Hi,

You can use the replaceAll() function of String class in Java.

We will use the regular expression "[^a-zA-Z0-9]" for finding all non alphanumeric characters and then replace it with required character.

Following example show how to replace all non alphanumeric characters present in a Java String variable.

public class TestReplaceAllNonAlphanumeric 
{
    public static void main(String[] args) 
    {
    String s = "What is use of[]. What {} is used.";
    s = s.replaceAll("[^a-zA-Z0-9]", "");
    System.out.println(s);
    }
}

Thanks