java - Regex Pattern, Matcher, split or pattern.split() which is the most efficient -


i trying improve speed of application playing way of getting information.

i read html page url , other information. use string.contains() , string.split(). wondering efficient way this. looked bit , tried of results quite similar me :/

here bit of code (some part here testing) : 

    pattern p = pattern.compile("\" title=\"read ");     //pattern p2 = pattern.compile("online\">");     //pattern p3 = pattern.compile("</a></th>");     pattern p4 = pattern.compile("online\">(.*)</a></th>");      while ((inputline = in.readline()) != null)     {         if(inputline.contains("<table id=\"updates\">"))         {             tmp = inputline.split("<tr><th><a href=\"");             for(string s : tmp)             {                 if(s.contains("\" title=\"read "))                 {                     //url = s.split("\" title=\"read ")[0].replace(" ", "%20");                     //name = s.split("online\">")[1].split("</a></th>")[0];                      url = p.split(s)[0].replace(" ", "%20");                     //name = p3.split(p2.split(s)[1])[0];                     matcher matcher = p4.matcher(s);                     while(matcher.find())                         name = matcher.group(1);                      array.add(new object(name, url));                  }             }             break;         }     }

as can see tried here pattern, matcher, split or pattern.split() know there replaceall or replacefirst.

in case best way ?

thanks lot.

ps: read here : http://chrononsystems.com/blog/hidden-evils-of-javas-stringsplit-and-stringr pattern.split better split() couldn't find bigger benchmark.

----- update ----

                pattern p1 = pattern.compile("\" title=\"read ");                 pattern p2 = pattern.compile("online\">(.*?)</a></th>");                 matcher matcher = p2.matcher("");                  while( (inputline = in.readline()) != null)                 {                     if( (tmp = inputline.split("<tr><th><a href=\"")).length > 1 )                     {                         for(string s : tmp)                         {                             if(s.contains("\" title=\"read "))                             {                                  url = p1.split(s)[0].replace(" ", "%20");                                 if(matcher.reset(s).find())                                     name = matcher.group(1);                                  arrays.add(new object(name, url));                             }                         }                         break;                     }                 }

any string function uses regular expressions (which matches(s), replaceall(s,s), replacefirst(s,s), split(s), , split(s,i)) compiles regular expression , creates matcher object every time, inefficient when used in loop.

if need speed thigs up, first step stop using string functions, , instead use pattern , matcher directly. here's an answer demonstrate this.

and ideally, should create single matcher object, describe in this answer.

for more regex information please check out faq


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