Spring Boot + Apache Kafka Tutorial - #12 - Create REST API to Send JSON Object

Welcome to Spring Boot + Apache Kafka Tutorial series.
In this lecture, we will create a REST API to send a JSON message in request. The REST API intern converts JSON into a User object and sends it to Kafka Producer. Kafka Producer intern sends that user object to Kafka topic.

#springboot #kafka #javaguides

[УмарКаригов]

Спасибо огромное!!!! Ты очень хорошо все объясняешь.👍👍👍👍

[wahyuusman]

many thanks about your tutorial, cuz your video i very help for learning about kafka

[krishnamadhav]

At 2:07, you have added PostMapping("/publish") and in the previous video in MessageController class you have added GetMapping("/publish"). Can you please explain the reason behind it? Please clarify this.

As per my understanding at both the places it should be GetMapping annotation only.

[johnbrooks]

Those who are getting the error trying to cast your User object to a String may need to update your producer properties to have a key serializer and value serializer instead of "deserializer".

[anshikamishra]

Some of the windows commands are not working for me giving "The syntax for the command is incorrect" specially when using --from-beginning

[arthurmukelyan]

Hi, I am getting 405 request method not supported, but I can’t understand why, anyone can help me?

[meduriravindra]

Please explain how to consume old data from Kafka after the old data get updated. Is it a possible scenario atleast from interview point of view ?

[pavanraju]

How to consume data by using browser or postman?

[elakkiyap]

hai sir. i tried to send Json Message to kafka topic but am getting internal server error in postman . As well as in intellij, ERROR [dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is Can't convert value of class to class specified in value.serializer] with root cause java.lang.ClassCastException: class cannot be cast to class java.lang.String is in unnamed module of loader 'app'; java.lang.String is in module java.base of loader 'bootstrap')...how to overcome this error. kindly help in this

[adityakendhe]

hello sir,
I am getting null pointer exception related to kafka template while using rest api to send json object on console.
And in postman it is showing internal server error.
please help.

[MDAnashAnsari]

Replace your KafkaConsumer class code with the below code if you are getting :- Can't convert value of class com.vinay.kafka.payload.User to class

public class KafkaConsumer {

@KafkaListener(topics = "nepdroid", groupId = "myGroup")
public void consume(User user) {
received -> %s", user.toString()));
}
}

[vinay]

Anyone please help me to resolve this error Can't convert value of class com.vinay.kafka.payload.User to class