Question

我创建了这个插件，但它说错误，我不知道如何解决它，对于每个答案，谢谢。插件是当命令发送消息预加密时，后缀设置在配置中。

来源：

package cz.denowq.flatrov;


import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import org.bukkit.plugin.java.JavaPlugin;

public class flatrov extends JavaPlugin{

    @Override
    public void onEnable() {

        getLogger().info("[FlatRov] Načítávaní pluginu na verzi 1.0.1");

        getConfig().options().copyDefaults();
        saveConfig();

    }

    @Override
    public void onDisable() {

        getLogger().info("[FlatRov] Byl vypnut!");

    }

    @Override
    public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) {

        Player player = (Player) sender;
        String text = "";
        if (player.hasPermission("flatrov.zprava")) {
            if (cmd.getName().equalsIgnoreCase("zprava")) {
                if((text = getConfig().getString("flatrav.zprava.prikaz")).length() != 0) {
                    String message = joinArgs(args);
                     Bukkit.broadcastMessage(ChatColor.translateAlternateColorCodes('&', "" + getConfig().getString("flatrav.zprava.prefix") + " " + getConfig().getString("flatrav.zprava.suffix") + message));
                } else {
                    player.sendMessage(ChatColor.RED + " Použij /zprava <zprava> pro napsání zpravy!");
                }
            }
        } else {
            player.sendMessage(ChatColor.RED + " Nemáš povolený používat tento příkaz!");
        }
        return false;
    }

    private String joinArgs(String[] args) {
        String separator = ""; // empty on first iteration
        StringBuilder builder = new StringBuilder();
        for (String arg : args) {
            builder.append(separator).append(arg);
            separator = " "; // space after each arg
        }
        return builder.toString(); // return result
    }
    //String message = joinArgs(args);
}

错误：

[20:04:14] [Server thread/ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'zprava' in plugin FlatRov v1.0.1
    at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[spigot.jar:git-Spigot-1564]
    at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:181) ~[spigot.jar:git-Spigot-1564]
    at org.bukkit.craftbukkit.v1_7_R4.CraftServer.dispatchCommand(CraftServer.java:767) ~[spigot.jar:git-Spigot-1564]
    at net.minecraft.server.v1_7_R4.PlayerConnection.handleCommand(PlayerConnection.java:1016) [spigot.jar:git-Spigot-1564]
    at net.minecraft.server.v1_7_R4.PlayerConnection.a(PlayerConnection.java:846) [spigot.jar:git-Spigot-1564]
    at net.minecraft.server.v1_7_R4.PacketPlayInChat.a(PacketPlayInChat.java:28) [spigot.jar:git-Spigot-1564]
    at net.minecraft.server.v1_7_R4.PacketPlayInChat.handle(PacketPlayInChat.java:65) [spigot.jar:git-Spigot-1564]
    at net.minecraft.server.v1_7_R4.NetworkManager.a(NetworkManager.java:184) [spigot.jar:git-Spigot-1564]
    at net.minecraft.server.v1_7_R4.ServerConnection.c(ServerConnection.java:81) [spigot.jar:git-Spigot-1564]
    at net.minecraft.server.v1_7_R4.MinecraftServer.v(MinecraftServer.java:731) [spigot.jar:git-Spigot-1564]
    at net.minecraft.server.v1_7_R4.DedicatedServer.v(DedicatedServer.java:289) [spigot.jar:git-Spigot-1564]
    at net.minecraft.server.v1_7_R4.MinecraftServer.u(MinecraftServer.java:584) [spigot.jar:git-Spigot-1564]
    at net.minecraft.server.v1_7_R4.MinecraftServer.run(MinecraftServer.java:490) [spigot.jar:git-Spigot-1564]
    at net.minecraft.server.v1_7_R4.ThreadServerApplication.run(SourceFile:628) [spigot.jar:git-Spigot-1564]
Caused by: java.lang.NullPointerException
    at cz.denowq.flatrov.flatrov.onCommand(flatrov.java:36) ~[?:?]
    at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[spigot.jar:git-Spigot-1564]
    ... 13 more
[20:04:25] [Server thread/INFO]: DenOwq issued server command: /zprava test
[20:04:25] [Server thread/ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'zprava' in plugin FlatRov v1.0.1
    at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[spigot.jar:git-Spigot-1564]
    at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:181) ~[spigot.jar:git-Spigot-1564]
    at org.bukkit.craftbukkit.v1_7_R4.CraftServer.dispatchCommand(CraftServer.java:767) ~[spigot.jar:git-Spigot-1564]
    at net.minecraft.server.v1_7_R4.PlayerConnection.handleCommand(PlayerConnection.java:1016) [spigot.jar:git-Spigot-1564]
    at net.minecraft.server.v1_7_R4.PlayerConnection.a(PlayerConnection.java:846) [spigot.jar:git-Spigot-1564]
    at net.minecraft.server.v1_7_R4.PacketPlayInChat.a(PacketPlayInChat.java:28) [spigot.jar:git-Spigot-1564]
    at net.minecraft.server.v1_7_R4.PacketPlayInChat.handle(PacketPlayInChat.java:65) [spigot.jar:git-Spigot-1564]
    at net.minecraft.server.v1_7_R4.NetworkManager.a(NetworkManager.java:184) [spigot.jar:git-Spigot-1564]
    at net.minecraft.server.v1_7_R4.ServerConnection.c(ServerConnection.java:81) [spigot.jar:git-Spigot-1564]
    at net.minecraft.server.v1_7_R4.MinecraftServer.v(MinecraftServer.java:731) [spigot.jar:git-Spigot-1564]
    at net.minecraft.server.v1_7_R4.DedicatedServer.v(DedicatedServer.java:289) [spigot.jar:git-Spigot-1564]
    at net.minecraft.server.v1_7_R4.MinecraftServer.u(MinecraftServer.java:584) [spigot.jar:git-Spigot-1564]
    at net.minecraft.server.v1_7_R4.MinecraftServer.run(MinecraftServer.java:490) [spigot.jar:git-Spigot-1564]
    at net.minecraft.server.v1_7_R4.ThreadServerApplication.run(SourceFile:628) [spigot.jar:git-Spigot-1564]
Caused by: java.lang.NullPointerException
    at cz.denowq.flatrov.flatrov.onCommand(flatrov.java:36) ~[?:?]
    at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[spigot.jar:git-Spigot-1564]
    ... 13 more

