Wowww!
Nice catch Otávio!
That is really a good improvement!
Em seg, 26 de nov de 2018 às 10:47, Otávio Gonçalves de Santana <
osant...@tomitribe.com> escreveu:
> The reason to prefer StringBuilder is that both + and concat create a new
> object every time you call them (provided the right-hand side argument is
> not empty). This can quickly add up to a lot of objects, almost all of
> which are completely unnecessary.
>
> public class Main{
> public static void main(String[] args)
> {
> long now = System.currentTimeMillis();
> slow();
> System.out.println("slow elapsed " +
> (System.currentTimeMillis() - now) + " ms");
>
> now = System.currentTimeMillis();
> fast();
> System.out.println("fast elapsed " +
> (System.currentTimeMillis() - now) + " ms");
> }
>
> private static void fast()
> {
> StringBuilder s = new StringBuilder();
> for(int i=0;i<100000;i++)
> s.append("*");
> }
>
> private static void slow()
> {
> String s = "";
> for(int i=0;i<100000;i++)
> s+="*";
> }
> }
>
>
> - slow elapsed 11741 ms
> - fast elapsed 7 ms
>
> Also, this PR avoids unnecessary call in StringBuilder
> Ref: https://github.com/apache/tomee/pull/219
>
--
Daniel "soro" Cunha
https://twitter.com/dvlc_
