Added POST end point for adding product and GET end point to fetch product based on id

src/main/java/com/nisum/example/constants/ProductConstants.java

 package com.nisum.example.constants;
 
+/**
+ * Product Constants with equivalent values
+ */
 public interface ProductConstants {
-
     String PRODUCT_SERVICE_ROOT="product-service";
 }

src/main/java/com/nisum/example/controller/ProductController.java

@@ -4,16 +4,16 @@ import com.nisum.example.constants.ProductConstants;
 import com.nisum.example.mapper.ProductMapper;
 import com.nisum.example.model.Product;
 import com.nisum.example.service.IProductService;
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
-import org.springframework.web.bind.annotation.PostMapping;
-import org.springframework.web.bind.annotation.RequestBody;
-import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.bind.annotation.*;
 import reactor.core.publisher.Mono;
 
 @RestController
 @RequestMapping(value = ProductConstants.PRODUCT_SERVICE_ROOT,produces = MediaType.APPLICATION_JSON_VALUE)
+@Slf4j
 public class ProductController {
 
     @Autowired
@@ -22,11 +22,22 @@ public class ProductController {
     @Autowired
     private IProductService productService;
 
-    @PostMapping(value = "/product-create")
+    @PostMapping(value = "/product-create",consumes = MediaType.APPLICATION_JSON_VALUE)
+    @ResponseStatus(HttpStatus.CREATED)
     public Mono<Product> createProduct(@RequestBody Product product){
-
+        log.info("Calling service saveProduct() ...");
        return productService.saveProduct(productMapper.toDto(product))
                .map(productMapper::toModel)
                .log();
     }
+
+    @GetMapping(value = "/product-get/{id}")
+    @ResponseStatus(HttpStatus.OK)
+    public Mono<Product> fetchProduct(@PathVariable String id){
+        log.info("Calling service getProduct()...");
+        return productService.getProduct(id)
+                .map(productMapper::toModel)
+                .log();
+
+    }
 }

src/main/java/com/nisum/example/mapper/LocationMapper.java

@@ -4,7 +4,7 @@ import com.nisum.example.dto.LocationDTO;
 import com.nisum.example.model.Location;
 import org.mapstruct.Mapper;
 
-@Mapper
+@Mapper(componentModel = "spring")
 public interface LocationMapper {
     LocationDTO toDto(Location location);
 }

src/main/java/com/nisum/example/mapper/ProductMapper.java

@@ -11,5 +11,6 @@ public interface ProductMapper {
     @Mapping(source = "product.prodLocationList",target = "prodLocationDTOList")
     ProductDTO toDto(Product product);
 
+    @Mapping(source = "productDTO.prodLocationDTOList",target = "prodLocationList")
     Product toModel(ProductDTO productDTO);
 }

src/main/java/com/nisum/example/service/IProductService.java

@@ -6,4 +6,5 @@ import reactor.core.publisher.Mono;
 public interface IProductService {
 
     Mono<ProductDTO> saveProduct(ProductDTO productDTO);
+    Mono<ProductDTO> getProduct(String id);
 }

src/main/java/com/nisum/example/service/ProductServiceImpl.java

 package com.nisum.example.service;
 
 import com.nisum.example.dto.ProductDTO;
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.mongodb.core.ReactiveMongoTemplate;
 import org.springframework.stereotype.Service;
 import reactor.core.publisher.Mono;
 
+/**
+ * Product Service class
+ */
 @Service
+@Slf4j
 public class ProductServiceImpl implements IProductService {
 
     @Autowired
     private ReactiveMongoTemplate reactiveMongoTemplate;
 
+    /**
+     *Perform save operation of one product
+     * @param productDTO
+     * @return Mono<ProductDTO>
+     */
     @Override
     public Mono<ProductDTO> saveProduct(ProductDTO productDTO) {
+        log.info("Calling template save()...");
         return reactiveMongoTemplate.save(productDTO);
     }
+
+    /**
+     * Perform get operation based on id
+     * @param id
+     * @return Mono<ProductDTO>
+     */
+    @Override
+    public Mono<ProductDTO> getProduct(String id) {
+        log.info("Calling service findById()...");
+        return reactiveMongoTemplate.findById(id,ProductDTO.class);
+    }
 }