import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Example {
public static void main(String[] args) {
final String regex = "(<fileName>)(.+)?(<\\/fileName>)";
final String string = " <file> \n"
+ " <fileType>Mezza</fileType>\n"
+ " <fileName></fileName>\n"
+ " <segments>0000</segments>\n"
+ " </file>";
final String subst = "\\1[!] value does not exist!\\3";
final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE);
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);
}
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Java, please visit: https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html