Extract strings from csv file in java

Question

I have a text file that contains some strings separated by ",". Strings are in the form of: "x:somestring:any string". I'm interested in extracting "somestring" value only. I could extract "somestring:any string" by replacing the "x:" with "" using:

Pattern p= Pattern.compile("x:", Pattern.CASE_INSENSITIVE);
Matcher m = p.matcher("");

But as I said before, I'm interested only in "somestring". Is it possible to add a second pattern in order to replace ":any string" with "". I thought of repeating the same process again, but I wanted to ask about a better way. Is there any way to improve my regular expression? Please note that "somestring" and "any string" are not fixed values.

DanLebrero · Accepted Answer · 2012-06-23 19:07:44Z

1

Use split:

    for (String s : subjectString.split(",")) {
        s.split(":")[1];
    }

edited Jun 23, 2012 at 19:07

answered Jun 23, 2012 at 18:46

DanLebrero

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Comments

Tim Pietzcker · Accepted Answer · 2012-06-23 18:41:44Z

0

If you have a string subjectString that contains "x:somestring:any string", then the following will extract somestring:

Pattern regex = Pattern.compile(
    "(?<=x:) # Assert position right after 'x:'\n" +
    "[^:]*   # Match any number of characters except colons", 
    Pattern.COMMENTS);
Matcher regexMatcher = regex.matcher(subjectString);
if (regexMatcher.find()) {
    ResultString = regexMatcher.group();
}

answered Jun 23, 2012 at 18:41

Tim Pietzcker

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2 Comments

Jury A Over a year ago

your solutions works fine. But this means I have to split the strings in my file since it is CSV file.Then treat each splitted string using your code in a loop. My file is going to have soooooo many strings. any suggestions to treat my sequence of strings (string1, string2, string3, ..etc.) at once without the need to split each strings and treat them in a loop separately?

Tim Pietzcker Over a year ago

I would steer clear of using regexes to parse a CSV file directly. This is bound to cause problems (think embedded newlines, quoted fields etc.). Better use a CSV library to handle the file itself, and then apply regexes to the fields you have parsed.

user unknown · Accepted Answer · 2012-06-24 09:02:09Z

0

Another, simple way is:

"x:somestring:any string".replaceAll (".*:(.*):.*", "$1")

answered Jun 24, 2012 at 9:02

user unknown

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1 Comment

user unknown Over a year ago

$1 is the first group of elements, captured between round parens; here is only one such group declared: The word between the two colons.

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