子串可删除第一个句号之前和第二个句号之后的所有内容

Question

So I have a filename that looks like this:

myFile.12345.txt

If I wanted to end up with just the "12345" how would I go about removing that from the filename if the 12345 could be anywhere between 1 and 5 numbers in length?

Answer 1

If you are sure that there would be 2 periods . for sure

String fileName = string.split("\\.")[1]

Answer 2

Assuming you want to extract all the numbers, you could use a simple regex to remove all the non-digits characters:

String s = "myFile.12345.txt";
String numbers = s.replaceAll("[^\\d]","");
System.out.println(numbers); //12345

Note: It would not work with file12.12345.txt for example

Answer 3

static final Pattern P = Pattern.compile("^(.*?)\\.(.*?)\\.(.*?)$");
...
...
...
Matcher m = P.matcher(input);
if (m.matches()) {
  //String first = m.group(1);
  String middle = m.group(2);
  //String last = m.group(3);
  ...
}

Answer 4

you can use this

String s="ghgj.7657676.jklj";
String p = s.substring(s.indexOf(".")+1,s.lastIndexOf("."));