Tutorial Using MySQL In your Plugins!

Not at all. My query's only purpose is that of checking if the Location entry is the same as the location of the player. It's an if inside an event handler.

 

@dadus33 RingOfStorms is correct. You already know that the location is correct, because that is part of the query. If the result set is closed, then it is empty, so the location is not correct.

 

I can see that, but how can I check if the location of the player is that found inside the database? I mean, without the exception.

 

@dadus33

Code:

ResultSet set = l.statement.executeQuery("SELECT Location FROM LaunchPlate WHERE Location = '"+ serializeLoc(loc.getBlock().getLocation())+"';");
if (!set.next()) {
//code here

 

I still don't get your query. You are selecting the Location column where the Location column is equal to something you already know. Maybe you should just COUNT rather than select the same exact column that you already know.

SELECT COUNT(*) FROM LaunchPlate WHERE Location = ....

This way you just get the number matching, and are also not having the SQL server send a bunch of useless data.

And another thing, your second line with the IF statement doesn't make a whole lot of sense.
if(player.hasPermission(l.p)&& set.getString("Location").equals(serializeLoc(loc.getBlock().getLocation()))){

You should probably check the permissions FIRST before you start using sql as you are just wasting bandwidth if you do absolutely nothing with the result due to no permission. And then the second part of your if statement will never be false because you've already had SQL return you a location that does equal the one you just asked for. What you wrote there was basically
if(player has permission && true == true)

So use count instead and format it more like

Pseudo code:

Code:

if(player has permission) {
   Result ... "SELECT COUNT(*)..."
   if(result > 0) {
      /code
   }
}

@dadus33
@pie_flavor

 

Look, I'm not an SQL expert, actualy, I'm more of a begginer, so I don't kinda understand what you mean. I want to check if a player's location exists inside the database. As far as I know, the COUNT(*) function will return the number of entries in a table, and I really don't know how that would be useful to me. I don't want to get the location from the table, because, as you said, I already know it. However, I want to CHECK if it exists. But thank you for the idea of putting the permission thingy first.

EDIT:
Eh, I think I got it now. Using the COUNT function I can check wheter the location is present in the db or not. If it is, it will return 1, else, 0. Thank you so much!

Hmm, guys, how can I get the value of a result set? I mean, I can't just do 'if (res>0)'. And getInt doesn't work...

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

 

@dadus33

Code:

if (result.next() && result.getInt("value") > 0) {

A ResultSet has a pointer. The value you pass, in this case "value", is the column label; the pointer designates the row number. It starts before the first one. The boolean function next() moves it one farther, and returns false if it is now past the entire set.

 

if (getResultSet().first() && getResultSet().getInt(1) > 0)
Same as above but doesn't require you to know column 1's name which makes it a little easier to remember and use elsewhere

 

@RingOfStorms Except the correct column isn't necessarily the first one.
However, he does know the name.

 

Thanks guys, solved it. Just used res.getInt(1) and it worked.

 

@dadus33 I would also hope you are not doing IO on the database on the main thread, and instead use some sort of hashmap to store the data

 

Hey guys, Just started using this lib and it is great I am having a problem with my code. I followed A YouTube video but I am getting some errors. Bellow is my code and the errors. I hope you can help me.

Code:

package me.flamboo.WebbedMCAuth;
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
import org.bukkit.ChatColor;
import org.bukkit.Server;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.command.ConsoleCommandSender;
import org.bukkit.configuration.file.FileConfiguration;
import org.bukkit.entity.Player;
import org.bukkit.event.Listener;
import org.bukkit.plugin.PluginManager;
import org.bukkit.plugin.java.JavaPlugin;
import code.husky.mysql.MySQL;
public class Main extends JavaPlugin implements Listener{
      
