(강상문) StringCalculator 리뷰 요청드립니다.

src/main/java/calculator/CalculatorMain.java

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+package calculator;
+
+import calculator.controller.CalculatorController;
+import calculator.model.Operator;
+import calculator.util.FormulaParser;
+import calculator.view.InputView;
+import calculator.view.OutputView;
+
+
+public class CalculatorMain {
+    public static void main(String[] args) {
+        Operator operator = new Operator();
+        InputView inputView = new InputView();
+        OutputView outputView = new OutputView();
+        FormulaParser formulaParser = new FormulaParser();
+
+        CalculatorController controller = new CalculatorController(operator, inputView, outputView, formulaParser);
+        controller.calculatorRun();
+    }
+}

src/main/java/calculator/controller/CalculatorController.java

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+package calculator.controller;
+
+import calculator.model.Operator;
+import calculator.util.FormulaParser;
+import calculator.view.InputView;
+import calculator.view.OutputView;
+
+public class CalculatorController {
+    private final Operator operator;
+    private final InputView inputView;
+    private final OutputView outputView;
+    private final FormulaParser formulaParser;
+
+    public CalculatorController(Operator operator, InputView inputView, OutputView outputView, FormulaParser formulaParser) {
+        this.operator = operator;
+        this.inputView = inputView;
+        this.outputView = outputView;
+        this.formulaParser = formulaParser;
+    }
+
+    public void calculatorRun() {
+        String formula = inputView.formulaInput();
+        String[] values = formulaParser.parse(formula);
+        int result = operator.calculate(values);
+        outputView.resultOutput(result);
+    }
+}

src/main/java/calculator/model/Operator.java

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+package calculator.model;
+
+public class Operator {
+
+    public int calculate(String[] values) {
+        int result = Integer.parseInt(values[0]);
+
+        for (int i = 1; i < values.length; i += 2) {
+            String symbol = values[i];
+            int nextNumber = Integer.parseInt(values[i + 1]);
+            OperatorType operatorType = OperatorType.fromString(symbol);
+            result = operatorType.apply(result, nextNumber);
+        }
+
+        return result;
+    }
+}

src/main/java/calculator/model/OperatorType.java

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+package calculator.model;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.BiFunction;
+
+public enum OperatorType {
+    ADDITION("+", (a, b) -> a + b),
+    SUBTRACTION("-", (a, b) -> a - b),
+    MULTIPLICATION("*", (a, b) -> a * b),
+    DIVISION("/", (a, b) -> {
+        if (b == 0) {
+            throw new ArithmeticException("0으로 나눌 수 없습니다.");
+        }
+        return a / b;
+    });
+
+    private static final Map<String, OperatorType> SYMBOL_MAP = new HashMap<>();
+
+    static {
+        for (OperatorType type : values()) {
+            SYMBOL_MAP.put(type.symbol, type);
+        }
+    }
+
+    private final String symbol;
+    private final BiFunction<Integer, Integer, Integer> operation;
+
+    OperatorType(String symbol, BiFunction<Integer, Integer, Integer> operation) {
+        this.symbol = symbol;
+        this.operation = operation;
+    }
+
+    public static OperatorType fromString(String symbol) {
+        OperatorType type = SYMBOL_MAP.get(symbol);
+        if (type == null) {
+            throw new IllegalArgumentException("잘못된 연산자입니다.");
+        }
+        return type;
+    }
+
+    public int apply(int a, int b) {
+        return operation.apply(a, b);
+    }
+}

src/main/java/calculator/util/FormulaParser.java

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+package calculator.util;
+
+public class FormulaParser {
+    public String[] parse(String input) {
+        return input.split(" ");
+    }
+}

src/main/java/calculator/view/InputView.java

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+package calculator.view;
+
+import java.util.Scanner;
+
+public class InputView {
+    public String formulaInput() {
+        Scanner scanner = new Scanner(System.in);
+        System.out.print("수식을 입력하세요 : ");
+        return scanner.nextLine();
+    }
+}

src/main/java/calculator/view/OutputView.java

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+package calculator.view;
+
+public class OutputView {
+
+    public void resultOutput(int result) {
+        System.out.print("결과 : " + result);
+    }
+}