Spring-Boot Apache Kafka 中 ProducerConfigs 的默认值

Question

我有一个 Spring Boot 项目启动并运行，Kafka 正在实施。

我配置了一个生产者并发送了一条主题为“演示”的消息。
但我没有设置任何属性，例如
bootstrap.servers = [localhost:9092]
value.serializer = class org.apache.kafka .common.serialization.StringSerializer
我们通常在运行 kafka project-Producer 时设置的
我的项目成功运行，我能够使用该消息

我的问题是 Spring-Boot 是如何知道这些 ProducerConfig 属性的？有没有默认值

我在日志中也看到了

acks = 1
batch.size = 16384
bootstrap.servers = [localhost:9092]
buffer.memory = 33554432
client.id = 
compression.type = none
connections.max.idle.ms = 540000
enable.idempotence = false
interceptor.classes = null
key.serializer = class org.apache.kafka.common.serialization.StringSerializer
linger.ms = 0
max.block.ms = 60000
max.in.flight.requests.per.connection = 5
max.request.size = 1048576
metadata.max.age.ms = 300000
metric.reporters = []
metrics.num.samples = 2
metrics.recording.level = INFO
metrics.sample.window.ms = 30000
partitioner.class = class org.apache.kafka.clients.producer.internals.DefaultPartitioner
receive.buffer.bytes = 32768
reconnect.backoff.max.ms = 1000
reconnect.backoff.ms = 50
request.timeout.ms = 30000
retries = 0
retry.backoff.ms = 100
sasl.jaas.config = null
sasl.kerberos.kinit.cmd = /usr/bin/kinit
sasl.kerberos.min.time.before.relogin = 60000
sasl.kerberos.service.name = null
sasl.kerberos.ticket.renew.jitter = 0.05
sasl.kerberos.ticket.renew.window.factor = 0.8
sasl.mechanism = GSSAPI
security.protocol = PLAINTEXT
send.buffer.bytes = 131072
ssl.cipher.suites = null
ssl.enabled.protocols = [TLSv1.2, TLSv1.1, TLSv1]
ssl.endpoint.identification.algorithm = null
ssl.key.password = null
ssl.keymanager.algorithm = SunX509
ssl.keystore.location = null
ssl.keystore.password = null
ssl.keystore.type = JKS
ssl.protocol = TLS
ssl.provider = null
ssl.secure.random.implementation = null
ssl.trustmanager.algorithm = PKIX
ssl.truststore.location = null
ssl.truststore.password = null
ssl.truststore.type = JKS
transaction.timeout.ms = 60000
transactional.id = null
value.serializer = class org.apache.kafka.common.serialization.StringSerializer

这些属性在哪里设置？

Answer 1

看看org.apache.kafka.clients.producer.ProducerConfig。 在那里你可以发现一些属性有默认值

define(BATCH_SIZE_CONFIG, Type.INT, 16384, atLeast(0), Importance.MEDIUM, BATCH_SIZE_DOC)

Answer 2

请参阅Boot documentation。

向下滚动到 Kafka 并单击 link to KafkaProperties。