java提取QQ邮箱中的邮箱地址

其实很简单，一个正则表达式，搞定。。上代码：

package cn.abc.regex;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.PrintWriter;
import java.util.HashSet;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class EmailExtract {

    public static void main(String[] args) throws Exception {
            
        Set<String> es=EmailUtils.EmailExtract(new File("E:\\javaStuday\\email.txt"));
        PrintWriter pw = new PrintWriter(new File("E:\\javaStuday\\email2.txt"));
        System.out.println(es.size());
        for(String i:es)
        {
            pw.println(i);
        }
        pw.close();
        
    }
    

}
class EmailUtils{
    
    public static Set<String> EmailExtract(File f)throws Exception
    {
        Set<String> emails =new HashSet<String>();
        BufferedReader buff = new BufferedReader(new FileReader(f));
        String line = null;
        String reg = "\\w{5,}@\\w+(\\.[a-zA-Z]+)+";
        Pattern pt = Pattern.compile(reg);
        while((line = buff.readLine())!=null)
        {
            Matcher m = pt.matcher(line);
            while(m.find())
            {
                emails.add(m.group());
            }
        }
        buff.close();
        return emails;
    }
}