hi friend,

Try the following code snippet may this will be helpful for you

private static final String REGEX = "\\bcat\\b";
private static final String INPUT ="bat";
public static void main( String args[] ){
Pattern p = Pattern.compile(REGEX);
        Matcher m = p.matcher(INPUT); // get a matcher object
        int count = 0;
        if(!(m.find()))
        {
            System.out.println(p.pattern());
        }
 }

Thanks.