Coming soon: serial lint warning enabled in the jdk build

[Joe Darcy]

Hello,

Following up, the serial warning is now enabled in the jdk repo in the 
dev forest:

     8032977: Add serial lint warning to build of jdk repository
     http://hg.openjdk.java.net/jdk9/dev/jdk/rev/a73632def406

Therefore the introduction of any new serializable class without a 
serialVerionUID (or @SuppressWarning("serial") annotation) will not pass 
the build.

Cheers,

-Joe

On 02/24/2014 10:55 AM, Joe Darcy wrote:
> Hello,
>
> In my JDK 9 development forest, I have a collection of changes that 
> will resolve all the serial warnings in the jdk repo. [1] Over the 
> next few weeks, these changes will go through review and integration. 
> Once all the warnings are resolved, the serial lint warning will be 
> enabled in the build. [2]
>
> Once that warning is enabled, all serializable classes must either 
> declare a serialVersionUID or must have a @SuppressWarnings("serial") 
> annotation.
>
> If a class has the usual long-term serialization contract, then it 
> should declare a serialVersionUID. This is true  both for classes that 
> are part of Java SE (generally the java.* and javax.* namespaces) and 
> classes that are marked as jdk.Exported(true) in the com.sun.* and 
> jdk.* packages. If the class existed in JDK 8 or earlier, the 
> serialVersionUID should match the result of the serialver computation 
> in the earlier release. If the class is new in JDK 9, any value for 
> the serialVersionUID can be used at the discretion of the maintainer 
> of the class.
>
> If a class is serializable but does *not* have a long-term 
> serialization contract, such as many swing classes, then the class 
> should have a @SuppressWarnings("serial") annotation with a comment 
> explaining why the warning should be suppressed. In the patches I've 
> worked on explanation have included:
>
> * "Same-version serialization only"  -- swing serial contract
> * "Superclass is not serializable across versions" -- subclass of a 
> swing class
> * "JDK implementation class" -- e.g. a sun.* class or a 
> jdk.Exported(false) class
> * "Anonymous class" -- anonymous classes and long-term serialization 
> don't interact well
>
> In particular, since all exception types are serializable (thanks 
> RMI!), new exception types introduced in JDK 9 must either have a 
> serialVersionUID or a @SuppressWarnings("serial") annotation.
>
> Cheers,
>
> -Joe
>
> [1] JDK-8032976 Fix serial lint warnings in jdk libraries,
> https://bugs.openjdk.java.net/browse/JDK-8032976
>
> [2] JDK-8032977, Add serial lint warning to build of jdk repository,
> https://bugs.openjdk.java.net/browse/JDK-8032977
g