some simplifications and code cleanup

README.md

@@ -1 +1,3 @@
 # supermarket
+
+this is one of my solutions for ["Back to the checkout code cata"](http://codekata.com/kata/kata09-back-to-the-checkout/)

pom.xml

@@ -13,19 +13,24 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
-                <version>3.2</version>
+                <version>3.6.1</version>
                 <configuration>
-                    <source>1.7</source>
+                    <source>1.8</source>
-                    <target>1.7</target>
+                    <target>1.8</target>
                 </configuration>
             </plugin>
         </plugins>
     </build>
     <dependencies>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-text</artifactId>
+            <version>1.0</version>
+        </dependency>
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
-            <version>4.11</version>
+            <version>4.12</version>
             <scope>test</scope>
         </dependency>
     </dependencies>

src/main/java/de/dj_steam/CheckOut.java

@@ -1,6 +1,10 @@
 package de.dj_steam;
 
-import de.dj_steam.strategy.*;
+import de.dj_steam.strategy.AStrategy;
+import de.dj_steam.strategy.BStrategy;
+import de.dj_steam.strategy.CStrategy;
+import de.dj_steam.strategy.DStrategy;
+import de.dj_steam.strategy.PriceCalculator;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -8,12 +12,12 @@ import java.util.List;
 /**
  * Created by steam on 24.02.15.
  */
-public class CheckOut {
+class CheckOut {
 
     private String bucket = "";
-    private List<PricingStrategy> strategies;
+    private List<PriceCalculator> strategies;
 
-    public CheckOut(){
+    CheckOut() {
         initPriceStrategies();
     }
 
@@ -28,28 +32,28 @@ public class CheckOut {
         strategies.add(new DStrategy());
     }
 
-    public int scan(char product){
+    int scan(char product) {
         putIntoBucket(product);
         return updateTotalPrice();
     }
 
-    public int calculatePriceForBucket(String products){
+    int calculatePriceForBucket(String products) {
         int total = 0;
         this.bucket = products;
         PriceContext context = new PriceContext();
 
-        for(PricingStrategy strategy : strategies){
+        for (PriceCalculator strategy : strategies) {
             context.setStrategy(strategy, bucket);
             total += context.calculatePriceForProduct();
         }
         return total;
     }
 
-    private void putIntoBucket(char product){
+    private void putIntoBucket(char product) {
         bucket += product;
     }
 
-    private int updateTotalPrice(){
+    private int updateTotalPrice() {
         return calculatePriceForBucket(bucket);
     }
 }

src/main/java/de/dj_steam/PriceContext.java

@@ -1,20 +1,20 @@
 package de.dj_steam;
 
-import de.dj_steam.strategy.PricingStrategy;
+import de.dj_steam.strategy.PriceCalculator;
 
 /**
  * Created by steam on 24.02.15.
  */
-public class PriceContext {
+class PriceContext {
-    private PricingStrategy strategy = null;
+    private PriceCalculator strategy = null;
     private String bucket = "";
 
-    public void setStrategy(final PricingStrategy strategy, String bucket){
+    void setStrategy(final PriceCalculator strategy, final String bucket){
         this.strategy = strategy;
         this.bucket = bucket;
     }
 
-    public int calculatePriceForProduct() {
+    int calculatePriceForProduct() {
         if (strategy != null){
             return strategy.calculatePrice(bucket);
         }

src/main/java/de/dj_steam/strategy/AStrategy.java

@@ -3,7 +3,7 @@ package de.dj_steam.strategy;
 /**
  * Created by steam on 24.02.15.
  */
-public class AStrategy extends AbstractPricingStrategy implements PricingStrategy {
+public class AStrategy extends PricingStrategy implements  PriceCalculator {
 
     private static final char PRODUCT_ID = 'A';
     private static final int PRICE = 50;
@@ -12,9 +12,8 @@ public class AStrategy extends AbstractPricingStrategy implements PricingStrateg
 
 
     @Override
-    public int calculatePrice(String products) {
+    public int calculatePrice(final String bucket) {
-        int productsNumber = calculateNumberOfProductsForType(products, PRODUCT_ID);
+        return calculatePriceForGivenProduct(bucket, PRODUCT_ID, PRICE, PRICE_THRESHOLD, DISCOUNT);
-        return calculatePriceForAllProducts(productsNumber, PRICE, PRICE_THRESHOLD, DISCOUNT);
     }
 }
 

src/main/java/de/dj_steam/strategy/AbstractPricingStrategy.java

@@ -1,27 +0,0 @@
-package de.dj_steam.strategy;
-
-/**
- * Created by steam on 24.02.15.
- */
-public class AbstractPricingStrategy {
-
-    protected int calculateNumberOfProductsForType(String products, char product) {
-        int numberOfProducts = 0;
-        for (int i = 0; i < products.length(); i++) {
-            if (products.charAt(i) == product) {
-                numberOfProducts++;
-            }
-        }
-        return numberOfProducts;
-    }
-
-    protected int calculatePriceForAllProducts(int numberOfProducts, int price, int priceThreshold, int discount) {
-        if (priceThreshold > 0) {
-            int remainder = numberOfProducts % priceThreshold;
-            int triples = numberOfProducts / priceThreshold;
-            return (triples * discount) + (remainder * price);
-        } else {
-            return numberOfProducts * price;
-        }
-    }
-}

