[JAVA] About Serializable and serialVersionUID

Serializable

• Java interface
• Can declare that it can be serialized
• There is no definition of method or field (= marker interface) Just making a declaration does not add any functionality

SerialVersionUID

• Something like a version of the class that declared serialization
• Same ID guarantees the same structure
• Things to change when the structure changes

@SuppressWarnings("serial")

• In order to guarantee the structure, it is necessary to operate the version of SerialVersionUID properly, but if the cost is not worth it, add the following annotation to avoid it.
• ʻImplements Serializable` only gives the following warning

Sample with warning

Person.java

package sample;

import java.io.Serializable;

public class Person implements Serializable {
	public String name;

	public SerializablePerson(String name) {
		this.name = name;
	}
}

If you compile with the option (to give all warnings)

javac -Xlint SerializablePerson.java

I get a warning (It may not be displayed on Eclipse depending on the settings (Preferences-> Java-> Compiler-> Error / Warning))

Japanese

Serializable.java:5:warning: [serial]SerialVersionUID is not defined in the serializable class Serializable

English (probably)

The serializable class Mutter does not declare a static final serialVersionUID field of type long

It does not appear when executed with annotations.

Person.java

package sample;

import java.io.Serializable;

@SuppressWarnings("serial")
public class Person implements Serializable {
	public String name;

	public SerializablePerson(String name) {
		this.name = name;
	}
}

reference

What I know about the esoteric Serializable specification, or my understanding Add Star The story of responsibility for inheritance was very helpful