[Refactor/next-step#1] Lotto, Lottery 불변 리스트구현

Author: borntocode2

src/main/java/model/Lotto.java

@@ -1,5 +1,6 @@
 package model;
 
+import java.util.Collections;
 import java.util.List;
 
 public class Lotto {
@@ -15,7 +16,7 @@ public Lotto(List<Integer> numbers) {
             throw new IllegalArgumentException("로또 번호 목록이 비어 있거나 null 입니다.");
         }
         validateNumbers(numbers);
-        this.numbers = numbers; // numbers를 초기화
+        this.numbers = Collections.unmodifiableList(numbers);
     }
 
     private void validateNumbers(List<Integer> numbers) {

src/main/java/model/LottoTicketMachine.java

@@ -1,11 +1,12 @@
 package model;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
 public class LottoTicketMachine {
 
-    private static final int LOTTO_TICKET_PRICE = 1000;
+    private static final int LOTTO_TICKET_PRICE = 1_000;
     private final int ticketCount;
     private final LottoGenerator lottoGenerator;
     private final List<Lotto> lottery = new ArrayList<>();
@@ -20,7 +21,7 @@ public List<Lotto> generateLottery() {
             lottery.add(lottoGenerator.generateLottoNumbers());
         }
 
-        return lottery;
+        return Collections.unmodifiableList(lottery);
     }
 
     public int getTicketCount() {

src/main/java/view/InputView.java

@@ -5,11 +5,11 @@
 
 public class InputView {
 
-    public int getPurchaseAmount() {
+    public int getPurchaseAmount(){
         try (Scanner scanner = new Scanner(System.in)) {
             System.out.println("구입금액을 입력해 주세요.");
             int purchaseAmount = scanner.nextInt();
-            validatePositive(purchaseAmount);
+            validatePurchaseAmount(purchaseAmount);
 
             return purchaseAmount;
         } catch (InputMismatchException e) {
@@ -19,9 +19,20 @@ public int getPurchaseAmount() {
         }
     }
 
-    private void validatePositive(int number) {
-        if (number < 0) {
+    private void validatePurchaseAmount(int number){
+        validatePositive(number);
+        validateMinimumPrice(number);
+    }
+
+    private void validatePositive(int number){
+        if (number < 0){
             throw new IllegalArgumentException("양수가 아닌 음수가 입력되어 예외가 발생되었습니다.");
         }
     }
+
+    private void validateMinimumPrice(int number){
+        if (number < 1000){
+            throw new IllegalArgumentException("로또의 최소 구입금액은 1000원 입니다.");
+        }
+    }
 }