[JAVA] Isn't there a name collision when enum has the same name in the switch statement?

Introduction

In Java switch statement, when enum is used as an expression, qualified name is not given. It was strange that the compilation passed when there were two or more same constants, so I checked it. First of all, no modification is required, so you can use it as it is without worrying about it.

When there is one enum

Suppose you have an enum like this.

FoodType.java

public enum FoodType {
    RICE,
    BREAD,
    OTHER,
}

Main.java

import lombok.AllArgsConstructor;

public class Main {
    public static void main(String[] args) {
        Food food = new Food(FoodType.RICE);
        switch (food.foodType){
        case RICE:
            System.out.println("Solder");
            break;
        case BREAD:
            System.out.println("It's bread");
            break;

        default:
            System.out.println("Other");
            break;
        }
    }
}

@AllArgsConstructor
class Food {
    FoodType foodType;
}

On the Main side, the enum (FoodType) is branched by the switch statement. In this case, write the case as RICE instead of FoodType.RICE. (Why RICE is good will be explained later.)

When there are two enums

Let's add an enum to the code above. Suppose you want to subdivide the rice category.

RiceType

public enum RiceType {
    RICE,
    FriedRice,
}

Main also changed.

Main.java

import lombok.AllArgsConstructor;

public class Main {
    public static void main(String[] args) {
        Food food = new Food(FoodType.RICE,RiceType.RICE);
        switch (food.foodType){
            case RICE:
                switch (food.riceType){
                    case RICE:
                        System.out.println("Solder");
                        break;
                    case FriedRice:
                        System.out.println("It's fried rice");
                        break;
                }
                break;
            case BREAD:
                System.out.println("It's bread");
                break;

            default:
                System.out.println("Other");
                break;
        }
    }
}
@AllArgsConstructor
class Food {
    FoodType foodType;
    RiceType riceType;
}

Why names don't collide

The above code will compile. This is correct code, but I was wondering if case RICE: and case RICE: would compile without conflict in the following parts of Main: Also, import is not used because all the code is included.

      switch (food.foodType){
            case RICE:
                switch (food.riceType){
                    case RICE:　

Qualifies at compile time

Upon examination, the class names are now qualified at compile time, so the names don't seem to conflict. It's a bit old, but you can see the result of decompiling enums in the "Implementing a switch" section of the following site. http://www.ne.jp/asahi/hishidama/home/tech/java/enum.html#h2_switch

Summary

It was a mechanism that was qualified at compile time.