Java和正则表达式，子字符串

Question

I'm am tottaly lost when coming to regular expressions. I get generated strings like:

Your number is (123,456,789)

How can I filter out 123,456,789 ?

Answer 1

You can use this regex for extracting the number including the commas

\(([\d,]*)\)

The first captured group will have your match. Code will look like this

String subjectString = "Your number is (123,456,789)";
Pattern regex = Pattern.compile("\\(([\\d,]*)\\)");
Matcher regexMatcher = regex.matcher(subjectString);
if (regexMatcher.find()) {
    String resultString = regexMatcher.group(1);
    System.out.println(resultString);
}

Explanation of the regex

"\\(" +          // Match the character “(” literally
"(" +           // Match the regular expression below and capture its match into backreference number 1
   "[\\d,]" +       // Match a single character present in the list below
                      // A single digit 0..9
                      // The character “,”
      "*" +           // Between zero and unlimited times, as many times as possible, giving back as needed (greedy)
")" +
"\\)"            // Match the character “)” literally

This will get you started http://www.regular-expressions.info/reference.html

Answer 2

String str="Your number is (123,456,789)";
str = str.replaceAll(".*\\((.*)\\).*","$1");                    

or you can make the replacement a bit faster by doing:

str = str.replaceAll(".*\\(([\\d,]*)\\).*","$1");                    

Answer 3

try

"\\(([^)]+)\\)"

or

int start = text.indexOf('(')+1;
int end = text.indexOf(')', start);
String num = text.substring(start, end);

Answer 4

private void showHowToUseRegex()
{
    final Pattern MY_PATTERN = Pattern.compile("Your number is \\((\\d+),(\\d+),(\\d+)\\)");
    final Matcher m = MY_PATTERN.matcher("Your number is (123,456,789)");
    if (m.matches()) {
        Log.d("xxx", "0:" + m.group(0));
        Log.d("xxx", "1:" + m.group(1));
        Log.d("xxx", "2:" + m.group(2));
        Log.d("xxx", "3:" + m.group(3));
    }
}

You'll see the first group is the whole string, and the next 3 groups are your numbers.

Answer 5

String str = "Your number is (123,456,789)";
str = new String(str.substring(16,str.length()-1));