java - Cron Job 仅在 Google App Engine for Java 中执行一次

Question

我想设置一个 cron 作业，每 2 分钟发送一封电子邮件。但是，当我启动 cron 作业时，它会立即发送一封电子邮件，然后就不再发送了。但是，当我转到 Google Cloud Console 并查看我的 cron 作业时，它说它运行成功，但我没有收到电子邮件。

我遵循了本教程:https://rominirani.com/episode-9-using-the-cron-service-to-run-scheduled-tasks-8bc7dba91a77

web.xml file:

<servlet>
    <servlet-name>subscribe</servlet-name>
    <servlet-class>blogapp.CronServlet</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>subscribe</servlet-name>
    <url-pattern>/subscribe</url-pattern>
</servlet-mapping>

cron.xml file:

<cronentries>
  <cron>
    <url>/subscribe</url>
    <description>Daily Digest from The Rambling Programmer</description>
    <!-- <schedule>every day 17:00</schedule> -->
    <schedule>every 2 minutes</schedule>
    <timezone>America/Chicago</timezone>
  </cron>
</cronentries>

CronServlet.java file:

public class CronServlet extends HttpServlet {

private static final Logger _logger = Logger.getLogger(CronServlet.class.getName());
public void doGet(HttpServletRequest req, HttpServletResponse resp)
throws IOException {
    try {
    _logger.info("Cron Job has been executed");
    /// other logic to send email
    /// sendEmail(email, subject, content);
    }

    resp.sendRedirect("/subscribe.jsp");
    }
    catch (Exception ex) {
        resp.getWriter().println("Error subscribing");
    }
}
@Override
public void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
doGet(req, resp);

}

没有弹出错误，一封电子邮件已成功发送，所以我不确定为什么它没有像我希望的那样每两分钟运行一次。

谢谢!

Answer 1

我发现这是因为由于某种原因它没有调用sendEmail()!