正则表达式有什么应用？

  import java。io。*;import java。util。regex。*;public class Printer { public static void main(String[] args) { System。out。println("\nPlease enter the input string:\n"); BufferedReader reader = new BufferedReader(new InputStreamReader(System。

  in)); String inputString; boolean isOK = false; try { while(!isOK) { if((inputString = reader。readLine()) != null) { if(inputString。

  length() > 200) { System。out。println("The string exceeds 200 characters。\nPlease enter again!\n"); } else { Pattern regex = Pattern。

  compile("[^@#$%&*/^]+"); Matcher matcher = regex。matcher(inputString); boolean isMatched = matcher。matches(); if(!isMatched) { System。

  out。println("The String can't contain @,#,$,%,*,& and ^。\nPlease enter again!\n"); } else { isOK = true; System。out。println("\nYour input string is: \n" + inputString); } } } } } catch(IOException e) { e。

  printStackTrace(); } }}。