Why doesn't this work?

Hello.

I am still trying to get familiar with Java, but this just stumps me.

This code gives me an error:

Code:java

public class TestPlugin extends JavaPlugin {
    public static TestPlugin plugin;
    public final ChatListener chat = new ChatListener();
    public final GameJumpListener jump = new GameJumpListener();
    private static final Logger log = Logger.getLogger("Minecraft");
    public PluginManager pm = getServer().getPluginManager();
 
    @Override
    public void onEnable(){
        log.info( "TestPlugin enabled." );
 
        pm.registerEvents(this.chat, this);
        pm.registerEvents(this.jump, this);
    }
    @Override
    public void onDisable(){
        log.info( "TestPlugin disabled." );
    }
}

In Netbeans, it shows no errors. But when I put the plugin into my server,

Code:

2012-09-06 19:25:04 [SEVERE] Could not load 'plugins\TestPlugin.jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: java.lang.NullPointerException
    at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:153)
    at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:305)
    at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:230)
    at org.bukkit.craftbukkit.CraftServer.loadPlugins(CraftServer.java:222)
    at org.bukkit.craftbukkit.CraftServer.<init>(CraftServer.java:198)
    at net.minecraft.server.ServerConfigurationManagerAbstract.<init>(ServerConfigurationManagerAbstract.java:50)
    at net.minecraft.server.ServerConfigurationManager.<init>(SourceFile:11)
    at net.minecraft.server.DedicatedServer.init(DedicatedServer.java:105)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:378)
    at net.minecraft.server.ThreadServerApplication.run(SourceFile:539)
Caused by: java.lang.NullPointerException
    at com.TyphoonMC.Puyttre.TestPlugin.TestPlugin.<init>(TestPlugin.java:14)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:149)
    ... 9 more

The listeners don't have anything to do with it. I already tried removing both listeners and it had no effect. If anyone has any information that could help, I would appreciate it.

Thanks!
Also, in advance, I know, I probably sound like a total noob.

 

"InvalidPluginException" usually means you forgot to package a valid plugin.yml file with the jar.

 

makskay
When I open my TestPlugin.jar with WinRar, it shows plugin.yml along with com and META-INF in the main folder. Should plugin.yml be somewhere else?

EDIT: Also, in my plugin.yml I include the name, the version, and the main method. I believe that is all that is required.

 

You sound like you have plugin.yml in the right place but the fact that you say "main method" makes me think there's an error in plugin.yml itself. Could you post your plugin.yml here?

 

Sorry for the late reply.

Code:

name: TestPlugin
version: 1.0
author: Puyttre
description: A test plugin.
 
main: com.TyphoonMC.Puyttre.TestPlugin.TestPlugin
 
website: http://www.typhoonmc.com/

 

puyttre :: Hrm, that's really odd - the error doesn't seem to have anything to do with plugin.yml. You could maybe try removing the "@Override" annotations on the onEnable() and onDisable() methods but it's a long shot that the issue has anything to do with that and I'm out of ideas otherwise.

 

Alright thanks. Removing the @Override doesn't work. I think it may have something to do while creating a new instance of something because of this line in the error

Code:

at java.lang.reflect.Constructor.newInstance(Unknown Source)

Is there anything wrong with my Logger or PluginManager constructors?

 

I don't think so - both of them look to be fine. Based on some quick research this particular version of this error usually crops up when someone overrides the default JavaPlugin constructor itself, which you don't appear to be doing.

 

makskay
Alright thanks for your help anyways. I'll do some experimenting and see if I can get it to work.

 

Give us the entire class including imports, please.

Actually, you never implemented listener. Right after extends JavaPlugin put implements Listener
puyttre

 

Try putting pm = getServer().getPluginManager(); Right before you register the events.

 

Really need you to post the entire source including the package of the class. It's failing during the constructor, so it shouldn't have anything to do with the onEnable or onDisable

 

@puyttre I did this very thing in a test using the code you provided and the plugin.yml remaking the listener class (just blank) got the same error till I the above. Luckily I read other posts or I would have suggested the same thing

Code:Java

public class TestPlugin extends JavaPlugin {
    public static TestPlugin plugin;
    public final ChatListener chat = new ChatListener();
    public final GameJumpListener jump = new GameJumpListener();
    private static final Logger log = Logger.getLogger("Minecraft");
 
    @Override
    public void onEnable() {
        log.info("TestPlugin enabled.");
 
        PluginManager pm = getServer().getPluginManager();
        pm.registerEvents(this.chat, this);
        pm.registerEvents(this.jump, this);
    }
 
    @Override
    public void onDisable() {
        log.info("TestPlugin disabled.");
    }
}
 

 

Can you post the entire class as it appears in your text editor? (including the correct line numbers)

 

getServer() returns null when you use it outside of your onEnable constructor.

 

Thanks for the help guys but I completely restarted with my code. I don't know what it was, but my code works now. All the imports were correct and like I said, there were no errors.

Sorry to people coming here to look for a fix. I don't know the answer.

 

Jesus, I gave you the answer dude. You never implemented Listener so when you tried to call events it came up with errors. puyttre

 

Right, but you replied a day after I restarted.

I said thanks, either say you're welcome or just leave.

p.s. I don't think your solution was right, either. I don't see why I would need to Implement Listener...

 

Right, but I responded an hour and a half after you posted this. And you're stupid for not thinking you need to implement Listener, that's what listens for events idiot. You need to implement it or else you can't register events (Like you did in your onEnable, which was what caused the error) or access EventHandler.

 

Weird... My new code doesn't implement Listener but it works fine!

 

code me.

 

Code:java

public class TestPlugin extends JavaPlugin {
    private static FileConfiguration config;
    private ChatListener chat = new ChatListener();
    private GameJumpListener jump = new GameJumpListener();
 
    @Override
    public void onEnable(){
        File config = new File(this.getDataFolder(), "config.yml");
        PluginManager pm = getServer().getPluginManager();
 
        log("[TestPlugin] TestPlugin enabled.");
        pm.registerEvents(this.chat, this);
        pm.registerEvents(this.jump, this);
 
        if(config.exists()){
            log("[TestPlugin] Found config. Using current config.");
        }else{
            warn("[TestPlugin] Confing not found. Generating a new one.");
            this.saveDefaultConfig();
        }
    }
    @Override
    public void onDisable(){
        log("[TestPlugin] TestPlugin disabled.");
    }
 
    public void log(String info){
        getServer().getLogger().info(info);
    }
    public void warn(String warning){
        getServer().getLogger().warning(warning);
    }
}

 

Not even going to respond to you..

 

Dude you are wrong, it was Chiller that originally post the fix. What you said was complete unrelated to this error.

Notice line 9 on that, that is what you had wrong at first.

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

Finally someone that knows what was wrong unlike the other guy that was talking about implementing Listener.

Tirelessly please learn java before trying to help other people with java...

 

Hahahahaaha good one.