited May 23 '17 at 12:01

0

If you have the option to use a 3rd party library for serialization, then you can use for example kryo. This has a default serialization which doesn't require implementing interfaces or annotating fields.

You can check Which is the best alternative for Java Serialization? for more alternatives.

edited May 23 '17 at 12:01

Community

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answered Sep 05 '13 at 18:35

Katona

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Serializing a class variable which does not implement serializable

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