    public String sqhost = getConfig().getString("Database.Host");
    public String sqport = getConfig().getString("Database.port");
    public String sqdb = getConfig().getString("Database.Database");
    public String squser = getConfig().getString("Database.User");
    public String sqpass = getConfig().getString("Database.Password");
    public String sqtable = getConfig().getString("Database.Table");
       public MySQL db;
       public boolean logDB = true ;
          public void onEnable(){
               Server server = getServer();
        ConsoleCommandSender console = server.getConsoleSender();
               console.sendMessage(ChatColor.RED + getDescription().getName());
        console.sendMessage(ChatColor.RED + "Version " + getDescription().getVersion());
             PluginManager pm = getServer().getPluginManager();
      pm.registerEvents(this, this);
           FileConfiguration config = getConfig();
           config.addDefault("Database.Host", "localhost");
      config.addDefault("Database.Port", 3306);
      config.addDefault("Database.Database", "test");
      config.addDefault("Database.User", "root");
      config.addDefault("Database.Password", "fliplip1");
      config.addDefault("Database.Table", "test");
      config.options().copyDefaults(true);
      saveConfig();
           try {
        this.setupDB();
    } catch (ClassNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
        this.logDB = false;
        console.sendMessage("Error (1) :" + e);
    } catch (SQLException e) {
        // TODO Auto-generated catch block
        this.logDB = false;
        e.printStackTrace();
        console.sendMessage("Error (2) :" + e);
    }
          }
          public void onEnalbe(){
          }
    public boolean onCommand(CommandSender sender, Command cmd, String commandLabel, String[] arg)
      {
        Player player = (Player)sender;
        Server server = getServer();
        ConsoleCommandSender console = server.getConsoleSender();
        if (commandLabel.equalsIgnoreCase("auth")) {
            if (player.hasPermission("auth.can")) {
                if(arg.length == 0){
                    player.sendMessage(ChatColor.GRAY + "You need to enter your site ID");
                }
                else if(arg.length == 1){
                    Player ap = player.getServer().getPlayer(arg[0]);
                    String pname = player.getDisplayName().toLowerCase();
                    try{
                    if(!this.db.checkConnection())
                        this.db.openConnection();
                    Statement statement = this.db.getConnection().createStatement();
                    statement.executeUpdate("UPDATE '"+sqtable+" SET 'Auth'='1' WHERE 'Site'="+ap+"';");
                    statement.executeUpdate("UPDATE '"+sqtable+" SET 'Name'='"+pname+"' WHERE 'Site'="+ap+"';");
                    } catch (ClassNotFoundException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                        this.logDB = false;
                        console.sendMessage("Error: (3) " + e);
                    } catch (SQLException e) {
                        // TODO Auto-generated catch block
                        this.logDB = false;
                        e.printStackTrace();
                        console.sendMessage("Error: (4) " + e);
                    }
                }
            }
            else
            {
            }
        }
        return true;
      }
        public void setupDB() throws SQLException, ClassNotFoundException{
        this.db = new MySQL(this, sqhost, sqport, sqdb, squser, sqpass);
        this.db.openConnection();
        Statement statement = this.db.getConnection().createStatement();
        statement.executeUpdate("CREATE TABLE IF NOT EXISTS '"+sqtable+"' ('Site' int,'name' varchar(32),'Auth' int)");
        statement.close();
    }
}

Code:

