The result will be a directory structure like the following

Note: we have created a project called "OpenCVBackendJava"

• package = grewe.ilab.vision

• src has the created servlet = OpenCVVancendJavaServlet.java

• war/WEB-INF/web.xml and apengine-web.xml = the xml configuration files

web.xml file that was autogenerated- can edit in design or source

<?xml version="1.0" encoding="utf-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">
	<servlet>
		<servlet-name>OpenCVBackendJava</servlet-name>
		<servlet-class>grewe.ilab.vision.OpenCVBackendJavaServlet</servlet-class>
	</servlet>
	<servlet-mapping>
		<servlet-name>OpenCVBackendJava</servlet-name>
		<url-pattern>/opencvbackendjava</url-pattern>
	</servlet-mapping>
	<welcome-file-list>
		<welcome-file>index.html</welcome-file>
	</welcome-file-list>
</web-app>

          

appengine-web.xml file that was autogenerated

basically this says we are runing an application named opencv-backend-test
and it is version 1 of this application. This is where you can also control behaviors
like static files and sessions (see Chapter 3 of book and later materials)

<?xml version="1.0" encoding="utf-8"?>
<appengine-web-app xmlns="http://appengine.google.com/ns/1.0">
<application>opencv-backend-test</application>
<version>1</version>

<!--
Allows App Engine to send multiple requests to one instance in parallel:
-->
<threadsafe>true</threadsafe>

<!-- Configure java.util.logging -->
<system-properties>
<property name="java.util.logging.config.file" value="WEB-INF/logging.properties"/>
</system-properties>

<!--
HTTP Sessions are disabled by default. To enable HTTP sessions specify:

<sessions-enabled>true</sessions-enabled>

It's possible to reduce request latency by configuring your application to
asynchronously write HTTP session data to the datastore:

<async-session-persistence enabled="true" />

With this feature enabled, there is a very small chance your app will see
stale session data. For details, see
https://cloud.google.com/appengine/docs/java/config/appconfig#Java_appengine_web_xml_Enabling_sessions
-->

</appengine-web-app>

OpenCVBackendJavaServlet.java auotogenerated file

package grewe.ilab.vision;

import java.io.IOException;
import javax.servlet.http.*;

@SuppressWarnings("serial")
     public class OpenCVBackendJavaServlet extends HttpServlet {
         public void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
         resp.setContentType("text/plain");
         resp.getWriter().println("Hello, world");
     }
 }