Java regular expression with Matching text and special charachter-CodePudding

Hi I am new to java regex. I have the below string

String s = " "KBC_2022-12-20-2004_IDEAL333_MASTER333_2022-12-20-1804_SUCCESS";

I wanted to only Print "333" which is appended with MASTER . The output should be 333. Can someone help me writing the regex for this . Basically the code should print the value between "MASTER" and the next "_". here its 333 but the value might be of any number of character not limit to length 3.

CodePudding user response：

You can do MASTER(\\d )_

Pattern p = Pattern.compile("MASTER(\\d )_");
Matcher m = p.matcher(" KBC_2022-12-20-2004_IDEAL333_MASTER333_2022-12-20-1804_SUCCESS");
if (m.find()) {
    System.out.println(m.group(1)); // 333
}
m = p.matcher(" KBC_2022-12-20-2004_IDEAL333_MASTER123_2022-12-20-1804_SUCCESS");
if (m.find()) {
    System.out.println(m.group(1)); // 123
}

CodePudding user response：

You can use this regex: (?<=MASTER)[0-9] (?=\_).

We are looking for everything between MASTER and _:

lookbehind: everything that goes after MASTER: (?<=MASTER)
lookahead: everything that goes before _: (?=\_)

Try on regex101.com