chore: initial commit.

.gitignore

+HELP.md
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**
+!**/src/test/**
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+.mvn/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+
+### VS Code ###
+.vscode/

README.md

+# Order Processing API
+
+1. order-processing-api will consume order information from kafka topic using reactive kafka connector and process the received record
+2. This API using the conversion of Dto to Collection and vice-versa using @mapStruct API dependency
+3. This API using reactiveOperations framework instead of repository enablers for each mongo db collection.
+4. This API is demonstrating CRUD operations of Order information.
+
+Technologies Used :
+
+1. Spring boot
+2. Java8
+3. Reactive Kafka
+4. Reactive Mongo
+5. Spring Webflux
\ No newline at end of file

pom.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-starter-parent</artifactId>
+		<version>2.3.0.BUILD-SNAPSHOT</version>
+		<relativePath/> <!-- lookup parent from repository -->
+	</parent>
+	<groupId>com.nisum</groupId>
+	<artifactId>order-processing-api</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>order-processing-api</name>
+	<description>Demo project for Spring Boot</description>
+
+	<properties>
+		<java.version>1.8</java.version>
+	</properties>
+
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-webflux</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.kafka</groupId>
+			<artifactId>spring-kafka</artifactId>
+		</dependency>
+
+		<!-- https://mvnrepository.com/artifact/io.projectreactor.kafka/reactor-kafka -->
+		<dependency>
+			<groupId>io.projectreactor.kafka</groupId>
+			<artifactId>reactor-kafka</artifactId>
+			<version>1.1.2.RELEASE</version>
+		</dependency>
+
+
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+			<exclusions>
+				<exclusion>
+					<groupId>org.junit.vintage</groupId>
+					<artifactId>junit-vintage-engine</artifactId>
+				</exclusion>
+			</exclusions>
+		</dependency>
+		<dependency>
+			<groupId>io.projectreactor</groupId>
+			<artifactId>reactor-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.kafka</groupId>
+			<artifactId>spring-kafka-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+
+		<dependency>
+			<groupId>org.projectlombok</groupId>
+			<artifactId>lombok</artifactId>
+			<version>1.18.26</version>
+			<scope>provided</scope>
+		</dependency>
+
+		<dependency>
+			<groupId>com.google.code.gson</groupId>
+			<artifactId>gson</artifactId>
+			<version>2.10.1</version>
+		</dependency>
+
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-data-mongodb-reactive</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>de.flapdoodle.embed</groupId>
+			<artifactId>de.flapdoodle.embed.mongo</artifactId>
+			<scope>test</scope>
+		</dependency>
+
+
+		<dependency>
+			<groupId>org.mapstruct</groupId>
+			<artifactId>mapstruct</artifactId>
+			<version>1.5.3.Final</version>
+		</dependency>
+
+		<dependency>
+			<groupId>org.mongodb</groupId>
+			<artifactId>mongodb-driver-reactivestreams</artifactId>
+			<version>4.1.0</version>
+		</dependency>
+
+		<dependency>
+			<groupId>org.mongodb</groupId>
+			<artifactId>mongodb-driver-sync</artifactId>
+			<version>4.0.5</version>
+		</dependency>
+
+	</dependencies>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+			</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-surefire-plugin</artifactId>
+				<version>2.19.1</version>
+			</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-compiler-plugin</artifactId>
+				<version>3.5.1</version>
+				<configuration>
+					<source>1.8</source>
+					<target>1.8</target>
+					<annotationProcessorPaths>
+						<path>
+							<groupId>org.mapstruct</groupId>
+							<artifactId>mapstruct-processor</artifactId>
+							<version>1.5.3.Final</version>
+						</path>
+						<path>
+							<groupId>org.projectlombok</groupId>
+							<artifactId>lombok</artifactId>
+							<version>1.18.26</version>
+						</path>
+						<path>
+							<groupId>org.projectlombok</groupId>
+							<artifactId>lombok-mapstruct-binding</artifactId>
+							<version>0.2.0</version>
+						</path>
+					</annotationProcessorPaths>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+
+
+
+</project>

