java实现发送邮件

package com.mzule.simplemail;

import javax.mail.Authenticator;
import javax.mail.PasswordAuthentication;

/**
 * 服务器邮箱登录验证
 *
 * @author MZULE
 *
 */
public class MailAuthenticator extends Authenticator {

    /**
     * 用户名（登录邮箱）
     */
    private String username;
    /**
     * 密码
     */
    private String password;

    /**
     * 初始化邮箱和密码
     *
     * @param username 邮箱
     * @param password 密码
     */
    public MailAuthenticator(String username, String password) {
 this.username = username;
 this.password = password;
    }

    String getPassword() {
 return password;
    }

    @Override
    protected PasswordAuthentication getPasswordAuthentication() {
 return new PasswordAuthentication(username, password);
    }

    String getUsername() {
 return username;
    }

    public void setPassword(String password) {
 this.password = password;
    }

    public void setUsername(String username) {
 this.username = username;
    }

}

package com.mzule.dp.observer.factory;

import com.mzule.dp.observer.constant.MailSenderType;
import com.mzule.simplemail.SimpleMailSender;

/**
 * 发件箱工厂
 *
 * @author MZULE
 *
 */
public class MailSenderFactory {

    /**
     * 服务邮箱
     */
    private static SimpleMailSender serviceSms = null;

    /**
     * 获取邮箱
     *
     * @param type 邮箱类型
     * @return 符合类型的邮箱
     */
    public static SimpleMailSender getSender(MailSenderType type) {
 if (type == MailSenderType.SERVICE) {
     if (serviceSms == null) {
  serviceSms = new SimpleMailSender("[email protected]",
   "hidden");
     }
     return serviceSms;
 }
 return null;
    }

}

package com.mzule.dp.observer.observer;

import java.util.ArrayList;
import java.util.List;
import java.util.Observable;
import java.util.Observer;

import javax.mail.MessagingException;
import javax.mail.internet.AddressException;

import com.mzule.dp.observer.constant.MailSenderType;
import com.mzule.dp.observer.factory.MailSenderFactory;
import com.mzule.dp.observer.po.Product;
import com.mzule.simplemail.SimpleMailSender;

public class ProductPriceObserver implements Observer {

    @Override
    public void update(Observable obj, Object arg) {
 Product product = null;
 if (obj instanceof Product) {
     product = (Product) obj;
 }
 if (arg instanceof Float) {
     Float price = (Float) arg;
     Float decrease = product.getPrice() - price;
     if (decrease > 0) {
  // 发送邮件
  SimpleMailSender sms = MailSenderFactory
   .getSender(MailSenderType.SERVICE);
  List recipients = new ArrayList();
  recipients.add("[email protected]");
  recipients.add("[email protected]");
  try {
      for (String recipient : recipients) {
   sms.send(recipient, "价格变动", "您关注的物品"
    + product.getName() + "降价了，由"
    + product.getPrice() + "元降到" + price + "元，降幅达"
    + decrease + "元人民币。赶快购物吧。");
      }
  } catch (AddressException e) {
      e.printStackTrace();
  } catch (MessagingException e) {
      e.printStackTrace();
  }
     }
 }
    }

}