Add API to retrieve device filters

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

@@ -2188,4 +2188,43 @@ public interface DeviceManagementService {
                     value = "The device identifier")
             @PathParam("id") String deviceId,
             OperationStatusBean operationStatusBean);
+
+    @GET
+    @Path("/filters")
+    @ApiOperation(
+            produces = MediaType.APPLICATION_JSON,
+            httpMethod = "GET",
+            value = "Retrieving filters of device.",
+            notes = "Provides filters in devices of Entgra IoT Server which can be used in UI for filtering.",
+            tags = "Device Management",
+            extensions = {
+                    @Extension(properties = {
+                            @ExtensionProperty(name = Constants.SCOPE, value = "perm:devices:view")
+                    })
+            }
+    )
+    @ApiResponses(
+            value = {
+                    @ApiResponse(
+                            code = 200,
+                            message = "OK. \n Successfully fetched the device filters.",
+                            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 = 500,
+                            message = "Error occurred while getting the version data.",
+                            response = ErrorResponse.class)
+            })
+    Response getDeviceFilters();
 }

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

@@ -44,6 +44,7 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.wso2.carbon.context.CarbonContext;
 import org.wso2.carbon.device.mgt.common.Device;
+import org.wso2.carbon.device.mgt.common.DeviceFilters;
 import org.wso2.carbon.device.mgt.common.DeviceIdentifier;
 import org.wso2.carbon.device.mgt.common.EnrolmentInfo;
 import org.wso2.carbon.device.mgt.common.Feature;
@@ -1274,4 +1275,36 @@ public class DeviceManagementServiceImpl implements DeviceManagementService {
             return Response.status(Response.Status.BAD_REQUEST).entity(msg).build();
         }
     }
+
+    @GET
+    @Path("/filters")
+    @Override
+    public Response getDeviceFilters() {
+        try {
+            List<String> deviceTypeNames = new ArrayList<>();
+            List<String> ownershipNames = new ArrayList<>();
+            List<String> statusNames = new ArrayList<>();
+            List<DeviceType> deviceTypes = DeviceMgtAPIUtils.getDeviceManagementService().getDeviceTypes();
+            for (DeviceType deviceType : deviceTypes) {
+                deviceTypeNames.add(deviceType.getName());
+            }
+            EnrolmentInfo.OwnerShip[] ownerShips = EnrolmentInfo.OwnerShip.values();
+            for (EnrolmentInfo.OwnerShip ownerShip : ownerShips) {
+                ownershipNames.add(ownerShip.name());
+            }
+            EnrolmentInfo.Status[] statuses = EnrolmentInfo.Status.values();
+            for (EnrolmentInfo.Status status : statuses) {
+                statusNames.add(status.name());
+            }
+            DeviceFilters deviceFilters = new DeviceFilters();
+            deviceFilters.setDeviceTypes(deviceTypeNames);
+            deviceFilters.setOwnerships(ownershipNames);
+            deviceFilters.setStatuses(statusNames);
+            return Response.status(Response.Status.OK).entity(deviceFilters).build();
+        } catch (DeviceManagementException e) {
+            String msg = "Error occurred white retrieving device types to be used in device filters.";
+            log.error(msg, e);
+            return Response.status(Response.Status.INTERNAL_SERVER_ERROR).entity(msg).build();
+        }
+    }
 }

components/device-mgt/org.wso2.carbon.device.mgt.common/src/main/java/org/wso2/carbon/device/mgt/common/DeviceFilters.java

@@ -0,0 +1,40 @@
+package org.wso2.carbon.device.mgt.common;
+
+import java.io.Serializable;
+import java.util.List;
+
+/**
+ * This class carries information related to device filtering values which will be used in the UI to filter devices.
+ */
+public class DeviceFilters implements Serializable {
+
+    private static final long serialVersionUID = -5249449134602406387L;
+
+    private List<String> deviceTypes;
+    private List<String> ownerships;
+    private List<String> statuses;
+
+    public List<String> getDeviceTypes() {
+        return deviceTypes;
+    }
+
+    public void setDeviceTypes(List<String> deviceTypes) {
+        this.deviceTypes = deviceTypes;
+    }
+
+    public List<String> getOwnerships() {
+        return ownerships;
+    }
+
+    public void setOwnerships(List<String> ownerships) {
+        this.ownerships = ownerships;
+    }
+
+    public List<String> getStatuses() {
+        return statuses;
+    }
+
+    public void setStatuses(List<String> statuses) {
+        this.statuses = statuses;
+    }
+}