src/main/java/de/dj_steam/strategy/BStrategy.java

@@ -3,7 +3,7 @@ package de.dj_steam.strategy;
 /**
  * Created by steam on 24.02.15.
  */
-public class BStrategy extends AbstractPricingStrategy implements PricingStrategy {
+public class BStrategy extends PricingStrategy implements PriceCalculator{
 
     private static final char PRODUCT_ID = 'B';
     private static final int PRICE = 30;
@@ -11,8 +11,7 @@ public class BStrategy extends AbstractPricingStrategy implements PricingStrateg
     private static final int DISCOUNT = 45;
 
     @Override
-    public int calculatePrice(String products) {
+    public int calculatePrice(final String bucket) {
-        int productsNumber = calculateNumberOfProductsForType(products, PRODUCT_ID);
+        return calculatePriceForGivenProduct(bucket, PRODUCT_ID, PRICE, PRICE_THRESHOLD, DISCOUNT);
-        return calculatePriceForAllProducts(productsNumber, PRICE, PRICE_THRESHOLD, DISCOUNT);
     }
 }

src/main/java/de/dj_steam/strategy/CStrategy.java

@@ -3,7 +3,7 @@ package de.dj_steam.strategy;
 /**
  * Created by steam on 24.02.15.
  */
-public class CStrategy extends AbstractPricingStrategy implements PricingStrategy {
+public class CStrategy extends PricingStrategy implements PriceCalculator {
 
     private static final char PRODUCT_ID = 'C';
     private static final int PRICE = 20;
@@ -12,8 +12,7 @@ public class CStrategy extends AbstractPricingStrategy implements PricingStrateg
 
 
     @Override
-    public int calculatePrice(String products) {
+    public int calculatePrice(final String bucket) {
-        int productsNumber = calculateNumberOfProductsForType(products, PRODUCT_ID);
+        return calculatePriceForGivenProduct(bucket, PRODUCT_ID, PRICE, PRICE_THRESHOLD, DISCOUNT);
-        return calculatePriceForAllProducts(productsNumber, PRICE, PRICE_THRESHOLD, DISCOUNT);
     }
 }

src/main/java/de/dj_steam/strategy/DStrategy.java

@@ -3,7 +3,7 @@ package de.dj_steam.strategy;
 /**
  * Created by steam on 24.02.15.
  */
-public class DStrategy extends AbstractPricingStrategy implements PricingStrategy {
+public class DStrategy extends PricingStrategy implements PriceCalculator {
 
     private static final char PRODUCT_ID = 'D';
     private static final int PRICE = 15;
@@ -11,8 +11,7 @@ public class DStrategy extends AbstractPricingStrategy implements PricingStrateg
     private static final int DISCOUNT = 0;
 
     @Override
-    public int calculatePrice(String products) {
+    public int calculatePrice(final String bucket) {
-        int productsNumber = calculateNumberOfProductsForType(products, PRODUCT_ID);
+        return calculatePriceForGivenProduct(bucket, PRODUCT_ID, PRICE, PRICE_THRESHOLD, DISCOUNT);
-        return calculatePriceForAllProducts(productsNumber, PRICE, PRICE_THRESHOLD, DISCOUNT);
     }
 }

src/main/java/de/dj_steam/strategy/PriceCalculator.java

@@ -0,0 +1,8 @@
+package de.dj_steam.strategy;
+
+/**
+ * Created by steam on 24.02.15.
+ */
+public interface PriceCalculator {
+    int calculatePrice(String bucket);
+}

src/main/java/de/dj_steam/strategy/PricingStrategy.java

@@ -1,8 +1,28 @@
 package de.dj_steam.strategy;
 
+import org.apache.commons.lang3.StringUtils;
+
 /**
  * Created by steam on 24.02.15.
  */
-public interface PricingStrategy {
+class PricingStrategy {
-    public int calculatePrice(String products);
+
+    int calculatePriceForGivenProduct( final String bucket, final char productId, final int productPrice, final int priceThreshold, final int discount){
+        int productsNumber = calculateNumberOfProductsForType(bucket, productId);
+        return calculatePriceForAllProducts(productsNumber, productPrice, priceThreshold, discount);
+    }
+
+   private int calculateNumberOfProductsForType(final String products, final char product) {
+        return StringUtils.countMatches(products, product);
+    }
+
+    private int calculatePriceForAllProducts(final int numberOfProducts, final int price, final int priceThreshold, final int discount) {
+        if (priceThreshold > 0) {
+            int remainder = numberOfProducts % priceThreshold;
+            int triples = numberOfProducts / priceThreshold;
+            return (triples * discount) + (remainder * price);
+        } else {
+            return numberOfProducts * price;
+        }
+    }
 }