Added configurable item spawn delay after join

This might fix the issue, that items won't be spawned after joining.

src/main/java/de/epiceric/shopchest/ShopChest.java

@@ -288,8 +288,6 @@ public class ShopChest extends JavaPlugin {
             debug(e);
         }
 
-        initializeShops();
-
         debug("Registering listeners...");
         getServer().getPluginManager().registerEvents(new HologramUpdateListener(this), this);
         getServer().getPluginManager().registerEvents(new ShopItemListener(this), this);
@@ -300,6 +298,7 @@ public class ShopChest extends JavaPlugin {
         if (!Utils.getServerVersion().equals("v1_8_R1"))
             getServer().getPluginManager().registerEvents(new BlockExplodeListener(this), this);
 
+        initializeShops();
     }
 
     @Override

src/main/java/de/epiceric/shopchest/config/Config.java

@@ -106,6 +106,9 @@ public class Config {
     /** Whether the item amount should be calculated to fit the available money or inventory space **/
     public boolean auto_calculate_item_amount;
 
+    /** Delay in ticks after a player joins, when the shop item spawn packets should be sent to the player **/
+    public long item_spawn_delay;
+
     /** Amount the hologram should be lifted **/
     public double two_line_hologram_lift;
 
@@ -283,6 +286,7 @@ public class Config {
         shopLimits_group = (plugin.getConfig().getConfigurationSection("shop-limits.group") == null) ? new HashSet<String>() : plugin.getConfig().getConfigurationSection("shop-limits.group").getKeys(true);
         shopLimits_player = (plugin.getConfig().getConfigurationSection("shop-limits.player") == null) ? new HashSet<String>() : plugin.getConfig().getConfigurationSection("shop-limits.player").getKeys(true);
         blacklist = (plugin.getConfig().getStringList("blacklist") == null) ? new ArrayList<String>() : plugin.getConfig().getStringList("blacklist");
+        item_spawn_delay = plugin.getConfig().getLong("item-spawn-delay");
         buy_greater_or_equal_sell = plugin.getConfig().getBoolean("buy-greater-or-equal-sell");
         hopper_protection = plugin.getConfig().getBoolean("hopper-protection");
         two_line_prices = plugin.getConfig().getBoolean("two-line-prices");

src/main/java/de/epiceric/shopchest/listeners/ShopItemListener.java

@@ -15,8 +15,6 @@ import org.bukkit.event.Listener;
 import org.bukkit.event.block.*;
 import org.bukkit.event.player.*;
 
-import java.lang.reflect.InvocationTargetException;
-
 public class ShopItemListener implements Listener {
 
     private ShopUtils shopUtils;
@@ -27,12 +25,21 @@ public class ShopItemListener implements Listener {
         this.shopUtils = plugin.getShopUtils();
     }
 
-    @EventHandler
-    public void onPlayerJoin(PlayerJoinEvent e) {
+    @EventHandler(priority = EventPriority.MONITOR)
+    public void onPlayerJoin(final PlayerJoinEvent e) {
+        long spawnDelay = plugin.getShopChestConfig().item_spawn_delay;
+
+        if (spawnDelay > 0) {
+            Bukkit.getScheduler().runTaskLater(plugin, new Runnable() {
+                @Override
+                public void run() {
                     for (Shop shop : plugin.getShopUtils().getShops()) {
                         shop.getItem().setVisible(e.getPlayer(), true);
                     }
                 }
+            }, spawnDelay);
+        }
+    }
 
     @EventHandler
     public void onPlayerLeave(PlayerQuitEvent e) {

src/main/java/de/epiceric/shopchest/utils/Utils.java

@@ -196,8 +196,10 @@ public class Utils {
      */
     public static boolean sendPacket(ShopChest plugin, Object packet, Player player) {
         try {
-            if (packet == null)
+            if (packet == null) {
+                plugin.debug("Failed to send packet: Packet is null");
                 return false;
+            }
 
             Class<?> packetClass = Class.forName("net.minecraft.server." + getServerVersion() + ".Packet");
             Object nmsPlayer = player.getClass().getMethod("getHandle").invoke(player);

src/main/resources/config.yml

@@ -18,6 +18,12 @@ show-shop-items: true
 # The file may get large! Please enable this setting when reporting bugs.
 enable-debug-log: false
 
+# Set the delay in ticks (20 ticks = 1 second) after a player joins, when the spawn packets of the
+# floating shop item should be sent to the player. If you experience errors, that the items won't spawn
+# after joining, you may increase this value a bit. You can also set this to '0' to send the packets
+# without a delay after joining.
+item-spawn-delay: 20
+
 # Set whether the buy- and sell price should be arranged below each other.
 # The first line will be the buy price with the message "message.hologram.only-buy",
 # the second line will be the sell price with the message "message.hologram.only-sell".