1 package test_21_2;
 2 
 3 import java.util.HashSet;
 4 import java.util.Set;
 5 import java.util.regex.Matcher;
 6 import java.util.regex.Pattern;
 7 
 8 public class RegularTest {
 9 
10     public static void main(String[] args) {
11         
12         String str = "Twas brillig, and the slithy toves\n" +
13                      "Did gyre and gimble in the wabe.\n" + 
14                      "All mimsy were the borogoves,\n" + 
15                      "Beware the Jabberwock, my son,\n" +
16                      "The jaws that bite, the claws that catch.\n" + 
17                      "Beware the Jubjub bird, and shun\n" + 
18                      "The frumious Bandersnatch.";
19         // 找出所有不以大写字母开头的词，不重复地计算其个数
20         String regex = "\\b[a-z]\\w+";
21         
22         Matcher m = Pattern.compile(regex).matcher(str);
23         
24         Set<String> set = new HashSet<String>();
25         
26         while (m.find()) {
27             set.add(m.group());
28         }
29         
30         System.out.println(set.size());
31     }
32 }

 

结果如下：

22