提取Java中的某个substring

Question

I have a sentence, which is:

User update personal account ID from P150567 to A250356.

I want to extract the keywords " P10567 " from this sentence.

How do I extract data between the sentence using regex or string method?

Answer 1

• String method:

  Use StringUtils.substringBetween() of Apache Commons :

   public static void main(String[] args) { String sentence = "User update personal account ID from P150567 to A250356."; String id = StringUtils.substringBetween(sentence, "from ", " to"); System.out.println(id); }

• Regex method:

  Use regex from (.*) to , the string surrounded by parentheses is called group(1) , just extract it:

   public static void main(String[] args) { String regex = "from (.*) to"; String sentence = "User update personal account ID from P150567 to A250356."; Pattern pattern = Pattern.compile(regex); Matcher matcher = pattern.matcher(sentence); matcher.find(); System.out.println(matcher.group(1)); }

Answer 2

Consider this string:

      String s = “Hey Hello from Scaler”

If you want only a “Hello” substring in the output of your program then call the substring method with 4 as its startIndex and 9 as its endIndex as you want the part of the given string starting from index 0 and ending at index 8.

String s_substring = s.substring(4, 9)
//s_substring will contain “Hello” which is substring of string s

read more about Using Substring Method in Java here