如何在 android 中使用正则表达式替换字符串中的某些部分，除了某些单词

Question

I have 100 such files with string containing Vol - {some digit}. I want to replace all word except this Vol - {0-9}.

Problem : Kirtan _ Vol - 4 _ android - 1 _ bhai sahib.mp3

Needed Result : Vol - 4.mp3

Answer 1

You can use the regex , .*(Vol - [0-9]).* where .* means any character any number of times and (Vol - [0-9]) is the capturing group (1) referred by $1 in the code. The pattern, [0-9] means one digit in the range, 0-9.

public class Main {
    public static void main(String[] args) {
        String str = "Kirtan _ Vol - 4 _ android - 1 _ bhai sahib.mp3";

        str = str.replaceAll(".*(Vol - [0-9]).*", "$1");

        System.err.println(str);
    }
}

Output:

Vol - 4

If the number of digits can be more than one, replace [0-9] with [0-9]+ or \d+ .