删除所有非数字字符但保留特定字词

Question

I'm working on a script that can download mangas from www.mangafox.me in Java.

Unfortunately, this website doesn't have any APIs thus I use some archaic ways to get my data. However, it's possible to get an xml with every chapters of a manga. For example : http://mangafox.me/rss/nisekoi.xml .

I parse this xml and use the title tag to get a chapter's number and associated volume.

For example, I have a string like this : Nisekoi Vol TBD Ch 215 and I want to keep only TBD and 215 .

At the moment, I replace all non-numeric characters with spaces and keep every occurences of TBD by using :

String title = "Nisekoi Vol TBD Ch 215";
title = title.replaceAll("[^0-9.\bTBD\b]+", " ").trim();

title equals to "TBD 215" and then I use title.split(" ") to get the volume and the chapter.

This is working just fine until I do the same with a manga that starts with an T. Apparently, the capital T isn't replaced by a space.

I'm not very good at Regular expression so how do I get to replace every character that is not a number, a dot (for decimals) or the word "TBD" by a space in Java ?

Thanks !

Answer 1

KISS - 保持简单愚蠢：用\\\\d+$抓住标题末尾的数字，然后像TBD + your_number一样将你的标题your_number 。

Answer 2

I guess that "Vol" and "Ch" are the fixed parts here, so you could use this regex :

Vol (.*) Ch (.*)

and retrieve it's first group for the volume and its second for the chapter.

You can see the java code in action here .

FYI, you're having an error because you're using a character class ( [...] ) which means "any character of the following class" rather than "this sequence of characters".

Answer 3

Without a regex, I'd try something like this:

StringBuilder sb = new StringBuilder(title.length());
for (int i = 0; i < title.length(); ++i) {
  char ch = title.charAt(i);
  if (ch == '.' || Character.isDigit(ch) {
    sb.append(ch);
  } else if (ch == 'T' && title.indexOf("TBD", i) == i) {
    sb.append("TBD");
    i += 2;
  }
}
title = sb.toString();

Answer 4

This should do the trick

Pattern pattern = Pattern.compile("Vol ([A-Z]{3}) Ch (\\d{3})");
Matcher matcher = pattern.matcher(input);
if(matcher.find()){
  String volume = matcher.group(1);
  String chapter = matcher.group(2);
}

Answer 5

There are many answers here - so here is mine which extends the answer from Jan.

String title = "Nisekoi Vol TBD Ch 215.5";
Pattern pattern = Pattern.compile("[\\.\\d]+$");
Matcher matcher = pattern.matcher(title);
   if (matcher.find())
   {
     System.out.println("TBD " + matcher.group(0));
   }

output is : TBD 215.5 .

---

This will always match the numbers at the end of the string. So it does not matter what is leading the string. This will also match dots.