I have a listener that listens to a queue. The message from the queue is a json text. I need to process them and then save in a mongodb database. I have used a DTO for incoming json. The problem is I can save the data as lower case only since I have used a DTO. But, the incoming data is upper case. How can I gracefully do this using jackson/spring?
I tried #JsonGetter and #JsonSetter in the DTO. But, that didn't work. It is still saving the data as lower case.
Mini version of my code:
DTO:
public String getMessage() {
return message;
}
#JsonSetter("MESSAGE")
public void setMessage(String message){
this.message = message;
}
Datasaver:
mongoOperations.save(DTO,collectionname);
Document in database:
_id: ObjectId("5da831183852090ddc7075fb")
message: "hi"
I want the data in mongodb as:
_id: ObjectId("5da831183852090ddc7075fb")
MESSAGE: "hi"
The incoming data has key as MESSAGE.So, I would like the same to store. I would not want the DTO fields names to be in uppercase.
As per #MichaelZiober on comment above, none of the annotations related to jackson helped my need. #Field annotation of spring worked.
Should work with #JsonProperty("MESSAGE")
If not (for some reason) - you could use custom serializer for this field
class CustomStringSerializer extends JsonSerializer<String> {
#Override
public void serialize(String value, JsonGenerator jgen, SerializerProvider provider) throws IOException {
jgen.writeStartObject();
jgen.writeObjectField("MESSAGE", value);
jgen.writeEndObject();
}
}
and init mapper in this way:
ObjectMapper objectMapper = new ObjectMapper();
SimpleModule mod = new SimpleModule("message");
mod.addSerializer(String.class, new CustomStringSerializer());
objectMapper.registerModule(mod);
Related
I'm using simple kafka handler:
#KafkaListener(
topics = Topic.NAME,
clientIdPrefix = KafkaHandler.LISTENER_ID)
public class KafkaHandler {
public static final String LISTENER_ID = "kafka_listener";
#KafkaHandler(isDefault = true)
#Description(value = "Event received")
public void onEvent(#Payload Payload payload) {
...
}
However, my object (Payload in the example) is not mapped properly (some fields are null).
Is there a way to log all incoming kafka KV pairs somewhere in spring-kafka app?
You can process the entire Kafka record instead only the payload.
#KafkaListener(topics = "any-topic")
void listener(ConsumerRecord<String, String> record) {
log.info("{}",record.key());
log.info("{}",record.value());
log.info("{}",record.partition());
log.info("{}",record.topic());
log.info("{}",record.offset());
}
Replace the String for your desired key, value format, and define the deserializer class in your app properties.
spring.kafka.consumer.key-deserializer=YourKeyDeserializer.class
spring.kafka.consumer.value-deserializer=YourValueDeserializer.class
I am using Spring Boot 2.3.1 and want to publish records that could not be deserialized using the DeadLetterPublishingRecoverer.
Everything looks fine, except that the original payload isn't written to the DLT topic. Instead I see it Base64 encoded.
In a different posting I have read that this is caused by the JsonSerializer that is used in the Kafkatemplate, so I tried using a different template. But now I get an SerializationException:
org.apache.kafka.common.errors.SerializationException: Can't convert value of class [B to class org.apache.kafka.common.serialization.BytesSerializer specified in value.serializer
A similar exception occurs when using the StringSerializer.
My code looks like this:
#Autowired
private KafkaProperties kafkaProperties;
private ProducerFactory<String, String> pf() {
return new DefaultKafkaProducerFactory<>(kafkaProperties.buildProducerProperties());
}
private KafkaTemplate<String, String> stringTemplate() {
return new KafkaTemplate<>(pf(), Collections.singletonMap(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class));
}
#Bean
public SeekToCurrentErrorHandler errorHandler() {
SeekToCurrentErrorHandler eh = new SeekToCurrentErrorHandler(new DeadLetterPublishingRecoverer(stringTemplate()));
eh.setLogLevel(Level.WARN);
return eh;
}
Found it just 5 minutes later.
I had to use the ByteArraySerializer instead.
I am trying to cache Kafka Records within 3 minutes of interval post that it will get expired and removed from the cache.
