Re: Java Bean Question

From:
Lew <lew@lewscanon.com>
Newsgroups:
comp.lang.java.programmer
Date:
Mon, 08 Oct 2007 04:37:52 -0400
Message-ID:
<9KidnSkEtJn9cZTanZ2dnUVZ_r-vnZ2d@comcast.com>
Franz-Josef Herpers wrote:

It will work, but according to the JavaBean [sic] specification JavaBeans should


Please do not top-post.

implement the Serializable interface. So it's simply good practice to do so.


Unnecessary for JSPs unless the bean scope is session or larger, and incorrect
in any case.

It's not required that JavaBeans implement java.io.Serializable, which the
specification explicitly states right at the start:

A bean is not required to inherit from any particular base class or interface.

<http://javashoplm.sun.com/ECom/docs/Welcome.jsp?StoreId=22&PartDetailId=7224-javabeans-1.01-fr-spec-oth-JSpec&SiteId=JSC&TransactionId=noreg>
Section 2.1, "What is a Bean?"

Franz-Josef Herpers wrote:

And if you are in a clustered envirnment you need it anyway, so from the
point of view of a scalable architecture it is recimmende [sic] too.


Again, only if used at session scope or larger.

It's actually much better not to make the Bean Serializable unless you
absolutely have to. There is a lot of work to make a class implement
java.io.Serializable correctly. Don't do it unnecessarily.

By the way: Does your Javabean [sic] have an explicit default constructor ;-)


It only needs to be explicit if there is a non-default constructor or if it
does significant construction work, not usual for JSP beans. Why the smiley?

Summary: JavaBeans do not need to be Serializable, and should not be unless
necessary. Only make the default constructor explicit if necessary.

--
Lew

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