Chapter 1: Introduction to Spigot

1. IDE Setup

We're gonna be using IntelliJ IDEA as the IDE for this project. If you're using other IDEs like NetBeans or Eclipse and do not know how to replicate the process, you can ask our Discord community (or just search google)! Firstly, create a project. I'm naming mine MCPlugin. Next, visit getbukkit.org and download Spigot 1.14jar (at this time, this is the latest, most stable and updated Spigot library, so we'll be using this for the tutorial. If you wish to use any other version, go ahead, but different versions may have different formats and methods e.g. Player Inventory changes, new items, new entities). Then, in your project settings for the project you just created, add the jar file as a new library dependency. You can add the documentation url if you want (as of today, it is https://hub.spigotmc.org/javadocs/spigot). The documnetation url gives you a javadoc tooltip when you hover on Spigot library content, which we will use. Click apply and then OK to close the project settings window.

Now, we need to create the package within the src folder of the project. Usually, the package name's naming convention is a reversed website link. Different examples include org.mywebsitename.myname.projectname or com.myname.projectname. I'll creating a package with name me.thatonerr.mcplugin (ThatOneRR's my current in-game name I use). In that package, we need a Main class. People usually use names like Core, Main or the project name itself. I'll be using Main as the name of the main class (ba dum tsss!). The package and the main class are the 2 of 3 requirements for any plugins to work, the last one being the plugin.yml file. That's all for the project setup! I'll be touching on the Main class in the next part.

2. Main Classes

A Minecraft plugin is a .jar file (like the spigot library .jar, yes). When the Spigot server.jar file is run, it looks for these .jar files in the plugins folder of the server and loads them, even if they are in the wrong format (to run, the .jar file must at least have a package with a main class, as well as a plugin.yml file, all with the right formats). A Main Class must extend the JavaPlugin class, and each plugin will only have ONE JavaPlugin main class instance running at any point of time. That is to say, there can only be one instance of each plugin running at a time. It would not make sense to run two instances of your plugin at one time, will it?

So let's let our Main class extend the JavaPlugin class so that the server.jar knows that that is the class to look for when it finds your plugin. Then, we need to override 2 methods from the JavaPlugin class, onEnable and onDisable. When the server.jar finds your plugin, then your main class extending the JavaPlugin class, it will run the onLoad, onEnable() and onDisable() methods. Therefore, we need to override these methods (we don't usually use onLoad because that is called before everything related to your plugin is). As the name suggests, onEnable() will be called when the server first starts, and onDisable() when the server is stopped. Everything you want your plugin to be done will usually be done within this two methods, such as registering events and commands.

Let's make this processes visual (to a certain extent) by sending console messages in the onEnable() and onDisable() methods with the handy method Bukkit.getLogger().info("Your text here"). Bukkit.getLogger() gets the console and .info() shows the text to the console as an Info string. You can also do .warning() and .severe(), respectively, should the need arises.

3. plugin.yml

When server.jar finds your .jar file, it looks for the plugin.yml and reads the fields there. The compulsory ones to write in order for your plugin to work are: Name, which registers your plugin name;
Main, which tells the server.jar where to look for your main class; and version, which is the version of your plugin. Right click on your src folder and create a new file called plugin.yml. Let's fill those blanks in, shall we?

4. Compiling/Finishing your plugin

In order to export your plugin into a .jar file, we need to tell IntelliJ how to compile it! There is a format to follow in a .jar file, and that is: the .jar file should contain the project package, the plugin.yml and any other files or packages that you need to use. In this case, we just need the project package and the plugin.yml.

To do this, go into your project settings, click 'Artifacts', the 'Add (+) button', JAR, From modules with dependencies, then "Ok". The settings for that module should then show up on the right. Then, removed the "Extrated spigot-1.13.2.jar" part - We don't need the entire library compiled into our plugin; the library used is the server.jar. Then click add within the module, select 'File', find and select your plugin.yml file. Click apply and OK to close the window.

Now all you need to do is hover over 'Build' in the toolbar at the top of the window, click 'Build Artifacts' and then 'Build'.

5. Setting up a Spigot server

For those of you who already know how to set up a Spigot server or use a server host, good for you! You ca skip this part if you want. But for those of you who are unsure how to set up your Spigot server, here's how. We'll be using a localhost server, meaning the server is going to set up on your computer, and using your network!

Remember the spigot jar you downloaded? Create a folder and drop a copy in, rename it to server.jar, then create a text file and open it. Type in "java -jar server.jar" (without the quotes) and save it as run.bat (you can specify arguments if you want to control runtime parameters like memory allocation). Run it to allow it to generate the eula file the first time. Then accept the eula.txt by change "eula=false" to "eula=true" and run the jar file again. This time, it should generate all the necessary files, like world folders, temp folders, server files and the plugin folder. If you're using cracked Minecraft, change the option "online-mode" to true in the server-properties file.

See that plugin folder? Double click it to enter it and drop a copy of your build artifact found in your project file's out > artifacts folder into there. Then, restart your server by closing and re-opening run.bat.