给 Java SE 注入脚本语言的活力

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

public class Find5Words {
    public static void main(String[] args) throws IOException {
        String result = "";
        String line = null;
        int num = 0;
        FileReader fr = new FileReader("filename");
        BufferedReader br = new BufferedReader(fr);
        while ((line = br.readLine()) != null) {
            result += line;
        }
        br.close();
        fr.close();
        String[] s = result.split(" ");
        for (int i = 0; i < s.length; i++) {
            if (s[i].matches("^\\w{5}$")) {
                num++;
            }
        }
        System.out.println(num);
    }
}