苍穹外卖--redis缓存菜品功能业务实现

sky-server/src/main/java/com/sky/controller/user/DishController.java

@@ -9,6 +9,7 @@ import io.swagger.annotations.Api;
 import io.swagger.annotations.ApiOperation;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.redis.core.RedisTemplate;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
@@ -22,6 +23,9 @@ public class DishController {
     @Autowired
     private DishService dishService;
 
+    @Autowired
+    private RedisTemplate redisTemplate;
+
     /**
      * 根据分类id查询菜品
      *
@@ -31,11 +35,23 @@ public class DishController {
     @GetMapping("/list")
     @ApiOperation("根据分类id查询菜品")
     public Result<List<DishVO>> list(Long categoryId) {
+        //这里采用redis中string数据类型进行缓存数据：key:value (dish_分类id : 菜品集合的字符串)
+        //1.构造redis中的key，规则：dish_分类id
+        String key = "dish_"+categoryId;
+        //2.查询redis中是否存在菜品数据,
+        List<DishVO> list  = (List<DishVO>) redisTemplate.opsForValue().get(key);
+        if (list != null && list.size() > 0) {
+            //3.如果存在缓存，直接返回，无需查询数据库
+            return Result.success(list);
+        }
+        //4.如果不存在缓存，查询数据库，将查询到的数据保存到redis中
+
         Dish dish = new Dish();
         dish.setCategoryId(categoryId);
         dish.setStatus(StatusConstant.ENABLE);//查询起售中的菜品
-
-        List<DishVO> list = dishService.listWithFlavor(dish);
+        list = dishService.listWithFlavor(dish);
+        //5.缓存到reids中
+        redisTemplate.opsForValue().set(key,list);
 
         return Result.success(list);
     }