非法论据例外:绑定必须为正数

我收到一个错误,说我的绑定必须是正数。这是我得到的一行:

inv.setItem(i, items.get(r.nextInt(items.size())));

据我所知,它来自我从项目列表中请求随机整数的部分。以下是我定义列表的方式:

List<ItemStack> items = getAllItems(level);

其中,该方法如下所示:getAllItems()

public List<ItemStack> getAllItems(int level) {
    List<ItemStack> items = new ArrayList<ItemStack>();
    for (String item : settings.getChests().getStringList("chestitems." + level)) {
        ItemStack toAdd = parseItem(item);
        items.add(toAdd);
    }
    return items;
}

我得到这个堆栈跟踪:

[19:03:53 ERROR]: Error occurred while enabling KitPvP v0.5 (Is it up to date?)
java.lang.IllegalArgumentException: bound must be positive
        at java.util.Random.nextInt(Unknown Source) ~[?:1.8.0_51]
        at me.iamguus.gamegetsiepunt.kitpvp.chests.ChestsUtil.randomlyFillInv(ChestsUtil.java:101) ~[?:?]
        at me.iamguus.gamegetsiepunt.kitpvp.Main.onEnable(Main.java:40) ~[?:?]
        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:321) ~[spigot.jar:git-Spigot-5818108-a486600]
        at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:335) [spigot.jar:git-Spigot-5818108-a486600]
        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:405) [spigot.jar:git-Spigot-5818108-a486600]
        at org.bukkit.craftbukkit.v1_8_R3.CraftServer.loadPlugin(CraftServer.java:356) [spigot.jar:git-Spigot-5818108-a486600]
        at org.bukkit.craftbukkit.v1_8_R3.CraftServer.enablePlugins(CraftServer.java:316) [spigot.jar:git-Spigot-5818108-a486600]
        at org.bukkit.craftbukkit.v1_8_R3.CraftServer.reload(CraftServer.java:746) [spigot.jar:git-Spigot-5818108-a486600]
        at org.bukkit.Bukkit.reload(Bukkit.java:534) [spigot.jar:git-Spigot-5818108-a486600]
        at org.bukkit.command.defaults.ReloadCommand.execute(ReloadCommand.java:25) [spigot.jar:git-Spigot-5818108-a486600]
        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) [spigot.jar:git-Spigot-5818108-a486600]
        at org.bukkit.craftbukkit.v1_8_R3.CraftServer.dispatchCommand(CraftServer.java:646) [spigot.jar:git-Spigot-5818108-a486600]
        at org.bukkit.craftbukkit.v1_8_R3.CraftServer.dispatchServerCommand(CraftServer.java:632) [spigot.jar:git-Spigot-5818108-a486600]
        at net.minecraft.server.v1_8_R3.DedicatedServer.aO(DedicatedServer.java:405) [spigot.jar:git-Spigot-5818108-a486600]
        at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:369) [spigot.jar:git-Spigot-5818108-a486600]
        at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:657) [spigot.jar:git-Spigot-5818108-a486600]
        at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:560) [spigot.jar:git-Spigot-5818108-a486600]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_51]

答案 1

问题是你用零打电话,它不喜欢这样。发生这种情况是因为 from 是空的。我会通过在执行逻辑之前检查列表是否包含项目来防止这种情况:Random.nextInt()ListgetAllItems()

List<ItemStack> items = getAllItems(level);
if(!items.isEmpty()) {
    inv.setItem(i, items.get(r.nextInt(items.size())));
}

答案 2

正如您的堆栈跟踪所说,

java.lang.IllegalArgumentException: bound must positive at java.util.Random.nextInt(Unknown Source) ~[?:1.8.0_51]

参数需要为正整数。您需要找出将非正输入传递到该方法的位置。nextInt()


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