[18:54:55 INFO]: [WebbedMC_Auth] Enabling WebbedMC_Auth v1.0
[18:54:55 INFO]: WebbedMC_Auth
[18:54:55 INFO]: Version 1.0
[18:54:55 WARN]: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Cannot load connection class because of underlying exception: 'java.lang.NumberFormatException: For input string: "null"'.
[18:54:55 WARN]: at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
[18:54:55 WARN]: at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
[18:54:55 WARN]: at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
[18:54:55 WARN]: at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
[18:54:55 WARN]: at com.mysql.jdbc.Util.handleNewInstance(Util.java:407)
[18:54:55 WARN]: at com.mysql.jdbc.Util.getInstance(Util.java:382)
[18:54:55 WARN]: at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1013)
[18:54:55 WARN]: at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:987)
[18:54:55 WARN]: at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:982)
[18:54:55 WARN]: at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:927)
[18:54:55 WARN]: at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:314)
[18:54:55 WARN]: at java.sql.DriverManager.getConnection(DriverManager.java:571)
[18:54:55 WARN]: at java.sql.DriverManager.getConnection(DriverManager.java:215)
[18:54:55 WARN]: at code.husky.mysql.MySQL.openConnection(MySQL.java:58)
[18:54:55 WARN]: at me.flamboo.WebbedMCAuth.Main.setupDB(Main.java:123)
[18:54:55 WARN]: at me.flamboo.WebbedMCAuth.Main.onEnable(Main.java:60)
[18:54:55 WARN]: at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:321)
[18:54:55 WARN]: at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:340)
[18:54:55 WARN]: at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:405)
[18:54:55 WARN]: at org.bukkit.craftbukkit.v1_8_R3.CraftServer.loadPlugin(CraftServer.java:356)
[18:54:55 WARN]: at org.bukkit.craftbukkit.v1_8_R3.CraftServer.enablePlugins(CraftServer.java:316)
[18:54:55 WARN]: at net.minecraft.server.v1_8_R3.MinecraftServer.s(MinecraftServer.java:418)
[18:54:55 WARN]: at net.minecraft.server.v1_8_R3.MinecraftServer.k(MinecraftServer.java:382)
[18:54:55 WARN]: at net.minecraft.server.v1_8_R3.MinecraftServer.a(MinecraftServer.java:337)
[18:54:55 WARN]: at net.minecraft.server.v1_8_R3.DedicatedServer.init(DedicatedServer.java:256)
[18:54:55 WARN]: at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:528)
[18:54:55 WARN]: at java.lang.Thread.run(Thread.java:745)
[18:54:55 WARN]: Caused by: java.lang.NumberFormatException: For input string: "null"
[18:54:55 WARN]: at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
[18:54:55 WARN]: at java.lang.Integer.parseInt(Integer.java:492)
[18:54:55 WARN]: at java.lang.Integer.parseInt(Integer.java:527)
[18:54:55 WARN]: at com.mysql.jdbc.NonRegisteringDriver.port(NonRegisteringDriver.java:831)
[18:54:55 WARN]: at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:305)
[18:54:55 WARN]: ... 16 more

the errors

 

Code:

MySQL MySQL = new MySQL(this, ip, port, name, user, pass);
        try {
            c = MySQL.openConnection();
        } catch (ClassNotFoundException e) {
            getLogger().severe("ClassNotFoundException");
        } catch (SQLException e) {
            getLogger().severe("SQLException");
        }

When running this code the last log message is shown. I have checked so many times and I am using the same connection values loaded from a config as another mysql plugin that works fine on the same test server and test database.

 

Helloo There Bukkit Community, I was wondering how would i make it so it will add a player to the table on my mysql database but if the player is already on there do nothing?

 

When the player first joins the server check if they exist in the table with SELECT * and if it they don't exist create a new table for them.

 

@Eos Why would you select "*"?

 

Are you still active on the forums? I need help

 

@Konato_K why not?

 

@MCMatters Because it's slower, more overload to the database and unnecessary data sent?

 

Nice tutorial, worked. I only bumped into this small problem:

Code:

 MySQL MySQL = new MySQL("host.name", "port", "database", "user", "pass");
    Connection c = null;

    @Override
    public void onEnable() {
        c = MySQL.openConnection();
//Unhandled exception type ClassNotFoundException

And btw, how do you close the connection? I assume it isnt as simple as c = MySQL.closeConnection(); (In onDisable())?

 

@shizleshizle
If there is a "CNF" error, that means you imported the wrong thing. Can we see your imports?

Also, to close a port I believe is "c.close()" or "c.closeConnection();".

