Bukkit.getPlayer引发数字格式异常

如何解决Bukkit.getPlayer引发数字格式异常

我对Minecraft插件开发很陌生，我正在尝试制作自己的精简版Essentials插件。我正在尝试创建一个命令，该命令将允许我设置飞行速度以及其他飞行速度。设置速度就可以了，但是，瞄准其他玩家是我似乎无法管理的事情。当我执行命令时，它会出现在日志中：

[23:55:50 INFO]: swalloich issued server command: /flyspeed swalloich 2
[23:55:50 INFO]: swalloichtargeted swalloich with the flySpeed command.
[23:55:50 ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'flyspeed' in plugin EssentialsLite v0.2
    at org.bukkit.command.PluginCommand.execute(PluginCommand.java:47) ~[craftbukkit-1.16.2.jar:git-Bukkit-43c7ff9]
    at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:148) ~[craftbukkit-1.16.2.jar:git-Bukkit-43c7ff9]
    at org.bukkit.craftbukkit.v1_16_R2.CraftServer.dispatchCommand(CraftServer.java:735) ~[craftbukkit-1.16.2.jar:git-Bukkit-43c7ff9]
    at net.minecraft.server.v1_16_R2.PlayerConnection.handleCommand(PlayerConnection.java:1647) ~[craftbukkit-1.16.2.jar:git-Bukkit-43c7ff9]
    at net.minecraft.server.v1_16_R2.PlayerConnection.a(PlayerConnection.java:1504) ~[craftbukkit-1.16.2.jar:git-Bukkit-43c7ff9]
    at net.minecraft.server.v1_16_R2.PacketPlayInChat.a(SourceFile:36) ~[craftbukkit-1.16.2.jar:git-Bukkit-43c7ff9]
    at net.minecraft.server.v1_16_R2.PacketPlayInChat.a(SourceFile:9) ~[craftbukkit-1.16.2.jar:git-Bukkit-43c7ff9]
    at net.minecraft.server.v1_16_R2.PlayerConnectionUtils.lambda$0(PlayerConnectionUtils.java:19) ~[craftbukkit-1.16.2.jar:git-Bukkit-43c7ff9]
    at net.minecraft.server.v1_16_R2.TickTask.run(SourceFile:18) ~[craftbukkit-1.16.2.jar:git-Bukkit-43c7ff9]
    at net.minecraft.server.v1_16_R2.IAsyncTaskHandler.executeTask(SourceFile:144) ~[craftbukkit-1.16.2.jar:git-Bukkit-43c7ff9]
    at net.minecraft.server.v1_16_R2.IAsyncTaskHandlerReentrant.executeTask(SourceFile:23) ~[craftbukkit-1.16.2.jar:git-Bukkit-43c7ff9]
    at net.minecraft.server.v1_16_R2.IAsyncTaskHandler.executeNext(SourceFile:118) ~[craftbukkit-1.16.2.jar:git-Bukkit-43c7ff9]
    at net.minecraft.server.v1_16_R2.MinecraftServer.ba(MinecraftServer.java:899) ~[craftbukkit-1.16.2.jar:git-Bukkit-43c7ff9]
    at net.minecraft.server.v1_16_R2.MinecraftServer.executeNext(MinecraftServer.java:892) ~[craftbukkit-1.16.2.jar:git-Bukkit-43c7ff9]
    at net.minecraft.server.v1_16_R2.IAsyncTaskHandler.awaitTasks(SourceFile:127) ~[craftbukkit-1.16.2.jar:git-Bukkit-43c7ff9]
    at net.minecraft.server.v1_16_R2.MinecraftServer.sleepForTick(MinecraftServer.java:876) ~[craftbukkit-1.16.2.jar:git-Bukkit-43c7ff9]
    at net.minecraft.server.v1_16_R2.MinecraftServer.w(MinecraftServer.java:815) ~[craftbukkit-1.16.2.jar:git-Bukkit-43c7ff9]
    at net.minecraft.server.v1_16_R2.MinecraftServer.lambda$0(MinecraftServer.java:155) ~[craftbukkit-1.16.2.jar:git-Bukkit-43c7ff9]
    at java.lang.Thread.run(Thread.java:832) [?:?]
Caused by: java.lang.NumberFormatException: For input string: "swalloich"
    at java.lang.NumberFormatException.forInputString(NumberFormatException.java:68) ~[?:?]
    at java.lang.Integer.parseInt(Integer.java:652) ~[?:?]
    at java.lang.Integer.parseInt(Integer.java:770) ~[?:?]
    at me.swall.essentialsLite.commands.FlySpeed.onCommand(FlySpeed.java:62) ~[?:?]
    at org.bukkit.command.PluginCommand.execute(PluginCommand.java:45) ~[craftbukkit-1.16.2.jar:git-Bukkit-43c7ff9]
    ... 18 more

我几乎可以肯定的代码部分是：

    float flySpeed = (float)(Integer.parseInt(args[1]) / 10.0);
    Bukkit.getLogger().info(player.getDisplayName() + " targeted " + args[0] + " with the flySpeed command.");
    if (Integer.parseInt(args[0]) > 10 || Integer.parseInt(args[0]) < 0)
    {
        sender.sendMessage("The speed argument must be a whole number between 0 and 10.");
    }
    else
    {
        //set the target player's fly speed to the value provided as the second argument
        Player targetPlayer = Bukkit.getPlayerExact(args[0]);
        Bukkit.getLogger().info("targetPlayer was initialized.");
        if (targetPlayer != null && player.isOnline())
        {
            targetPlayer.setFlySpeed(flySpeed);
            Bukkit.getLogger().info("The fly speed for user " + player.getDisplayName() 
                                    + " has been set to" + args[0]);
        }
        else
        {
            sender.sendMessage("That player was not found.");
        }
    }

我在做什么错了？

解决方法

在代码的第1行， 您正在将String（args [1]）除以float（10.0）。

  float flySpeed = (float)(Integer.parseInt(args[1] / 10.0));

应更改为：

  float flySpeed = (float)(Integer.parseInt(args[1]) / 10.0);

+如果要在代码中多次使用解析后的整数， 我建议为此创建整数变量。

如果这样，代码将如下所示：

    int flySpeedArg = Integer.parseInt(args[1]);
    float flySpeed = (float)(Integer.parseInt(args[1]) / 10.0);

    Bukkit.getLogger().info(player.getDisplayName() + " targeted " + args[0] + " with the flySpeed command.");
    if (flySpeedArg > 10 || flySpeedArg < 0)
    {
        sender.sendMessage("The speed argument must be a whole number between 0 and 10.");
    }
    else
    {
        //set the target player's fly speed to the value provided as the second argument
        Player targetPlayer = Bukkit.getPlayerExact(args[0]);
        Bukkit.getLogger().info("targetPlayer was initialized.");
        if (targetPlayer != null && player.isOnline())
        {
            targetPlayer.setFlySpeed(flySpeed);
            Bukkit.getLogger().info("The fly speed for user " + player.getDisplayName() 
                                    + " has been set to" + args[0]);
        }
        else
        {
            sender.sendMessage("That player was not found.");
        }
    }