feat: add OrderController with delete and update endpoints

src/main/java/com/business/controllers/OrderController.java

@@ -1,10 +1,57 @@
 package com.business.controllers;
 
+import com.business.entities.Orders;
+import com.business.repositories.OrderRepository;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.ResponseEntity;
 import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.*;
 
 @Controller
-public class OrderController
-{
-	
+@RestController
+@RequestMapping("/api/orders")
+public class OrderController {
 
-}
+    private final OrderRepository orderRepository;
+
+    @Autowired
+    public OrderController(OrderRepository orderRepository) {
+        this.orderRepository = orderRepository;
+    }
+
+    /**
+     * DELETE /api/orders/{id}
+     * 删除指定 ID 的订单
+     */
+    @DeleteMapping("/{id}")
+    public ResponseEntity<Void> deleteOrder(@PathVariable("id") int orderId) {
+        if (!orderRepository.existsById(orderId)) {
+            // 如果找不到，返回 404
+            return ResponseEntity.notFound().build();
+        }
+        orderRepository.deleteById(orderId);
+        // 删除成功，返回 204 No Content
+        return ResponseEntity.noContent().build();
+    }
+
+    /**
+     * PATCH /api/orders/{id}?quantity=新的数量
+     * 更新指定 ID 订单的数量，并重算 totalAmmout
+     */
+    @PatchMapping("/{id}")
+    public ResponseEntity<Orders> updateOrderQuantity(
+            @PathVariable("id") int orderId,
+            @RequestParam("quantity") int newQuantity) {
+
+        return orderRepository.findById(orderId)
+                .map(order -> {
+                    // 更新数量
+                    order.setoQuantity(newQuantity);
+                    // 重新计算总价
+                    order.setTotalAmmout(order.getoPrice() * newQuantity);
+                    Orders updated = orderRepository.save(order);
+                    return ResponseEntity.ok(updated);
+                })
+                .orElseGet(() -> ResponseEntity.notFound().build());
+    }
+}