Simple Regex application in Java

Regex mode is a valuable foundation tool that can be used for many types of text processing, such as matching, searching, extracting, replacing, and analyzing structured content. Pattern.matches (string pattern, string resource) methods and string matches methods are all suitable for one-time use, but they are less efficient if reused. Creating a pattern instance by using a static pattern.compile (String pattern) method results in a more efficient schema for performing a compiled version that matches more than once.
Import Java.util.Scanner;
Import Java.util.regex.Pattern;
Import Java.util.regex.Matcher;

public class Simpleregex ... {

public static void Main (string[] args) ... {

Scanner SCA = new Scanner (system.in);
Match a natural number less than 99999
Pattern pattern = Pattern.compile ("/d{1,5}");

Matcher Matcher;

System.out.println ("Please enter a number:");

while (true) ... {

Matcher = Pattern.matcher (Sca.nextline ());

if (!matcher.matches ()) ... {//input mismatch
SYSTEM.OUT.PRINTLN ("must enter the 0~99999 number, input terminates");
Break Exit loop
}

System.out.println ("right");
}

Sca.close ();

}
}