Question

I’m writing a file renamer program in java. The issue is when giving input pattern.

When the input is complex like (][) in that case, I’m getting errors by java.util.regex.Pattern class..

The major issue of writing this code is that the input pattern and replacement pattern are user input. How can I handle such characters during processing ???

Answer 1

This is an example of how one can escape the special RegExp characters in the Java source code. I believe that you will have to escape the special characters manually if the pattern is being entered by a user.

package edu.mew.test.regexp;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class RegExpPatternTester {

  public static void main(String[] args) {
    String s1 = "filename()[].txt";
    Pattern p = Pattern.compile(".*\\(\\)\\[\\].*");
    Matcher m1 = p.matcher(s1);
    System.out.println(m1.matches());
    String s2 = "filename.txt";
    Matcher m2 = p.matcher(s2);
    System.out.println(m2.matches());
  }

}