在检查字段是否为null后抛出NullPointerException [英] NullPointerException thrown after field is check if it is null

问题描述

我正在为Bukkit开发一个插件（ http://bukkit.org ），并在确认该插件不为空之后，它在第二行给了我NullPointerException

I am developing a plugin for Bukkit (http://bukkit.org) and after verifying that it is not null, it gives me a NullPointerException at the 2nd line

    String description = getConfig().getString("core.commands."+cmd+".description");
    if (!(description.isEmpty()))
          getCommand(cmd).setDescription(description);
    else 
          getLogger().warning("NO description assigned to: " + cmd);
    description = null;

推荐答案

您的代码！（说明.isEmpty（））不会验证描述不为空。为此，您需要 description！= null 。

Your code !(description.isEmpty()) doesn't verify that description is not null. For that you need description != null.

您的测试应为：

if (description != null && !description.isEmpty()) ...

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