src/main/java/com/nisum/orderprocessingapi/OrderProcessingApplication.java

+package com.nisum.orderprocessingapi;
+
+import com.google.gson.Gson;
+import org.apache.kafka.clients.producer.ProducerConfig;
+import org.apache.kafka.common.serialization.StringSerializer;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+import reactor.kafka.sender.KafkaSender;
+import reactor.kafka.sender.SenderOptions;
+
+import java.util.HashMap;
+import java.util.Map;
+
+@SpringBootApplication
+public class OrderProcessingApplication {
+
+	private static final String TOPIC = "test-order";
+	private static final String BOOTSTRAP_SERVERS = "HYD-LAP-00484.corp.nisum.com:9092";
+	private static final String CLIENT_ID_CONFIG = "trans-string-consumer-test-order";
+
+	public static void main(String[] args) {
+		SpringApplication.run(OrderProcessingApplication.class, args);
+	}
+
+
+	@Bean
+	public KafkaSender<String, String> kafkaSender()
+	{
+		Map<String, Object> props = new HashMap<>();
+		props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, BOOTSTRAP_SERVERS);
+		props.put(ProducerConfig.CLIENT_ID_CONFIG, CLIENT_ID_CONFIG);
+		props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
+		props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
+
+		SenderOptions<String, String> senderOptions = SenderOptions.create(props);
+		return KafkaSender.create(senderOptions);
+	}
+
+
+	@Bean
+	public Gson gson ()
+	{
+		return new Gson();
+	}
+
+}

src/main/java/com/nisum/orderprocessingapi/config/KafkaConfiguaration.java

+package com.nisum.orderprocessingapi.config;
+
+import org.apache.kafka.clients.consumer.ConsumerConfig;
+import org.apache.kafka.common.serialization.StringDeserializer;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import reactor.kafka.receiver.KafkaReceiver;
+import reactor.kafka.receiver.ReceiverOptions;
+import reactor.kafka.receiver.internals.ConsumerFactory;
+import reactor.kafka.receiver.internals.DefaultKafkaReceiver;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+@Configuration
+public class KafkaConfiguaration {
+
+    private static final String TOPIC = "test-order";
+    private static final String BOOTSTRAP_SERVERS = "HYD-LAP-00484.corp.nisum.com:9092";
+    private static final String CLIENT_ID_CONFIG = "trans-string-consumer-test-order";
+    private static final String GROUP_ID_CONFIG = "trans-string-cg-test-order";
+
+    @Bean
+    public KafkaReceiver kafkaReceiver(){
+
+        Map<String, Object> props = new HashMap<>();
+        props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, BOOTSTRAP_SERVERS);
+        props.put(ConsumerConfig.CLIENT_ID_CONFIG, CLIENT_ID_CONFIG);
+        props.put(ConsumerConfig.GROUP_ID_CONFIG, GROUP_ID_CONFIG);
+        props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
+        props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
+        props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
+        props.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, true);
+
+        return new DefaultKafkaReceiver(ConsumerFactory.INSTANCE, ReceiverOptions.create(props).subscription(Collections.singleton(TOPIC)));
+    }
+}

src/main/java/com/nisum/orderprocessingapi/config/ReactiveMongoConfig.java

+package com.nisum.orderprocessingapi.config;
+
+
+import com.mongodb.reactivestreams.client.MongoClient;
+import com.mongodb.reactivestreams.client.MongoClients;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.mongodb.config.AbstractReactiveMongoConfiguration;
+import org.springframework.data.mongodb.repository.config.EnableReactiveMongoRepositories;
+
+
+@Configuration
+@EnableReactiveMongoRepositories(basePackages = "com.nisum.orderprocessingapi")
+public class ReactiveMongoConfig extends AbstractReactiveMongoConfiguration{
+
+    @Override
+    public MongoClient reactiveMongoClient() {
+        return MongoClients.create();
+    }
+
+    @Override
+    protected String getDatabaseName() {
+        return "orderdb";
+    }
+}
\ No newline at end of file

