SerStaticOk

Class Overview

This annotation is used to prevent the generation of warnings when static fields (they are not serializable) are of a type that is serializable.

Why is this a potential problem? Consider the following code:

 
 @Ser
 class A {
     @SerId(1)
     int x;
 
     A(int x) {
         this.x = x;
     }
 }
 
 @Ser
 class B { // static, not ser. static A a = new A(3); @SerId(1) A b;
     void copyref() {
         this.b = a;
     }
 }
 
 B o = new B();
 o.copyref();
 
 // ... 
 // serialization happens
 

=> when is "o.b == B.a" true?
- when working on a new instance, it is true
- when working on a deserialized instance, it is false, since B.a is NOT restored; it is reinstantiated the first time an object of type B is used by the deserialization process
=> reference equality would work only on a non-deserialized objects graph
=> therefore, proper equals/hashCode would be required, if for instance, deep-equality is be used between such statics and non-static field

A safe solution is to consider using a static factory to create objects of type A.

Summary

[Expand] Inherited Methods
From interface java.lang.annotation.Annotation abstract Class<? extends Annotation> annotationType() abstract boolean equals(Object arg0) abstract int hashCode() abstract String toString()