Each incoming records which is fetched using kafka consumer written in springboot needs to be updated in cache first then if it is present i need to discard the next duplicate records if it matches the cache record.
I have tried using Caffeine cache as below,
#EnableCaching
public class AppCacheManagerConfig {
#Bean
public CacheManager cacheManager(Ticker ticker) {
CaffeineCache bookCache = buildCache("declineRecords", ticker, 3);
SimpleCacheManager cacheManager = new SimpleCacheManager();
cacheManager.setCaches(Collections.singletonList(bookCache));
return cacheManager;
}
private CaffeineCache buildCache(String name, Ticker ticker, int minutesToExpire) {
return new CaffeineCache(name, Caffeine.newBuilder().expireAfterWrite(minutesToExpire, TimeUnit.MINUTES)
.maximumSize(100).ticker(ticker).build());
}
#Bean
public Ticker ticker() {
return Ticker.systemTicker();
}
}
and my Kafka Consumer is as below,
#Autowired
CachingServiceImpl cachingService;
#KafkaListener(topics = "#{'${spring.kafka.consumer.topic}'}", concurrency = "#{'${spring.kafka.consumer.concurrentConsumers}'}", errorHandler = "#{'${spring.kafka.consumer.errorHandler}'}")
public void consume(Message<?> message, Acknowledgment acknowledgment,
#Header(KafkaHeaders.RECEIVED_TIMESTAMP) long createTime) {
logger.info("Recieved Message: " + message.getPayload());
try {
boolean approveTopic = false;
boolean duplicateRecord = false;
if (cachingService.isDuplicateCheck(declineRecord)) {
//do something with records
}
else
{
//do something with records
}
cachingService.putInCache(xmlJSONObj, declineRecord, time);
and my caching service is as below,
#Component
public class CachingServiceImpl {
private static final Logger logger = LoggerFactory.getLogger(CachingServiceImpl.class);
#Autowired
CacheManager cacheManager;
#Cacheable(value = "declineRecords", key = "#declineRecord", sync = true)
public String putInCache(JSONObject xmlJSONObj, String declineRecord, String time) {
logger.info("Record is Cached for 3 minutes interval check", declineRecord);
cacheManager.getCache("declineRecords").put(declineRecord, time);
return declineRecord;
}
public boolean isDuplicateCheck(String declineRecord) {
if (null != cacheManager.getCache("declineRecords").get(declineRecord)) {
return true;
}
return false;
}
}
But Each time a record comes in consumer my cache is always empty. Its not holding the records.
Modifications Done:
I have added Configuration file as below after going through the suggestions and more kind of R&D removed some of the earlier logic and now the caching is working as expected but duplicate check is failing when all the three consumers are sending the same records.
`
#Configuration
public class AppCacheManagerConfig {
public static Cache<String, Object> jsonCache =
Caffeine.newBuilder().expireAfterWrite(3, TimeUnit.MINUTES)
.maximumSize(10000).recordStats().build();
#Bean
public CacheLoader<Object, Object> cacheLoader() {
CacheLoader<Object, Object> cacheLoader = new CacheLoader<Object, Object>() {
#Override
public Object load(Object key) throws Exception {
return null;
}
#Override
public Object reload(Object key, Object oldValue) throws Exception {
return oldValue;
}
};
return cacheLoader;
}
`
Now i am using the above cache as manual put and get.
I guess you're trying to implement records deduplication for Kafka.
Here is the similar discussion:
https://github.com/spring-projects/spring-kafka/issues/80
Here is the current abstract class which you may extend to achieve the necessary result:
https://github.com/spring-projects/spring-kafka/blob/master/spring-kafka/src/main/java/org/springframework/kafka/listener/adapter/AbstractFilteringMessageListener.java
Your caching service is definitely incorrect: Cacheable annotation allows marking the data getters and setters, to add caching through AOP. While in the code you clearly implement some low-level cache updating logic of your own.
At least next possible changes may help you:
Remove #Cacheable. You don't need it because you work with cache manually, so it may be the source of conflicts (especially as soon as you use sync = true). If it helps, remove #EnableCaching as well - it enables support for cache-related Spring annotations which you don't need here.
