In java how to get substring from a string till a character c?

Question

I have a string (which is basically a file name following a naming convention) abc.def.ghi

I would like to extract the substring before the first

Answer 1

If your project already uses commons-lang, StringUtils provide a nice method for this purpose:

String filename = "abc.def.ghi";

String start = StringUtils.substringBefore(filename, "."); // returns "abc"

see javadoc [2.6] [3.1]

Answer 2

You can just split the string..

public String[] split(String regex)

Note that java.lang.String.split uses delimiter's regular expression value. Basically like this...

String filename = "abc.def.ghi";     // full file name
String[] parts = filename.split("\\."); // String array, each element is text between dots

String beforeFirstDot = parts[0];    // Text before the first dot

Of course, this is split into multiple lines for clairity. It could be written as

String beforeFirstDot = filename.split("\\.")[0];

Answer 3

or you may try something like

"abc.def.ghi".substring(0,"abc.def.ghi".indexOf(c)-1);