To tell the application server where and how the incoming HTTP requests should be routed, we need to define a web.xml inside the WEB-INF directory.

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
    <listener>
        <listener-class>com.couchbase.beersample.ConnectionManager</listener-class>
    </listener>
    <servlet>
        <servlet-name>WelcomeServlet</servlet-name>
        <servlet-class>com.couchbase.beersample.WelcomeServlet</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>BreweryServlet</servlet-name>
        <servlet-class>com.couchbase.beersample.BreweryServlet</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>BeerServlet</servlet-name>
        <servlet-class>com.couchbase.beersample.BeerServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>WelcomeServlet</servlet-name>
        <url-pattern>/welcome</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>BreweryServlet</servlet-name>
        <url-pattern>/breweries/*</url-pattern>
        <url-pattern>/breweries</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>BeerServlet</servlet-name>
        <url-pattern>/beers/*</url-pattern>
        <url-pattern>/beers</url-pattern>
    </servlet-mapping>
  <welcome-file-list>
    <welcome-file>welcome</welcome-file>
  </welcome-file-list>
</web-app>

Don't try to run this yet, because none of these classes are already implemented. The listener directive references the ConnectionMananger class, which we'll implement to manage the connection instance to our Couchbase cluster. The servlet directives define our servlet classes that we're going to use (three of them) and the following servlet-mapping directives map HTTP URLs to them. The final welcome-file-list directive is used to tell the application server where to route the root URL ("/").

For now, comment out all servlet, servlet-mapping and welcome-file-list directives, because the application server will complain if they're not implemented. When you implement the appropriate servlets, remove the comments accordingly (if you don't know how comment inside an XML file, use the <!-- and --> characters). If you plan to add your own servlets, don't forget to add and map them inside the web.xml properly!