≪ View Page

差别

这里会显示出您选择的修订版和当前版本之间的差别。

到此差别页面的链接

两侧同时换到之前的修订记录前一修订版
后一修订版		前一修订版
modding:pluginandjvm [2022/10/04 01:06] – old revision restored (2022/03/14 13:37) 111.225.149.108modding:pluginandjvm [2022/10/04 03:58] (当前版本) – 外部编辑 127.0.0.1
行 1: 行 1:
 +====== Plugins & JVM Mods ======
 +
 +Mindustry supports loading ''%%jar%%'' files with Java bytecode on desktop & Android. These function similarly to JS mods, and must supply a single main class to instantiate when the mod is created.
 +
 +Theoretically, all JVM languages should be supported.
 +
 +Jar/JVM mods use the same ''%%mod.hjson%%'' meta file that standard mods do, with one addition: The //fully qualified main class// can be specified with ''%%main: "mypackage.MyMod"%%''. This class should extend ''%%mindustry.mod.Mod%%''.
 +
 +If a main class is not specified, it defaults to ''%%modnameinlowercase.ModName + "Mod".%%''
 +
 +A simple ''%%mod.hjson%%'' for a Java mod could look like this:
 +
 +<code hjson>
 +name: "Nothing"
 +author: "Yourself"
 +main: "nothing.NothingMod"
 +description: "..."
 +version: "99.99"
 +</code>
 +
 +See the [[https://github.com/Anuken/MindustryJavaModTemplate|example Java mod repo]] or the [[https://github.com/Anuken/MindustryKotlinModTemplate|example Kotlin mod repo]] for more instructions.
 +
 +===== Plugins =====
 +
 +Plugins are Java mods that are intended to be run on servers only. Usually, these add //new commands// or //new gamemodes//. All plugin main classes should extend ''%%mindustry.mod.Plugin%%''. This makes them implicitly //hidden// - clients will not need to download the plugin to join the server. They are server-side only. To install a plugin, place the JAR in ''%%<server directory>/config/mods/%%''.
 +
 +Plugins name their meta file ''%%plugin.[h]json%%''. The file structure is identical to that of other Java mods - see above for details.
 +
 +You can see an example plugin [[https://github.com/Anuken/MindustryPluginTemplate|here]]. For a more practical example that can be used on real servers, see [[https://github.com/Anuken/AuthorizePlugin|this repo]].
 +===== Importing =====
 +
 +Unlike JS or JSON mods, JAR mods need to be compiled. This means that they cannot be imported directly from Github - instead, //Github Releases// are used.
 +
 +When a user tries to install a JAR mod, Mindustry will check the latest (and //only// the latest) Github release for ''%%.jar%%'' artifacts. When the first artifact is found, it is downloaded to the client. Note that pre-releases are ignored.
 +
 +I recommend using Github Actions (or any other CI) to automatically build and upload jar artifacts to new releases.
 +
 +===== Multithreading =====
 +
 +Unless otherwise noted, **no Mindustry code is thread-safe**. Performing any actions (e.g. sending packets, changing tiles) from a thread other than the main one will result in random crashes or network errors. To run something on the main thread, use ''%%Core.app.post(() -> { /* code */ })%%''.
 +
 +===== Capabilities & Security =====
 +
 +As jar mods are loaded directly through a ''%%URLClassLoader%%'' with no sandboxing, they do not have any security limitations. This means:
 +
 +  * All Java APIs can be accessed.
 +  * Reflection can be used to access private/hidden properties.
 +  * Mods have full access to the client’s computer, opening the door to potentially malicious actions.
 +  * Mods can change game files or rewrite core bytecode.
 +
 +Thus, you should //never import jar mods from untrusted sources.// Now, you may be wondering: Why aren’t jar mods sandboxed? Isn’t that a massive security risk?
 +
 +The answer is: //Yes//, it is. However, there are no good alternatives. Even if I implemented a ''%%SecurityManager%%'' to limit mod capabilities, it wouldn’t help - Java is inherently insecure, and any reasonably-“secure” sandbox implementation (//if one even exists//) would require disabling reflection in mods, which is unacceptable.
 +
 +As a point of comparison, Forge (//a popular Java mod loader for Minecraft//) doesn’t sandbox mods either.
 +
 +
 +