src/main/java/com/nisum/orderprocessingapi/controller/OrderController.java

+package com.nisum.orderprocessingapi.controller;
+
+import com.google.gson.Gson;
+import com.nisum.orderprocessingapi.dto.IdAndOrderIdMapper;
+import com.nisum.orderprocessingapi.dto.OrderCollectionDto;
+import com.nisum.orderprocessingapi.dto.OrderDto;
+import com.nisum.orderprocessingapi.dto.OrderResponseDto;
+import com.nisum.orderprocessingapi.producer.OrderEventGenerator;
+import com.nisum.orderprocessingapi.service.OrderProcessingService;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.MediaType;
+import org.springframework.web.bind.annotation.*;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+import reactor.kafka.receiver.KafkaReceiver;
+import reactor.kafka.receiver.ReceiverRecord;
+
+@Slf4j
+@RestController
+@RequestMapping(path = "/order")
+public class OrderController {
+
+    @Autowired
+    private KafkaReceiver<String,String> kafkaReceiver;
+
+    @Autowired
+    private  OrderEventGenerator orderEventGenerator;
+
+    @Autowired
+    private OrderProcessingService orderProcessingService;
+
+    @Autowired
+    private Gson gson;
+
+    @GetMapping(produces = MediaType.TEXT_EVENT_STREAM_VALUE)
+    public Flux getAllOrderEvents(){
+        Flux<ReceiverRecord<String,String>> kafkaFlux = kafkaReceiver.receive();
+        return kafkaFlux.checkpoint("Messages are started being consumed").log()
+                .doOnNext(order->
+        {
+            String key = order.key();
+            OrderDto orderDto = gson.fromJson(order.value(), OrderDto.class);
+
+            orderProcessingService.save(orderDto,key).onErrorResume(o->{
+                log.info("Unable to save document in mongo DB {} ",o);
+                order.receiverOffset().acknowledge();
+                return  Mono.empty();
+            }).subscribe(orderStatus -> {
+                log.info("Mongo DB : Order Key : {} saved status {}", key,orderStatus);
+                order.receiverOffset().acknowledge();
+            });
+
+        }).map(ReceiverRecord::value)
+                .checkpoint("Messages are done consumed");
+
+    }
+
+    @PostMapping(produces = MediaType.APPLICATION_JSON_VALUE)
+    public Flux<OrderResponseDto> createOrderEventInKafka(@RequestBody OrderCollectionDto orderCollectionDto) throws InterruptedException {
+
+        log.info("orderCollection Received : {}",orderCollectionDto);
+        return orderEventGenerator.publishOrderEvent("test-order",orderCollectionDto);
+
+
+     }
+
+    @PostMapping(path = "/create",produces = MediaType.APPLICATION_JSON_VALUE)
+    public Flux<IdAndOrderIdMapper> createOrderEvent(@RequestBody OrderCollectionDto orderCollectionDto) throws InterruptedException {
+
+        log.info("orderCollection Received : {}",orderCollectionDto);
+        return orderProcessingService.saveAll(orderCollectionDto);
+
+
+    }
+
+    @PutMapping(path = "/update/{id}",produces = MediaType.APPLICATION_JSON_VALUE)
+    public Mono<OrderDto> updateOrderEvent(@PathVariable String id, @RequestBody OrderDto orderDto) throws InterruptedException {
+
+        log.info("orderCollection Received for update : {}",orderDto);
+        return orderProcessingService.update(orderDto);
+
+
+    }
+
+    @DeleteMapping("/delete/{id}")
+    public Mono<Boolean> deleteOrderEvent(@PathVariable String id) throws InterruptedException {
+
+        log.info("Order id Received for deletion : {}",id);
+        return orderProcessingService.delete(id);
+
+
+    }
+
+    @GetMapping("/get/{id}")
+    public Mono<OrderDto> readOrderEvent(@PathVariable String id) throws InterruptedException {
+
+        log.info("Order id Received for retrieval : {}",id);
+        return orderProcessingService.read(id);
+
+
+    }
+
+
+
+}

src/main/java/com/nisum/orderprocessingapi/dto/BuyerInfoDto.java

+package com.nisum.orderprocessingapi.dto;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+
+@Data
+@Builder
+@AllArgsConstructor
+@NoArgsConstructor
+public class BuyerInfoDto {
+
+
+    private String id;
+    private String buyerEmail;
+    private String buyerName;
+    private BuyerTaxInfoDto buyerTaxInfo;
+    private String purchaseOrderNumber;
+
+}

src/main/java/com/nisum/orderprocessingapi/dto/BuyerTaxInfoDto.java

+package com.nisum.orderprocessingapi.dto;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@Builder
+@AllArgsConstructor
+@NoArgsConstructor
+public class BuyerTaxInfoDto {
+
+
+    private String id;
+    private String companyLegalName;
+}

src/main/java/com/nisum/orderprocessingapi/dto/IdAndOrderIdMapper.java

+package com.nisum.orderprocessingapi.dto;
+
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+@Builder
+public class IdAndOrderIdMapper {
+    
+    private String id;
+    private String orderId;
+}

src/main/java/com/nisum/orderprocessingapi/dto/OrderCollectionDto.java

+package com.nisum.orderprocessingapi.dto;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.util.List;
+
+@Data
+@Builder
+@AllArgsConstructor
+@NoArgsConstructor
+public class OrderCollectionDto{
+
+
+    private List<OrderDto> ordersDto;
+
+}

