ApsaraMQ for RocketMQ：Metode dan parameter

Informasi latar belakang

ApsaraMQ for RocketMQ mendukung mode berikut untuk memperoleh pesan:

• Push: ApsaraMQ for RocketMQ mendorong pesan ke konsumen. Dalam mode push, ApsaraMQ for RocketMQ dapat mendorong beberapa pesan ke konsumen sekaligus. Untuk informasi lebih lanjut, lihat Konsumsi Batch.

• Pull: Konsumen menarik pesan dari ApsaraMQ for RocketMQ.

Mode pull memberikan lebih banyak opsi untuk menerima pesan serta kontrol yang lebih besar atas penarikan pesan dibandingkan dengan mode push.

Parameter umum

Metode untuk mengirim pesan

Parameter untuk mengirim pesan

Metode untuk berlangganan pesan

Berikut adalah deskripsi metode yang dapat dipanggil dalam mode pull:

public interface PullConsumer extends Admin {

    /**
     * Query the partition information of a topic. This method returns all partitions of the topic. You can call this method only after your pull consumers start to run. 
     */
    Set<TopicPartition> topicPartitions(String topic);

    /**
     * Specify a partition from which you want to pull messages. This method does not implement rebalancing. You must make sure that messages in all partitions can be consumed. If this method is called multiple times, the system replaces the partitions to which subscribers have subscribed instead of increasing the number of partitions to which subscribers subscribe. 
     */
    void assign(Collection<TopicPartition> topicPartitions);

    /**
     * Pull messages. The maxBatchMessageCount parameter specifies the maximum number of messages that can be pulled at a time. You can specify a timeout period in milliseconds. 
     */
    List<Message> poll(long timeout);

    /**
     * Reset the consumer offset of a specified partition to a specified position. The specified position must be between the minimum offset and the maximum offset of the partition. You can call this method only after your pull consumers start to run. A subscriber must subscribe to the specified partition. 
     */
    void seek(TopicPartition topicPartition, long offset);

    /**
     * Reset the consumer offset of a specified partition to the minimum offset of the partition. You can call this method only after your pull consumers start to run. A subscriber must subscribe to the specified partition. 
     */
    void seekToBeginning(TopicPartition topicPartition);

    /**
     * Reset the consumer offset of a specified partition to the maximum offset of the partition. You can call this method only after your pull consumers start to run. A subscriber must subscribe to the specified partition. 
     */
    void seekToEnd(TopicPartition topicPartition);

    /**
     * Suspend message consumption in a specified partition.
     */
    void pause(Collection<TopicPartition> topicPartitions);

    /**
     * Resume message consumption in a specified partition.
     */
    void resume(Collection<TopicPartition> topicPartitions);

    /**
     * Query an offset based on a timestamp in a specified partition. The timestamp indicates when a message is stored to a broker. The offset corresponds to the first timestamp that is greater than or equal to the specified timestamp. 
     */
    Long offsetForTimestamp(TopicPartition topicPartition, Long timestamp);

    /**
     * Query the latest consumer offset of a specified partition.
     */
    Long committed(TopicPartition topicPartition);

    /**
     * Manually commit a consumer offset. The consumer offset is synchronized to your on-premises client and then committed to your broker by using a thread in an asynchronous environment. 
     */
    void commitSync();
    
    interface TopicPartitionChangeListener {
        /**
         * This method is called when the partitions of a topic change, for example, when the number of partitions of a topic changes due to broker scaling. 
         */
        void onChanged(Set<TopicPartition> topicPartitions);
    }
    
    /**
     * Register TopicPartitionChangeListener that listens for changes in the partitions of a topic. The onChanged method can be called back for the registered listener when the number of partitions of a topic changes due to broker scaling. By default, the maximum delay for a callback is five seconds. 
     */
    void registerTopicPartitionChangedListener(String topic, TopicPartitionChangeListener callback);
}

Parameter

Untuk informasi lebih lanjut tentang partisi dan offset, lihat Istilah.

Referensi

Untuk informasi lebih lanjut tentang kode contoh untuk mengirim dan berlangganan pesan, lihat topik-topik berikut:

• Kirim Pesan Normal dalam Salah Satu dari Tiga Mode Transmisi

• Kirim dan Terima Pesan Terurut

• Kirim dan Terima Pesan Terjadwal

• Kirim dan Terima Pesan Tertunda

• Kirim dan Terima Pesan Transaksional

• Berlangganan Pesan