[ES-1436915] Add additional null check for connection-context (#810)

* Add extra null check

Author: gopalldb

src/main/java/com/databricks/jdbc/telemetry/TelemetryClientFactory.java

@@ -34,7 +34,9 @@ public static TelemetryClientFactory getInstance() {
 
   public ITelemetryClient getTelemetryClient(
       IDatabricksConnectionContext connectionContext, DatabricksConfig databricksConfig) {
-    if (connectionContext != null && connectionContext.isTelemetryEnabled()) {
+    if (connectionContext != null
+        && connectionContext.isTelemetryEnabled()
+        && databricksConfig != null) {
       return telemetryClients.computeIfAbsent(
           connectionContext.getConnectionUuid(),
           k ->

src/main/java/com/databricks/jdbc/telemetry/TelemetryHelper.java

@@ -113,44 +113,54 @@ static void exportLatencyLog(
       long latencyMilliseconds,
       SqlExecutionEvent executionEvent,
       StatementId statementId) {
-    TelemetryEvent telemetryEvent =
-        new TelemetryEvent()
-            .setLatency(latencyMilliseconds)
-            .setSqlOperation(executionEvent)
-            .setDriverConnectionParameters(getDriverConnectionParameter(connectionContext));
-    if (statementId != null) {
-      telemetryEvent.setSqlStatementId(statementId.toString());
+    // Though we already handle null connectionContext in the downstream implementation,
+    // we are adding this check for extra sanity
+    if (connectionContext != null) {
+      TelemetryEvent telemetryEvent =
+          new TelemetryEvent()
+              .setLatency(latencyMilliseconds)
+              .setSqlOperation(executionEvent)
+              .setDriverConnectionParameters(getDriverConnectionParameter(connectionContext));
+      if (statementId != null) {
+        telemetryEvent.setSqlStatementId(statementId.toString());
+      }
+      TelemetryFrontendLog telemetryFrontendLog =
+          new TelemetryFrontendLog()
+              .setFrontendLogEventId(getEventUUID())
+              .setContext(getLogContext())
+              .setEntry(new FrontendLogEntry().setSqlDriverLog(telemetryEvent));
+      TelemetryClientFactory.getInstance()
+          .getTelemetryClient(
+              connectionContext, DatabricksThreadContextHolder.getDatabricksConfig())
+          .exportEvent(telemetryFrontendLog);
     }
-    TelemetryFrontendLog telemetryFrontendLog =
-        new TelemetryFrontendLog()
-            .setFrontendLogEventId(getEventUUID())
-            .setContext(getLogContext())
-            .setEntry(new FrontendLogEntry().setSqlDriverLog(telemetryEvent));
-    TelemetryClientFactory.getInstance()
-        .getTelemetryClient(connectionContext, DatabricksThreadContextHolder.getDatabricksConfig())
-        .exportEvent(telemetryFrontendLog);
   }
 
   public static void exportLatencyLog(
       IDatabricksConnectionContext connectionContext,
       long latencyMilliseconds,
       DriverVolumeOperation volumeOperationEvent) {
-    TelemetryFrontendLog telemetryFrontendLog =
-        new TelemetryFrontendLog()
-            .setFrontendLogEventId(getEventUUID())
-            .setContext(getLogContext())
-            .setEntry(
-                new FrontendLogEntry()
-                    .setSqlDriverLog(
-                        new TelemetryEvent()
-                            .setLatency(latencyMilliseconds)
-                            .setVolumeOperation(volumeOperationEvent)
-                            .setDriverConnectionParameters(
-                                getDriverConnectionParameter(connectionContext))));
+    // Though we already handle null connectionContext in the downstream implementation,
+    // we are adding this check for extra sanity
+    if (connectionContext != null) {
+      TelemetryFrontendLog telemetryFrontendLog =
+          new TelemetryFrontendLog()
+              .setFrontendLogEventId(getEventUUID())
+              .setContext(getLogContext())
+              .setEntry(
+                  new FrontendLogEntry()
+                      .setSqlDriverLog(
+                          new TelemetryEvent()
+                              .setLatency(latencyMilliseconds)
+                              .setVolumeOperation(volumeOperationEvent)
+                              .setDriverConnectionParameters(
+                                  getDriverConnectionParameter(connectionContext))));
 
-    TelemetryClientFactory.getInstance()
-        .getTelemetryClient(connectionContext, DatabricksThreadContextHolder.getDatabricksConfig())
-        .exportEvent(telemetryFrontendLog);
+      TelemetryClientFactory.getInstance()
+          .getTelemetryClient(
+              connectionContext, DatabricksThreadContextHolder.getDatabricksConfig())
+          .exportEvent(telemetryFrontendLog);
+    }
   }
 
   private static DriverConnectionParameters getDriverConnectionParameter(