changes from review

Author: jasonlamz

wrapper/src/main/java/software/amazon/jdbc/dialect/AuroraMysqlDialect.java

@@ -84,7 +84,7 @@ public HostListProviderSupplier getHostListProvider() {
         IS_READER_QUERY);
   }
 
-  public static String getTopologyQuery() {
+  public String getTopologyQuery() {
     return TOPOLOGY_QUERY;
   }
 }

wrapper/src/main/java/software/amazon/jdbc/dialect/AuroraPgDialect.java

@@ -128,7 +128,7 @@ public HostListProviderSupplier getHostListProvider() {
         IS_READER_QUERY);
   }
 
-  public static String getTopologyQuery() {
+  public String getTopologyQuery() {
     return TOPOLOGY_QUERY;
   }
 }

wrapper/src/main/java/software/amazon/jdbc/dialect/RdsMultiAzDbClusterMysqlDialect.java

@@ -110,7 +110,7 @@ public void prepareConnectProperties(
             : connectProperties.getProperty("connectionAttributes") + "," + connectionAttributes);
   }
 
-  public static String getTopologyQuery() {
+  public String getTopologyQuery() {
     return TOPOLOGY_QUERY;
   }
 }

wrapper/src/main/java/software/amazon/jdbc/dialect/RdsMultiAzDbClusterPgDialect.java

@@ -110,7 +110,7 @@ public HostListProviderSupplier getHostListProvider() {
         FETCH_WRITER_NODE_QUERY_COLUMN_NAME);
   }
 
-  public static String getTopologyQuery() {
+  public String getTopologyQuery() {
     return TOPOLOGY_QUERY;
   }
 }

wrapper/src/main/java/software/amazon/jdbc/hostlistprovider/RdsHostListProvider.java

@@ -423,6 +423,7 @@ private HostSpec createHost(final ResultSet resultSet) throws SQLException {
     // According to the topology query the result set
     // should contain 4 columns: node ID, 1/0 (writer/reader), CPU utilization, node lag in time.
     String hostName = resultSet.getString(1);
+    hostName = hostName == null ? "?" : hostName;
     final boolean isWriter = resultSet.getBoolean(2);
     final float cpuUtilization = resultSet.getFloat(3);
     final float nodeLag = resultSet.getFloat(4);
@@ -439,8 +440,7 @@ private HostSpec createHost(final ResultSet resultSet) throws SQLException {
     return createHost(hostName, isWriter, weight, lastUpdateTime);
   }
 
-  private HostSpec createHost(String host, final boolean isWriter, final long weight, final Timestamp lastUpdateTime) {
-    host = host == null ? "?" : host;
+  private HostSpec createHost(String host, final boolean isWriter, final long weight, final @Nullable Timestamp lastUpdateTime) {
     final String endpoint = getHostEndpoint(host);
     final int port = this.clusterInstanceTemplate.isPortSpecified()
         ? this.clusterInstanceTemplate.getPort()

wrapper/src/test/java/integration/container/tests/TopologyQueryTests.java

@@ -54,6 +54,7 @@
 import org.junit.jupiter.api.extension.ExtendWith;
 import software.amazon.jdbc.dialect.AuroraMysqlDialect;
 import software.amazon.jdbc.dialect.AuroraPgDialect;
+import software.amazon.jdbc.dialect.Dialect;
 import software.amazon.jdbc.dialect.RdsMultiAzDbClusterMysqlDialect;
 import software.amazon.jdbc.dialect.RdsMultiAzDbClusterPgDialect;
 
@@ -65,6 +66,7 @@
 public class TopologyQueryTests {
   private static final Logger LOGGER = Logger.getLogger(TopologyQueryTests.class.getName());
   private final AuroraTestUtility util = new AuroraTestUtility();
+  private String query = null;
 
   @TestTemplate
   @EnableOnDatabaseEngineDeployment(DatabaseEngineDeployment.AURORA)
@@ -95,9 +97,9 @@ public void testAuroraTypes(TestDriver testDriver) throws SQLException {
             TestEnvironment.getCurrent().getInfo().getDatabaseInfo().getDefaultDbName());
     LOGGER.finest("Connecting to " + url);
 
-    String query = null;
     if (TestEnvironment.getCurrent().getCurrentDriver() == TestDriver.PG) {
-      query = AuroraPgDialect.getTopologyQuery();
+      AuroraPgDialect dialect = new AuroraPgDialect();
+      query = dialect.getTopologyQuery();
       expectedTypes = Arrays.asList(
           "text",
           "bool",
@@ -106,7 +108,8 @@ public void testAuroraTypes(TestDriver testDriver) throws SQLException {
           "timestamptz"
       );
     } else {
-      query = AuroraMysqlDialect.getTopologyQuery();
+      AuroraMysqlDialect dialect = new AuroraMysqlDialect();
+      query = dialect.getTopologyQuery();
       expectedTypes = Arrays.asList(
           "VARCHAR",
           "BIGINT",
@@ -169,14 +172,15 @@ public void testAuroraTimestamp(TestDriver testDriver) throws SQLException, Pars
     assertDoesNotThrow(() -> util.updateInstanceCertificateIdentifier(
         dbInstanceIdentifier, "rds-ca-rsa4096-g1"));
 
-    String query = null;
     SimpleDateFormat format;
     if (TestEnvironment.getCurrent().getCurrentDriver() == TestDriver.PG) {
-      query = AuroraPgDialect.getTopologyQuery();
+      AuroraPgDialect dialect = new AuroraPgDialect();
+      query = dialect.getTopologyQuery();
       format = new SimpleDateFormat("yyy-MM-dd HH:mm:ssX");
       format.setTimeZone(TimeZone.getTimeZone("GMT"));
     } else {
-      query = AuroraMysqlDialect.getTopologyQuery();
+      AuroraMysqlDialect dialect = new AuroraMysqlDialect();
+      query = dialect.getTopologyQuery();
       format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSSSS");
     }
 
@@ -227,17 +231,19 @@ public void testRdsMultiAzTypes(TestDriver testDriver) throws SQLException {
                 .getPort(),
             TestEnvironment.getCurrent().getInfo().getDatabaseInfo().getDefaultDbName());
     LOGGER.finest("Connecting to " + url);
+
     List<String> expectedTypes;
-    String query = null;
     if (TestEnvironment.getCurrent().getCurrentDriver() == TestDriver.PG) {
-      query = RdsMultiAzDbClusterPgDialect.getTopologyQuery();
+      RdsMultiAzDbClusterPgDialect dialect = new RdsMultiAzDbClusterPgDialect();
+      query = dialect.getTopologyQuery();
       expectedTypes = Arrays.asList(
           "text",
           "text",
           "int4"
       );
     } else {
-      query = RdsMultiAzDbClusterMysqlDialect.getTopologyQuery();
+      RdsMultiAzDbClusterMysqlDialect dialect = new RdsMultiAzDbClusterMysqlDialect();
+      query = dialect.getTopologyQuery();
       expectedTypes = Arrays.asList(
           "VARCHAR",
           "VARCHAR",