src/main/java/com/nisum/orderprocessingapi/dto/OrderDto.java

+package com.nisum.orderprocessingapi.dto;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.util.List;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+@Builder
+public class OrderDto {
+
+
+    private String id;
+    private String orderId;
+    private String purchaseDate;
+    private String lastUpdateDate;
+    private String orderStatus;
+    private String fulfillmentChannel;
+    private Integer numberOfItemsShipped;
+    private Integer numberOfItemsUnshipped;
+    private String paymentMethod;
+    private List<String> paymentMethodDetails;
+    private String marketplaceId;
+    private String shipmentServiceLevelCategory;
+    private String orderType;
+    private String earliestShipDate;
+    private String latestShipDate;
+    private ShippingAddressDto shippingAddress;
+    private BuyerInfoDto buyerInfo;
+
+
+}
\ No newline at end of file

src/main/java/com/nisum/orderprocessingapi/dto/OrderResponseDto.java

+package com.nisum.orderprocessingapi.dto;
+
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.util.List;
+
+@Data
+@Builder
+@AllArgsConstructor
+@NoArgsConstructor
+public class OrderResponseDto {
+
+    private String topicName;
+    @JsonIgnore
+    private List<IdAndOrderIdMapper> orderKey;
+
+}

src/main/java/com/nisum/orderprocessingapi/dto/ShippingAddressDto.java

+package com.nisum.orderprocessingapi.dto;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+@Data
+@Builder
+@AllArgsConstructor
+@NoArgsConstructor
+public class ShippingAddressDto {
+
+
+    private String id;
+    private String name;
+    private String addressLine1;
+    private String city;
+    private String stateOrRegion;
+    private String postalCode;
+    private String countryCode;
+
+}

src/main/java/com/nisum/orderprocessingapi/entity/BuyerInfo.java

+package com.nisum.orderprocessingapi.entity;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import org.springframework.data.annotation.Id;
+import org.springframework.data.mongodb.core.mapping.Document;
+
+
+@Data
+@Builder
+@AllArgsConstructor
+@NoArgsConstructor
+@Document("buyer_info")
+public class BuyerInfo {
+
+    @Id
+    private String id;
+    private String buyerEmail;
+    private String buyerName;
+    private String purchaseOrderNumber;
+
+}

src/main/java/com/nisum/orderprocessingapi/entity/BuyerTaxInfo.java

+package com.nisum.orderprocessingapi.entity;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import org.springframework.data.annotation.Id;
+import org.springframework.data.mongodb.core.mapping.Document;
+
+@Data
+@Builder
+@AllArgsConstructor
+@NoArgsConstructor
+@Document("buyer_tax_info")
+public class BuyerTaxInfo {
+    @Id
+    private String id;
+    private String companyLegalName;
+}

src/main/java/com/nisum/orderprocessingapi/entity/Order.java

+package com.nisum.orderprocessingapi.entity;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import org.springframework.data.annotation.Id;
+import org.springframework.data.mongodb.core.mapping.Document;
+
+import java.util.List;
+
+@Data
+@Builder
+@AllArgsConstructor
+@NoArgsConstructor
+@Document("order")
+public class Order {
+
+    @Id
+    private String id;
+    private String orderId;
+    private String purchaseDate;
+    private String lastUpdateDate;
+    private String orderStatus;
+    private String fulfillmentChannel;
+    private Integer numberOfItemsShipped;
+    private Integer numberOfItemsUnshipped;
+    private String paymentMethod;
+    private List<String> paymentMethodDetails;
+    private String marketplaceId;
+    private String shipmentServiceLevelCategory;
+    private String orderType;
+    private String earliestShipDate;
+    private String latestShipDate;
+
+
+}
\ No newline at end of file

src/main/java/com/nisum/orderprocessingapi/entity/ShippingAddress.java

+package com.nisum.orderprocessingapi.entity;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import org.springframework.data.annotation.Id;
+import org.springframework.data.mongodb.core.mapping.Document;
+
+@Data
+@Builder
+@AllArgsConstructor
+@NoArgsConstructor
+@Document("shipping_address")
+public class ShippingAddress {
+
+
+    @Id
+    private String id;
+    private String name;
+    private String addressLine1;
+    private String city;
+    private String stateOrRegion;
+    private String postalCode;
+    private String countryCode;
+
+}

