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From Dain Sundstrom <d...@coredevelopers.net>
Subject Re: JMX Management Console (ObjectName hog)
Date Wed, 03 Sep 2003 15:32:14 GMT
The caching that in ObjectName most likely makes it faster, but for 
your test, you should try a name with like 5 key value pairs, because 
the JSR 77 names tend to be very long.

-dain


On Wednesday, September 3, 2003, at 03:34 AM, gianny DAMOUR wrote:

> Simon wrote:
>> > My guess it it is faster to use a (pre-compiled) regular
>> > expression to
>> > grab the chunk you are interested in out our the string
>> > directly.  Last
>> > I checked constructing an ObjectName was very expensive.
>>
> [...]
>> So, IMHO no need to use regexp.
>
> I have done a micro-bench and the regexp approach is an order of 
> magnitude (2 times) slower than a naive ObjectName.getKeyProperty.
>
> I used the RE of the JDK1.4, yet perhaps that Jakarta regexp is 
> quicker.
>
> A snippet to check it for yourself:
>
>            Pattern pattern = Pattern.compile("(.*):j2eeType=(.*)");
>
>            int iter = 100000;
>            long start = System.currentTimeMillis();
>            for (int i = 0; i < iter; i++) {
>                Matcher m = pattern.matcher("fwewe:j2eeType=ffqwefqwe");
>                m.matches();
>                m.group(2);
>            }
>            long end = System.currentTimeMillis();
>            System.out.println("perf=" + (end - start));
>            start = System.currentTimeMillis();
>            for (int i = 0; i < iter; i++) {
>                ObjectName name = new 
> ObjectName("fwewe:j2eeType=ffqwefqwe");
>                name.getKeyProperty("j2eeType");
>            }
>            end = System.currentTimeMillis();
>            System.out.println("perf=" + (end - start));
>
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/*************************
  * Dain Sundstrom
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