regex to find this pattern?

Question

I have below content in file

/** 
 some text
 text1 
 text2
 some text
**/

I want to check if "text1" or "text2" is contained in between /** **/ as mentioned in above example.

I tried below code

  Pattern p = Pattern.compile("//*/*.*?text1.*?/*/*/");
  Matcher m = p.matcher(fileAsString);
  while (m.find()) {
    System.out.println("match found");
  }

but it has two shortcomings . These are :-

1) It checks for text1 in between /** text1 **/ but does not work when text1 is in next line

2)I am not sure how to check any of the two strings i.e "text1" or "text2" in this regex?

Answer 1

You can use:

Pattern p = Pattern.compile("/\\*\\*.*?(?:text1|text2).*?\\*\\*/", Pattern.DOTALL);

1. Pattern.DOTALL is required to make sure to match text spanning multiple lines
2. * needs to be escaped using \\*
3. (?:text1|text2) is a non capturing alternation, needed to match text1 or text2.

Answer 2

The following pattern will ensure that you are always inside the comment part when text1 or text2 is found. To do that I repeat a group that can not match the comment end **/: (?>[^*]|\\*(?!\\*/))*

Pattern p = Pattern.compile("\\Q/**\\E"
                          + "(?>[^*]|\\*(?!\\*/))*?"
                          + "(?:text1|text2)"
                          + "(?>[^*]|\\*(?!\\*/))*"
                          + "\\Q**/\\E");

Answer 3

do you have to use a regex? would String.indexOf be a possible way to tell if the text is contained? You can substring the inner string between the /* */ tags and then do an indexOf