如何从非字母数字字符中清除字符串，但保留某些字符？

Question

I have a string that has non-alphanumeric characters, this string contains English and non English alphabets. I need to clean the string from non-alphanumeric characters, but I want to keep some of them. For instance: Let's say that I want to keep comma and colon only.

Example: String st = "I, Love: ( Coding {}+-), codificación"

I want the output to be "I,Love:Coding,codificación"

Is there a regex that can do that?

Note the method below will clean the text from all non-alphanumeric characters.

public static String cleanText(String text) {
     return text.replaceAll("\\P{LD}+", "");
}

Answer 1

You can use

public static String cleanText(String text) {
    return text.replaceAll("[^\\p{L}\\p{N}:,]+", "");
    // or return text.replaceAll("[^\\p{LD}:,]+", "");
}

Details :

• [^ - start of a negated character class
  • \p{L} - any Unicode letter
  • \p{N} - any digit
  • : - a colon
  • , - a comma
• ]+ - end of the character class, repeat one or more times.

See the regex demo . See a Java demo :

import java.util.*;
import java.io.*;

class Test
{
    public static void main (String[] args) throws java.lang.Exception
    {
        String st = "I, Love: ( Coding {}+-), codificación";
        System.out.println(cleanText(st));

    }
    public static String cleanText(String text) {
        return text.replaceAll("[^\\p{L}\\p{N}:,]+", "");
    }
}
// => I,Love:Coding,codificación