A SourceTask used by a CloudPubSubSourceConnector to write messages to Apache Kafka. Due to at-last-once semantics in Google Cloud
Pub/Sub duplicates in Kafka are possible.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-28 UTC."],[],[],null,["# Package com.google.pubsub.kafka.source (1.2.0)\n\nVersion latestkeyboard_arrow_down\n\n- [1.2.0 (latest)](/java/docs/reference/pubsub-group-kafka-connector/latest/com.google.pubsub.kafka.source)\n- [1.1.0](/java/docs/reference/pubsub-group-kafka-connector/1.1.0/com.google.pubsub.kafka.source)\n- [1.0.0](/java/docs/reference/pubsub-group-kafka-connector/1.0.0/com.google.pubsub.kafka.source)\n- [0.1.5](/java/docs/reference/pubsub-group-kafka-connector/0.1.5/com.google.pubsub.kafka.source) \n\nClasses\n-------\n\n### [AckBatchingSubscriber](/java/docs/reference/pubsub-group-kafka-connector/latest/com.google.pubsub.kafka.source.AckBatchingSubscriber)\n\n### [CloudPubSubGRPCSubscriber](/java/docs/reference/pubsub-group-kafka-connector/latest/com.google.pubsub.kafka.source.CloudPubSubGRPCSubscriber)\n\nA [CloudPubSubSubscriber](/java/docs/reference/pubsub-group-kafka-connector/latest/com.google.pubsub.kafka.source.CloudPubSubSubscriber) that uses [gRPC](http://www.grpc.io/) to pull messages\nfrom [Google Cloud Pub/Sub](https://cloud.google.com/pubsub). This class is not\nthread-safe.\n\n### [CloudPubSubRoundRobinSubscriber](/java/docs/reference/pubsub-group-kafka-connector/latest/com.google.pubsub.kafka.source.CloudPubSubRoundRobinSubscriber)\n\nA [CloudPubSubSubscriber](/java/docs/reference/pubsub-group-kafka-connector/latest/com.google.pubsub.kafka.source.CloudPubSubSubscriber) that distributes a single subscription in round-robin fashion\nover a set of [CloudPubSubGRPCSubscriber](/java/docs/reference/pubsub-group-kafka-connector/latest/com.google.pubsub.kafka.source.CloudPubSubGRPCSubscriber)s.\n\n### [CloudPubSubSourceConnector](/java/docs/reference/pubsub-group-kafka-connector/latest/com.google.pubsub.kafka.source.CloudPubSubSourceConnector)\n\nA SourceConnector that writes messages to a specific topic in [Apache Kafka](http://kafka.apache.org/).\n\n### [CloudPubSubSourceConnector.PartitionScheme.Validator](/java/docs/reference/pubsub-group-kafka-connector/latest/com.google.pubsub.kafka.source.CloudPubSubSourceConnector.PartitionScheme.Validator)\n\nValidator class for [CloudPubSubSourceConnector.PartitionScheme](/java/docs/reference/pubsub-group-kafka-connector/latest/com.google.pubsub.kafka.source.CloudPubSubSourceConnector.PartitionScheme).\n\n### [CloudPubSubSourceTask](/java/docs/reference/pubsub-group-kafka-connector/latest/com.google.pubsub.kafka.source.CloudPubSubSourceTask)\n\nA SourceTask used by a [CloudPubSubSourceConnector](/java/docs/reference/pubsub-group-kafka-connector/latest/com.google.pubsub.kafka.source.CloudPubSubSourceConnector) to write messages to [Apache Kafka](http://kafka.apache.org/). Due to at-last-once semantics in Google Cloud\nPub/Sub duplicates in Kafka are possible.\n\n### [StreamingPullSubscriber](/java/docs/reference/pubsub-group-kafka-connector/latest/com.google.pubsub.kafka.source.StreamingPullSubscriber)\n\nInterfaces\n----------\n\n### [CloudPubSubSubscriber](/java/docs/reference/pubsub-group-kafka-connector/latest/com.google.pubsub.kafka.source.CloudPubSubSubscriber)\n\nAn interface for clients that want to subscribe to messages from to [Google Cloud Pub/Sub](https://cloud.google.com/pubsub).\n\n### [StreamingPullSubscriberFactory](/java/docs/reference/pubsub-group-kafka-connector/latest/com.google.pubsub.kafka.source.StreamingPullSubscriberFactory)\n\nEnums\n-----\n\n### [CloudPubSubSourceConnector.PartitionScheme](/java/docs/reference/pubsub-group-kafka-connector/latest/com.google.pubsub.kafka.source.CloudPubSubSourceConnector.PartitionScheme)\n\nDefines the accepted values for the #KAFKA_PARTITION_SCHEME_CONFIG."]]
