Question

As the question states given the following code:

public class Foo
{
   public static void main(String[] args)
   {  
         String test = "Cats go meow";  
         String[] tokens = test.split(" ");
   }
}

is it possible to precompile that regex in the split function along the lines of this:

public class Foo
{  
   Pattern pattern = Pattern.compile(" ");
   public static void main(String[] args)
   {  
         String test = "Cats go meow";  
         String[] tokens = test.split(pattern);
   }
}

Answer 1

Yes, it is possible. Also, make pattern static so the static method main can access it.

public class Foo
{  
   private static Pattern pattern = Pattern.compile(" ");
   public static void main(String[] args)
   {  
         String test = "Cats go meow";  
         String[] tokens = pattern.split(test);
   }
}

According to the docs for the split method in String, you can use String’s split or Pattern’s split, but String’s split compiles a Pattern and calls its split method, so use Pattern to precompile a regex.