Plugin isn't enabling -- Null Pointer Exception

Discussion in 'Plugin Development' started by Caprei, Oct 24, 2014.

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  1. Offline

    Caprei

    Hey all. I'm trying to create a plugin, however it's having trouble enabling. Here's the important parts of the stack trace:
    Code:
    java.lang.NullPointerException
        at me.Caprei.PvPRanks.PvPListener.<init>(PvPListener.java:21) ~[?:?]
        at me.Caprei.PvPRanks.PvPRanks.onEnable(PvPRanks.java:21) ~[?:?]
    Here is the first class:

    Code:java
    1. package me.Caprei.PvPRanks;
    2.  
    3. import java.util.HashMap;
    4.  
    5. import org.bukkit.Bukkit;
    6. import org.bukkit.ChatColor;
    7. import org.bukkit.command.Command;
    8. import org.bukkit.command.CommandSender;
    9. import org.bukkit.configuration.file.FileConfiguration;
    10. import org.bukkit.entity.Player;
    11. import org.bukkit.plugin.java.JavaPlugin;
    12.  
    13. public class PvPRanks extends JavaPlugin{
    14.  
    15.     HashMap<Integer, Integer> levels = new HashMap<Integer, Integer>();
    16.     FileConfiguration config = getConfig();
    17.     private boolean found = false;
    18.     int level;
    19.  
    20.     public void onEnable(){
    21.         Bukkit.getServer().getPluginManager().registerEvents(new PvPListener(this), this);
    22.         getConfig().options().copyDefaults(true);
    23.         int x = 1;
    24.         while(x < 28){
    25.             levels.put(x, (int) Math.pow(config.getInt("Initial amount of points needed between first and second level"), config.getDouble("Multiplier between levels (will be rounded)")));
    26.         }
    27.         getServer().getLogger().info("HashMap containing all values for each level has now been loaded. The multiplier between levels is: " + config.getDouble("Multiplier between levels (will be rounded)"  + ". This can be changed in the config."));
    28.     }
    29.  
    30.     public void onDisable(){
    31.  
    32.     }
    33.  
    34.     public boolean onCommand(CommandSender sender, Command cmd, String commandLabel, String [] args){
    35.         if(cmd.getName().equalsIgnoreCase("pvp")){
    36.             if(args.length < 2){
    37.                 sender.sendMessage(ChatColor.RED + ChatColor.ITALIC.toString() + "All PvP commands require at LEAST two arguments of the form: /pvp <command> <playername>");
    38.             }
    39.  
    40.  
    41.  
    42.             if(args[0].equalsIgnoreCase("rankup")){
    43.                 if(args[2] == null){
    44.                 if(!(sender.hasPermission("pvpr.rankup"))){
    45.                     sender.sendMessage(ChatColor.RED + ChatColor.ITALIC.toString() + "You don't have permission to do that.");
    46.                     return true;
    47.                 }
    48.                 String name = args[1];
    49.  
    50.                 for(Player player:Bukkit.getOnlinePlayers()){
    51.                     if(player.getName().equalsIgnoreCase(name)){
    52.                         player.sendMessage(ChatColor.RED + ChatColor.BOLD.toString() + "You were promoted by: " + sender);
    53.                         int x = 1;
    54.                         while(x < 28){
    55.                             int value = (int) levels.get(x);
    56.                             if(config.getInt("players." + player.getUniqueId().toString()) < value){
    57.                                 level = levels.get(x);
    58.                             }
    59.                         }
    60.                         config.set("players." + player.getUniqueId().toString(), config.getInt("players." + player.getUniqueId().toString()) + (level - config.getInt("players." + player.getUniqueId().toString())));
    61.                         found = true;
    62.                         break;
    63.                     }
    64.                 }
    65.                 if(found == false){
    66.                     sender.sendMessage(ChatColor.RED + ChatColor.BOLD.toString() + "Couldn't find player: " + args[1] + "!");
    67.                 }else{
    68.                     found = false;
    69.                 }
    70.  
    71.  
    72.             }
    73.  
    74.                 return true;
