Java Regexp capturing group includes space, why?
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I am trying to parse this string, 

    "斬釘截鐵 斩钉截铁 [zhan3 ding1 jie2 tie3] /to chop the nail and slice the iron (idiom)/resolute and decisive/unhesitating/definitely/without any doubt/";

With this code


    private static final Pattern TRADITIONAL = Pattern.compile("(.*?) ");
    
    	private String extractSinglePattern(String row, Pattern pattern) {
    		Matcher matcher = pattern.matcher(row);
    		if (matcher.find()) {
    			return matcher.group();
    		}
    		return null;
    	}


However, for some reason the string returned contains a space at the end


    org.junit.ComparisonFailure: expected:<斬釘截鐵[]> but was:<斬釘截鐵[ ]>

Is there something wrong with my pattern?
I have also tried

    private static final Pattern TRADITIONAL = Pattern.compile("(.*?)\\s");

but to no avail

I have also tried matching with two spaces at the end of the pattern, but it doesn't match (there is only one space).