已知一段英文句子，查找裏面由三個字母構成的單詞

 1 import java.util.regex.Matcher;
 2 import java.util.regex.Pattern;
 3 
 4 //已知一段英文，查找裏面由三個字母構成的單詞的個數
 5 public class redex1 {
 6     public static void main(String[] args) {
 7         String s="IT is within my memory that Melville Clarendon, a lad of sixteen years, was riding through Southern Minnesota, in company with his sister Dorothy, a sweet little miss not quite half his own age.";
 8         //定義正則表達式，即3個字母而且兩邊是邊界
 9         String redex="\\b\\w{3}\\b";
10         Pattern p=Pattern.compile(redex);
11         Matcher m=p.matcher(s);
12         while (m.find()){
13             System.out.println(m.group());
14         }
15 
16     }
17 }