如果正则表达式模式在Java中匹配，则提取文件的下一行数据

Question

I want to extract the next line data of a text file if regex pattern matches in Java. I am able to detect and match the pattern data in a text file, But unable to print the next line of pattern data.

Test data:

*** Explorer
GenV Deno Znet

Regular Expression for matching the Explorer

[*\\+]+[\\s+]+[Explorer]+[:]

Kindly help me on how to get the next line if *** Explorer pattern is found.

Answer 1

You can use this regex with a capturing group for the next line after your search pattern:

[*]+\s+Explorer\R(.*)

Next line is captured in group #1

Regex Breakup:

• [*]+\\s+Explorer - Match your search pattern
• \\R - Match any newline character
• (.*) - Match and captured full line in group #1

In Java use:

import java.util.regex.Matcher;
import java.util.regex.Pattern;

final String regex = "[*]+\\s+Explorer\\R(.*)";
final String input = "*** Explorer\nGenV Deno Znet";

final Pattern pattern = Pattern.compile(regex);
final Matcher matcher = pattern.matcher(input);

while (matcher.find()) {
    System.out.println("match: " + matcher.group(1));
}

RegEx Demo

Answer 2

You can Use:

[*\s]+Explorer\n(.*?)$

---

Regex Demo

Answer 3

Well, for starters the regex is not going to match "*** Explorer"

It will match "*** Explorer:"

If this is java, can't you just read the next line?

        while ((lineText = lineReader.readLine()) != null) {
            hasMatch = lineText.matches(regex);
            if(hasMatch) {
                lineText = lineReader.readLine();
                System.out.println(lineText);
            }
        }

Works for me.