Request for Review: 7116914 (Miscellaneous warnings (sun.text)) (original) (raw)

Masayoshi Okutsu masayoshi.okutsu at oracle.com
Sun Dec 4 20:47:30 UTC 2011

We know serialVersionUID is useless for this case. But we decided to add it, which is the standard fix, in order to eliminate the warning message. I think serialization compatibility of anonymous inner classes is another issue.

Thanks, Masayoshi

On 2011/12/02 13:53, Stuart Marks wrote:

On 12/1/11 11:51 PM, Yuka Kamiya wrote:

Hello,

Could someone please review this fix? http://cr.openjdk.java.net/~peytoia/7116914/webrev.00/ Some warnings are still issued even after this fix, and that's intentional. I'd like to solve them in another way rather than using @SuppressWarnings("deprecation") in the future. The original number of warnings in this area was 70. Now 16. Hi Yuka, I wanted to ask about this bit of code in BidiBase.java: 3492 return new AttributedCharacterIterator.Attribute(name) { 3493 static final long serialVersionUID = -4899048055171307694L; 3494 }; This is defining a serialVersionUID for an anonymous inner class. Serialization of anonymous classes is quite problematic. Among the problems is that anonymous classes have generated names that aren't specified. In this case the name is sun.text.bidi.BidiBase$TextAttributeConstants$1 which appears to be where you got the UID value. Unfortunately a different compiler might assign a different name. Or if this file is modified to use another anonymous class, this class might get a suffix of $2 (even if the same compiler is used). This means that it's pretty much impossible to guarantee serialization compatibility of anonymous classes. (Thanks to Joe Darcy, who explained this to me just yesterday.) You probably added a serialVersionUID because the compiler issued a warning about the lack of one. :-) In this case I think what makes the most sense is simply to suppress the warning. Actually the original code is a little odd, as it returns an instance of an anonymous subclass of AttributedCharacterIterator.Attribute, instead of an instance of AttributedCharacterIterator.Attribute itself. I don't if this is right or wrong. s'marks

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