Regex expression to find

Question

I am working on a Java program that replaces variable values in a text file.

The variables to be replaced are encapsulated as...

 side    /*{{*/ red /*TEAM}}*/

or

detect_range   /*{{*/ 200 /*RANGE}}*/  nm

So in the first case I want to replace the value red with another value. The second I would replace 200.

Here I am reading the file line by line looking for that pattern.

       File file = new File(currentFile);

    try {
        Scanner scanner = new Scanner(file);


        int lineNum = 0;
        while (scanner.hasNextLine()) {
            String line = scanner.nextLine();
            lineNum++;
            if (<match regex expression for xxxxx /*{{*/ value /*VariableNAME}}*/ >) {

            }
        }
    } catch (Exception e) {
        System.out.println(e.toString());
        //handle this
    }

What is a regex expression to that I Could use to find these patterns?

Edit:

I have a line in the file that would say

side    /*{{*/ red /*TEAM}}*/

The output change the line in the file to

side    /*{{*/ blue /*TEAM}}*/

The string "TEAM" is the identifier.

the /* */ pairs, are they part of the pattern, or just comment markers? — Adam Yost
– Adam Yost, Commented Aug 11, 2014 at 17:35
You need to specify the problem more clearly. Show some examples of actual input and the expected output and explain how the replacement values are mapped to the tags they replace. — Jim Garrison
– Jim Garrison, Commented Aug 11, 2014 at 17:39
TEAM and RANGE are are just variable names. I must retrieve the variable names to know what values to append to them. — user758114
– user758114, Commented Aug 11, 2014 at 18:23

Braj · Accepted Answer · 2014-08-11 18:26:08Z

1

You can use below use with String.replaceAll() method.

(?<=\/\*\{\{\*\/ ).*?(?= \/\*(TEAM|RANGE)\}\}\*\/)

Here is online demo

Note: Use \w+ if value "TEAM" and "RANGE" are dynamic.

Sample code:

String str1 = "side    /*{{*/ red /*team}}*/ ";
String str2 = "detect_range   /*{{*/ 200 /*RANGE}}*/  nm";
String pattern = "(?i)(?<=\\/\\*\\{\\{\\*\\/ ).*?(?= \\/\\*(TEAM|RANGE)\\}\\}\\*\\/)";
System.out.println(str1.replaceAll(pattern, "XXX"));
System.out.println(str2.replaceAll(pattern, "000"));

output:

side    /*{{*/ XXX /*team}}*/ 
detect_range   /*{{*/ 000 /*RANGE}}*/  nm

If you want to get "TEAM" or "RANGE" then get it from index 1.

Pattern p = Pattern.compile(pattern);
Matcher m = p.matcher(str1);
if (m.find()) {
    System.out.println(m.group(1));
}

edited Aug 11, 2014 at 18:26

answered Aug 11, 2014 at 17:37

Braj

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7 Comments

user758114 Over a year ago

How could I extract the variable name "team" for example, to compare it to know what value to insert.

Braj Over a year ago

just get the matched group from index 1 as shown in demo as well. Do you need code as well?

user758114 Over a year ago

That would be helpful.

user758114 Over a year ago

In the pattern String pattern = "(?i)(?<=\\/\*\\{\\{\*\\/ ).*?(?= \\/\*(TEAM|RANGE)\\}\\}\*\\/)"; Could I replace TEAM|RANGE with a wildcard so that it would match no matter what the variable name is?

Braj Over a year ago

yes you can use it, as I mentioned use \w+ instead of (TEAM|RANGE). Are you looking for only variable names then I can optimize it, if you need?

|

Community · Accepted Answer · 2020-06-20 09:12:55Z

0

You can use this regex:

/\*{{\*/ *(\S+) */\*[^}]*}}\*/

and grab captured group #1

RegEx Demo

edited Jun 20, 2020 at 9:12

CommunityBot

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answered Aug 11, 2014 at 17:38

anubhava

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