add the filter api

components/device-mgt/org.wso2.carbon.device.mgt.api/src/main/java/org/wso2/carbon/device/mgt/jaxrs/service/api/DeviceEventManagementService.java

@@ -296,6 +296,67 @@ public interface DeviceEventManagementService {
                               @PathParam("type") String deviceType,
                               @ApiParam(name = "limit", value = "limit of the records that needs to be picked up", required = false)
                               @QueryParam("limit") int limit);
+
+    @GET
+    @Path("filter/{type}/{parameter}")
+    @ApiOperation(
+            produces = MediaType.APPLICATION_JSON,
+            httpMethod = "GET",
+            value = "Getting the filtered devices",
+            notes = "Get the list of devices based on the filter parameter",
+            tags = "Device Event Management",
+            extensions = {
+                    @Extension(properties = {
+                            @ExtensionProperty(name = Constants.SCOPE, value = "perm:device-types:events:view")
+                    })
+            }
+    )
+    @ApiResponses(
+            value = {
+                    @ApiResponse(
+                            code = 200,
+                            message = "OK. \n Successfully fetched the event.",
+                            response = EventRecords.class,
+                            responseHeaders = {
+                                    @ResponseHeader(
+                                            name = "Content-Type",
+                                            description = "The content type of the body"),
+                                    @ResponseHeader(
+                                            name = "ETag",
+                                            description = "Entity Tag of the response resource.\n" +
+                                                    "Used by caches, or in conditional requests."),
+                                    @ResponseHeader(
+                                            name = "Last-Modified",
+                                            description =
+                                                    "Date and time the resource was last modified.\n" +
+                                                            "Used by caches, or in conditional requests."),
+                            }
+                    ),
+                    @ApiResponse(
+                            code = 400,
+                            message =
+                                    "Bad Request. \n"),
+                    @ApiResponse(
+                            code = 406,
+                            message = "Not Acceptable.\n The requested media type is not supported"),
+                    @ApiResponse(
+                            code = 500,
+                            message = "Internal Server Error. \n Server error occurred while fetching the " +
+                                    "list of supported device types.",
+                            response = ErrorResponse.class)
+            }
+    )
+    Response getFilteredDevices(
+            @ApiParam(name = "type", value = "name of the device type", required = true)
+            @PathParam("type") String deviceType,
+            @ApiParam(name = "type", value = "name of the parameter", required = true)
+            @PathParam("type") String parameter,
+            @ApiParam(name = "limit", value = "minimum value the parameter can have", required = false)
+            @QueryParam("min") int min,
+            @ApiParam(name = "max", value = "max value the parameter can have", required = false)
+            @QueryParam("max") int max
+    );
+
   
     @GET
     @Path("/{type}")

components/device-mgt/org.wso2.carbon.device.mgt.api/src/main/java/org/wso2/carbon/device/mgt/jaxrs/service/impl/DeviceEventManagementServiceImpl.java

@@ -429,6 +429,61 @@ public class DeviceEventManagementServiceImpl implements DeviceEventManagementSe
         }
     }
 
+
+
+    /**
+     * Returns the filterd device list. Devices are filterd using the paramter given.
+     * parameter can be given as a range or a single value.
+     */
+    @GET
+    @Path("filter/{type}/{parameter}")
+    @Override
+    public Response getFilteredDevices( @PathParam("type") String deviceType, @PathParam("parameter") String parameter,
+                                        @QueryParam("min") int min,@QueryParam("max") int max) {
+        String query;
+        if (min != 0 & max != 0) {
+            query = "DISTINCT "+DEFAULT_META_DEVICE_ID_ATTRIBUTE
+                    + " AND " + parameter + " : [" + min + " TO " + max + "]";
+        } else if (min != 0 & max == 0) {
+            query = "DISTINCT "+DEFAULT_META_DEVICE_ID_ATTRIBUTE
+                    + " AND " + parameter + " : [" + min + " TO " + max + "]";
+        }else if(max != 0 & min==0){
+            query = "DISTINCT "+DEFAULT_META_DEVICE_ID_ATTRIBUTE
+                    + " AND " + parameter + " : [" + min + " TO " + max + "]";
+        }else{
+            String errorMessage = "One of the range values need to be given";
+            log.error(errorMessage);
+            return Response.status(Response.Status.BAD_REQUEST).build();
+        }
+
+        String tenantDomain = PrivilegedCarbonContext.getThreadLocalCarbonContext().getTenantDomain();
+        String sensorTableName = getTableName(DeviceMgtAPIUtils.getStreamDefinition(deviceType, tenantDomain));
+        try {
+            if (deviceType == null ||
+                    !DeviceMgtAPIUtils.getDeviceManagementService().getAvailableDeviceTypes().contains(deviceType)) {
+                String errorMessage = "Invalid device type";
+                log.error(errorMessage);
+                return Response.status(Response.Status.BAD_REQUEST).build();
+            }
+
+            List<SortByField> sortByFields = new ArrayList<>();
+            SortByField sortByField = new SortByField(TIMESTAMP_FIELD_NAME, SortType.DESC);
+            sortByFields.add(sortByField);
+
+            EventRecords eventRecords = getAllEventsForDevice(sensorTableName, query, sortByFields, 0, 1);
+            return Response.status(Response.Status.OK.getStatusCode()).entity(eventRecords).build();
+
+        } catch (AnalyticsException e) {
+            String errorMsg = "Error on retrieving stats on table " + sensorTableName + " with query " + query;
+            log.error(errorMsg);
+            return Response.status(Response.Status.INTERNAL_SERVER_ERROR.getStatusCode()).entity(errorMsg).build();
+        } catch (DeviceManagementException e) {
+            String errorMsg = "Error on retrieving stats on table " + sensorTableName + " with query " + query;
+            log.error(errorMsg);
+            return Response.status(Response.Status.INTERNAL_SERVER_ERROR.getStatusCode()).entity(errorMsg).build();
+        }
+    }
+
     private void publishEventReceivers(String streamNameWithVersion, TransportType transportType
             , String requestedTenantDomain, String deviceType)
             throws RemoteException, UserStoreException, JWTClientException {