Java正则表达式使用

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class EmailSpider {
  public static void main(String[] args) {
    try {
      BufferedReader br = new BufferedReader(new FileReader("C:\\emailSpider.html"));
      String line = "";
      while((line=br.readLine()) != null) {
        parse(line);
      }
    } catch (FileNotFoundException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
  private static void parse(String line) {
    Pattern p = Pattern.compile("[\\w[.-]]+@[\\w[.-]]+\\.[\\w]+");
    Matcher m = p.matcher(line);
    while(m.find()) {
      System.out.println(m.group());
    }
  }
}

import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
public class CodeCounter {
  static long normalLines = 0;//正常代码行
  static long commentLines = 0;//注释行
  static long whiteLines = 0;//空白行
  public static void main(String[] args) {
    //找到某个文件夹,该文件夹下面在没有文件夹，这里没有写递归处理不在同一文件夹的文件
    File f = new File("E:\\Workspaces\\eclipse\\Application\\JavaMailTest\\src\\com\\java\\mail");
    File[] codeFiles = f.listFiles();
    for(File child : codeFiles){
      //只统计java文件
      if(child.getName().matches(".*\\.java$")) {
        parse(child);
      }
    }
    System.out.println("normalLines:" + normalLines);
    System.out.println("commentLines:" + commentLines);
    System.out.println("whiteLines:" + whiteLines);
  }
  private static void parse(File f) {
    BufferedReader br = null;
    //表示是否为注释开始
    boolean comment = false;
    try {
      br = new BufferedReader(new FileReader(f));
      String line = "";
      while((line = br.readLine()) != null) {
        //去掉注释符/*前面可能出现的空白
        line = line.trim();
        //空行 因为readLine()将字符串取出来时，已经去掉了换行符\n
        //所以不是"^[\\s[^\\n]]*\\n$"
        if(line.matches("^[\\s[^\\n]]*$")) {
          whiteLines ++;
        } else if (line.startsWith("/*")  !line.endsWith("*/")) {
          //统计多行/*****/
          commentLines ++;
          comment = true;  
        } else if (line.startsWith("/*")  line.endsWith("*/")) {
          //统计一行/**/
          commentLines ++;
        } else if (true == comment) {
          //统计*/
          commentLines ++;
          if(line.endsWith("*/")) {
            comment = false;
          }
        } else if (line.startsWith("//")) {
          commentLines ++;
        } else {
          normalLines ++;
        }
      }
    } catch (FileNotFoundException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    } finally {
      if(br != null) {
        try {
          br.close();
          br = null;
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
    }
  }
}