Minecraft Java programmierungs fehler "MineCraft"

[I-Net]

Guten Tag,

ich habe ein Plugin für Minecraft Programmiert. Es kommt nicht zu ein Fehler im Eclipse aber beim Start von mein MineCraft Server.

2012-11-11 16:01:59 [INFO] This server is running CraftBukkit version git-Bukkit-1.4.2-R0.2-1-g3d8a353-b2457jnks (MC: 1.4.2) (Implementing API version 1.4.2-R0.3-SNAPSHOT)
2012-11-11 16:02:00 [SEVERE] Could not load 'plugins\MyLog++.jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: java.lang.NullPointerException
        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:152)
        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:229)
        at org.bukkit.craftbukkit.CraftServer.<init>(CraftServer.java:205)
        at net.minecraft.server.ServerConfigurationManagerAbstract.<init>(ServerConfigurationManagerAbstract.java:51)
        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:400)
        at net.minecraft.server.ThreadServerApplication.run(SourceFile:818)
Caused by: java.lang.NullPointerException
        at main.BlockListener.<init>(BlockListener.java:20)
        at main.MyLog.<init>(MyLog.java:12)
        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:148)
        ... 9 more

PROGRAMMIERCODE

package main;

import org.bukkit.ChatColor;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import org.bukkit.plugin.PluginManager;
import org.bukkit.plugin.java.JavaPlugin;

public class MyLog extends JavaPlugin {
	
	public final BlockListener blockListener = new BlockListener(this);
	
	@Override
	public void onDisable() {
		System.out.println("[MyLog] Plugin is disable!");
		System.out.println("[MyLog] Version 1.4");
	}
	
	@Override
	public void onEnable() {
		System.out.println("[MyLog] Plugin by MineMarcel!");
		System.out.println("[MyLog] Plugin is enable!");
		System.out.println("[MyLog] Version 1.4");
		
		PluginManager pm = getServer().getPluginManager();
		pm.registerEvents(new BlockListener(this),this);
	}
	
	public boolean onCommand(CommandSender sender, Command cmd, String cmdLabel, String[] args) {
		boolean erfolg = false;
		
		
		Player p = (Player)sender;
		
		if (cmd.getName().equalsIgnoreCase("mylog")) {
			if (args.length==0) {
				p.sendMessage(ChatColor.YELLOW + "[MyLog++] " + ChatColor.GREEN + "Plugin by MineMarcel");
				p.sendMessage(ChatColor.YELLOW + "[MyLog++] " + ChatColor.GREEN + "Version 1.4");
				
				
			}
			erfolg = false;
		}
		
		
		
		
		
		return erfolg;
	}
	
}

package main;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;

import org.bukkit.Bukkit;
import org.bukkit.Location;
import org.bukkit.Material;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.block.BlockBreakEvent;
import org.bukkit.event.block.BlockPlaceEvent;
import org.bukkit.event.player.AsyncPlayerChatEvent;
import org.bukkit.event.player.PlayerCommandPreprocessEvent;

public class BlockListener implements Listener {
	
	 private MyLog t;
	 private File blocklog = new File(t.getDataFolder(), "log_mined.txt");
	 private File blocklog2 = new File(t.getDataFolder(), "log_set.txt");
	 private File blocklog3 = new File(t.getDataFolder(), "log_chat.txt");
	 private File blocklog4 = new File(t.getDataFolder(), "log_command.txt");
	 public BlockListener(MyLog instance) {
		 t = instance;
		 if (!blocklog.exists()) {
			 try {
                 blocklog.createNewFile();
         } catch (IOException e) {
                 Bukkit.getLogger().warning("Can't create log_mined.txt (Bukkit Bug?)!");
         }
		 }
		 if (!blocklog2.exists()) {
			 try {
                 blocklog2.createNewFile();
         } catch (IOException e) {
                 Bukkit.getLogger().warning("Can't create log_set.txt (Bukkit Bug?)!");
         }
		 }
		 if (!blocklog3.exists()) {
			 try {
                 blocklog3.createNewFile();
         } catch (IOException e) {
                 Bukkit.getLogger().warning("Can't create log_chat.txt (Bukkit Bug?)!");
         }
		 }
		 if (!blocklog4.exists()) {
			 try {
                 blocklog4.createNewFile();
         } catch (IOException e) {
                 Bukkit.getLogger().warning("Can't create log_command.txt (Bukkit Bug?)!");
         }
		 }
	 }
	 
