Hello,

i'm currently working on a mysql database which im trying implement in with my minecraft project.

My problem is, that if i export my project (with the minecraft classes of course) it throws an ClassNotFoundException for "com.mysql.cj.jdbc.Driver"

Strangely, its working in debug mode but not when i export it.

I have also already added the correct mysql-connector.jar to the libraries, as well as searching for reasons online..

I hope that someone will the cause for this and help me out with it.

 

Console output: 

01:47:16	game		info	java.lang.ClassNotFoundException: com.mysql.cj.jdbc.Driver
01:47:16	game		info	at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
01:47:16	game		info	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
01:47:16	game		info	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
01:47:16	game		info	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
01:47:16	game		info	at java.lang.Class.forName0(Native Method)
01:47:16	game		info	at java.lang.Class.forName(Class.java:264)
01:47:16	game		info	at me.freakzboy.testclient.TestClient.startClient(CountDown.java:41)
01:47:16	game		info	at net.minecraft.client.Minecraft.startGame(Minecraft.java:575)
01:47:16	game		info	at net.minecraft.client.Minecraft.run(Minecraft.java:410)
01:47:16	game		info	at net.minecraft.client.main.Main.main(Main.java:114)
01:47:16	game		info	jdbc driver unavailable!

 

	public void startClient() {
		
		instance = this;
		
		try {
			
		    Class.forName("com.mysql.cj.jdbc.Driver");
		    
		    //this accesses Driver in jdbc.
		} catch (ClassNotFoundException e) {
		    e.printStackTrace();
		    System.err.println("jdbc driver unavailable!");
		    return;
		}
		MySQL.connect(); 
    	}

 

	public static void connect() {
		
		if(isConnected() == false) {
			try {
				
				con = DriverManager.getConnection("jdbc:mysql://" + host + ":" + port + "/" + database, username, password);
				
				System.out.println("[MySQL] Successfully connected!");
				
			} catch (SQLException e) {
				
				System.out.println("[MySQL] Error.");
				
				e.printStackTrace();
			}
		}
		
	}

 

Thanks,

Freakz

Edited August 24, 20187 yr by FreakzBoy

Minecraft does not ship with this package, you have to shade it into your compiled jar.

1 hour ago, diesieben07 said:

Shading is inferior to the jar-in-jar mechanism in Forge.

Good to know. Hadn't heard about this, or if I did, I didn't know it was different.

Hey, thanks for you responses. Wouldn't packaging the mysql-connector-java.jar file also be a solution to this?

Edited August 25, 20187 yr by FreakzBoy

Ok, i tried packaging the mysql-connector-java.jar after i exported my minecraft project and (put the com folder as well as the META-INF folder into my minecraft jar). Unfortunately, its still throwing the ClassNotFoundException: com.mysql.cj.jdbc.Driver and doesnt connect to my mysql database. I did some research on the internet too, and people were talking about dependencies in the META-INF folder and pom.xml which I'm not familiar. Any ideas?

Edited August 25, 20187 yr by FreakzBoy

Yes i did, I've also tried putting the jar into my minecraft jar, which forge is supposed to extract into the mod repository and load them. For me this is not the case tho. That's why i've also tried the method written above

I forgot to mention that i'm not working on a mod thats going to be added, but on a whole minecraft client that should connect to the database. I basically export my client jar and place the things that are inside it into a normal minecraft jar, thats how i can basically start my client in the launcher. I dont know if you had experience with clients in general yet or only with mods, but it should be close to the same. By the way the link you have posted above, tells me, that i have to put dependency jars into my jar, which i can only get by converting my project into Maven. Is that correct?

Edited August 25, 20187 yr by FreakzBoy

Do not create clients.

This is not negotiable or debatable, thread locked.