    75.             }
    76.  
    77.  
    78.  
    79.             else if(args[0].equalsIgnoreCase("rankdown")){
    80.                 if(args[2] == null){
    81.               if(!(sender.hasPermission("pvpr.rankdown"))){
    82.                     sender.sendMessage(ChatColor.RED + ChatColor.ITALIC.toString() + "You don't have permission to do that.");
    83.                     return true;
    84.                 }
    85.               String name = args[1];
    86.  
    87.                 for(Player player:Bukkit.getOnlinePlayers()){
    88.                     if(player.getName().equalsIgnoreCase(name)){
    89.                         player.sendMessage(ChatColor.RED + ChatColor.BOLD.toString() + "You were demoted by: " + sender);
    90.                         int x = 1;
    91.                         while(x < 28){
    92.                             int value = (int) levels.get(x);
    93.                             if(config.getInt("players." + player.getUniqueId().toString()) < value){
    94.                                 level = levels.get(x - 2);
    95.                             }
    96.                         }
    97.                         config.set("players." + player.getUniqueId().toString(), config.getInt("players." + player.getUniqueId().toString()) - (config.getInt("players." + player.getUniqueId().toString()) - level));
    98.                         found = true;
    99.                         break;
    100.                     }
    101.                 }
    102.                 if(found == false){
    103.                     sender.sendMessage(ChatColor.RED + ChatColor.BOLD.toString() + "Couldn't find player: " + args[1] + "!");
    104.                 }else{
    105.                     found = false;
    106.                 }
    107.             }
    108.                 return true;
    109.             }
    110.  
    111.  
    112.             else if(args[0].equalsIgnoreCase("rankup")){
    113.                 if(!(sender.hasPermission("pvpr.setrank"))){
    114.                         sender.sendMessage(ChatColor.RED + ChatColor.ITALIC.toString() + "You don't have permission to do that.");
    115.                         return true;
    116.                     }
    117.                   String name = args[1];
    118.                     Integer rank = Integer.parseInt(args[2]);
    119.  
    120.                     for(Player player:Bukkit.getOnlinePlayers()){
    121.                         if(player.getName().equalsIgnoreCase(name)){
    122.                             if(levels.containsKey(rank)){
    123.                                 int needed = levels.get(rank);
    124.                                 config.set("players." + player.getUniqueId().toString(), config.getInt("players." + player.getUniqueId().toString()) + (needed - config.getInt("players." + player.getUniqueId().toString())));
    125.  
    126.                             }else{
    127.                                 sender.sendMessage(ChatColor.RED + ChatColor.ITALIC.toString() + "Couldn't find that rank.");
    128.                             }
    129.                             config.set("players." + player.getUniqueId().toString(), config.getInt("players." + player.getUniqueId().toString()) - (level - config.getInt("players." + player.getUniqueId().toString())));
    130.                             found = true;
    131.                             break;
    132.                         }
    133.                     }
    134.                     if(found == false){
    135.                         sender.sendMessage(ChatColor.RED + ChatColor.BOLD.toString() + "Couldn't find player: " + args[1] + "!");
    136.                     }else{
    137.                         found = false;
    138.                     }
    139.                 return true;
    140.             }
    141.  
    142.             else if(args[0].equalsIgnoreCase("rankdown")){
    143.                 if(!(sender.hasPermission("pvpr.setrank"))){
    144.                         sender.sendMessage(ChatColor.RED + ChatColor.ITALIC.toString() + "You don't have permission to do that.");
    145.                         return true;
    146.                     }
    147.                   String name = args[1];
