replace \n and \r\n with <br /> in java

Question

This has been asked several times for several languages but I can't get it to work. I have a string like this

String str = "This is a string.\nThis is a long string.";

And I'm trying to replace the \n with <br /> using

str = str.replaceAll("(\r\n|\n)", "<br />");

but the \n is not getting replaced. I tried to use this RegEx Tool to verify and I see the same result. The input string does not have a match for "(\r\n|\n)" . What am i doing wrong ?

どのように解決するのですか？

私の場合はうまくいきました。

public class Program
{
    public static void main(String[] args) {
        String str = "This is a string.\nThis is a long string.";
        str = str.replaceAll("(\r\n|\n)", "<br />");
        System.out.println(str);
    }
}

結果

これは文字列です。<br />これは長い文字列です。

あなたの問題は別のところにあります。