Map a servlet to a cron url? - google-app-engine

Question

How do I map a servlet to a cron url? This question results from the comment to the answer in the following post: Use Cron jobs with Appengine Endpoints API
In my project the cron job is called as shown in the log in Google App Engine and the url https://[url-commented-out].appspot.com/_ah/api/stocksApi/v1/stocks executes properly when tested in the web browser and returns the proper value.
But I am getting the error 405: HTTP method GET not supported by this URL, when I try to run it in GAE. I've read https://cloud.google.com/appengine/docs/java/config/cron My code in cron.xml file is:
<?xml version="1.0" encoding="UTF-8"?>
<cronentries>
<cron>
<url>/_ah/api/stocksApi/v1/stocks</url>
<description>Backend Process Stocks</description>
<schedule>every 1 minutes from 11:10 to 11:30</schedule>
<timezone>America/New_York</timezone>
</cron>
</cronentries>
My web.xml is:
<?xml version="1.0" encoding="utf-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee" version="2.5">
<servlet>
<servlet-name>SystemServiceServlet</servlet-name>
<servlet-class>com.google.api.server.spi.SystemServiceServlet</servlet-class>
<init-param>
<param-name>services</param-name>
<param-value>
[package].StocksEndpoint</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>SystemServiceServlet</servlet-name>
<url-pattern>/_ah/spi/*</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>SystemServiceServlet</servlet-name>
<url-pattern>/_ah/api/*</url-pattern>
</servlet-mapping>
<security-constraint>
<web-resource-collection>
<web-resource-name>cron</web-resource-name>
<url-pattern>/_ah/api/*</url-pattern>
</web-resource-collection>
<auth-constraint>
<role-name>admin</role-name>
</auth-constraint>
</security-constraint>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
</welcome-file-list>
<filter>
<filter-name>ObjectifyFilter</filter-name>
<filter-class>com.googlecode.objectify.ObjectifyFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>ObjectifyFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>
I am using Android Studio and have added a backend module by following HelloEndpoints and I have a StocksEndpoint.java
file with a getStocks(); method that returns stocks.

Answer 1

First add a servlet mapping for your cron to web.xml:
<!-- stock servlet -->
<servlet>
<servlet-name>StockServlet</servlet-name>
<servlet-class>YOUR.PACKAGE.HERE.StockServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>StockServlet</servlet-name>
<url-pattern>/cron/stocks</url-pattern>
</servlet-mapping>
make sure to update the servlet class for your servlet!
Then finally put the new cron url in your cron.xml:
<cron>
<url>/cron/stocks</url>
<description>Backend Process Stocks</description>
<schedule>every 1 minutes from 11:10 to 11:30</schedule>
<timezone>America/New_York</timezone>
</cron>

Answer 2

Unfortunately urls under /_ah/api are restricted and cannot be called from within your App.
There are a couple of ways to go around this but the most accepted option is usually to use a regular servlet to serve Cron requests rather connecting to the endpoint.