add itemstack serialization

src/main/java/com/songoda/core/utils/ItemSerializer.java

@@ -0,0 +1,72 @@
+package com.songoda.core.utils;
+
+import org.bukkit.inventory.ItemStack;
+import org.bukkit.util.io.BukkitObjectInputStream;
+import org.bukkit.util.io.BukkitObjectOutputStream;
+import org.yaml.snakeyaml.external.biz.base64Coder.Base64Coder;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Class based off of https://gist.github.com/graywolf336/8153678
+ */
+public class ItemSerializer {
+
+    /**
+     * A method to serialize an {@link ItemStack} list to Base64 String.
+     *
+     * @param items to turn into a Base64 String.
+     * @return Base64 string of the items.
+     */
+    public static String toBase64(List<ItemStack> items) {
+        try {
+            ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+            BukkitObjectOutputStream dataOutput = new BukkitObjectOutputStream(outputStream);
+
+            // Write the size of the inventory
+            dataOutput.writeInt(items.size());
+
+            // Save every element in the list
+            for (ItemStack item : items)
+                dataOutput.writeObject(item);
+
+            // Serialize that array
+            dataOutput.close();
+            return Base64Coder.encodeLines(outputStream.toByteArray());
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+
+        return null;
+    }
+
+    /**
+     * Gets a list of ItemStacks from Base64 string.
+     *
+     * @param data Base64 string to convert to ItemStack list.
+     * @return ItemStack array created from the Base64 string.
+     */
+    public static List<ItemStack> fromBase64(String data) {
+        try {
+            ByteArrayInputStream inputStream = new ByteArrayInputStream(Base64Coder.decodeLines(data));
+            BukkitObjectInputStream dataInput = new BukkitObjectInputStream(inputStream);
+            int length = dataInput.readInt();
+            List<ItemStack> items = new ArrayList<>();
+
+            // Read the serialized itemstack list
+            for (int i = 0; i < length; i++)
+                items.add((ItemStack) dataInput.readObject());
+
+            dataInput.close();
+            return items;
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+
+        return null;
+    }
+
+}