的NoSuchMethodError當方法存在明顯

20:15:43 [INFO] macintosh264 issued server command: /sell hand 
20:15:43 [INFO] [XYZShop] MacCommand sell executed 
20:15:43 [SEVERE] null 
org.bukkit.command.CommandException: Unhandled exception executing command 'sell' in plugin XYZShop v0.1.3 
     at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) 
     at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:186) 
     at org.bukkit.craftbukkit.v1_4_6.CraftServer.dispatchCommand(CraftServer.java:510) 
     at net.minecraft.server.v1_4_6.PlayerConnection.handleCommand(PlayerConnection.java:979) 
     at net.minecraft.server.v1_4_6.PlayerConnection.chat(PlayerConnection.java:897) 
     at net.minecraft.server.v1_4_6.PlayerConnection.a(PlayerConnection.java:852) 
     at net.minecraft.server.v1_4_6.Packet3Chat.handle(Packet3Chat.java:44) 
     at net.minecraft.server.v1_4_6.NetworkManager.b(NetworkManager.java:290) 
     at net.minecraft.server.v1_4_6.PlayerConnection.d(PlayerConnection.java:112) 
     at net.minecraft.server.v1_4_6.ServerConnection.b(SourceFile:39) 
     at net.minecraft.server.v1_4_6.DedicatedServerConnection.b(SourceFile:30) 
     at net.minecraft.server.v1_4_6.MinecraftServer.r(MinecraftServer.java:598) 
     at net.minecraft.server.v1_4_6.DedicatedServer.r(DedicatedServer.java:224) 
     at net.minecraft.server.v1_4_6.MinecraftServer.q(MinecraftServer.java:494) 
     at net.minecraft.server.v1_4_6.MinecraftServer.run(MinecraftServer.java:427) 
     at net.minecraft.server.v1_4_6.ThreadServerApplication.run(SourceFile:849) 
Caused by: java.lang.NoSuchMethodError: dev.xyzcraft.net.database.DatabaseHandler.getItem(IS)Ldev/xyzcraft/net/xyzshop/dataObject/MSItem; 
     at dev.xyzcraft.net.xyzshop.commands.SellCommand.onCommand(SellCommand.java:63) 
     at dev.xyzcraft.net.xyzshop.util.MacCommand.onCommand(MacCommand.java:44) 
     at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) 
     ... 15 more

我得到異常的NoSuchMethodError當方法存在明顯

下面的代碼： https://github.com/macintosh264/XYZShop

最後，我使用的是國防部API的流行的視頻遊戲，我的世界，題爲Bukkit。這裏的JavaDoc和庫

http://dl.bukkit.org/downloads/bukkit/

http://jd.bukkit.org

「我也有這個問題與使用MySQL的另一個項目，並出現堆棧跟蹤每次使用MySQL的類。」