src/main/java/com/nisum/orderprocessingapi/producer/OrderEventGenerator.java

+package com.nisum.orderprocessingapi.producer;
+
+import com.google.gson.Gson;
+import com.nisum.orderprocessingapi.dto.IdAndOrderIdMapper;
+import com.nisum.orderprocessingapi.dto.OrderCollectionDto;
+import com.nisum.orderprocessingapi.dto.OrderResponseDto;
+import com.nisum.orderprocessingapi.service.OrderProcessingService;
+import lombok.extern.slf4j.Slf4j;
+import org.apache.kafka.clients.producer.ProducerRecord;
+import org.apache.kafka.clients.producer.RecordMetadata;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+import reactor.core.publisher.Flux;
+import reactor.kafka.sender.KafkaSender;
+import reactor.kafka.sender.SenderRecord;
+
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.List;
+import java.util.UUID;
+import java.util.stream.Collectors;
+
+
+@Component
+@Slf4j
+public class OrderEventGenerator {
+
+    @Autowired
+    private KafkaSender<String, String> kafkaSender;
+
+    @Autowired
+    private OrderProcessingService orderProcessingService;
+
+    @Autowired
+    private Gson gson;
+
+
+    public Flux<OrderResponseDto> publishOrderEvent(String topic, OrderCollectionDto orderCollectionDto) throws InterruptedException {
+
+        SimpleDateFormat dateFormat = new SimpleDateFormat("HHmmssSSSzddMMyyyy");
+
+
+        OrderResponseDto response= new OrderResponseDto();
+        response.setTopicName(topic);
+        List<IdAndOrderIdMapper> idAndOrderIdMappers=orderCollectionDto.getOrdersDto().stream().map(orderDto -> {
+            String uuid= UUID.randomUUID().toString();
+            String orderId= orderDto.getOrderId();
+            String orderString=gson.toJson(orderDto);
+            log.info("Order Information: {} ",orderString);
+            kafkaSender.send(Flux.just(
+                    SenderRecord.create(new ProducerRecord<>(topic, uuid, orderString),uuid)))
+                    .doOnError(e -> log.error("Send failed", e))
+                    .subscribe(r -> {
+                        RecordMetadata metadata = r.recordMetadata();
+                        System.out.printf("Message %s sent successfully, topic-partition=%s-%d offset=%d timestamp=%s%n",
+                                r.correlationMetadata(),
+                                metadata.topic(),
+                                metadata.partition(),
+                                metadata.offset(),
+                                dateFormat.format(new Date(metadata.timestamp())));
+
+                    });
+
+            return IdAndOrderIdMapper.builder().orderId(orderId).id(uuid).build();
+        }).collect(Collectors.toList());
+        response.setOrderKey(idAndOrderIdMappers);
+        return Flux.just(response);
+
+    }
+
+
+}

src/main/java/com/nisum/orderprocessingapi/repository/OrderMapper.java

+package com.nisum.orderprocessingapi.repository;
+
+import com.nisum.orderprocessingapi.dto.BuyerInfoDto;
+import com.nisum.orderprocessingapi.dto.BuyerTaxInfoDto;
+import com.nisum.orderprocessingapi.dto.OrderDto;
+import com.nisum.orderprocessingapi.dto.ShippingAddressDto;
+import com.nisum.orderprocessingapi.entity.BuyerInfo;
+import com.nisum.orderprocessingapi.entity.BuyerTaxInfo;
+import com.nisum.orderprocessingapi.entity.Order;
+import com.nisum.orderprocessingapi.entity.ShippingAddress;
+import org.mapstruct.Mapper;
+import org.mapstruct.Mapping;
+import org.mapstruct.factory.Mappers;
+
+@Mapper
+public interface OrderMapper {
+
+   OrderMapper INSTANCE = Mappers.getMapper(OrderMapper.class);
+
+   OrderDto orderEntityToDto(Order order);
+
+   @Mapping(target = "id", source = "orderKey")
+   Order orderDtoToEntity(OrderDto orderDto,String orderKey);
+
+   ShippingAddressDto shippingAddressEntityToDTO(ShippingAddress shippingAddress);
+
+   @Mapping(target = "id", source = "orderKey")
+   ShippingAddress shippingAddressDtoToEntity(ShippingAddressDto shippingAddressDto,String orderKey);
+
+   BuyerInfoDto buyerInfoEntityToDto(BuyerInfo buyerInfo);
+
+   @Mapping(target = "id", source = "orderKey")
+   BuyerInfo buyerInfoDtoToEntity(BuyerInfoDto buyerInfo,String orderKey);
+
+   @Mapping(target = "id", source = "orderKey")
+   BuyerTaxInfo buyerTaxInfoDtoToEntity(BuyerTaxInfoDto buyerTaxInfoDto,String orderKey);
+
+   BuyerTaxInfoDto buyerTaxInfoEntityToDto(BuyerTaxInfo buyerTaxInfo);
+}

src/main/resources/application.properties

+spring.data.mongodb.uri=mongodb://localhost:27017/orderdb
+spring.data.mongodb.database=orderdb

src/test/java/com/egen/serversentevents/ServerSentEventsApplicationTests.java

+package com.egen.serversentevents;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+class ServerSentEventsApplicationTests {
+
+	@Test
+	void contextLoads() {
+	}
+
+}