 

r

 

I'm getting the "no database selected" error
(

Code:

[21:35:59 WARN]: java.sql.SQLException: No database selected
[21:35:59 WARN]:        at com.mysql.jdbc.SQLError.createSQLException(SQLError.j
ava:1073)
[21:35:59 WARN]:        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:
3593)
[21:35:59 WARN]:        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:
3525)
[21:35:59 WARN]:        at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1986)

[21:35:59 WARN]:        at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:21
40)
[21:35:59 WARN]:        at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.
java:2620)
[21:35:59 WARN]:        at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.
java:2570)
[21:35:59 WARN]:        at com.mysql.jdbc.StatementImpl.executeQuery(StatementIm
pl.java:1474)
[21:35:59 WARN]:        at me.pvpdog.sqlproject.commands.AddCommand.onCommand(Ad
dCommand.java:64)
[21:35:59 WARN]:        at org.bukkit.command.PluginCommand.execute(PluginComman
d.java:44)
[21:35:59 WARN]:        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCo
mmandMap.java:141)
[21:35:59 WARN]:        at org.bukkit.craftbukkit.v1_8_R3.CraftServer.dispatchCo
mmand(CraftServer.java:640)
[21:35:59 WARN]:        at net.minecraft.server.v1_8_R3.PlayerConnection.handleC
ommand(PlayerConnection.java:1162)
[21:35:59 WARN]:        at net.minecraft.server.v1_8_R3.PlayerConnection.a(Playe
rConnection.java:997)
[21:35:59 WARN]:        at net.minecraft.server.v1_8_R3.PacketPlayInChat.a(Packe
tPlayInChat.java:45)
[21:35:59 WARN]:        at net.minecraft.server.v1_8_R3.PacketPlayInChat.a(Packe
tPlayInChat.java:1)
[21:35:59 WARN]:        at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.
run(SourceFile:13)
[21:35:59 WARN]:        at java.util.concurrent.Executors$RunnableAdapter.call(U
nknown Source)
[21:35:59 WARN]:        at java.util.concurrent.FutureTask.run(Unknown Source)
[21:35:59 WARN]:        at net.minecraft.server.v1_8_R3.SystemUtils.a(SystemUtil
s.java:19)
[21:35:59 WARN]:        at net.minecraft.server.v1_8_R3.MinecraftServer.B(Minecr
aftServer.java:714)
[21:35:59 WARN]:        at net.minecraft.server.v1_8_R3.DedicatedServer.B(Dedica
tedServer.java:374)
[21:35:59 WARN]:        at net.minecraft.server.v1_8_R3.MinecraftServer.A(Minecr
aftServer.java:653)
[21:35:59 WARN]:        at net.minecraft.server.v1_8_R3.MinecraftServer.run(Mine
craftServer.java:556)
[21:35:59 WARN]:        at java.lang.Thread.run(Unknown Source)

On

Code:

try {
                    ResultSet res = statement.executeQuery("SELECT * FROM players WHERE email = "+args[1].toLowerCase());
                    res.next();

                    if(res.getString("email")==null){
                        p.sendMessage(ChatColor.GREEN+"You have not registered!");
                        return true;
                    }else{
                        p.sendMessage(ChatColor.RED+"You have already registered your email!");
                        return false;
                    }
                } catch (SQLException e) {
                    e.printStackTrace();
                    return false;
                }

Plz help.

 

You have to actually connect to the database first.

 

I do have a connection.

 

In c = MySQL.openConnection(); i have to add that in my onEnable() with try/catch ?

 

Probably, your IDE will tell you

 

Could anyone help me please? Im getting this error:

Code:

