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 ?
This question is related to
java
regex
replaceall
It works for me.
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);
}
}
Result:
This is a string.<br />This is a long string.
Your problem is somewhere else.
A little more robust version of what you're attempting:
str = str.replaceAll("(\r\n|\n\r|\r|\n)", "<br />");
For me, this worked:
rawText.replaceAll("(\\\\r\\\\n|\\\\n)", "\\\n");
Tip: use regex tester for quick testing without compiling in your environment
Since my account is new I can't up-vote Nino van Hooff's answer. If your strings are coming from a Windows based source such as an aspx based server, this solution does work:
rawText.replaceAll("(\\\\r\\\\n|\\\\n)", "<br />");
Seems to be a weird character set issue as the double back-slashes are being interpreted as single slash escape characters. Hence the need for the quadruple slashes above.
Again, under most circumstances "(\\r\\n|\\n)" should work, but if your strings are coming from a Windows based source try the above.
Just an FYI tried everything to correct the issue I was having replacing those line endings. Thought at first was failed conversion from Windows-1252 to UTF-8. But that didn't working either. This solution is what finally did the trick. :)
That should work, but don't kill yourself trying to figure it out. Just use 2 passes.
str = str.replaceAll("(\r\n)", "<br />");
str = str.replaceAll("(\n)", "<br />");
Disclaimer: this is not very efficient.
It works for me. The Java code works exactly as you wrote it. In the tester, the input string should be:
This is a string.
This is a long string.
...with a real linefeed. You can't use:
This is a string.\nThis is a long string.
...because it treats \n as the literal sequence backslash 'n'.
This should work. You need to put in two slashes
str = str.replaceAll("(\\r\\n|\\n)", "<br />");
In this Reference, there is an example which shows
private final String REGEX = "\\d"; // a single digit
I have used two slashes in many of my projects and it seems to work fine!
Source: Stackoverflow.com