[PECO-1759] Added null handling for calendar in setTimestamp (#307)

* testing

* fixed the issue

* minor changes

* minor changes

* bugfixes

Author: agnipratimnag-db

src/main/java/com/databricks/jdbc/core/DatabricksPreparedStatement.java

@@ -357,11 +357,15 @@ public void setTimestamp(int parameterIndex, Timestamp x, Calendar cal) throws S
     LoggingUtil.log(
         LogLevel.DEBUG, "public void setTimestamp(int parameterIndex, Timestamp x, Calendar cal)");
     checkIfClosed();
-    TimeZone originalTimeZone = TimeZone.getDefault();
-    TimeZone.setDefault(cal.getTimeZone());
-    x = new Timestamp(x.getTime());
-    TimeZone.setDefault(originalTimeZone);
-    setObject(parameterIndex, x, DatabricksTypeUtil.TIMESTAMP);
+    if (cal != null) {
+      TimeZone originalTimeZone = TimeZone.getDefault();
+      TimeZone.setDefault(cal.getTimeZone());
+      x = new Timestamp(x.getTime());
+      TimeZone.setDefault(originalTimeZone);
+      setObject(parameterIndex, x, DatabricksTypeUtil.TIMESTAMP);
+    } else {
+      setTimestamp(parameterIndex, x);
+    }
   }
 
   @Override

src/test/java/com/databricks/jdbc/core/DatabricksPreparedStatementTest.java

@@ -267,6 +267,15 @@ public void testSetTimestampWithCalendar() throws DatabricksSQLException {
                 1, new Timestamp(System.currentTimeMillis()), Calendar.getInstance()));
   }
 
+  @Test
+  public void testSetTimestampWithNullCalendar() throws DatabricksSQLException {
+    setupMocks();
+    DatabricksPreparedStatement preparedStatement =
+        new DatabricksPreparedStatement(connection, STATEMENT);
+    assertDoesNotThrow(
+        () -> preparedStatement.setTimestamp(1, new Timestamp(System.currentTimeMillis()), null));
+  }
+
   @Test
   public void testSetAsciiStream() throws DatabricksSQLException {
     setupMocks();