springboot手动提交kafka offset

enable.auto.commit参数设置成了false

可是测试发现enable.auto.commit参数设置成了false，kafka的offset依然提交了（也没有进行人工提交offset）。

查看源码

若是咱们enable.auto.commit设置为false，那么就会走标红的if语句。并且下面有个stopInvokerAndCommitManualAcks()方法，看名字就知道是人工提交的意思。那么咱们进去stopInvokerAndCommitManualAcks()方法瞅瞅。 

如上图所示有个processCommits()方法，那么继续追进去： 

单单看标红的方法是否是就知道这方法里面是更新offset和提交offset的方法。那么咱们继续追进去：

结论：若是咱们把enable.auto.commit参数设置成true。那么offset交给kafka来管理，offset进行默认的提交模式。 
enable.auto.commit参数设置成false。那么就是Spring来替为咱们作人工提交，从而简化了人工提交的方式。 
因此kafka和springboot结合中的enable.auto.commit为false为spring的人工提交模式。enable.auto.commit为true是采用kafka的默认提交模式。 

手动提交

spring.kafka.consumer.enable-auto-commit设置为false，设置AckMode的值

/**
     * The offset commit behavior enumeration.
     */
    public enum AckMode {

        /**
         * Commit after each record is processed by the listener.
         */
        RECORD,

        /**
         * Commit whatever has already been processed before the next poll.
         */
        BATCH,

        /**
         * Commit pending updates after
         * {@link ContainerProperties#setAckTime(long) ackTime} has elapsed.
         */
        TIME,

        /**
         * Commit pending updates after
         * {@link ContainerProperties#setAckCount(int) ackCount} has been
         * exceeded.
         */
        COUNT,

        /**
         * Commit pending updates after
         * {@link ContainerProperties#setAckCount(int) ackCount} has been
         * exceeded or after {@link ContainerProperties#setAckTime(long)
         * ackTime} has elapsed.
         */
        COUNT_TIME,

        /**
         * User takes responsibility for acks using an
         * {@link AcknowledgingMessageListener}.
         */
        MANUAL,

        /**
         * User takes responsibility for acks using an
         * {@link AcknowledgingMessageListener}. The consumer is woken to

• RECORD
  每处理一条commit一次
• BATCH(默认)
  每次poll的时候批量提交一次，频率取决于每次poll的调用频率
• TIME 
  每次间隔ackTime的时间去commit
• COUNT 
  累积达到ackCount次的ack去commit
• COUNT_TIME
  ackTime或ackCount哪一个条件先知足，就commit
• MANUAL
  listener负责ack，可是背后也是批量上去
• MANUAL_IMMEDIATE
  listner负责ack，每调用一次，就当即commit

manual commit

@KafkaListener(topics = "k010")
    public void listen(ConsumerRecord<?, ?> cr,Acknowledgment ack) throws Exception {
        LOGGER.info(cr.toString());
        ack.acknowledge();
    }

方法参数里头传递Acknowledgment，而后手工ack

若是只添加上面语句会报错：

the listener container must have a MANUAL Ackmode to populate the Acknowledgment

咱们要配置AckMode为MANUAL Ackmode

factory.getContainerProperties().setAckMode(AbstractMessageListenerContainer.AckMode.MANUAL);