	 @EventHandler
     public void onBlockBreak(BlockBreakEvent event) {
             Player player = event.getPlayer();
             Material blockmaterial = event.getBlock().getType();
             Location location = player.getLocation();
             
             try {
                     FileWriter writer = new FileWriter(blocklog, true);
                     writer.append(player.getName() + " have " + blockmaterial.name() + " mined!" + " [ " + location + " ]");
                     writer.close();
             } catch (IOException e) {
                     Bukkit.getLogger().warning("Can't write log_mined.txt! ERROR!");
             }
	 }
		
	 @EventHandler
     public void onBlockPlace(BlockPlaceEvent event) {
             Player player = event.getPlayer();
             Material blockmaterial = event.getBlock().getType();
             Location location = player.getLocation();
            
             try {
                     FileWriter writer = new FileWriter(blocklog2, true);
                     writer.append(player.getName() + " have " + blockmaterial.name() + " set!" + " [ " + location + " ]");
                     writer.close();
             } catch (IOException e) {
                     Bukkit.getLogger().warning("Can't write log_set.txt! ERROR!");
             }
	 }
	 
	 @EventHandler
     public void onAsyncPlayerChatEvent(AsyncPlayerChatEvent event) {
             Player player = event.getPlayer();
             String message = event.getMessage();
            
             try {
                     FileWriter writer = new FileWriter(blocklog3, true);
                     writer.append(player.getName() + " wrote " + message);
                     writer.close();
             } catch (IOException e) {
                     Bukkit.getLogger().warning("Can't write log_chat.txt! ERROR!");
             }
	 }
	 
	 @EventHandler
     public void onPlayerCommandPreqrocessEvent(PlayerCommandPreprocessEvent event) {
             Player player = event.getPlayer();
             String message = event.getMessage();
            
             try {
                     FileWriter writer = new FileWriter(blocklog4, true);
                     writer.append(player.getName() + " = " + message);
                     writer.close();
             } catch (IOException e) {
                     Bukkit.getLogger().warning("Can't write log_command.txt! ERROR!");
             }
	 }
}

name: MyLog
version: 1.4
author: MineMarcel
description: A log plugin
Website: http://www.minemarcel.de/

main: main.MyLog

commands:
  heal:
    description: command
    usage: /<command> <player>

permissions:

Hoffe auf Hilfe. Danke

 

[Michael...]

public class BlockListener implements Listener {
	
	 private MyLog t;
	 private File blocklog = new File(t.getDataFolder(), "log_mined.txt");

Sowas wirft immer - auch in Eclipse - eine NullPointer Exception. t ist beim Zugriff noch gar nicht initialisiert.

 

[I-Net]

Ich bin erst vor 5 Tagen angefangen, was muss ich tun?

 

[SlaterB]

erstmal Java lernen?

     private MyLog t;
     private File blocklog;
     ...

     public BlockListener(MyLog instance) {
         t = instance; 
         // jetzt ist t ja da
         blocklog = new File(t.getDataFolder(), "log_mined.txt") 
         ...

 

[I-Net]

Ich habe ein kleines Buch gelesen mit den Grundlagen aber ganz verstehe ich das noch nicht, da ich noch 2 Andere Programmiersprachen kann. Java lerne ich noch

Müsste der Code folgenermassen aussehen?

package main;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;

import org.bukkit.Bukkit;
import org.bukkit.Location;
import org.bukkit.Material;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.block.BlockBreakEvent;
import org.bukkit.event.block.BlockPlaceEvent;
import org.bukkit.event.player.AsyncPlayerChatEvent;
import org.bukkit.event.player.PlayerCommandPreprocessEvent;

