Unable to understand web.xml mapping and package definitions - web-services

Question

My web.xml is
<servlet>
<servlet-name>SwipeXBackendServices</servlet-name>
<servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
<init-param>
<param-name>com.sun.jersey.config.property.packages</param-name>
<param-value>com.mycompany.backend.webservices</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>SwipeXBackendServices</servlet-name>
<url-pattern>/webservices/*</url-pattern>
</servlet-mapping>
Why does the mapping have to be /webservices/* and not com.mycompany.backend.webservices/*.
This is my webservice code
package com.swipex.backend.webservices;
#Path("/Activation")
public class Activation {
private static final Logger log = Logger.getLogger(Activation.class);
private DeviceDetails deviceDetailsTable = DeviceDetails.getInstance();
#POST
#Path("Request")
#Consumes({ MediaType.APPLICATION_JSON })
public Response post(JAXBElement<CDeviceDetails> device) {
Edit : Junit Client Code
#Test
public void testPost() throws Exception {
/*
* Activate
*/
// Initialize Web Services
ClientConfig config = new DefaultClientConfig();
Client client = Client.create(config);
//
// Activation Service
//
URI url = UriBuilder.fromUri(
"http://" + SERVER + "/SwipeXBackEnd/Activation/Request")
.build();
WebResource service = client.resource(url);
System.out.println(url);
// Get the data ready
CDeviceDetails newDevice = new CDeviceDetails(null, "mac id", "model",
"manufacturer", "androidVersion", Calendar.getInstance()
.getTime(), "buildID", "fingerPrint", "board",
"bootLoader", "hardware", "id", "product", "serial", Calendar
.getInstance().getTime(), Calendar.getInstance()
.getTime(), Globals.ACTIVE);
String deviceUniqueIdentity = service.type(MediaType.APPLICATION_JSON)
.post(String.class, newDevice);
assertNotNull(deviceUniqueIdentity);
System.out.println("Activation Passed " + deviceUniqueIdentity);

Answer 1

Url pattern doesn't have any relationship with your java package structure. In your case, you've mapped the SwipeXBackendServices servlet to listen on the '/webservices' url (ex : http://localhost:8080/webservices/). i.e., when a request comes for '/webservices', it'll be routed to your 'SwipeXBackendServices' servlet class.
And also your jax-rs (rest) class 'Activation' is mapped to the url '/activation' (ex : http://localhost:8080/activation).
Mapping of url & class :
/webservices ===> SwipeXBackendServices
/activation ===> Activation
So, don't confuse the package name with the url name.

Answer 2

As Sriram says the servlet mappings have no relation with the packages.
The com.sun.jersey.config.property.packages parameter for the SwipeXBackendServices servlet just tells Jersey which package to scan for discovering REST resources.
The servlet-mapping for the SwipeXBackendServices servlet tells the servlet container on which URLs the servlet will answer. In this case, it will answer to all URLs prefixed with /webservices. Meaning that all REST resources will be prefixed with /webservices.
Then, the URLs for any REST resource will be the concatenation of
The WAR context root
The Jersey servlet mapping
The REST resource path (being itself the concatenation of the class's path and the method's path)
Hence, assuming the context root for your WAR is /myWebApp, the URL for a POST request to your Activation resource will be: http://localhost:8080/myWebApp/webservices/Activation/Request