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
[13:06:42 WARN]:        at sun.reflect.GeneratedConstructorAccessor226.newInstance(Unknown Source)
[13:06:42 WARN]:        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
[13:06:42 WARN]:        at java.lang.reflect.Constructor.newInstance(Unknown Source)
[13:06:42 WARN]:        at com.mysql.jdbc.Util.handleNewInstance(Util.java:404)
[13:06:42 WARN]:        at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:988)
[13:06:42 WARN]:        at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:341)
[13:06:42 WARN]:        at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2251)
[13:06:42 WARN]:        at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2284)
[13:06:42 WARN]:        at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2083)
[13:06:42 WARN]:        at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:806)
[13:06:42 WARN]:        at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
[13:06:42 WARN]:        at sun.reflect.GeneratedConstructorAccessor223.newInstance(Unknown Source)
[13:06:42 WARN]:        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
[13:06:42 WARN]:        at java.lang.reflect.Constructor.newInstance(Unknown Source)
[13:06:42 WARN]:        at com.mysql.jdbc.Util.handleNewInstance(Util.java:404)
[13:06:42 WARN]:        at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:410)
[13:06:42 WARN]:        at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:328)
[13:06:42 WARN]:        at java.sql.DriverManager.getConnection(Unknown Source)
[13:06:42 WARN]:        at java.sql.DriverManager.getConnection(Unknown Source)
[13:06:42 WARN]:        at me.zachbears27.MySQL.openConnection(MySQL.java:77)
[13:06:42 WARN]:        at me.zachbears27.DeathLocation.onEnable(DeathLocation.java:32)
[13:06:42 WARN]:        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:271)
[13:06:42 WARN]:        at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:337)
[13:06:42 WARN]:        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:405)
[13:06:42 WARN]:        at org.bukkit.craftbukkit.v1_11_R1.CraftServer.enablePlugin(CraftServer.java:375)
[13:06:42 WARN]:        at org.bukkit.craftbukkit.v1_11_R1.CraftServer.enablePlugins(CraftServer.java:325)
[13:06:42 WARN]:        at org.bukkit.craftbukkit.v1_11_R1.CraftServer.reload(CraftServer.java:749)
[13:06:42 WARN]:        at org.bukkit.Bukkit.reload(Bukkit.java:540)
[13:06:42 WARN]:        at org.bukkit.command.defaults.ReloadCommand.execute(ReloadCommand.java:25)
[13:06:42 WARN]:        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141)
[13:06:42 WARN]:        at org.bukkit.craftbukkit.v1_11_R1.CraftServer.dispatchCommand(CraftServer.java:649)
[13:06:42 WARN]:        at org.bukkit.craftbukkit.v1_11_R1.CraftServer.dispatchServerCommand(CraftServer.java:635)
[13:06:42 WARN]:        at net.minecraft.server.v1_11_R1.DedicatedServer.aM(DedicatedServer.java:437)
[13:06:42 WARN]:        at net.minecraft.server.v1_11_R1.DedicatedServer.D(DedicatedServer.java:400)
[13:06:42 WARN]:        at net.minecraft.server.v1_11_R1.MinecraftServer.C(MinecraftServer.java:675)
[13:06:42 WARN]:        at net.minecraft.server.v1_11_R1.MinecraftServer.run(MinecraftServer.java:574)
[13:06:42 WARN]:        at java.lang.Thread.run(Unknown Source)
[13:06:42 WARN]: Caused by: java.net.ConnectException: Connection refused: connect
[13:06:42 WARN]:        at java.net.DualStackPlainSocketImpl.connect0(Native Method)
[13:06:42 WARN]:        at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
[13:06:42 WARN]:        at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
[13:06:42 WARN]:        at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
[13:06:42 WARN]:        at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
[13:06:42 WARN]:        at java.net.PlainSocketImpl.connect(Unknown Source)
[13:06:42 WARN]:        at java.net.SocksSocketImpl.connect(Unknown Source)
[13:06:42 WARN]:        at java.net.Socket.connect(Unknown Source)
[13:06:42 WARN]:        at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:211)
[13:06:42 WARN]:        at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:300)
[13:06:42 WARN]:        ... 31 more

Code:

Code:

package me.zachbears27;
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;

import org.bukkit.Bukkit;
import org.bukkit.Location;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.entity.PlayerDeathEvent;
import org.bukkit.plugin.java.JavaPlugin;
import me.zachbears27.MySQL;

public class DeathLocation extends JavaPlugin implements Listener {
    DeathLocation plugin;

    MySQL MySQL = new MySQL("localhost", "3306", "id115504_mumbo", "STUFF", "STUFF");
       Connection connection = null;


