Problemas com ContextPath()

Olá. Na URL funciona (http://localhost:8080/casadocodigo/service/pagamento?uuid=9c5e2ed8-f490-427d-987b-73814f086ce2) Porém da HTTP ERROR 500 Segue Exception:

16:08:29,158 ERROR [org.jboss.resteasy.resteasy_jaxrs.i18n] (pool-13-thread-3) RESTEASY002010: Failed to execute: javax.ws.rs.WebApplicationException: HTTP 500 Internal Server Error
    at br.com.casadocodigo.service.PagamentoService.lambda$0(PagamentoService.java:55)
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: org.jboss.resteasy.spi.LoggableFailure: RESTEASY003880: Unable to find contextual data of type: javax.servlet.ServletContext
    at org.jboss.resteasy.core.ContextParameterInjector$GenericDelegatingProxy.invoke(ContextParameterInjector.java:75)
    at com.sun.proxy.$Proxy113.getContextPath(Unknown Source)
    at br.com.casadocodigo.service.PagamentoService.lambda$0(PagamentoService.java:46)

Segue código: @Inject private PagamentoGateWay pagamentoGateway;

@Context
private ServletContext context;

private static ExecutorService executor = Executors.newFixedThreadPool(50);

@POST public void pagar(@Suspended final AsyncResponse ar, @QueryParam("uuid") String uuid) {

    Compra compra = compraDao.buscaPorUuid(uuid);

    executor.submit(() -> {
        try {

            pagamentoGateway.pagar(compra.getTotal());

            System.out.println("http://localhost:8080" + context.getContextPath() + "/index.xhtml");

            URI responseURI = UriBuilder
                    .fromPath("http://localhost:8080" + context.getContextPath() + "/index.xhtml")
                    .queryParam("msg", "Compra realizada com sucesso!!!").build();

            Response response = Response.seeOther(responseURI).build();
            ar.resume(response);
        } catch (Exception e) {
            ar.resume(new WebApplicationException(e));
        }
    });

}

código finalizar do CheckoutBean: @Transactional public void finalizar() { Compra compra = new Compra(); compra.setUsuario(usuario); carrinho.finalizar(compra);

    String contextName = facesContext.getExternalContext().getRequestContextPath();
    HttpServletResponse response = (HttpServletResponse) facesContext
                                                        .getExternalContext()
                                                        .getResponse();
    response.setStatus(HttpServletResponse.SC_TEMPORARY_REDIRECT); //=307
    response.setHeader("Location", contextName + "/service/pagamento?uuid="+compra.getUuid());
}