DBZ-8325 Remove unused variable & update java doc

src/main/java/io/debezium/connector/vitess/TableTopicNamingStrategy.java

@@ -22,13 +22,13 @@
 public class TableTopicNamingStrategy extends AbstractTopicNamingStrategy<TableId> {
 
     private final String overrideDataChangeTopicPrefix;
-    private final String overrideSchemaChangeTopicName;
+    private final String overrideSchemaChangeTopic;
 
     public TableTopicNamingStrategy(Properties props) {
         super(props);
         Configuration config = Configuration.from(props);
         this.overrideDataChangeTopicPrefix = config.getString(VitessConnectorConfig.OVERRIDE_DATA_CHANGE_TOPIC_PREFIX);
-        this.overrideSchemaChangeTopicName = config.getString(VitessConnectorConfig.OVERRIDE_SCHEMA_CHANGE_TOPIC);
+        this.overrideSchemaChangeTopic = config.getString(VitessConnectorConfig.OVERRIDE_SCHEMA_CHANGE_TOPIC);
     }
 
     public static TableTopicNamingStrategy create(CommonConnectorConfig config) {
@@ -47,11 +47,19 @@ public String dataChangeTopic(TableId id) {
         return topicNames.computeIfAbsent(id, t -> sanitizedTopicName(topicName));
     }
 
+    /**
+     * Return the schema change topic. There are two cases:
+     * 1. If override schema change topic is specified - use this as the topic name
+     * 2. If override schema change topic is not specified - return the `topic.prefix` specified by the
+     * {@link CommonConnectorConfig.TOPIC_PREFIX} config (unique to
+     * each connector, so it doesn't risk name conflicts)
+     *
+     * @return String representing the schema change topic name.
+     */
     @Override
     public String schemaChangeTopic() {
-        String topicName;
-        if (!Strings.isNullOrBlank(overrideSchemaChangeTopicName)) {
-            return overrideSchemaChangeTopicName;
+        if (!Strings.isNullOrBlank(overrideSchemaChangeTopic)) {
+            return overrideSchemaChangeTopic;
         }
         else {
             return prefix;

src/main/java/io/debezium/connector/vitess/jdbc/VitessBinlogValueConverter.java

@@ -14,12 +14,15 @@
 import io.debezium.connector.binlog.jdbc.BinlogValueConverters;
 import io.debezium.connector.mysql.antlr.MySqlAntlrDdlParser;
 import io.debezium.connector.vitess.VitessConnectorConfig;
+import io.debezium.connector.vitess.VitessDatabaseSchema;
 import io.debezium.jdbc.JdbcValueConverters;
 import io.debezium.jdbc.TemporalPrecisionMode;
 import io.debezium.relational.Column;
 import io.debezium.service.spi.ServiceRegistry;
 
 /**
+ * Create a binlog value converter class to be passed into the
+ * {@link VitessDefaultValueConverter} in the {@link VitessDatabaseSchema}
  * @author Thomas Thornton
  */
 public class VitessBinlogValueConverter extends BinlogValueConverters {

src/main/java/io/debezium/connector/vitess/jdbc/VitessConnection.java

@@ -10,7 +10,9 @@
 import io.debezium.jdbc.JdbcConnection;
 
 /**
- * Needed to maintain compatibility with RelationalSnapshotChangeEventSource
+ * A connection with Vitess that is JDBC compatible.
+ *
+ * Needed to maintain compatibility with {@link io.debezium.relational.RelationalSnapshotChangeEventSource}
  *
  * TODO: Move all query-based interactions with Vitess onto this class.
  * Currently we do these with VitessReplicationConnection instead

src/main/java/io/debezium/connector/vitess/jdbc/VitessDefaultValueConverter.java

@@ -10,6 +10,8 @@
 import io.debezium.connector.binlog.jdbc.BinlogValueConverters;
 
 /**
+ * Create a binlog default value converter to be passed into the {@link io.debezium.relational.TableSchemaBuilder}
+ * in {@link io.debezium.connector.vitess.VitessDatabaseSchema}
  * @author Thomas Thornton
  */
 public class VitessDefaultValueConverter extends BinlogDefaultValueConverter {

src/test/java/io/debezium/connector/vitess/VitessTestCleanup.java

@@ -9,6 +9,9 @@
 import org.junit.After;
 
 /**
+ * Used to tear down the {@link VitessDatabaseSchema} and {@link VitessConnectorTask} after each
+ * test to avoid resource conflicts.
+ *
  * @author Thomas Thornton
  */
 public class VitessTestCleanup {

src/test/java/io/debezium/connector/vitess/connection/DdlMessageTest.java

@@ -13,6 +13,8 @@
 import org.junit.Test;
 
 /**
+ * Verify the behavior of {@link DdlMessage}
+ *
  * @author Thomas Thornton
  */
 public class DdlMessageTest {