编辑：删除配置

Answer 1

你似乎在2年前学过bukkit，或者你只是使用不良做法，因为大约2年前bukkit在你的插件启用或禁用时开始自动记录。

您不需要记录您的插件已启用/禁用，因为bukkit已经这样做了。

此代码可以简化

getConfig().options().copyDefaults();
saveConfig();

可以写成

saveDefaultConfig();

接下来，在命令处理程序中，您不应该检查那里的权限。您应该将权限节点添加到plugin.yml

中的命令

读取配置时应指定默认值。由于密钥不存在，因此当您尝试使用getString（）访问密钥时，它将返回null。请改用这样的东西。

getString("flatrav.zprava.prikaz"), "")

如果该字符串不存在，则此方法将返回空字符串。

此外，您的joinArgs（）函数会在输出中附加一个额外的空格。

在将所有元素附加到一起之后快速解决此问题，使用类似

的内容

sb.set length(sb.get length - 1);

Answer 2

您的堆栈跟踪在第36行显示错误。这是包含您的第一个配置调用的行：getConfig().getString("flatrav.zprava.prikaz")。

如果您的配置现在包含flatrav.zprava.prikaz的值，则该方法将返回null。在Java中，您无法在空值上运行方法。您将此null存储为text这是完全正常的，但是在该空值上调用.length()的第二个，您将获得NullPointerException。要解决此问题，您应该检查是text == null还是将getConfig().getString("flatrav.zprava.prikaz")更改为getConfig().getString("flatrav.zprava.prikaz", "")，如果在" flatrav.zprava.prikaz"找不到任何内容，该方法将返回空字符串。

Answer 3

这里也存在问题

@Override
public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) {

    Player player = (Player) sender;
    String text = "";

问题是，您是在立即强制发件人键入Player而不检查sender是否为player。只有在有人从控制台发送命令或者插件在调度命令时将服务器用作CommandSender时，才会出现此问题。要解决此问题，只需添加一个包含方法其余部分的if语句。

此外，如果return false方法中的onCommand，发件人将收到服务器发出的有关命令使用不正确/无效的消息。请尝试返回true，除非您希望将其发送此消息

@Override
public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) {

    if (sender instanceof Player) {
        Player player = (Player) sender;
        String text = "";
        if (player.hasPermission("flatrov.zprava")) {
            if (cmd.getName().equalsIgnoreCase("zprava")) {
                if((text = getConfig().getString("flatrav.zprava.prikaz")).length() != 0) {
                    String message = joinArgs(args);
                    Bukkit.broadcastMessage(ChatColor.translateAlternateColorCodes('&', "" + getConfig().getString("flatrav.zprava.prefix") + " " + getConfig().getString("flatrav.zprava.suffix") + message));
                } else {
                    player.sendMessage(ChatColor.RED + " Použij /zprava <zprava> pro napsání zpravy!");
                }
            }
        } else {
            player.sendMessage(ChatColor.RED + " Nemáš povolený používat tento příkaz!");
        }
    }
    return true;
}

Java，bukkit插件，错误

3 个答案: