updated EntityFieldsData getFieldValue method to filter out empty strings if ignoreNullStrings is set to true

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

@@ -68,20 +68,22 @@ public class EntityFieldsData {
                 break;
             }
         }
-        if (current != null) {
-            if(current.isNull() && ignoreNullStrings){
+        if (current == null) {
+            return null;
+        }
+        if (current.isNull() && ignoreNullStrings) {
+            return null;
+        }
+        if (current.isValueNode()) {
+            String textValue = current.asText();
+            if (StringUtils.isEmpty(textValue) && ignoreNullStrings) {
                 return null;
             }
-            if (current.isValueNode()) {
-                return current.asText();
-            } else {
-                try {
-                    return mapper.writeValueAsString(current);
-                } catch (JsonProcessingException e) {
-                    return null;
-                }
-            }
-        } else {
+            return textValue;
+        }
+        try {
+            return mapper.writeValueAsString(current);
+        } catch (JsonProcessingException e) {
             return null;
         }
     }

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

@@ -38,7 +38,7 @@ public class StringUtils {
     }
 
     public static boolean isBlank(String source) {
-        return source == null || source.isEmpty() || source.trim().isEmpty();
+        return isEmpty(source) || source.trim().isEmpty();
     }
 
     public static boolean isNotEmpty(String source) {
@@ -46,7 +46,7 @@ public class StringUtils {
     }
 
     public static boolean isNotBlank(String source) {
-        return source != null && !source.isEmpty() && !source.trim().isEmpty();
+        return !isBlank(source);
     }
 
     public static String notBlankOrDefault(String src, String def) {

rule-engine/rule-engine-components/src/test/java/org/thingsboard/rule/engine/metadata/TbGetOriginatorFieldsNodeTest.java

@@ -184,6 +184,48 @@ public class TbGetOriginatorFieldsNodeTest {
         assertThat(actualMessageCaptor.getValue().getMetaData()).isEqualTo(msgMetaData);
     }
 
+    @Test
+    public void givenDeviceWithEmptyLabel_whenOnMsg_thenShouldTellSuccessAndFetchToData() throws TbNodeException, ExecutionException, InterruptedException {
+        // GIVEN
+        var device = new Device();
+        device.setId(DUMMY_DEVICE_ORIGINATOR);
+        device.setName("Test device");
+        device.setType("Test device type");
+        device.setLabel("");
+
+        config.setDataMapping(Map.of(
+                "name", "originatorName",
+                "type", "originatorType",
+                "label", "originatorLabel"));
+        config.setIgnoreNullStrings(true);
+        config.setFetchTo(FetchTo.DATA);
+
+        node.config = config;
+        node.fetchTo = FetchTo.DATA;
+        var msgMetaData = new TbMsgMetaData();
+        var msgData = "{\"temp\":42,\"humidity\":77}";
+        msg = TbMsg.newMsg(POST_TELEMETRY_REQUEST.name(), DUMMY_DEVICE_ORIGINATOR, msgMetaData, msgData);
+
+        when(ctxMock.getDeviceService()).thenReturn(deviceServiceMock);
+        when(ctxMock.getTenantId()).thenReturn(DUMMY_TENANT_ID);
+        when(deviceServiceMock.findDeviceById(eq(DUMMY_TENANT_ID), eq(device.getId()))).thenReturn(device);
+
+        when(ctxMock.getDbCallbackExecutor()).thenReturn(DB_EXECUTOR);
+
+        // WHEN
+        node.onMsg(ctxMock, msg);
+
+        // THEN
+        var actualMessageCaptor = ArgumentCaptor.forClass(TbMsg.class);
+        verify(ctxMock, times(1)).tellSuccess(actualMessageCaptor.capture());
+        verify(ctxMock, never()).tellFailure(any(), any());
+
+        var expectedMsgData = "{\"temp\":42,\"humidity\":77,\"originatorName\":\"Test device\",\"originatorType\":\"Test device type\"}";
+
+        assertThat(actualMessageCaptor.getValue().getData()).isEqualTo(expectedMsgData);
+        assertThat(actualMessageCaptor.getValue().getMetaData()).isEqualTo(msgMetaData);
+    }
+
     @Test
     public void givenValidMsgAndFetchToMetaData_whenOnMsg_thenShouldTellSuccessAndFetchToMetaData() throws TbNodeException, ExecutionException, InterruptedException {
         // GIVEN