public class BlockListener implements Listener {
	
	 private MyLog t;
	 private File blocklog;
	 private File blocklog2;
	 private File blocklog3;
	 private File blocklog4;
	 public BlockListener(MyLog instance) {
		 t = instance;
		 blocklog = new File(t.getDataFolder(), "log_mined.txt");
		 if (!blocklog.exists()) {
			 try {
                 blocklog.createNewFile();
         } catch (IOException e) {
                 Bukkit.getLogger().warning("Can't create log_mined.txt (Bukkit Bug?)!");
         }
		 }
		 blocklog2 = new File(t.getDataFolder(), "log_set.txt");
		 if (!blocklog2.exists()) {
			 try {
                 blocklog2.createNewFile();
         } catch (IOException e) {
                 Bukkit.getLogger().warning("Can't create log_set.txt (Bukkit Bug?)!");
         }
		 }
		 blocklog3 = new File(t.getDataFolder(), "log_chat.txt");
		 if (!blocklog3.exists()) {
			 try {
                 blocklog3.createNewFile();
         } catch (IOException e) {
                 Bukkit.getLogger().warning("Can't create log_chat.txt (Bukkit Bug?)!");
         }
		 }
		 blocklog4 = new File(t.getDataFolder(), "log_command.txt");
		 if (!blocklog4.exists()) {
			 try {
                 blocklog4.createNewFile();
         } catch (IOException e) {
                 Bukkit.getLogger().warning("Can't create log_command.txt (Bukkit Bug?)!");
         }
		 }
	 }
	 
	 @EventHandler
     public void onBlockBreak(BlockBreakEvent event) {
             Player player = event.getPlayer();
             Material blockmaterial = event.getBlock().getType();
             Location location = event.getBlock().getLocation();
             
             try {
                     FileWriter writer = new FileWriter(blocklog, true);
                     writer.append(player.getName() + " have " + blockmaterial.name() + " mined!" + " [ " + location + " ]");
                     writer.close();
             } catch (IOException e) {
                     Bukkit.getLogger().warning("Can't write log_mined.txt! ERROR!");
             }
	 }
		
	 @EventHandler
     public void onBlockPlace(BlockPlaceEvent event) {
             Player player = event.getPlayer();
             Material blockmaterial = event.getBlock().getType();
             Location location = event.getBlock().getLocation();
            
             try {
                     FileWriter writer = new FileWriter(blocklog2, true);
                     writer.append(player.getName() + " have " + blockmaterial.name() + " set!" + " [ " + location + " ]");
                     writer.close();
             } catch (IOException e) {
                     Bukkit.getLogger().warning("Can't write log_set.txt! ERROR!");
             }
	 }
	 
	 @EventHandler
     public void onAsyncPlayerChatEvent(AsyncPlayerChatEvent event) {
             Player player = event.getPlayer();
             String message = event.getMessage();
            
             try {
                     FileWriter writer = new FileWriter(blocklog3, true);
                     writer.append(player.getName() + " wrote " + message);
                     writer.close();
             } catch (IOException e) {
                     Bukkit.getLogger().warning("Can't write log_chat.txt! ERROR!");
             }
	 }
	 
	 @EventHandler
     public void onPlayerCommandPreqrocessEvent(PlayerCommandPreprocessEvent event) {
             Player player = event.getPlayer();
             String message = event.getMessage();
            
             try {
                     FileWriter writer = new FileWriter(blocklog4, true);
                     writer.append(player.getName() + " = " + message);
                     writer.close();
             } catch (IOException e) {
                     Bukkit.getLogger().warning("Can't write log_command.txt! ERROR!");
             }
	 }
}

 

[SlaterB]

> da ich noch 2 Andere Programmiersprachen kann.

dann solltest du für diesen Fehler speziell Verständnis haben, das hat nämlich weniger mit java-spezifischer Syntax zu tun
als allgemeines Verständnis, Programmablauf, wann kommt welcher Code dran, welche Variablen werden verwendet,
welchen Wert haben die dann usw.

> Müsste der Code folgenermassen aussehen?

ist es nicht einfacher, wieder den richtigen Test, 'Start von MineCraft Server' auszuführen?
die fragliche Stelle sollte zum fraglichen Fehler besser sein, ja, aber es gibt immer andere mögliche Fehler

 

[I-Net]

Danke, es funktioniert zwar immer noch nicht aber Sie haben ein bisschen recht bloß ich komme ein bisschen durcheinander.

Danke für ihre Hilfe