Try removing Ticker bean with the appropriate parameters for other beans. It should not be harmful as per your configuration, but usually it's helpful only for tests, no need to define it otherwise.
Double-check what is declineRecord. If it's a serialized object, ensure that serialization works properly.
Add recordStats() for cache and output stats() to log for further analysis.
I am trying to set up a service that has both a REST (POST) endpoint and a Kafka endpoint, both of which should take a JSON representation of the request object (let's call it Foo). I would want to make sure that the Foo object is valid (via JSR-303 or whatever). So Foo might look like:
public class Foo {
#Max(10)
private int bar;
// Getter and setter boilerplate
}
Setting up the REST endpoint is easy:
#PostMapping(value = "/", produces = MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity<String> restEndpoint(#Valid #RequestBody Foo foo) {
// Do stuff here
}
and if I POST, { "bar": 9 } it processes the request, but if I post: { "bar": 99 } I get a BAD REQUEST. All good so far!
The Kafka endpoint is easy to create (along with adding a StringJsonMessageConverter() to my KafkaListenerContainerFactory so that I get JSON->Object conversion:
#KafkaListener(topics = "fooTopic")
public void kafkaEndpoint(#Valid #Payload Foo foo) {
// I shouldn't get here with an invalid object!!!
logger.debug("Successfully processed the object" + foo);
// But just to make sure, let's see if hand-validating it works
Validator validator = localValidatorFactoryBean.getValidator();
Set<ConstraintViolation<SlackMessage>> errors = validator.validate(foo);
if (errors.size() > 0) {
logger.debug("But there were validation errors!" + errors);
}
}
But no matter what I try, I can still pass invalid requests in and they process without error.
I've tried both #Valid and #Validated. I've tried adding a MethodValidationPostProcessor bean. I've tried adding a Validator to the KafkaListenerEndpointRegistrar (a la the EnableKafka javadoc):
#Configuration
public class MiscellaneousConfiguration implements KafkaListenerConfigurer {
private Logger logger = LoggerFactory.getLogger(this.getClass());
#Autowired
LocalValidatorFactoryBean validatorFactory;
#Override
public void configureKafkaListeners(KafkaListenerEndpointRegistrar registrar) {
logger.debug("Configuring " + registrar);
registrar.setMessageHandlerMethodFactory(kafkaHandlerMethodFactory());
}
#Bean
public MessageHandlerMethodFactory kafkaHandlerMethodFactory() {
DefaultMessageHandlerMethodFactory factory = new DefaultMessageHandlerMethodFactory();
factory.setValidator(validatorFactory);
return factory;
}
}
I've now spent a few days on this, and I'm running out of other ideas. Is this even possible (without writing validation into every one of my kakfa endpoints)?
Sorry for the delay; we are at SpringOne Platform this week.
The infrastructure currently does not pass a Validator into the payload argument resolver. Please open an issue on GitHub.
Spring kafka listener by default do not scan for #Valid for non Rest controller classes. For more details please refer this answer
https://stackoverflow.com/a/71859991/13898185
I am experiencing problems when configurating my Jersey Client with the ApacheConnector. It seems to ignore all request headers that I define in a WriterInterceptor. I can tell that the WriterInterceptor is called when I set a break point within WriterInterceptor#aroundWriteTo(WriterInterceptorContext). Contrary to that, I can observe that the modification of an InputStream is preserved.
Here is a runnable example demonstrating my problem:
public class ApacheConnectorProblemDemonstration extends JerseyTest {
private static final Logger LOGGER = Logger.getLogger(JerseyTest.class.getName());
private static final String QUESTION = "baz", ANSWER = "qux";
private static final String REQUEST_HEADER_NAME_CLIENT = "foo-cl", REQUEST_HEADER_VALUE_CLIENT = "bar-cl";
private static final String REQUEST_HEADER_NAME_INTERCEPTOR = "foo-ic", REQUEST_HEADER_VALUE_INTERCEPTOR = "bar-ic";
private static final int MAX_CONNECTIONS = 100;
private static final String PATH = "/";
#Path(PATH)
public static class TestResource {
#POST
public String handle(InputStream questionStream,
#HeaderParam(REQUEST_HEADER_NAME_CLIENT) String client,
#HeaderParam(REQUEST_HEADER_NAME_INTERCEPTOR) String interceptor)
throws IOException {
assertEquals(REQUEST_HEADER_VALUE_CLIENT, client);
// Here, the header that was set in the client's writer interceptor is lost.
