This is my first post. I have problem with String in Java. I want to use regular expression. Thank you in advance for any help.
My String is:
String str = "abXYxyzXYZabXasdfggXYZ".
I want to replace all characters with "+" but not variable below:
String word = "XYZ"
So the output should be like that:
+++++++XYZ+++++++++XYZ.
I started out with:
str.replaceAll("[^" + word + "]", "+")
But I got different output like that:
++XY+++XYZ++X++++++XYZ
This can actually be accomplished. It's an interesting approach since Java doesn't allow regex If clauses, but you can actually use a combination of lookaheads and lookbehinds within a negative lookahead to mimic a sort of If clause.
(?!(?:(?=XYZ)|(?<=X)(?=YZ)|(?<=XY)(?=Z))).
Replacement: +
Below code auto-generated from regex101.
See code below in use here
import java.util.regex.Matcher;
import java.util.regex.Pattern;
final String regex = "(?!(?:(?=XYZ)|(?<=X)(?=YZ)|(?<=XY)(?=Z))).";
final String string = "abXYxyzXYZabXasdfggXYZ";
final String subst = "+";
final Pattern pattern = Pattern.compile(regex);
final Matcher matcher = pattern.matcher(string);
// The substituted value will be contained in the result variable
final String result = matcher.replaceAll(subst);
System.out.println("Substitution result: " + result);
abXYxyzXYZabXasdfggXYZ
+++++++XYZ+++++++++XYZ
(?!(?:(?=XYZ)|(?<=X)(?=YZ)|(?<=XY)(?=Z))) Negative lookahead ensuring what follows doesn't match(?:(?=XYZ)|(?<=X)(?=YZ)|(?<=XY)(?=Z)) Match either of the following
(?=XYZ) Positive lookahead ensuring what follows matches XYZ literally(?<=X)(?=YZ) Match the following
(?<=X) Positive lookbehind ensuring what precedes is X literally(?=YZ) Positive lookahead ensuring what follows is YZ literally(?<=XY)(?=Z) Match the following
(?<=XY) Positive lookbehind ensuring what precedes is XY literally(?=Z) Positive lookahead ensuring what follows is Z literally. Match any character
java.util.regexdoes not support a construct that matches any text other than a certain multicharacter string of text. Almost all regex flavors do not support it.[...]in regex denotes a set of single characters. You can't that easily denote the inverse of whole words. So[^XYZ]matches every character that is notX, notYand notZ, so the whole alphabet exceptX, Y, Z. It does not match whole words that are unequal to the wordXYZ.