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Spring's Kafka producer embeds type header into messages which specifies to which class the message should be deserialized by a consumer.This is a problem when the producer isn't using Spring Kafka, but the consumer is.In that case, JsonDeserializer cannot deserialize a message and will throw an exception "No type information in headers and no default type provided".
One way to get around this is to set a default deserialization type.This won't work in cases where a single topic contains multiple message schemas. Another solution I've found is to set

spring.kafka.consumer.properties.spring.json.use.type.headers

to false (in application.properties file).This doesn't do anything as the same exception is thrown again.
How do I make sure that JsonDeserializer ignores type headers?

See this option of that deserializer:

* Set to false to ignore type information in headers and use the configured * target type instead. * Only applies if the preconfigured type mapper is used. * Default true. * @param useTypeHeaders false to ignore type headers. * @since 2.2.8 public void setUseTypeHeaders(boolean useTypeHeaders) {

It can be configured via property as:

* Kafka config property for using type headers (default true). * @since 2.2.3 public static final String USE_TYPE_INFO_HEADERS = "spring.json.use.type.headers";

In this case the logic is going to be like this:

this.typeMapper.setTypePrecedence(this.useTypeHeaders ? TypePrecedence.TYPE_ID : TypePrecedence.INFERRED);
which means that the type for deserialization is inferred from the listener method.
See more info in docs: https://docs.spring.io/spring-kafka/reference/html/#json-serde
                The deserializer can't infer the type from the method signature; only the message converter can do that; with the deserializer you have to provide the default type via a property. docs.spring.io/spring-kafka/docs/current/reference/html/… JsonDeserializer.VALUE_DEFAULT_TYPE: Fallback type for deserialization of values if no header information is present.
– Gary Russell
                Jul 25, 2022 at 14:20
                To infer the type from the listener method, use a ByteArrayDeserializer with a JsonMessageConverter docs.spring.io/spring-kafka/docs/current/reference/html/…
– Gary Russell
                Jul 25, 2022 at 14:26
                So where do I tell the deserializer to not use type header?Setting spring.json.use.type.headers to false in application.properties doesn't do anything.Is there any way to use Spring boot's auto configuration and avoid creating a new factory for every listener?It's fascinating how difficult it is to change such basic property.These type headers shouldn't even exist.
– The light one
                Jul 25, 2022 at 14:35
                It's not "using the headers" See the error message No type information in headers and no default type provided - there is no type information, so you need to set spring.kafka.consumer.properties.spring.json.value.default.type=com.demo.MyDto.
– Gary Russell
                Jul 25, 2022 at 15:14
                If you are using @KafkaListener you can override that property for each listener or, as I said, use a ByteArrayDeserializer and add a JsonMessageConverter bean which Boot will automatically wire into the container factory and the type will be inferred from the method signature.
– Gary Russell
                Jul 25, 2022 at 15:16
        
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