解决这个问题确实很痛苦，但最后我还是通过流畅的Kafka流测试成功了：
额外依赖项：

testImplementation("org.springframework.kafka:spring-kafka-test")
testImplementation("com.bakdata.fluent-kafka-streams-tests:schema-registry-mock-junit5:2.0.0")

关键是将必要的配置设置为系统属性。为此，我创建了一个单独的测试配置类：

@Configuration
class KafkaTestConfiguration(private val embeddedKafkaBroker: EmbeddedKafkaBroker) {

    private val schemaRegistryMock = SchemaRegistryMock()

    @PostConstruct
    fun init() {
        System.setProperty("spring.kafka.bootstrap-servers", embeddedKafkaBroker.brokersAsString)
        System.setProperty("spring.cloud.stream.kafka.streams.binder.brokers", embeddedKafkaBroker.brokersAsString)
        schemaRegistryMock.start()
        System.setProperty("spring.cloud.stream.schema-registry-client.endpoint", schemaRegistryMock.url)
        System.setProperty("spring.cloud.stream.kafka.streams.binder.configuration.schema.registry.url", schemaRegistryMock.url)
    }

    @Bean
    fun schemaRegistryMock(): SchemaRegistryMock {
        return schemaRegistryMock
    }

    @PreDestroy
    fun preDestroy() {
        schemaRegistryMock.stop()
    }
}

最后是test类，您现在可以在其中生成和使用avro消息，并使用kstream处理它们并利用模拟模式注册表：

@EmbeddedKafka
@SpringBootTest(properties = [
    "spring.profiles.active=local",
    "schema-registry.user=",
    "schema-registry.password=",
    "spring.cloud.stream.bindings.event.destination=event",
    "spring.cloud.stream.bindings.event.producer.useNativeEncoding=true",
    "spring.cloud.stream.kafka.streams.binder.configuration.application.server=localhost:8080",
    "spring.cloud.stream.kafka.streams.bindings.event.consumer.keySerde=io.confluent.kafka.streams.serdes.avro.SpecificAvroSerde",
    "spring.cloud.stream.kafka.streams.bindings.event.consumer.valueSerde=io.confluent.kafka.streams.serdes.avro.SpecificAvroSerde"])
class MyApplicationTests {

    @Autowired
    private lateinit var embeddedKafka: EmbeddedKafkaBroker

    @Autowired
    private lateinit var schemaRegistryMock: SchemaRegistryMock

    @Test
    fun `should process events`() {
        val senderProps = KafkaTestUtils.producerProps(embeddedKafka)
        senderProps[ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG] = "io.confluent.kafka.serializers.KafkaAvroSerializer"
        senderProps[ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG] = "io.confluent.kafka.serializers.KafkaAvroSerializer"
        senderProps["schema.registry.url"] = schemaRegistryMock.url
        val pf = DefaultKafkaProducerFactory<Int, String>(senderProps)
        try {
            val template = KafkaTemplate(pf, true)
            template.defaultTopic = "event"
            ...

    }