Question

我有一个statement.executeQuery的问题。每次我打电话给我都会得到一个空指针异常，我真的不知道问题是什么。

这是我的GitHub Rep上的一行 GitHub Rep

这是Stacktrace

[21:16:53 INFO]：Xearox发出服务器命令：/ ecweb register Xearox 12345 org.bukkit.command.CommandException：插件xConomy v0.0.1中执行命令'ecweb'的未处理异常在org.bukkit.command.PluginCommand.execute（PluginCommand.java:46）〜[spigot-1.8.8.jar：git-Spigot-5f38d38-18fbb24] 在org.bukkit.command.SimpleCommandMap.dispatch（SimpleCommandMap.java:141）〜[spigot-1.8.8.jar：git-Spigot-5f38d38-18fbb24] 在org.bukkit.craftbukkit.v1_8_R3.CraftServer.dispatchCommand(CraftServer.java:641)~ [spigot-1.8.8.jar：git-Spigot-5f38d38-18fbb24] 在net.minecraft.server.v1_8_R3.PlayerConnection.handleCommand（PlayerConnection.java:1162）[spigot-1.8.8.jar：git-Spigot-5f38d38-18fbb24] at net.minecraft.server.v1_8_R3.PlayerConnection.a（PlayerConnection.java:997）[spigot-1.8.8.jar：git-Spigot-5f38d38-18fbb24] at net.minecraft.server.v1_8_R3.PacketPlayInChat.a（PacketPlayInChat.java:45）[spigot-1.8.8.jar：git-Spigot-5f38d38-18fbb24] at net.minecraft.server.v1_8_R3.PacketPlayInChat.a（PacketPlayInChat.java:1）[spigot-1.8.8.jar：git-Spigot-5f38d38-18fbb24] at net.minecraft.server.v1_8_R3.PlayerConnectionUtils $ 1.run（SourceFile：13）[spigot-1.8.8.jar：git-Spigot-5f38d38-18fbb24] at java.util.concurrent.Executors $ RunnableAdapter.call（Unknown Source）[？：1.7.0_79] at java.util.concurrent.FutureTask.run（Unknown Source）[？：1.7.0_79] at net.minecraft.server.v1_8_R3.SystemUtils.a（SourceFile：44）[spigot-1.8.8.jar：git-Spigot-5f38d38-18fbb24] at net.minecraft.server.v1_8_R3.MinecraftServer.B（MinecraftServer.java:715）[spigot-1.8.8.jar：git-Spigot-5f38d38-18fbb24] at net.minecraft.server.v1_8_R3.DedicatedServer.B（DedicatedServer.java:374）[spigot-1.8.8.jar：git-Spigot-5f38d38-18fbb24] at net.minecraft.server.v1_8_R3.MinecraftServer.A（MinecraftServer.java:654）[spigot-1.8.8.jar：git-Spigot-5f38d38-18fbb24] at net.minecraft.server.v1_8_R3.MinecraftServer.run（MinecraftServer.java:557）[spigot-1.8.8.jar：git-Spigot-5f38d38-18fbb24] 在java.lang.Thread.run（未知来源）[？：1.7.0_79] 引起：java.lang.NullPointerException 在org.sqlite.Stmt.executeUpdate（Stmt.java:152）〜[spigot-1.8.8.jar：git-Spigot-5f38d38-18fbb24] at de.xearox.xconomy.utility.Database.createNewPlayer（Database.java:95）〜[？：？] 在de.xearox.xconomy.XConomy.onCommand（XConomy.java:241）〜[？：？] 在org.bukkit.command.PluginCommand.execute（PluginCommand.java:44）〜[spigot-1.8.8.jar：git-Spigot-5f38d38-18fbb24] ......还有15个

创建数据库表工作正常。

也许你可以帮助我在这里我真的不知道我在这里做错了什么：/

谢谢

Answer 1

空指针异常意味着返回null。添加空检查

if(!sql == null){
    //Not null
    statement.executeUpdate(sql);
}
else{//Its null do whatever}

在statement.executeQuery中的NPE

1 个答案: