Add java doc.

Author: Bingqin Zhou

kcbq-connector/src/main/java/com/wepay/kafka/connect/bigquery/convert/KafkaDataBuilder.java

@@ -9,7 +9,7 @@
 import java.util.Map;
 
 /**
- * Helper class to construct kafka data schema and kafka data record.
+ * Helper class to construct schema and record for Kafka Data Field.
  */
 public class KafkaDataBuilder {
 
@@ -18,6 +18,12 @@ public class KafkaDataBuilder {
     public static final String KAFKA_DATA_OFFSET_FIELD_NAME = "offset";
     public static final String KAFKA_DATA_INSERT_TIME_FIELD_NAME = "insertTime";
 
+    /**
+     * Construct schema for Kafka Data Field
+     *
+     * @param kafkaDataFieldName The configured name of Kafka Data Field
+     * @return Field of Kafka Data, with definitions of kafka topic, partition, offset, and insertTime.
+     */
     public static Field buildKafkaDataField(String kafkaDataFieldName) {
         Field topicField = com.google.cloud.bigquery.Field.of(KAFKA_DATA_TOPIC_FIELD_NAME, LegacySQLTypeName.STRING);
         Field partitionField = com.google.cloud.bigquery.Field.of(KAFKA_DATA_PARTITION_FIELD_NAME, LegacySQLTypeName.INTEGER);
@@ -32,6 +38,12 @@ public static Field buildKafkaDataField(String kafkaDataFieldName) {
                 .setMode(com.google.cloud.bigquery.Field.Mode.NULLABLE).build();
     }
 
+    /**
+     * Construct a map of Kafka Data record
+     *
+     * @param kafkaConnectRecord Kafka sink record to build kafka data from.
+     * @return HashMap which contains the values of kafka topic, partition, offset, and insertTime.
+     */
     public static Map<String, Object> buildKafkaDataRecord(SinkRecord kafkaConnectRecord) {
         HashMap<String, Object> kafkaData = new HashMap<>();
         kafkaData.put(KAFKA_DATA_TOPIC_FIELD_NAME, kafkaConnectRecord.topic());

kcbq-connector/src/main/java/com/wepay/kafka/connect/bigquery/convert/KafkaSchemaRecordType.java

@@ -1,6 +1,9 @@
 package com.wepay.kafka.connect.bigquery.convert;
 
 
+/**
+ *  Enum class for Kafka schema or record type, either value or key.
+ */
 public enum KafkaSchemaRecordType {
     VALUE("value"),
     KEY("key");