前缀为@的字符串的Java正则表达式

Question

Say I have the following string

"@apple @banna @? example@test.com"

now I want to make it

"apple banna ? example@test.com"

What should be my regular expression be to remove "@" symbols without effecting email addresses?

Answer 1

I think this will work.

str = str.replaceAll("(?<!\S)@(?=\S+)");

Here's what this does:

(?<!\S)     // Checks to make sure that the @ is preceded by a whitespace
            // character, or is the beginning of the string. This exists to make sure we're not in an email.
@           // Literal @
(?=\S+)     // Makes sure that something besides whitespace follows.

Here are some quick tests: http://fiddle.re/2vmt

Answer 2

This question has changed significantly since its original posting. My original answer, although correct for the question as originally posed, is no longer correct.

This code will do it:

String noStrayAts = input.replaceAll("(?<=\\s)@", ""); 

---

Fyi, here is my previous answer:

Since both input and output are Strings, and the thing being removed does not require a regex, you simply need:

String noAts = input.replace("@", "");

Answer 3

String fruit = fruit.replaceAll("@", " ");

Answer 4

one way of doing this is following :

str.replaceAll("@apple", "apple"); 
str.replaceAll("@banna", "banna"); 
str.replaceAll("@?", "?");