Refactor Product Controller for enhanced structure and error handling.

.vscode/launch.json

@@ -0,0 +1,14 @@
+{
+    "configurations": [
+        {
+            "type": "java",
+            "name": "Spring Boot-SpringBootWebApplication<spring-boot-web>",
+            "request": "launch",
+            "cwd": "${workspaceFolder}",
+            "mainClass": "guru.springframework.SpringBootWebApplication",
+            "projectName": "spring-boot-web",
+            "args": "",
+            "envFile": "${workspaceFolder}/.env"
+        }
+    ]
+}

src/main/java/guru/springframework/controllers/ProductController.java

@@ -1,55 +1,75 @@
 package guru.springframework.controllers;
 
-import guru.springframework.domain.Product;
-import guru.springframework.services.ProductService;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
 import org.springframework.stereotype.Controller;
 import org.springframework.ui.Model;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.ModelAttribute;
 import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RequestMethod;
+
+import guru.springframework.domain.Product;
+import guru.springframework.services.ProductService;
+
 
 @Controller
+@RequestMapping("/product")
 public class ProductController {
 
-    private ProductService productService;
+    private final ProductService productService;
 
     @Autowired
-    public void setProductService(ProductService productService) {
+    public ProductController(ProductService productService) {
         this.productService = productService;
     }
 
-    @RequestMapping(value = "/products", method = RequestMethod.GET)
-    public String list(Model model){
+    private ResponseEntity<Product> getProductById(Integer id) {
+        Product product = productService.getProductById(id);
+        if (product == null) {
+            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
+        }
+        return new ResponseEntity<>(product, HttpStatus.OK);
+    }
+
+    @GetMapping("/list")
+    public String list(Model model) {
         model.addAttribute("products", productService.listAllProducts());
-        System.out.println("Returning rpoducts:");
         return "products";
     }
 
-    @RequestMapping("product/{id}")
-    public String showProduct(@PathVariable Integer id, Model model){
-        model.addAttribute("product", productService.getProductById(id));
-        return "productshow";
+    @GetMapping("/{id}")
+    public ResponseEntity<Product> showProduct(@PathVariable Integer id) {
+        return getProductById(id);
     }
 
-    @RequestMapping("product/edit/{id}")
-    public String edit(@PathVariable Integer id, Model model){
-        model.addAttribute("product", productService.getProductById(id));
+    @GetMapping("/edit/{id}")
+    public String editProduct(@PathVariable Integer id, Model model) {
+        ResponseEntity<Product> responseEntity = getProductById(id);
+        if (responseEntity.getStatusCode() == HttpStatus.NOT_FOUND) {
+            return "error/404"; // Return 404 page if product is not found
+        }
+        model.addAttribute("product", responseEntity.getBody());
         return "productform";
     }
 
-    @RequestMapping("product/new")
-    public String newProduct(Model model){
+    @GetMapping("/new")
+    public String newProduct(Model model) {
         model.addAttribute("product", new Product());
         return "productform";
     }
 
-    @RequestMapping(value = "product", method = RequestMethod.POST)
-    public String saveProduct(Product product){
-
-        productService.saveProduct(product);
-
-        return "redirect:/product/" + product.getId();
+    @PostMapping
+    public ResponseEntity<String> saveProduct(@ModelAttribute Product product) {
+        try {
+            productService.saveProduct(product);
+            return ResponseEntity.status(HttpStatus.CREATED)
+                    .body("Product created with ID: " + product.getId());
+        } catch (Exception e) {
+            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
+                    .body("An error occurred while saving the product.");
+        }
     }
-
 }