Required Files and Configuration

This page describes the files that must be included in API in order to use Cloud Endpoints Frameworks for App Engine.

Your project must contain, at a minimum, the following files:

File and Location	Description
/src/main/java/<packagepath>/<your_api_class>.java	The class file (or files, if you implement your API across multiple classes) containing your backend API.
/src/main/webapp/WEB-INF/appengine-web.xml	The web app deployment descriptor required for App Engine configuration.
/src/main/webapp/WEB-INF/web.xml	The standard Java web app deployment descriptor mapping URLs to servlets and other information.

The contents of each of these required files is documented in the following sections.

The API class file

The required and optional contents of the class file (or files, if you use a multi-class API) are fully described in the topic Endpoint Annotations.

appengine-web.xml

The appengine-web.xml file is used to define the App Engine standard environment configuration when the API is deployed. See appengine-web.xml Reference for more information.

The bare minimum contents required for this file are as follows:

<appengine-web-app xmlns="http://appengine.google.com/ns/1.0">
    <runtime>java8</runtime>
    <threadsafe>true</threadsafe>

    <system-properties>
        <property name="java.util.logging.config.file" value="WEB-INF/logging.properties"/>
    </system-properties>
</appengine-web-app>

web.xml

You use the web.xml file to configure the Endpoints servlet, which handles incoming requests and forwards them to the backend service running on App Engine. The Endpoints servlet is required for your API to be managed by Cloud Endpoints.

The bare minimum contents required for this file are as follows:

<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
         http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
         version="3.1">
    <!-- Wrap the backend with Endpoints Frameworks v2. -->
    <servlet>
        <servlet-name>EndpointsServlet</servlet-name>
        <servlet-class>com.google.api.server.spi.EndpointsServlet</servlet-class>
        <init-param>
            <param-name>services</param-name>
            <param-value>com.example.skeleton.MyApi</param-value>
        </init-param>
    </servlet>
    <!-- Route API method requests to the backend. -->
    <servlet-mapping>
        <servlet-name>EndpointsServlet</servlet-name>
        <url-pattern>/_ah/api/*</url-pattern>
    </servlet-mapping>
</web-app>

Important: The URL pattern specified in the web.xml file defines the URL base path for the API. Make sure the pattern ends with a wildcard, as in /_ah/api/*.

For more information about web.xml, see The Deployment Descriptor: web.xml.