Jpa Repository instance is null in service layer

Question

So i want to save the data with the help of JPA repository but when i autowired it is giving me null. I don't know what else to do in here I have also tried with @EnableJPARepository annotation still no help. So here are the classes i am using. I want to save the data that is published by kafka so is it best to create a seperate function or can i put save to db function in consume json?

Repository

package com.prateek.addaKafka.addaKafka.kafkaConsumer;

import org.springframework.data.repository.CrudRepository;


public interface KafkaRepository extends CrudRepository<KafkaEntity,Long> {
}

KafkaEntityClass

package com.prateek.addaKafka.addaKafka.kafkaConsumer;

import javax.persistence.*;

@Entity
@Table(name = "messages")
public class KafkaEntity {
    @Id
    @GeneratedValue
    private Long id;
    @Column(nullable = false)
    private String userName;
    @Column(nullable = false)
    private String userMessage;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getUserMessage() {
        return userMessage;
    }

    public void setUserMessage(String userMessage) {
        this.userMessage = userMessage;
    }
}

ServiceClass

package com.prateek.addaKafka.addaKafka.kafkaConsumer;

import com.prateek.addaKafka.addaKafka.model.UserPublishModel;
import org.modelmapper.ModelMapper;
import org.modelmapper.convention.MatchingStrategies;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.kafka.annotation.KafkaListener;
import org.springframework.stereotype.Service;

@Service
public class KafkaListenerService {

    @Autowired
    KafkaRepository kafkaRepository;

    @KafkaListener(topics = "NewTopic",groupId = "group_json",
            containerFactory = "userKafkaListenerFactory")
    public UserPublishModel consumeJson(UserPublishModel userPublishModel) {
        return userPublishModel;
    }

    public void saveToDB(UserPublishModel userPublishModel){
        ModelMapper modelMapper=new ModelMapper();
        modelMapper.getConfiguration().setMatchingStrategy(MatchingStrategies.STRICT);
        KafkaEntity kafkaEntity=modelMapper.map(userPublishModel, KafkaEntity.class);
        kafkaRepository.save(kafkaEntity);
    }

}

MainClass

package com.prateek.addaKafka.addaKafka;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;

@SpringBootApplication
public class AddaKafkaApplication {

    public static void main(String[] args) {
        SpringApplication.run(AddaKafkaApplication.class, args);
    }

}