I never really had a big problem with String being final, although the claims that it was for security reasons seem a bit weak given that strings are also immutable.
On the other hand, making enums and the URL type final after giving them both such a hideously broken hashCode implementation... That definitely numbers amongst the top 10 questionable design decisions in Java. On 1 March 2012 11:14, Kirk Pepperdine <[email protected]> wrote: > > On 2012-03-01, at 12:08 PM, Fabrizio Giudici wrote: > > > On Thu, 01 Mar 2012 12:01:46 +0100, Kirk Pepperdine < > [email protected]> wrote: > > > > > >> On the question of Strings, StringBuffer/Builder and copying char > arrays. Sorry to say that this is still a huge performance drain in many > applications. It's the only place where I miss c pointers ;-). Hotspot > rarely does the right thing when it comes to string and string > manipulation. It's javac that makes the biggest impact (string1 + string2 > is converted to using StringBuilder and so on). So here are a few rules > when working with strings. > >> > >> Rule #1, don't copy them or force them to copy themselves. > >> Rule #2, use a flyweight instead of a copy > >> Rule #3, don't copy them or force them to copy themselves. > >> Rule #4, use System.arraycopy, it is the most efficient way to copy a > primitive array. > > > > Perhaps does this explain why e.g. Perl is still faster than Java in > some heavy text manipulation benchmarks? (not my direct experience, I'm not > using Perl since a lot of time, this assertion just came up a few weeks ago > in a JUG discussion out of a reputable commenter). > > I'm not sure how Perl treats strings but if it runs though it a char at a > time without copying... perfect.... it will beat the cr@p out of Java. > Not only a Java problem, I think Dick mentioned Smalltalk. Smalltalk was > also horrible with Strings. It's only saving grace was that String wasn't a > final class which meant you could extend it in some very useful ways that > mitigated the copy costs. Having String declared final by some developer in > Santa Clara wanting to be my mother is one of my top pet peeves... ;-) > > Regards, > Kirk > > -- You received this message because you are subscribed to the Google Groups "The Java Posse" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/javaposse?hl=en.
