Stuff about serializable

[Bill Lee]

I have a question about Serialization. What are the conditions for an object to be serializable?
I know that all member variable in the object must be a primitive type, String or Serializable object.

Does the method's return value and argument need to be serializable too?

What if the body of a method uses an object that is not serializable?

example:

   
Class A implements Serializable{
  //bunch of stuff and methods
}
Class B {
// bunch of stuff and methods
// B is not serializable
}

Class C implements Serializable{
   A a;
   B b; //this is a problem

  public A foo(B n){//is this a problem because it takes B argument which is not serializable?
   return new A(); 
  }
  
  public B bar(A n){
    return new B(); //is this a problem, returning B object?
  }

  public void quux(){
      A a = new A();
      B b = new B();
      a.doSomething();
      a.setSomething(b.getSomething()); //is this a problem?
      B.doSomthing()// how about calling static method of B?
  }
}
 

Thank you

[David Newton]

Only the object in question is being serialized--the return values of methods, or objects used inside methods, have nothing to do with it.

[Campbell Ritchie]

You will have to check in the Java Language Specification, but I think it is only the instance fields which have to be serializable. It is not a case of primitive, String or Serializable. A String is a Serializable. So is an array (provided its elements are Serlalizable). You can check any class in the API because it will say "implements Serializable" near the top of the page for that class.

[Bill Lee]

Thanks for the help guys.

[Campbell Ritchie]

You're welcome