feat: 계산하는 구현체 구현 및 테스트 통과

Author: wonu606

calculator/build/classes/java/main/com/wonu606/calculator/model/Operator.class

@@ -1,10 +1,14 @@
 package com.wonu606.calculator;
 
 import com.wonu606.app.App;
+import com.wonu606.calculator.calculator.PostfixCalculator;
+import com.wonu606.calculator.converter.InfixToPostfixConverter;
 import com.wonu606.calculator.storage.Persistence;
 import com.wonu606.calculator.storage.ResultStore;
+import com.wonu606.calculator.strategy.CalculationStrategy;
 import com.wonu606.calculator.strategy.CalculatorStrategy;
 import com.wonu606.calculator.util.CalculatorMessage;
+import com.wonu606.calculator.validator.InfixValidator;
 import com.wonu606.io.Input;
 import com.wonu606.io.Print;
 import java.util.HashMap;
@@ -20,7 +24,8 @@ public CalculatorApp() {
     }
 
     private void initStrategies() {
-        // TODO 조회와 계산 기능을 생성하여 추가해야 함
+        strategies.put("1", new CalculationStrategy(
+                new InfixValidator(), new InfixToPostfixConverter(), new PostfixCalculator()));
     }
 
     public void execute(Input input, Print printer) {

calculator/src/main/java/com/wonu606/calculator/CalculatorApp.java

@@ -0,0 +1,68 @@
+package com.wonu606.calculator.strategy;
+
+import com.wonu606.calculator.calculator.Calculator;
+import com.wonu606.calculator.converter.Converter;
+import com.wonu606.calculator.model.CalculationResult;
+import com.wonu606.calculator.storage.Persistence;
+import com.wonu606.calculator.util.CalculatorMessage;
+import com.wonu606.calculator.validator.Validator;
+import com.wonu606.io.Input;
+import com.wonu606.io.Print;
+import java.util.List;
+
+public class CalculationStrategy implements CalculatorStrategy {
+
+    Validator validator;
+    Converter<String, List<String>> converter;
+    Calculator calculator;
+
+    public CalculationStrategy(Validator validator, Converter<String, List<String>> converter,
+            Calculator calculator) {
+        this.validator = validator;
+        this.converter = converter;
+        this.calculator = calculator;
+    }
+
+    @Override
+    public void execute(Input input, Print printer, Persistence store) {
+        String inputExpression = input.getInput();
+        if (isNotValidExpression(inputExpression)) {
+            printer.print(CalculatorMessage.INVALID_INPUT.message);
+            return;
+        }
+
+        List<String> convertedExpression = converter.convert(inputExpression);
+        try {
+            double result = calculator.calculate(convertedExpression);
+
+            store.saveResult(new CalculationResult(inputExpression, result));
+            printCalculationResult(printer, result);
+        } catch (ArithmeticException exception) {
+            printer.print(exception.getMessage());
+        }
+    }
+
+    private static void printCalculationResult(Print printer, double result) {
+        String message = String.valueOf(roundResultToInt(result));
+        if (isResultOverflow(result)) {
+            message = CalculatorMessage.OVERFLOW_OCCURS.message;
+        }
+        printer.print(message);
+    }
+
+    private static int roundResultToInt(double result) {
+        return (int) Math.round(result);
+    }
+
+    private static boolean isResultOverflow(double result) {
+        return Double.isInfinite(result) || (isIntegerOverflow(result));
+    }
+
+    private static boolean isIntegerOverflow(double result) {
+        return result > Integer.MAX_VALUE;
+    }
+
+    private boolean isNotValidExpression(String inputExpression) {
+        return !validator.isValid(inputExpression);
+    }
+}