浅谈Mail

定义发送邮件API 

public interface SendMail {


    /**
     * @param subject
     * @param message
     * @param recipients
     * @throws MessagingException
     */
    void send(String subject, String message, String... recipients) throws MessagingException, UnsupportedEncodingException;


    /**
     * 向一个人发送邮件(带多个附件)
     *
     * @param subject
     * @param message
     * @param attachments
     * @param recipients
     * @throws MessagingException
     * @throws UnsupportedEncodingException
     */
    void send(String subject, String message, List attachments, String... recipients) throws MessagingException, UnsupportedEncodingException;
}

发送邮件具体实现 

public class SendMailImpl extends Authenticator implements SendMail {

    private String username;
    private String password;
    //发送邮件的props文件
    private Properties props = System.getProperties();
    //邮箱发送会话
    private Session session;

    /**
     * 带参数的构造器，初始化邮箱登录的用户名和密码
     *
     * @param username
     * @param password
     */
    public SendMailImpl(String username, String password) {
        this.username = username;
        this.password = password;

        //根据发送邮箱的账号解析出smtp服务器
        String smtpHostName = "smtp." + username.split("@")[1];
        //初始化props
        props.put("mail.smtp.auth", "true");
        props.put("mail.smtp.host", smtpHostName);
        props.put("mail.smtp.ssl.enable", true);
        //发送验证
        //创建邮箱收发会话的session
        session = Session.getInstance(props, this);
    }

    //重写该方法，获得  PasswordAuthentication  对象
    @Override
    protected PasswordAuthentication getPasswordAuthentication() {
        return new PasswordAuthentication(username, password);
    }


    @Override
    public void send(String subject, String message, String... recipients) throws MessagingException, UnsupportedEncodingException {
        this.send(subject,message,null,recipients);
    }

    @Override
    public void send(String subject, String message, List attachments, String... recipients) throws MessagingException, UnsupportedEncodingException {
        //根据session创建MimeMessage
        MimeMessage mimeMessage = new MimeMessage(this.session);
        //发件人
        mimeMessage.setFrom(new InternetAddress(this.username,"趁我们还未老","UTF-8"));
        //收件人们
        InternetAddress[] addresses = new InternetAddress[recipients.length];
        for (int i = 0; i < addresses.length; i++) {
            addresses[i] = new InternetAddress(recipients[i]);
        }
        mimeMessage.setRecipients(MimeMessage.RecipientType.TO, addresses);
        //主题
        mimeMessage.setSubject(subject);

//        msg.setFrom (new InternetAddress ("[email protected]", "这里是需要的昵称", "UTF-8"));
        //邮件附件
        if (attachments != null) {
            //邮件正文
            BodyPart contentPart = new MimeBodyPart();
            contentPart.setContent(message, "text/html;charset=utf-8");
            //附件
            Multipart multipart = new MimeMultipart();
            multipart.addBodyPart(contentPart);
            for (File attachment : attachments) {
                BodyPart attachmentPart = new MimeBodyPart();
                DataSource source = new FileDataSource(attachment);
                attachmentPart.setDataHandler(new DataHandler(source));
                //避免中文乱码的处理
                attachmentPart.setFileName(MimeUtility.encodeWord(attachment.getName()));
                multipart.addBodyPart(attachmentPart);
            }
            mimeMessage.setContent(multipart);
            //保存邮件
            mimeMessage.saveChanges();
        }else {
            //内容
            mimeMessage.setContent(message, "text/html;charset=utf-8");
        }
        //发送
        Transport.send(mimeMessage);
    }
}