[ISSUE apache#4770] Empty class member cause NullpointerException (apache#4777)

* Add null check in writeOffset method

* delete todo

* Move data.put inside null check in writeOffset method

* simplify if judgement

* remove dev environment

* fix style

Author: scwlkq

eventmesh-openconnect/eventmesh-openconnect-java/src/main/java/org/apache/eventmesh/openconnect/util/CloudEventUtil.java

@@ -67,7 +67,7 @@ public static CloudEvent convertRecordToEvent(ConnectRecord connectRecord) {
     public static ConnectRecord convertEventToRecord(CloudEvent event) {
         byte[] body = Objects.requireNonNull(event.getData()).toBytes();
         LogUtil.info(log, "handle receive events {}", () -> new String(event.getData().toBytes(), Constants.DEFAULT_CHARSET));
-        // todo: recordPartition & recordOffset
+
         ConnectRecord connectRecord = new ConnectRecord(null, null, System.currentTimeMillis(), body);
         for (String extensionName : event.getExtensionNames()) {
             connectRecord.addExtension(extensionName, Objects.requireNonNull(event.getExtension(extensionName)).toString());

eventmesh-openconnect/eventmesh-openconnect-offsetmgmt-plugin/eventmesh-openconnect-offsetmgmt-api/src/main/java/org/apache/eventmesh/openconnect/offsetmgmt/api/storage/OffsetStorageWriterImpl.java

@@ -53,9 +53,12 @@ public OffsetStorageWriterImpl(String connectorName, OffsetManagementService off
     }
 
     @Override
-    public void writeOffset(RecordPartition partition, RecordOffset position) {
-        ConnectorRecordPartition extendRecordPartition = new ConnectorRecordPartition(connectorName, partition.getPartition());
-        data.put(extendRecordPartition, position);
+    public void writeOffset(RecordPartition partition, RecordOffset offset) {
+        ConnectorRecordPartition extendRecordPartition;
+        if (partition != null) {
+            extendRecordPartition = new ConnectorRecordPartition(connectorName, partition.getPartition());
+            data.put(extendRecordPartition, offset);
+        }
     }
 
     /**