Question

Hello Guys !! 我开发了一个小应用程序，用于在单击提交按钮时将邮件发送到特定ID。现在根据我的需要：

我必须在一天中的特定时间自动发送邮件。
为了澄清这一点，邮件应该在特定时间发送给特定ID。

所以我需要的是自动完成我的过程。

任何建议都将受到高度赞赏..

protected void processRequest(HttpServletRequest request,
        HttpServletResponse response)
        throws IOException, ServletException {final String err = "/error.jsp";
    final String succ = "/success.jsp";


    String to = request.getParameter("to");
    String subject = request.getParameter("subject");
    String message = request.getParameter("message");
    String login = request.getParameter("login");
    String password = request.getParameter("password");

    try {
        Properties props = new Properties();
        props.setProperty("mail.host", "smtp.gmail.com");
        props.setProperty("mail.smtp.port", "587");
        props.setProperty("mail.smtp.auth", "true");
        props.setProperty("mail.smtp.starttls.enable", "true");

        Authenticator auth = new SMTPAuthenticator(login, password);

        Session session = Session.getInstance(props, auth);

        MimeMessage msg = new MimeMessage(session);
        msg.setText(message);
        msg.setSubject(subject);


        msg.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
        Transport.send(msg);

    } catch (AuthenticationFailedException ex) {
        request.setAttribute("ErrorMessage", "Authentication failed");

        RequestDispatcher dispatcher = request.getRequestDispatcher(err);
        dispatcher.forward(request, response);

    } catch (AddressException ex) {
        request.setAttribute("ErrorMessage", "Wrong email address");

        RequestDispatcher dispatcher = request.getRequestDispatcher(err);
        dispatcher.forward(request, response);

    } catch (MessagingException ex) {
        request.setAttribute("ErrorMessage", ex.getMessage());

        RequestDispatcher dispatcher = request.getRequestDispatcher(err);
        dispatcher.forward(request, response);
    }
    RequestDispatcher dispatcher = request.getRequestDispatcher(succ);
    dispatcher.forward(request, response);

}

private class SMTPAuthenticator extends Authenticator {

    private PasswordAuthentication authentication;

    public SMTPAuthenticator(String login, String password) {
        authentication = new PasswordAuthentication(login, password);
    }

    protected PasswordAuthentication getPasswordAuthentication() {
        return authentication;
    }
}

protected void doGet(HttpServletRequest request,
        HttpServletResponse response)
        throws ServletException, IOException {
    processRequest(request, response);
}

protected void doPost(HttpServletRequest request,
        HttpServletResponse response)
        throws ServletException, IOException {
    processRequest(request, response);
}
}

Answer 1

查看Quartz调度程序Java库。它具有广泛的配置和设置选项，并且将涵盖从最简单（例如类似于标准Java Timer）到复杂的类似cron行为的用例。

Quartz是一个功能齐全的开源作业调度服务与几乎任何Java EE或Java集成或一起使用 SE应用程序 - 从最小的独立应用程序到最大的电子商务系统。 Quartz可用于创建简单或执行数十，数百甚至甚至的复杂计划成千上万的工作;任务被定义为标准的作业 Java组件，可以执行您可能编程的几乎任何内容他们这样做。

Answer 2

除Quartz外，还有Timer API（http://java.sun.com/j2se/1.4.2/docs/api/java/util/Timer.html）

A facility for threads to schedule tasks for future execution in a background thread. Tasks may be scheduled for one-time execution, or for repeated execution at regular intervals.

您将计时器代码放入添加到您的新servlet中 Web应用程序。或者将您的代码添加到webapp中的现有servlet中。

还有很多其他开源调度API ......

Answer 3

维卡斯，

您必须使用计划机制来启动电子邮件作业。另外，我建议你将mail-job程序保存在一个单独的java类中，并使用servlet中的Scheduling代码。

Answer 4

public class ClassExecutingTask {

long delayfornextstart = 60*60*24*7*1000; // delay in ms : 10 * 1000 ms = 10 sec.
LoopTask tasktoexecute = new LoopTask();
Timer timer = new Timer("TaskName");
public void start() throws ParseException, InterruptedException {
timer.cancel();
timer = new Timer("TaskName");
//@SuppressWarnings("deprecation")
//Date executionDate = new Date(2013-05-04); // no params = now
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
System.out.println("waiting for the rght day to come");
Date executionDate = sdf.parse("2014-04-03");

Date date1 = sdf.parse("2014-04-07");

Date date2 = sdf.parse("2014-04-07");
System.out.println(date1+"and"+date2);
long waitTill=getTimeDiff(date2,date1);
if(date2==date1)
{
    waitTill=0;
     System.out.println(waitTill);
}

   System.out.println(waitTill);
  Thread.sleep(waitTill);
timer.scheduleAtFixedRate(tasktoexecute, executionDate, delayfornextstart);
}

private class LoopTask extends TimerTask {
public void run() {
    ExcelReadExample EE=new ExcelReadExample();
    try {
        EE.ReadFile();//ur Mail code or the method which send the MAil
    } catch (IOException e) {
        e.printStackTrace();
    }
}
}

public static void main(String[] args) throws ParseException, InterruptedException {
ClassExecutingTask executingTask = new ClassExecutingTask();
executingTask.start();
}
public static long getTimeDiff(Date dateOne, Date dateTwo) {
    String diff = "";
    long timeDiff = Math.abs(dateOne.getTime() - dateTwo.getTime());
    diff = String.format("%d hour(s) %d min(s)",     TimeUnit.MILLISECONDS.toHours(timeDiff),
            TimeUnit.MILLISECONDS.toMinutes(timeDiff) - TimeUnit.HOURS.toMinutes(TimeUnit.MILLISECONDS.toHours(timeDiff)));
    return timeDiff;
}


}

如何在java中的特定时间自动发送电子邮件

4 个答案: