swagger improvements

application/src/main/java/org/thingsboard/server/controller/DashboardController.java

@@ -120,7 +120,7 @@ public class DashboardController extends BaseController {
                     "Used to adjust view of the dashboards according to the difference between browser and server time.")
     @PreAuthorize("hasAnyAuthority('SYS_ADMIN', 'TENANT_ADMIN', 'CUSTOMER_USER')")
     @GetMapping(value = "/dashboard/serverTime")
-    @ApiResponse(responseCode = "200", description = "OK", content = @Content(mediaType = "application/json", examples = @ExampleObject(value = "1636023857137")))
+    @ApiResponse(responseCode = "200", description = "OK", content = @Content(schema = @Schema(type = "integer", format = "int64", example = "1636023857137")))
     public long getServerTime() {
         return System.currentTimeMillis();
     }
@@ -132,7 +132,7 @@ public class DashboardController extends BaseController {
                     "The actual value of the limit is configurable in the system configuration file.")
     @PreAuthorize("hasAnyAuthority('SYS_ADMIN', 'TENANT_ADMIN', 'CUSTOMER_USER')")
     @GetMapping(value = "/dashboard/maxDatapointsLimit")
-    @ApiResponse(responseCode = "200", description = "OK", content = @Content(mediaType = "application/json", examples = @ExampleObject(value = "5000")))
+    @ApiResponse(responseCode = "200", description = "OK", content = @Content(schema = @Schema(type = "integer", format = "int64", example = "1636023857137")))
     public long getMaxDatapointsLimit() {
         return maxDatapointsLimit;
     }
@@ -177,6 +177,8 @@ public class DashboardController extends BaseController {
                     "Referencing non-existing dashboard Id will cause 'Not Found' error. " +
                     "Remove 'id', 'tenantId' and optionally 'customerId' from the request body example (below) to create new Dashboard entity. " +
                     TENANT_AUTHORITY_PARAGRAPH)
+    @ApiResponse(responseCode = "200", description = "OK",
+            content = @Content(schema = @Schema(implementation = Dashboard.class)))
     @PreAuthorize("hasAuthority('TENANT_ADMIN')")
     @PostMapping(value = "/dashboard")
     public void saveDashboard(@io.swagger.v3.oas.annotations.parameters.RequestBody(description = "A JSON value representing the dashboard.")

common/data/src/main/java/org/thingsboard/server/common/data/Dashboard.java

@@ -70,7 +70,7 @@ public class Dashboard extends DashboardInfo implements ExportableEntity<Dashboa
     @Schema(description = "JSON object with main configuration of the dashboard: layouts, widgets, aliases, etc. " +
                           "The JSON structure of the dashboard configuration is quite complex. " +
                           "The easiest way to learn it is to export existing dashboard to JSON."
-            , implementation = com.fasterxml.jackson.databind.JsonNode.class)
+            , implementation = JsonNode.class)
     public JsonNode getConfiguration() {
         return configuration;
     }