问当方法明显存在时，NoSuchMethodError

EN

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