Using Java to find substring of a bigger string using Regular Expression

java regex string
digiarnie picture digiarnie · Mar 1, 2009 · Viewed 328.3k times · Source

If I have a string like this:

FOO[BAR]

I need a generic way to get the "BAR" string out of the string so that no matter what string is between the square brackets it would be able to get the string.

e.g.

FOO[DOG] = DOG
FOO[CAT] = CAT

Answer

Bryan Kyle picture Bryan Kyle · Mar 1, 2009

You should be able to use non-greedy quantifiers, specifically *?. You're going to probably want the following:

Pattern MY_PATTERN = Pattern.compile("\\[(.*?)\\]");

This will give you a pattern that will match your string and put the text within the square brackets in the first group. Have a look at the Pattern API Documentation for more information.

To extract the string, you could use something like the following:

Matcher m = MY_PATTERN.matcher("FOO[BAR]");
while (m.find()) {
    String s = m.group(1);
    // s now contains "BAR"
}

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