Template method initialized in order to update items respectively. Each item's quality and sellIn can be updated in a different manner

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

@@ -0,0 +1,15 @@
+package com.gildedrose;
+
+public class AgedBrieUpdater extends ItemUpdater {
+    @Override
+    void updateQuality(Item item) {
+        if (item.quality < 50) {
+            item.quality += 1;
+        }
+    }
+
+    @Override
+    void updateSellIn(Item item) {
+        item.sellIn -=1;
+    }
+}

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

@@ -0,0 +1,25 @@
+package com.gildedrose;
+
+public class BackstagePassUpdater extends ItemUpdater {
+    @Override
+    void updateQuality(Item item) {
+        if (item.sellIn < 0) {
+            item.quality = 0;
+        } else if (item.quality < 50) {
+            item.quality += 1;
+
+            if (item.sellIn < 11 && item.quality < 50) {
+                item.quality += 1;
+            }
+
+            if (item.sellIn < 6 && item.quality < 50) {
+                item.quality += 1;
+            }
+        }
+    }
+
+    @Override
+    void updateSellIn(Item item) {
+        item.sellIn -=1;
+    }
+}

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

@@ -0,0 +1,17 @@
+package com.gildedrose;
+
+public class ConjuredUpdater extends ItemUpdater {
+    @Override
+    void updateQuality(Item item) {
+        if (item.quality > 0) {
+            item.quality -= 2;
+            if (item.quality < 0 )
+                item.quality =0;
+        }
+    }
+
+    @Override
+    void updateSellIn(Item item) {
+        item.sellIn -= 1;
+    }
+}

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

@@ -0,0 +1,16 @@
+package com.gildedrose;
+
+class GildedRosePrototype {
+    Item[] items;
+
+    public GildedRosePrototype(Item[] items) {
+        this.items = items;
+    }
+
+    public void updateQuality() {
+        for (Item item : items) {
+            ItemUpdaterFactory.getItemUpdater(item)
+                    .updateStateFor(item);
+        }
+    }
+}

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

@@ -0,0 +1,10 @@
+package com.gildedrose;
+
+public abstract class ItemUpdater {
+    public void updateStateFor(Item item){
+        updateSellIn(item);
+        updateQuality(item);
+    }
+    abstract void updateQuality(Item item);
+    abstract void updateSellIn(Item item);
+}

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

@@ -0,0 +1,38 @@
+package com.gildedrose;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+
+public class ItemUpdaterFactory {
+
+    private static final Map<String, ItemUpdater> registeredCustomUpdaters = new HashMap<>();
+    static {
+        registeredCustomUpdaters.put("Aged Brie", new AgedBrieUpdater());
+        registeredCustomUpdaters.put("Backstage passes to a TAFKAL80ETC concert", new BackstagePassUpdater());
+        registeredCustomUpdaters.put("Sulfuras, Hand of Ragnaros", new SulfurasUpdater());
+        registeredCustomUpdaters.put("Conjured", new ConjuredUpdater());
+    }
+
+    public static void registerCustomUpdater(String type, ItemUpdater updater ){
+        registeredCustomUpdaters.put(type, updater);
+    }
+
+    public static ItemUpdater getItemUpdater(Item item) {
+        return Optional.ofNullable(registeredCustomUpdaters.get(item.name))
+                .orElse(new StandardItemUpdater());
+    }
+
+    /*public static ItemUpdater getItemUpdater_(Item item) {
+        if ("Aged Brie".equals(item.name))
+            return new AgedBrieUpdater();
+        else if ("Backstage passes to a TAFKAL80ETC concert".equals(item.name))
+            return new BackstagePassUpdater();
+        else if ("Sulfuras, Hand of Ragnaros".equals(item.name))
+            return new SulfurasUpdater();
+        else if ("Conjured".equals(item.name))
+            return new ConjuredUpdater();
+        else
+            return new StandardItemUpdater();
+    }*/
+}

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

@@ -0,0 +1,16 @@
+package com.gildedrose;
+
+public class StandardItemUpdater extends ItemUpdater{
+
+    @Override
+    void updateQuality(Item item) {
+        if (item.quality > 0) {
+            item.quality  -= 1;
+        }
+    }
+
+    @Override
+    void updateSellIn(Item item) {
+        item.sellIn -= 1;
+    }
+}

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

@@ -0,0 +1,13 @@
+package com.gildedrose;
+
+public class SulfurasUpdater extends ItemUpdater {
+    @Override
+    void updateQuality(Item item) {
+        System.out.println("########Sulfuras is a legendary product");
+    }
+
+    @Override
+    void updateSellIn(Item item) {
+        System.out.println("########Never gets old");
+    }
+}

Java/src/test/java/com/gildedrose/TexttestFixture.java

@@ -13,6 +13,8 @@ public class TexttestFixture {
                 new Item("Backstage passes to a TAFKAL80ETC concert", 15, 20),
                 new Item("Backstage passes to a TAFKAL80ETC concert", 10, 49),
                 new Item("Backstage passes to a TAFKAL80ETC concert", 5, 49),
+                new Item("Backstage passes to a TAFKAL80ETC concert", 1, 30),
+                new Item("Backstage passes to a TAFKAL80ETC concert", 0, 30),
                 // this conjured item does not work properly yet
                 new Item("Conjured Mana Cake", 3, 6) };