正则表达式在java中用空格和双引号标记字符串

Question

I'm trying to create a regex to tokenize a string. An example string would be.

"hello world" Alexandros Alex "I Am" Something

I need to get responce back:

hello world
Alexandros
Alex 
I am
Something

So to make it clear, tokenize with space but not words within quotes. If this is an easy regural expresion sorry in advance but i always strugle with these.

Answer 1

You could try: \\b(?:(?<=")[^"]*(?=")|\\w+)\\b . This will exclude the actual quotes from the matches.

import java.util.regex.*;
public class Test {
    public static void main(String...args) {
        String line = "\"hello world\" Alexandros Alex \"I Am\" Something";
        Pattern pattern = Pattern.compile("\\b(?:(?<=\")[^\"]*(?=\")|\\w+)\\b");
        Matcher matcher = pattern.matcher(line);
        while (matcher.find()) {
            System.out.println(matcher.group(0));
        }
    }
}

When executed, you get this output:

$ javac Test.java
$ java Test
hello world
Alexandros
Alex
I Am
Something

Answer 2

This regular expression will match either words or entire strings within quotes: "[^"]*"|\\w*

You can create a matcher with this regex and just iterate through all the matches. You can find some sample code here

Answer 3

If you want to split ,you can do so by checking if " are balanced..

Now obviously if the space is between "" the number of " would not be even..This is what the below regex do

\s(?=(?:([^"]*"[^"]*"[^"]*)*|[^"]*)$)