added multiplication, division. made tests to them and refactored the result to double. Exercise 8

src/main/java/resources/CalculatorResource.java

@@ -21,11 +21,11 @@ public class CalculatorResource {
     @POST
     @Consumes(MediaType.TEXT_PLAIN)
     @Produces(MediaType.TEXT_PLAIN)
-    public int calculate(String expression){
+    public double calculate(String expression){
         // Removes all whitespaces
         String expressionTrimmed = expression.replaceAll("\\s+","");
 
-        int result = -1;
+        double result = -1;
 
         /*
          * .matches use regex expression to decide if a String matches a given pattern.
@@ -37,8 +37,15 @@ public class CalculatorResource {
          * 1+2,
          * 10000+1000
          */
-        if(expressionTrimmed.matches("[0-9]+[+][0-9]+")) result = sum(expressionTrimmed);
-        else if(expressionTrimmed.matches("[0-9]+[-][0-9]+")) result = subtraction(expressionTrimmed);
+        if(expressionTrimmed.matches("[0-9]+[+][0-9]+[.]+")) {
+            result = sum(expressionTrimmed);
+        } else if(expressionTrimmed.matches("[0-9]+[-][0-9]+[.]+")) {
+            result = subtraction(expressionTrimmed);
+        } else if(expressionTrimmed.matches("[0-9]+[*][0-9]+[.]+")) {
+            result = multiplication(expressionTrimmed);
+        } else if(expressionTrimmed.matches("[0-9]+[/][0-9]+[.]+")) {
+            result = division(expressionTrimmed);
+        }
 
         return result;
     }
@@ -48,11 +55,11 @@ public class CalculatorResource {
      * @param expression the equation to be calculated as a String
      * @return the answer as an int
      */
-    public int sum(String expression){
+    public double sum(String expression){
         String[] split = expression.split("[+]");
 
-        int number1 = Integer.parseInt(split[0]);
-        int number2 = Integer.parseInt(split[1]);
+        double number1 = Double.parseDouble(split[0]);
+        double number2 = Double.parseDouble(split[1]);
 
         return number1 + number2;
     }
@@ -62,12 +69,38 @@ public class CalculatorResource {
      * @param expression the expression to be calculated as a String
      * @return the answer as an int
      */
-    public int subtraction(String expression){
+    public double subtraction(String expression){
         String[] split = expression.split("[-]");
 
-        int number1 = Integer.parseInt(split[0]);
-        int number2 = Integer.parseInt(split[1]);
+        double number1 = Double.parseDouble(split[0]);
+        double number2 = Double.parseDouble(split[1]);
 
         return number1 - number2;
     }
+    /**
+     * Method used to calculate a product expression.
+     * @param expression the expression to be calculated as a String
+     * @return the answer as an int
+     */
+    public double multiplication(String expression){
+        String[] split = expression.split("[*]");
+
+        double number1 = Double.parseDouble(split[0]);
+        double number2 = Double.parseDouble(split[1]);
+
+        return number1 * number2;
+    }
+    /**
+     * Method used to calculate a quotient expression.
+     * @param expression the expression to be calculated as a String
+     * @return the answer as an int
+     */
+    public double division(String expression){
+        String[] split = expression.split("[/]");
+
+        double number1 = Double.parseDouble(split[0]);
+        double number2 = Double.parseDouble(split[1]);
+
+        return number1 / number2;
+    }
 }

src/test/java/CalculatorResourceTest.java

@@ -38,4 +38,24 @@ public class CalculatorResourceTest{
         expression = "20-2";
         assertEquals(18, calculatorResource.subtraction(expression));
     }
+    @Test
+    public void testMultiplication(){
+        CalculatorResource calculatorResource = new CalculatorResource();
+
+        String expression = "999*100";
+        assertEquals(99900, calculatorResource.multiplication(expression));
+
+        expression = "9.9*2";
+        assertEquals(19.8, calculatorResource.multiplication(expression));
+    }
+    @Test
+    public void testDivision(){
+        CalculatorResource calculatorResource = new CalculatorResource();
+
+        String expression = "999/100";
+        assertEquals(9.99, calculatorResource.division(expression));
+
+        expression = "9.9/2";
+        assertEquals(4.95, calculatorResource.division(expression));
+    }
 }