[FIXED] SerializationException on junit test

Issue

I have the following classes:

import lombok.Data;

import java.io.Serializable;

@Data
public class Person implements Serializable {
    private String age;
}

---

Main Application

import org.apache.commons.lang3.SerializationUtils;

public class MainApp {
    public static void main(String[] args) {
        Person v = new Person() {{
            setAge("SD");
        }};
        Person person2 = SerializationUtils.clone(v);
    }
}

---

Test Class

import org.apache.commons.lang3.SerializationUtils;
import org.junit.Test;

public class TestClass {
    @Test
    public void test() {
        Person v = new Person() {{
            setAge("SD");
        }};
        Person person2 = SerializationUtils.clone(v);
    }
}

In the main application the serialization works and in the unit test it doesn't. It throws SerializationException with the following details: org.apache.commons.lang3.SerializationException: java.io.NotSerializableException: com.mypackage.TestClass

I'm using intellij and the project is maven project and the tests are JUnit4. dependency version:

  <dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.3.2</version>
  </dependency>

Please advise how can I solve it?

Solution

You are declaring an anonymous class in the test.

Anonymous classes in non-static scopes (in an instance method, constructor, instance initializer, or instance member initializer) implicitly enclose a reference to the enclosing class (in this case, TestClass).

As that class isn't serializable, it can't be serialized.

Declare your anonymous subclass as a static class instead.

public class TestClass {
    @Test
    public void test() {
        Person v = new TestPerson();
        Person person2 = SerializationUtils.clone(v);
    }

  static class TestPerson extends Person {
    {
      setAge("SD");
    }
  }
}

Or, better, don't use double-brace initialization, especially if you don't understand the problems it causes with respect to serialization (as well as other problems):

Person v = new Person();
v.setAge("SD");
Person person2 = SerializationUtils.clone(v);

Answered By - Andy Turner