Kafka ErrorHandlingDeserializer2 config values in application.properties

Question

I want to set Kafka ErrorHandlingDeserializer2 config values in application.properties using spring boot auto config instead of defining them in code like below:

... // other props
props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, ErrorHandlingDeserializer.class);
props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, ErrorHandlingDeserializer.class);
props.put(ErrorHandlingDeserializer.KEY_DESERIALIZER_CLASS, JsonDeserializer.class);
props.put(JsonDeserializer.KEY_DEFAULT_TYPE, "com.example.MyKey")
props.put(ErrorHandlingDeserializer.VALUE_DESERIALIZER_CLASS, JsonDeserializer.class.getName());
props.put(JsonDeserializer.VALUE_DEFAULT_TYPE, "com.example.MyValue")
props.put(JsonDeserializer.TRUSTED_PACKAGES, "com.example")
return new DefaultKafkaConsumerFactory<>(props); 

What I am doing is setting config values like below in application.properties trying to use spring boot auto config:

spring.kafka.consumer.key-deserializer=org.springframework.kafka.support.serializer.ErrorHandlingDeserializer2
spring.kafka.consumer.value-deserializer=org.springframework.kafka.support.serializer.ErrorHandlingDeserializer2
spring.deserializer.key.delegate.class=org.springframework.kafka.support.serializer.JsonDeserializer
spring.deserializer.value.delegate.class=org.springframework.kafka.support.serializer.JsonDeserializer

But I am getting below errors:

ConsumerConfig values: 
    auto.commit.interval.ms = 5000
    auto.offset.reset = latest
    bootstrap.servers = [abc1.xyz.def.dev:9092, abc2.xyz.def.dev:9092, abc3.xyz.def.dev:9092]
    check.crcs = true
    client.id = 
    connections.max.idle.ms = 540000
    default.api.timeout.ms = 60000
    enable.auto.commit = true
    exclude.internal.topics = true
    fetch.max.bytes = 52428800
    fetch.max.wait.ms = 500
    fetch.min.bytes = 1
    group.id = XYZ-CONSUMER
    heartbeat.interval.ms = 3000
    interceptor.classes = []
    internal.leave.group.on.close = true
    isolation.level = read_uncommitted
    key.deserializer = class org.springframework.kafka.support.serializer.ErrorHandlingDeserializer2
    max.partition.fetch.bytes = 1048576
    max.poll.interval.ms = 300000
    max.poll.records = 500
    metadata.max.age.ms = 300000
    metric.reporters = []
    metrics.num.samples = 2
    metrics.recording.level = INFO
    metrics.sample.window.ms = 30000
    partition.assignment.strategy = [class org.apache.kafka.clients.consumer.RangeAssignor]
    receive.buffer.bytes = 65536
    reconnect.backoff.max.ms = 1000
    reconnect.backoff.ms = 50
    request.timeout.ms = 30000
    retry.backoff.ms = 100
    sasl.client.callback.handler.class = null
    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.login.callback.handler.class = null
    sasl.login.class = null
    sasl.login.refresh.buffer.seconds = 300
    sasl.login.refresh.min.period.seconds = 60
    sasl.login.refresh.window.factor = 0.8
    sasl.login.refresh.window.jitter = 0.05
    sasl.mechanism = GSSAPI
    security.protocol = PLAINTEXT
    send.buffer.bytes = 131072
    session.timeout.ms = 10000
    ssl.cipher.suites = null
    ssl.enabled.protocols = [TLSv1.2, TLSv1.1, TLSv1]
    ssl.endpoint.identification.algorithm = https
    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
    value.deserializer = class org.springframework.kafka.support.serializer.ErrorHandlingDeserializer2

2019-11-20 00:40:01.630 ERROR [-,,,] 16013 --- [  restartedMain] org.apache.kafka.clients.ClientUtils     : Failed to close consumer key deserializer

java.lang.NullPointerException: null
    at org.springframework.kafka.support.serializer.ErrorHandlingDeserializer2.close(ErrorHandlingDeserializer2.java:199) ~[spring-kafka-2.2.7.RELEASE.jar:2.2.7.RELEASE]
    at org.apache.kafka.clients.ClientUtils.closeQuietly(ClientUtils.java:73) ~[kafka-clients-2.0.1.jar:na]
    at org.apache.kafka.clients.consumer.KafkaConsumer.close(KafkaConsumer.java:2149) [kafka-clients-2.0.1.jar:na]
    at org.apache.kafka.clients.consumer.KafkaConsumer.<init>(KafkaConsumer.java:797) [kafka-clients-2.0.1.jar:na]
    at org.apache.kafka.clients.consumer.KafkaConsumer.<init>(KafkaConsumer.java:615) [kafka-clients-2.0.1.jar:na]

Note: When I try to add these config values through code, error handling is working as expected.

Answer 1

I ran into the same issue. The documentation around ErrorHandlingDeserializer2 is not great.

It is however possible to set these values in config using the catch-all spring.kafka.consumer.properties.*

spring:
    kafka:
        consumer:
            value-deserializer: org.springframework.kafka.support.serializer.ErrorHandlingDeserializer2
            properties:
                spring:
                    deserializer:
                        value:
                            delegate:
                                class: my.delegate.NameOfClass