    148.                     Integer rank = Integer.parseInt(args[2]);
    149.  
    150.                     for(Player player:Bukkit.getOnlinePlayers()){
    151.                         if(player.getName().equalsIgnoreCase(name)){
    152.                             if(levels.containsKey(rank)){
    153.                                 int needed = levels.get(rank);
    154.                                 config.set("players." + player.getUniqueId().toString(), config.getInt("players." + player.getUniqueId().toString()) + (needed - config.getInt("players." + player.getUniqueId().toString())));
    155.  
    156.                             }else{
    157.                                 sender.sendMessage(ChatColor.RED + ChatColor.ITALIC.toString() + "Couldn't find that rank.");
    158.                             }
    159.                             config.set("players." + player.getUniqueId().toString(), config.getInt("players." + player.getUniqueId().toString()) - (config.getInt("players." + player.getUniqueId().toString()) - level));
    160.                             found = true;
    161.                             break;
    162.                         }
    163.                     }
    164.                     if(found == false){
    165.                         sender.sendMessage(ChatColor.RED + ChatColor.BOLD.toString() + "Couldn't find player: " + args[1] + "!");
    166.                     }else{
    167.                         found = false;
    168.                     }
    169.                 return true;
    170.             }
    171.  
    172.  
    173.  
    174.  
    175.             else if(args[0].equalsIgnoreCase("stats")){
    176.                 if(!(sender.hasPermission("pvpr.stats"))){
    177.                     sender.sendMessage(ChatColor.RED + ChatColor.ITALIC.toString() + "You don't have permission to do that.");
    178.                     return true;
    179.                 }
    180.  
    181.                 String name = args[1];
    182.  
    183.                 for(Player player:Bukkit.getOnlinePlayers()){
    184.                     if(player.getName().equalsIgnoreCase(name)){
    185.                         sender.sendMessage(ChatColor.GOLD + ChatColor.BOLD.toString() + ChatColor.STRIKETHROUGH + "======================" + ChatColor.GREEN + ChatColor.BOLD.toString() + "[PVPRANKS STATS]" + "======================" +
    186.                     ChatColor.BOLD + ChatColor.GREEN.toString() + "Player: " + ChatColor.GOLD + ChatColor.ITALIC.toString() + player.getName() +
    187.                     ChatColor.BOLD + ChatColor.GREEN.toString() + "Rank: " + ChatColor.GOLD + ChatColor.ITALIC.toString() + player.getName() +
    188.                     ChatColor.BOLD + ChatColor.GREEN.toString() + "Suffix: " + ChatColor.GOLD + ChatColor.ITALIC.toString() + player.getName() +
    189.                     ChatColor.BOLD + ChatColor.GREEN.toString() + "Points: " + ChatColor.GOLD + ChatColor.ITALIC.toString() + player.getName() +
    190.                     ChatColor.BOLD + ChatColor.GREEN.toString() + "Points to next level: " + ChatColor.GOLD + ChatColor.ITALIC.toString() + player.getName() +
    191.                     ChatColor.BOLD + ChatColor.GREEN.toString() + "KDR: " + ChatColor.GOLD + ChatColor.ITALIC.toString() + player.getName()       
    192.  
    193.                     //TODO:
    194.                     //ADD IN ACTUAL VALUES
    195.                     //TRACK KILLS
    196.                     //KILL FARMING PREVENTION
    197.  
    198.  
    199.  
    200.  
    201.  
    202.                                 );
    203.  
    204.                         found = true;
    205.                         break;
    206.                     }
    207.                 }if(found == false){
    208.                     sender.sendMessage(ChatColor.RED + ChatColor.BOLD.toString() + "Couldn't find player: " + args[1] + "!");
    209.                 }else{
    210.                     found = false;
    211.                 }
    212.             return true;
    213.  
    214.             }
    215.  
    216.  
    217.  
    218.  
    219.  
    220.  
    221.  
    222.  
    223.         }
    224.  
    225.         return true;
    226.     }
    227.  
    228.  
    229.  
    230.  
    231. }
    232.  


