commit 1

Java/src/main/java/com/gildedrose/AgedBrieItem.java

@@ -1,27 +1,22 @@
 package com.gildedrose;
 
-public class AgedBrieItem implements UpdatingItem {
-    private Item item;
+public class AgedBrieItem extends UpdateItem {
+    private final Item item;
 
     public AgedBrieItem(Item item) {
         this.item = item;
     }
 
     @Override
     public void updateQuality() {
-        if (item.sellIn > 0) {
-            item.quality += 1;
-            if (item.quality > 50) {
-                item.quality = 50;
-            }
-        } else {
-            item.quality += 2;
-            if (item.quality > 50) {
-                item.quality = 50;
-            }
+        increaseQuality(item);
+        if (item.sellIn < 0) {
+            increaseQuality(item);
         }
-        item.sellIn -= 1;
+        fixQuality(item);
+        decreaseSellIn(item);
     }
+
 }
 
 

Java/src/main/java/com/gildedrose/BackStageItem.java

@@ -1,6 +1,6 @@
 package com.gildedrose;
 
-public class BackStageItem implements UpdatingItem {
+public class BackStageItem extends UpdateItem {
     private Item item;
 
     public BackStageItem(Item item) {
@@ -9,20 +9,18 @@ public BackStageItem(Item item) {
 
     @Override
     public void updateQuality() {
+        increaseQuality(item);
+        if (item.sellIn <= 10) {
+            increaseQuality(item);
+        }
+        if (item.sellIn <= 5) {
+            increaseQuality(item);
+        }
         if (item.sellIn == 0) {
             item.quality = 0;
-        } else if (item.sellIn <= 5) {
-            item.quality += 3;
-            if (item.quality > 50) {
-                item.quality = 50;
-            }
-        } else if (item.sellIn <= 10) {
-            item.quality += 2;
-            if (item.quality > 50) {
-                item.quality = 50;
-            }
         }
-        item.sellIn -= 1;
+        fixQuality(item);
+        decreaseSellIn(item);
     }
 }
 

Java/src/main/java/com/gildedrose/CommonItem.java

@@ -1,6 +1,6 @@
 package com.gildedrose;
 
-public class CommonItem implements UpdatingItem {
+public class CommonItem extends UpdateItem {
 
     private Item item;
 
@@ -10,14 +10,11 @@ public CommonItem(Item item) {
 
     @Override
     public void updateQuality() {
-        if (item.quality > 0 && item.sellIn > 0) {
-            item.quality -= 1;
-        } else if (item.quality > 0 && item.sellIn < 0) {
-            item.quality -= 2;
-            if (item.quality < 0) {
-                item.quality = 0;
-            }
+        decreaseQuality(item);
+        if (item.sellIn < 0) {
+            decreaseQuality(item);
         }
-        item.sellIn -= 1;
+        fixQuality(item);
+        decreaseSellIn(item);
     }
 }

Java/src/main/java/com/gildedrose/ConjuredItem.java

@@ -1,6 +1,6 @@
 package com.gildedrose;
 
-public class ConjuredItem implements UpdatingItem {
+public class ConjuredItem extends UpdateItem {
     private Item item;
 
     public ConjuredItem(Item item) {
@@ -9,18 +9,12 @@ public ConjuredItem(Item item) {
 
     @Override
     public void updateQuality() {
-        if (item.sellIn > 0) {
-            item.quality -= 2;
-            if (item.quality < 0) {
-                item.quality = 0;
-            }
-        } else {
-            item.quality -= 4;
-            if (item.quality < 0) {
-                item.quality = 0;
-            }
+        doubleDecreaseQuality(item);
+        if (item.sellIn < 0) {
+            doubleDecreaseQuality(item);
         }
-        item.sellIn -= 1;
+        fixQuality(item);
+        decreaseSellIn(item);
     }
 }
 

Java/src/main/java/com/gildedrose/GildedRose.java

@@ -3,11 +3,11 @@
 class GildedRose {
     Item[] items;
 
-    UpdatingItem[] updatingItems;
+    UpdateItem[] updatingItems;
 
     public GildedRose(Item[] items) {
         this.items = items;
-        this.updatingItems = new UpdatingItem[items.length];
+        this.updatingItems = new UpdateItem[items.length];
         for (int i = 0; i < items.length; i++) {
             if (items[i].name.equals("Aged Brie")) {
                 updatingItems[i] = new AgedBrieItem(items[i]);
@@ -24,7 +24,7 @@ public GildedRose(Item[] items) {
     }
 
     public void updateQuality() {
-        for (UpdatingItem item : updatingItems) {
+        for (UpdateItem item : updatingItems) {
             item.updateQuality();
 
         }

Java/src/main/java/com/gildedrose/SulfurasItem.java

@@ -1,6 +1,6 @@
 package com.gildedrose;
 
-public class SulfurasItem implements UpdatingItem {
+public class SulfurasItem extends UpdateItem {
     private Item item;
 
     public SulfurasItem(Item item) {
@@ -9,7 +9,6 @@ public SulfurasItem(Item item) {
 
     @Override
     public void updateQuality() {
-
     }
 }
 

Java/src/main/java/com/gildedrose/UpdateItem.java

@@ -0,0 +1,30 @@
+package com.gildedrose;
+
+public abstract class UpdateItem {
+    protected void decreaseSellIn(Item item) {
+        item.sellIn -= 1;
+    }
+
+    protected void increaseQuality(Item item) {
+        item.quality += 1;
+    }
+
+    protected void decreaseQuality(Item item) {
+        item.quality -= 1;
+    }
+
+    protected void doubleDecreaseQuality(Item item) {
+        item.quality -= 2;
+    }
+
+    protected void fixQuality(Item item) {
+        if (item.quality > 50) {
+            item.quality = 50;
+        }
+        if (item.quality < 0) {
+            item.quality = 0;
+        }
+    }
+
+    protected abstract void updateQuality();
+}