Java 发送 Email

发送 email  需要 email.jar  activation.jar
-----------------------------------------------
package tao.email;
 
import java.util.Date;
import java.util.Properties;
 
import javax.mail.Authenticator;
import javax.mail.Message;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
 
public class MailSender {
   
    private String  smtp = "smtp.qq.com";  // 邮件服务器
   
    private String username = "786792111";
    private String password = "xxxxx";
   
    private String from = username+"@qq.com";
   
    EmailAuthenticator auth = new EmailAuthenticator(this.username,this.password);
   
    Properties props = System.getProperties();
    {
       props.put("mail.smtp.host",smtp);
       props.put("mail.smtp.auth", "true");
    }
   
    Session session = Session.getDefaultInstance(props,(Authenticator)auth);
    Message msg = new MimeMessage(session);
   
    public void sendTo(String to){
       try{
           msg.setfrom(new InternetAddress(from));
           msg.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
           msg.setSubject("用户注册验证");
           msg.setSentDate(new Date());