This is a complete working Spring MVC REST application. The only thing unspecified are the imports and the Maven pom.xml. Deploy this class as a .war using Spring MVC 3.2.x (and, specifically, the spring-webmvc library) and you're done!

MvcRestApplicationInitializer.java

 
/**
 * <p>This will be picked up in a Servlet 3 environment like Apache Tomcat 7. 
 *
 * <p>This replaces <code>web.xml</code>.
 * 
 */
public class MvcRestApplicationInitializer extends AbstractAnnotationConfigDispatcherServletInitializer  {
 
 @Override protected Class<?> [] getRootConfigClasses() {
  return new Class<?>[]{};
 }
 
 @Override protected Class<?>[] getServletConfigClasses() {
  return new Class<?>[]{ RestConfiguration.class };
 }
 
 @Override protected String[] getServletMappings(){ return new String[]{"/"}; }
  
} 
  	
/** 
 * Installs Spring MVC and all the required support for JSON assuming 
 * Jackson's on the CLASSPATH
 */
@EnableWebMvc
@ComponentScan 
@Configuration 
class RestConfiguration {
 // that's all!
} 
 
/**
 * A simple Spring MVC REST controller. The returned value (Customer) will
 * be converted into JSON if the client signals that it can read JSON (using the
 * <CODE>ACCEPT</CODE> header.)
 */
@Controller
class StatusController {
    
    @RequestMapping(value= "/customers/{customerId}", method= RequestMethod.GET)
    public @ResponseBody Customer loadCustomer(@PathVariable long customerId ) {
         // return a POJO Customer somehow (perhaps look it up in a database?)
        return someCustomer ; 
    }
}