How to get URL of REST endpoint?

Can someone explain why this URL returns 404?

http://localhost:8080/HelloWorld-1.0-SNAPSHOT/rest/hat

How should I be passing this so the parameter hat is passed in and see Hello hat! on the output

HelloService.java

package com.sentiment360.helloworld;
public class HelloService {
    String createHelloMessage(String name) {
        return "Hello " + name + "!";
    }
}

HelloWorld.java

package com.sentiment360.helloworld;
/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
import javax.inject.Inject;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
/**
 * A simple REST service which is able to say hello to someone using HelloService Please take a look at the web.xml where JAX-RS
 * is enabled
 *
 * @author gbrey@redhat.com
 *
 */
@Path("/")
public class HelloWorld {
    @Inject
    HelloService helloService;
    @GET
    @Path("/json")
    @Produces({ "application/json" })
    public String getHelloWorldJSON() {
        return "{\"result\":\"" + helloService.createHelloMessage("World") + "\"}";
    }
    @GET
    @Path("/xml")
    @Produces({ "application/xml" })
    public String getHelloWorldXML() {
        return "<xml><result>" + helloService.createHelloMessage("World") + "</result></xml>";
    }
}

JAXActivator.java

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package com.sentiment360.helloworld;
import javax.ws.rs.ApplicationPath;
import javax.ws.rs.core.Application;
/**
 * JAXActivator is an arbitrary name, what is important is that javax.ws.rs.core.Application is extended
 * and the @ApplicationPath annotation is used with a "rest" path.  Without this the rest routes linked to
 * from index.html would not be found.
 */
@ApplicationPath("rest")
public class JAXActivator extends Application {
    // Left empty intentionally
}

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<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">
    <session-config>
        <session-timeout>
            30
        </session-timeout>
    </session-config>
</web-app>

My directory structure: