Improving CalculatorDevops

devops_calculator.iml

@@ -0,0 +1,50 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module org.jetbrains.idea.maven.project.MavenProjectsManager.isMavenModule="true" type="JAVA_MODULE" version="4">
+  <component name="EclipseModuleManager">
+    <conelement value="org.eclipse.m2e.MAVEN2_CLASSPATH_CONTAINER" />
+    <src_description expected_position="0">
+      <src_folder value="file://$MODULE_DIR$/src/main/java" expected_position="0" />
+      <src_folder value="file://$MODULE_DIR$/src/test/java" expected_position="1" />
+    </src_description>
+  </component>
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_8">
+    <output url="file://$MODULE_DIR$/${project.build.directory}/classes" />
+    <output-test url="file://$MODULE_DIR$/${project.build.directory}/test-classes" />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src/main/java" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/java" isTestSource="true" />
+      <excludeFolder url="file://$MODULE_DIR$/${project.build.directory}/classes" />
+      <excludeFolder url="file://$MODULE_DIR$/${project.build.directory}/test-classes" />
+      <excludeFolder url="file://$MODULE_DIR$/target" />
+    </content>
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="jdk" jdkName="JavaSE-1.8" jdkType="JavaSDK" />
+    <orderEntry type="library" name="org.eclipse.m2e.MAVEN2_CLASSPATH_CONTAINER" level="application" />
+    <orderEntry type="module-library">
+      <library name="JUnit4">
+        <CLASSES>
+          <root url="jar://$MAVEN_REPOSITORY$/junit/junit/4.13.1/junit-4.13.1.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/hamcrest/hamcrest-core/1.3/hamcrest-core-1.3.jar!/" />
+        </CLASSES>
+        <JAVADOC />
+        <SOURCES />
+      </library>
+    </orderEntry>
+    <orderEntry type="module-library">
+      <library name="JUnit5.7.0">
+        <CLASSES>
+          <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter/5.7.0/junit-jupiter-5.7.0.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-api/5.7.0/junit-jupiter-api-5.7.0.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/apiguardian/apiguardian-api/1.1.0/apiguardian-api-1.1.0.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/opentest4j/opentest4j/1.2.0/opentest4j-1.2.0.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-commons/1.7.0/junit-platform-commons-1.7.0.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-params/5.7.0/junit-jupiter-params-5.7.0.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/junit/jupiter/junit-jupiter-engine/5.7.0/junit-jupiter-engine-5.7.0.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/junit/platform/junit-platform-engine/1.7.0/junit-platform-engine-1.7.0.jar!/" />
+        </CLASSES>
+        <JAVADOC />
+        <SOURCES />
+      </library>
+    </orderEntry>
+  </component>
+</module>

src/main/java/calculator/Addition.java

@@ -0,0 +1,29 @@
+package calculator;
+
+import java.text.DecimalFormat;
+
+/**
+ * The <code>Addition</code> class represents the operation of addition.
+ */
+public class Addition extends BinaryOperation {
+
+    public Addition() {
+        this.name = "Addition";
+        this.operator = "+";
+    }
+
+    public Addition(double a, double b) {
+        this();
+        this.firstOperand = a;
+        this.secondOperand = b;
+    }
+
+    public double perform() {
+        return this.firstOperand + this.secondOperand;
+    }
+
+    public String showExpression() {
+        return simplifyNumber(this.firstOperand) + " + " + (this.secondOperand < 0? "(": "") + simplifyNumber(this.secondOperand) + (this.secondOperand < 0? ")": "");
+    }
+
+}

src/main/java/calculator/App.java

@@ -2,57 +2,103 @@
 import java.util.*;
 public class App
 {
-    public static void main(String args[])
+    public static void main(String[] args)
     {
-        int choice, flag=0;
-        double num1,num2;
-        Scanner scan = new Scanner(System.in);
+        Calculator calculator = new Calculator();
+
+        int choice;
+        boolean validInput;
+        double num1 = 0, num2 = 0;
         System.out.println("Calculator");
+
         do {
-            System.out.println("1 for Addition\n2 for Subtraction\n3 for Multiplication\n4 for Division\n");
-            System.out.print("Enter your choice: ");
-            choice = scan.nextInt();
-            if (choice > 4 || choice <1) {
-                flag = 1;
-                System.out.println("Invalid choice, exiting\n");
+            // Choose an action
+            choice = calculator.chooseAction();
+
+            if (choice == 0) {
+                System.out.println("Exiting, Bye");
+                return;
             }
-            else if (flag != 1){
-            	 System.out.println("Enter two numbers");
-                 System.out.print("Enter number 1: ");
-                 num1 = scan.nextDouble();
-                 System.out.print("Enter number 2: ");
-                 num2 = scan.nextDouble();
-
-                 switch(choice) {
-                 case 1: System.out.println(num1+" + "+num2+" = "+Add(num1, num2));
-                 		break;
-                 case 2: System.out.println(num1+" - "+num2+" = "+Subtract(num1, num2));
-                 		break;
-                 case 3: System.out.println(num1+" * "+num2+" = "+Multiply(num1, num2));
-                 		break;
-                 case 4: System.out.println(num1+" / "+num2+" = "+Divide(num1, num2));
-                		break;
-                default: System.out.println("Exiting, Bye");
-                flag=1;
+
+            Operation chosenOperation = calculator.getOperations().get(choice - 1);
+            System.out.println(chosenOperation.getName());
+            Scanner scan = new Scanner(System.in).useLocale(Locale.US);
+
+            // Scan operand(s) of the chosen operation
+
+            // BINARY OPERATIONS (+, -, *, /)
+            if (chosenOperation instanceof BinaryOperation) {
+                System.out.println("Enter two numbers");
+
+                // first operand
+                validInput = false;
+                while (!validInput) {
+                    try {
+                        System.out.print("Enter number 1: ");
+                        num1 = scan.nextDouble();
+                    } catch (Exception e) {
+                        System.out.println("Invalid number, please try again.");
+                        scan.nextLine();
+                        continue;
+                    }
+                    validInput = true;
+                }
+
+                // second operand
+                validInput = false;
+                while (!validInput) {
+                    try {
+                        System.out.print("Enter number 2: ");
+                        num2 = scan.nextDouble();
+                    } catch (Exception e) {
+                        System.out.println("Invalid number, please try again.");
+                        scan.nextLine();
+                        continue;
+                    }
+                    validInput = true;
                 }
             }
-            System.out.println("\n");
-            }while(flag==0);
-    }
-
-    static double Add(double a, double b) {
-    	return a + b;
-    }
-    static double Subtract(double a, double b) {
-    	return a - b;
-    }
-    static double Multiply(double a, double b) {
-    	return a * b;
-    }
-    static double Divide(double a, double b) {
-    	if (b == 0) {
-    		throw new IllegalArgumentException("Divisor cannot be zero, Exiting");
-    	}
-    	else return a / b;
+
+            // UNARY OPERATIONS (sin, cos, tan, sqrt, exp)
+            if (chosenOperation instanceof UnaryOperation) {
+                validInput = false;
+                while (!validInput) {
+                    try {
+                        System.out.print("Enter number" + ((chosenOperation instanceof TrigonometricOperation)? " (in radians)": "") + ": ");
+                        num1 = scan.nextDouble();
+                    } catch (Exception e) {
+                        System.out.println("Invalid number, please try again.");
+                        scan.nextLine();
+                        continue;
+                    }
+                    validInput = true;
+                }
+            }
+
+            // Set operand(s) to the chosen operation,
+            // perform the operation and
+            // print the results.
+
+            double result;
+            chosenOperation = calculator.getOperations().get(choice - 1);
+            if (chosenOperation instanceof UnaryOperation) {
+                ((UnaryOperation) chosenOperation).setOperand(num1);
+
+                result = chosenOperation.perform();
+
+                System.out.println(chosenOperation.showExpression() + " = " + chosenOperation.simplifyNumber(result));
+
+            } else if (chosenOperation instanceof BinaryOperation) {
+                ((BinaryOperation) chosenOperation).setFirstOperand(num1);
+                ((BinaryOperation) chosenOperation).setSecondOperand(num2);
+
+                result = chosenOperation.perform();
+
+                System.out.println(chosenOperation.showExpression() + " = " + chosenOperation.simplifyNumber(result));
+            }
+
+        } while (choice != 0);
+
     }
-}
+
+}

src/main/java/calculator/BinaryOperation.java

@@ -0,0 +1,26 @@
+package calculator;
+
+/**
+ * The <code>BinaryOperation</code> class represents a binary operation.
+ */
+abstract public class BinaryOperation extends Operation {
+    protected double firstOperand;
+    protected double secondOperand;
+
+    public double getFirstOperand() {
+        return firstOperand;
+    }
+
+    public void setFirstOperand(double firstOperand) {
+        this.firstOperand = firstOperand;
+    }
+
+    public double getSecondOperand() {
+        return secondOperand;
+    }
+
+    public void setSecondOperand(double secondOperand) {
+        this.secondOperand = secondOperand;
+    }
+
+}