Matcher.matches() Vs. Matcher.find()

hey folks,

As the title suggests this is a performance issue i have with the Machter object. I am writing a simple script to pick the times of particular events in a log file. In my log processor class i have a method isTimeStamp() that performes a simple check to ensure i have picked up a timestamp and not some unfortunate list of digits.

String regexTS = "\\d{1,2}[.:]\\d{1,2}[.:]\\d{1,2}[.:,]\\d{3,}";

public static boolean isTimeStamp(String arg) throws NumberFormatException {

boolean timestamp = false;
Pattern pattern = Pattern.compile(regexTS);
Matcher matcher = pattern.matcher(arg);

if(matcher.matches()) { // or i can use if (matcher.find()){
int i = matcher.start();
String[] tmpArr = arg.substring(i).split("[,.:]");
try{
if (Integer.parseInt(tmpArr[0])<24 &
Integer.parseInt(tmpArr[1])<60 & Integer.parseInt(tmpArr[2])<60){
timestamp = true;
}
}catch (NumberFormatException e){
System.out.println("EOD_Report: NumberFormatException thrown:"
+" LogProcessor.isTimeStamp(): arg is "+arg);
}


In tests between the two options i have found the .matches() method to be more efficient can anyone please confirm this and if possible explain this please.

Thanks

Spudillon

both are different match operations so you cant compare them in my opinion.
Read Matcher (Java Platform SE 6)

But in your code, you don`t need the Matcher and Pattern class. You could use the matches method of the String class (String use Pattern and Matcher intern too...)

Code:

---

                if (arg.matches(regexTS)) {
                        String[] tmpArr = arg.split("[,.:]");

---

Or use a better/other regular expression then you could avoid the rest of your code (parseInt , compare and so on) :D

Thanks for taking the time to check out my query.

->"both are different match operations so you cant compare them"
<-point taken there is no generic answer so i have opted for the code "as is above".

->"But in your code, you don`t need the Matcher and Pattern class"
<-compared to String.matches() this is costly but necessary as i need matcher.start()
as i need to read multiple logs and timestamps are not always hh:mm:ss.mls(nsnsnsns)
some are prefixed with date YYYYMMDD-hh:mm:ss.mls and need to enure hh<24,
mm<60 and so on.

***If it helps anyone in the future in this case i found Matcher.matches() was more efficient than Macther.find() and this result is completely dependant on the example.