    And the second:

    Code:java
    1. package me.Caprei.PvPRanks;
    2.  
    3. import java.util.HashMap;
    4.  
    5. import org.bukkit.Bukkit;
    6. import org.bukkit.ChatColor;
    7. import org.bukkit.entity.Entity;
    8. import org.bukkit.entity.Player;
    9. import org.bukkit.event.EventHandler;
    10. import org.bukkit.event.Listener;
    11. import org.bukkit.event.entity.PlayerDeathEvent;
    12. import org.bukkit.event.player.AsyncPlayerChatEvent;
    13. import org.bukkit.event.player.PlayerJoinEvent;
    14.  
    15. public class PvPListener implements Listener{
    16.     PvPRanks plugin;
    17.     int experience;
    18.     int level;
    19.     String suffix;
    20.     HashMap<Integer, Integer> list = plugin.levels;
    21.     int x = 1;
    22.  
    23.     public PvPListener(PvPRanks instance){
    24.         plugin = instance;
    25.     }
    26.  
    27.     @EventHandler
    28.     public void onPlayerJoin(PlayerJoinEvent event){
    29.         String playeruuid = event.getPlayer().getUniqueId().toString();
    30.         if(!(plugin.config.contains("players." + playeruuid))){
    31.             plugin.config.addDefault("players." + playeruuid, 0);
    32.             experience = 0;
    33.             suffix = plugin.config.getString("suffix.0");
    34.             suffix = suffix.replaceAll("&", "§");
    35.         }else{
    36.             experience = plugin.config.getInt("players." + playeruuid);
    37.             while(x < 28){
    38.                 int value = (int) list.get(x);
    39.                 if(experience < value){
    40.                     level = x - 1;
    41.                     break;
    42.                 }
    43.             }
    44.             suffix = plugin.config.getString("suffix." + level);
    45.             suffix = suffix.replaceAll("&", "§");
    46.         }
    47.     }
    48.  
    49.     @EventHandler
    50.     public void onPlayerDeath(PlayerDeathEvent event){
    51.         Entity e = event.getEntity();
    52.         if(e instanceof Player){
    53.             Player p = (Player) e;
    54.  
    55.             if(!(p.getKiller() instanceof Player)){
    56.                 return;
    57.             }
    58.  
    59.  
    60.             String playeruuid = p.getUniqueId().toString();
    61.             int preexperience = plugin.config.getInt("players." + playeruuid);
    62.             if(preexperience == 0){
    63.                 p.sendMessage(ChatColor.GREEN + "You didn't lose any points because you're already on zero!");
    64.                 return;
    65.             }
    66.             plugin.config.set("players." + playeruuid, new Integer(experience - plugin.config.getInt("How many points do you lose when you die")));
    67.             int afterexperience = plugin.config.getInt("players." + playeruuid);
    68.             while(x < 28){
    69.                 int value = (int) list.get(x);
    70.                 if(preexperience >= value && afterexperience < value){
    71.                     level = x;
    72.                     p.sendMessage(ChatColor.RED + ChatColor.BOLD.toString() + "You went down 1 rank after being killed by " + ChatColor.YELLOW + "[" + ChatColor.GRAY + p.getKiller().getName() + ChatColor.YELLOW + "]");
    73.                     break;
    74.                 }
    75.             }
    76.  
    77.             Player killer = p.getKiller();
    78.             p.sendMessage(ChatColor.GREEN + "You lost: " + ChatColor.GOLD + plugin.config.getInt("How many points do you lose when you die") + ChatColor.GREEN + ", for being killed by: " + ChatColor.GOLD + killer.getName());
    79.             killer.sendMessage(ChatColor.GREEN + "You got: " + ChatColor.GOLD + plugin.config.getInt("How many points are awarded when you kill someone else") + ChatColor.GREEN + ", for killing: " + ChatColor.GOLD + p.getName());
    80.             String killeruuid = killer.getUniqueId().toString();
    81.             int killerpreexperience = plugin.config.getInt("players." + killeruuid);
    82.             plugin.config.set("players." + killeruuid, new Integer(experience - plugin.config.getInt("How many points do you lose when you die")));
    83.             int killerafterexperience = plugin.config.getInt("players." + killeruuid);
    84.             while(x < 28){
    85.                 int value = (int) list.get(x);
    86.                 if(killerpreexperience < value && killerafterexperience >= value){
    87.                     level = x;
    88.                     p.sendMessage(ChatColor.GREEN + ChatColor.BOLD.toString() + "You went up 1 rank after killing " + ChatColor.YELLOW + "[" + ChatColor.GRAY + p.getName() + ChatColor.YELLOW + "]");
    89.                     break;
    90.                 }
    91.             }
    92.  
    93.         }
    94.  
    95.  
    96.     }
    97.  
    98.  
    99.     @EventHandler
    100.     public void onAsyncPlayerChat(AsyncPlayerChatEvent event){
    101.         String firstmessage = event.getMessage();
    102.         String playerdisplayname = event.getPlayer().getDisplayName();
    103.         String finalmessage = playerdisplayname + suffix + ": " + firstmessage;
    104.         Bukkit.getServer().broadcastMessage(finalmessage);
    105.     }
    106.  
    107. }
    108.  


    Thank you very much for your help!
     
    Caprei, Oct 24, 2014
    #1
  2. Offline

    fireblast709

    Caprei plugin is null when you try to get plugin.levels. initialise list after you set plugin in the constructor.

    Also:
    • Don't call getConfig() before the plugin is initialised (this happens in the constructor of JavaPlugin).
    • flag == false is the same as !flag. flag == true is the same as flag.
    • Your while loops are infinite since x never increases in value.
    • Don't use the Minecraft Logger (getServer().getLogger()), use the getLogger() from JavaPlugin.
     
    fireblast709, Oct 24, 2014
    #2
    Caprei likes this.
  3. Offline

    Caprei

    fireblast709

    Thanks for your advice. I was really tired when writing this and prone to mistakes like
    • Your while loops are infinite since x never increases in value.
    Thank you so much. Fixing everything. :)
     
    Caprei, Oct 24, 2014
    #3
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