@GET
  @Path("{requestId}")
  @Produces(MediaType.TEXT_PLAIN)
  @ApiOperation(value = "Get the details of a request",
      nickname = "RequestService#getRequest",
      response = RequestResponse.class)
  @ApiImplicitParams({
      @ApiImplicitParam(name = QUERY_FIELDS, value = QUERY_FILTER_DESCRIPTION,
          defaultValue = "Requests/*",
          dataType = DATA_TYPE_STRING, paramType = PARAM_TYPE_QUERY)
  })
  @ApiResponses(value = {
      @ApiResponse(code = HttpStatus.SC_OK, message = MSG_SUCCESSFUL_OPERATION),
      @ApiResponse(code = HttpStatus.SC_UNAUTHORIZED, message = MSG_NOT_AUTHENTICATED),
      @ApiResponse(code = HttpStatus.SC_NOT_FOUND, message = MSG_RESOURCE_NOT_FOUND),
      @ApiResponse(code = HttpStatus.SC_INTERNAL_SERVER_ERROR, message = MSG_SERVER_ERROR)
  })
  public Response getRequest(String body, @Context HttpHeaders headers, @Context UriInfo ui,
                             @ApiParam @PathParam("requestId") String requestId) {

    return handleRequest(headers, body, ui, Request.Type.GET,
        createRequestResource(m_clusterName, requestId));
  }
Handles URL: /clusters/{clusterID}/requests/{requestID} or
/requests/{requestId}
Get a specific request.

@param headers    http headers
@param ui         uri info
@param requestId  request id

@return request resource representation
ambari-server/src/main/java/org/apache/ambari/server/api/services/RequestService.java