assertEquals(REQUEST_HEADER_VALUE_INTERCEPTOR, interceptor);
// However, the input stream got gzipped so the WriterInterceptor has been partly applied.
assertEquals(QUESTION, new Scanner(new GZIPInputStream(questionStream)).nextLine());
return ANSWER;
}
}
#Provider
#Priority(Priorities.ENTITY_CODER)
public static class ClientInterceptor implements WriterInterceptor {
#Override
public void aroundWriteTo(WriterInterceptorContext context)
throws IOException, WebApplicationException {
context.getHeaders().add(REQUEST_HEADER_NAME_INTERCEPTOR, REQUEST_HEADER_VALUE_INTERCEPTOR);
context.setOutputStream(new GZIPOutputStream(context.getOutputStream()));
context.proceed();
}
}
#Override
protected Application configure() {
enable(TestProperties.LOG_TRAFFIC);
enable(TestProperties.DUMP_ENTITY);
return new ResourceConfig(TestResource.class);
}
#Override
protected Client getClient(TestContainer tc, ApplicationHandler applicationHandler) {
ClientConfig clientConfig = tc.getClientConfig() == null ? new ClientConfig() : tc.getClientConfig();
clientConfig.property(ApacheClientProperties.CONNECTION_MANAGER, makeConnectionManager(MAX_CONNECTIONS));
clientConfig.register(ClientInterceptor.class);
// If I do not use the Apache connector, I avoid this problem.
clientConfig.connector(new ApacheConnector(clientConfig));
if (isEnabled(TestProperties.LOG_TRAFFIC)) {
clientConfig.register(new LoggingFilter(LOGGER, isEnabled(TestProperties.DUMP_ENTITY)));
}
configureClient(clientConfig);
return ClientBuilder.newClient(clientConfig);
}
private static ClientConnectionManager makeConnectionManager(int maxConnections) {
PoolingClientConnectionManager connectionManager = new PoolingClientConnectionManager();
connectionManager.setMaxTotal(maxConnections);
connectionManager.setDefaultMaxPerRoute(maxConnections);
return connectionManager;
}
#Test
public void testInterceptors() throws Exception {
Response response = target(PATH)
.request()
.header(REQUEST_HEADER_NAME_CLIENT, REQUEST_HEADER_VALUE_CLIENT)
.post(Entity.text(QUESTION));
assertEquals(200, response.getStatus());
assertEquals(ANSWER, response.readEntity(String.class));
}
}
I want to use the ApacheConnector in order to optimize for concurrent requests via the PoolingClientConnectionManager. Did I mess up the configuration?
PS: The exact same problem occurs when using the GrizzlyConnector.
After further research, I assume that this is rather a misbehavior in the default Connector that uses a HttpURLConnection. As I explained in this other self-answered question of mine, the documentation states:
Whereas filters are primarily intended to manipulate request and
response parameters like HTTP headers, URIs and/or HTTP methods,
interceptors are intended to manipulate entities, via manipulating
entity input/output streams
A WriterInterceptor is not supposed to manipulate the header values while a {Client,Server}RequestFilter is not supposed to manipulate the entity stream. If you need to use both, both components should be bundled within a javax.ws.rs.core.Feature or within the same class that implements two interfaces. (This can be problematic if you need to set two different Prioritys though.)
All this is very unfortunate though, since JerseyTest uses the Connector that uses a HttpURLConnection such that all my unit tests succeeded while the real life application misbehaved since it was configured with an ApacheConnector. Also, rather than suppressing changes, I wished, Jersey would throw me some exceptions. (This is a general issue I have with Jersey. When I for example used a too new version of the ClientConnectionManager where the interface was renamed to HttpClientConnectionManager I simply was informed in a one line log statement that all my configuration efforts were ignored. I did not discover this log statement til very late in development.)