Groups > comp.lang.java.programmer > #8128

Re: StringBuilder

From	Stanimir Stamenkov <s7an10@netscape.net>
Newsgroups	comp.lang.java.programmer
Subject	Re: StringBuilder
Date	2011-09-18 17:08 +0300
Organization	A noiseless patient Spider
Message-ID	<j54u0r$54c$1@dont-email.me> (permalink)
References	(3 earlier) <vp7a77lp3e5oe4h79pnmv95vb4lu13spmc@4ax.com> <GeednbWNqODBGOjTnZ2dnUVZ_rqdnZ2d@posted.palinacquisition> <j54nc9$tgk$1@dont-email.me> <j54rss$j3q$1@news.albasani.net> <j54svs$u9u$1@dont-email.me>

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Sun, 18 Sep 2011 09:50:03 -0400, /Eric Sosman/:
> On 9/18/2011 9:32 AM, Jan Burse wrote:
>
>> I guess first of all probably a reengineering was done, and
>> StringBuffer was split into AbstractStringBuilder and StringBuffer.
>> And then StringBuilder was created. The class diagramm is basically:
>>
>>           AbstractStringBuilder
>>           /                    \
>>       StringBuffer             StringBuilder
>
>      I do not know whether buffer-sharing was dropped before, after,
> or with the introduction of StringBuilder.

I don't know when the implementation has changed, also, but here's 
my guess on why it might have changed to make a copy.  Previously 
I've often used:

     StringBuffer buf;
     ...
     String str = buf.substring(0, buf.length());

to have the constructed String internal char[] always occupying 
exactly the size needed to hold the text.  Previously, with 
StringBuffer.toString() the String could hold as much as twice 
bigger char[] than needed.  If one constructs long lived String 
objects that way, the memory usage could grow unnecessary high.

-- 
Stanimir

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Re: StringBuilder Stanimir Stamenkov <s7an10@netscape.net> - 2011-09-17 19:56 +0300
  Re: StringBuilder Jan Burse <janburse@fastmail.fm> - 2011-09-17 20:35 +0200
  Re: StringBuilder Roedy Green <see_website@mindprod.com.invalid> - 2011-09-17 15:34 -0700
    Re: StringBuilder Jan Burse <janburse@fastmail.fm> - 2011-09-18 01:33 +0200
      Re: StringBuilder Jan Burse <janburse@fastmail.fm> - 2011-09-18 01:56 +0200
      Re: StringBuilder Roedy Green <see_website@mindprod.com.invalid> - 2011-09-17 20:58 -0700
    Re: StringBuilder Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2011-09-17 22:44 -0700
      Re: StringBuilder Jan Burse <janburse@fastmail.fm> - 2011-09-18 09:54 +0200
        Re: StringBuilder Jan Burse <janburse@fastmail.fm> - 2011-09-18 09:59 +0200
        Re: StringBuilder Peter Duniho <NpOeStPeAdM@NnOwSlPiAnMk.com> - 2011-09-18 07:28 -0700
      Re: StringBuilder Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-09-18 08:15 -0400
        Re: StringBuilder Jan Burse <janburse@fastmail.fm> - 2011-09-18 15:32 +0200
          Re: StringBuilder Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-09-18 09:50 -0400
            Re: StringBuilder Stanimir Stamenkov <s7an10@netscape.net> - 2011-09-18 17:08 +0300
            Re: StringBuilder Jan Burse <janburse@fastmail.fm> - 2011-09-18 22:13 +0200
              Re: StringBuilder Jan Burse <janburse@fastmail.fm> - 2011-09-18 22:29 +0200
                Re: StringBuilder Jan Burse <janburse@fastmail.fm> - 2011-09-18 22:39 +0200
      Re: StringBuilder Roedy Green <see_website@mindprod.com.invalid> - 2011-09-19 09:45 -0700

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