How to deploy a JAX-RS application?

There are a number of options for deploying into a Java EE 6 container (more specifically a Servlet 3.0 implementation):

The simplest is:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_3_0.xsd" version="3.0">
    <servlet>
        <servlet-name>javax.ws.rs.core.Application</servlet-name>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>javax.ws.rs.core.Application</servlet-name>
        <url-pattern>/rest/*</url-pattern>
    </servlet-mapping>
</web-app>

Then all the @Path and @Provider classes found in your web application will be available in the “default” JAX-RS application with a servlet URL pattern of "/rest/*".

If you have one or more classes that extends javax.ws.rs.core.Application, you can specify like so:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_3_0.xsd" version="3.0">
    <servlet>
        <servlet-name>com.example.jaxrs.MyApplication</servlet-name>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>com.example.jaxrs.MyApplication</servlet-name>
        <url-pattern>/rest/*</url-pattern>
    </servlet-mapping>
</web-app>

You may want to do the above in case you wish to only return specific sets of @Path/@Provider classes on a URL (so you could have a second MyApplication2 with a different URL pattern above).

You can also skip the whole web.xml altogether and just annotate your MyApplication class wih @ApplicationPath which will serve as the URL pattern. I would recommend keeping the web.xml in any case because you will probably have to add other information about the web application there anyway.

If you’re wondering where the servlet-class comes from, it is automatically added in by the environment. You can get an idea by looking at the Servlet 3.0 ServletContext.