intellij-ideajavaserialization
How do generate this value in IntelliJ IDEA?
I go to Settings -> Errors -> Serialization issues -> Serializable class without ‘serialVersionUID’, but it still doesn't show me the warning. My class PKladrBuilding parent implements interface Serializable.
Part of the code:
public class PKladrBuilding extends PRQObject
public abstract class PRQObject extends PObject
public abstract class PObject implements Serializable
From version 14.0 onwards, the path to the setting dialog is slightly different, a General submenu has been added between Editor and Appearance as shown below
From IntelliJ 8.1.2 onwards, this option is in File | Settings1. Within the IDE Settings section of that dialog, you'll find it under Editor | Appearance.
The docs for java.io.Serializable are probably about as good an explanation as you'll get:
The serialization runtime associates with each serializable class a version number, called a
serialVersionUID, which is used during deserialization to verify that the sender and receiver of a serialized object have loaded classes for that object that are compatible with respect to serialization. If the receiver has loaded a class for the object that has a differentserialVersionUIDthan that of the corresponding sender's class, then deserialization will result in anInvalidClassException. A serializable class can declare its ownserialVersionUIDexplicitly by declaring a field namedserialVersionUIDthat must be static, final, and of typelong:
ANY-ACCESS-MODIFIER static final long serialVersionUID = 42L;
If a serializable class does not explicitly declare a
serialVersionUID, then the serialization runtime will calculate a defaultserialVersionUIDvalue for that class based on various aspects of the class, as described in the Java(TM) Object Serialization Specification. However, it is strongly recommended that all serializable classes explicitly declareserialVersionUIDvalues, since the defaultserialVersionUIDcomputation is highly sensitive to class details that may vary depending on compiler implementations, and can thus result in unexpectedInvalidClassExceptionsduring deserialization. Therefore, to guarantee a consistentserialVersionUIDvalue across different java compiler implementations, a serializable class must declare an explicitserialVersionUIDvalue. It is also strongly advised that explicitserialVersionUIDdeclarations use the private modifier where possible, since such declarations apply only to the immediately declaring class —serialVersionUIDfields are not useful as inherited members.
Best Answer
I am not sure if you have an old version of IntelliJ IDEA, but if I go to menu File → Settings... → Inspections → Serialization issues → Serializable class without 'serialVersionUID'` enabled, the class you provide give me warnings.
If I try the first class I see:
BTW: It didn't show me a warning until I added
{ }to the end of each class to fix the compile error.