@Override
public void onDisable() {

}

@Override
public void onEnable() {

  getServer().getPluginManager().registerEvents(this, this);
  try {
    connection = MySQL.openConnection();
    Bukkit.broadcastMessage("uau");
} catch (ClassNotFoundException e) {
    e.printStackTrace();
} catch (SQLException e) {

    e.printStackTrace();
}

}

@EventHandler
public void onPlayerDeath(PlayerDeathEvent e) {
  if (e.getEntity() instanceof Player) {
   Player p = e.getEntity();
   Location loc = e.getEntity().getLocation();
   int x = loc.getBlockX();
   int y = loc.getBlockY();
   int z = loc.getBlockZ();
   String time = "its time";
   Bukkit.broadcastMessage(x + " " + y + " " + z );
   String statementstring = "INSERT INTO `" + "id115504_mumbo" + "`DeathLocations` (`PlayerName`, `X`, `Y`, `Z`, `Time`) VALUES (" + p.getName() + ", '" + x + "', '" + y + "', '" + z + "', '" + time + "');";
   try {
    Statement statement = this.connection.createStatement();
    statement.executeUpdate(statementstring);
} catch (SQLException e1) {
    // TODO Auto-generated catch block
    e1.printStackTrace();
}
}
}

}

 

Hey guys,

I have a problem.

These is my code:

Code:

package Main;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;

import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import org.bukkit.event.player.PlayerJoinEvent;
import org.bukkit.plugin.java.JavaPlugin;

import MySQL.MySQL;

public class one extends JavaPlugin{
   
   
    MySQL MySQL = new MySQL(plugin, "**********", "3306", "LoginSecurity", "********", "**********");
    Connection c = null;
   
    @Override
    public void onEnable() {
       
        c = MySQL.openConnection();
       
    }
   
    Statement statement = c.createStatement();
   
    public void OnJoin(PlayerJoinEvent e){
        Statement statement = c.createStatement();
        ResultSet res = statement.executeQuery("SELECT * FROM users WHERE UUID = '" + e.getPlayer().getUniqueId().toString() + "';");
        res.next();
       
        if(res.getString("UUID") == null){
            statement.executeQuery("INSERT INTO users (`id`, `UUID`) VALUES (`null`, `"+ e.getPlayer().getUniqueId().toString() +"`);");
            e.getPlayer().sendMessage("/register <passwort>");
           
        }
    }
   
    @Override
    public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) {
       
        Player p = (Player) p;
       
        if(cmd.getName().equalsIgnoreCase("register")){
            ResultSet res1 = statement.executeQuery("SELECT password FROM users WHERE UUID = '" + p.getUniqueId().toString() + "';");
            if(res1.getString("password") == null){
                if(args.length == 0){
                    p.sendMessage("/register <password>");
                } else if(args.length == 1){
                    String pw = args[0];
                    statement.executeQuery("UPDATE `users` set `password` = '"+ pw +"' WHERE UUID = " + p.getUniqueId().toString() + ";");
                    p.sendMessage("Du hast dich erfolgreich registriert!");
                    p.sendMessage("/email <email>");
                }
            } else {
                p.sendMessage("Du hast dich schon Registriert! (/login <password>)");
            }
           
            return true;
        }
       
        if(cmd.getName().equalsIgnoreCase("email")){
            ResultSet res2 = statement.executeQuery("SELECT email FROM users WHERE UUID = '" + p.getUniqueId().toString() + "';");
            if(res2.getString("email") == null){
                if(args.length == 0){
                    p.sendMessage("/email <email>");
                } else if(args.length == 1){
                    String email = args[0];
                    statement.executeQuery("UPDATE `users` set `email` = '"+ email +"' WHERE UUID = " + p.getUniqueId().toString() + ";");
                    p.sendMessage("Du hast deine Email-Adresse erfolgreich hinterlegt!");
                }
            } else {
                p.sendMessage("Du hast schon eine Email-Adresse hinterlegt!");
            }
            return true;
        }
       
       
        return false;
    }
   
    @Override
    public void onDisable() {
       
        MySQL.closeConnection();
       
    }
   
   
   
}

I have an error on line 18.

Line 18:

Code:

 MySQL MySQL = new MySQL(plugin, "*********", "3306", "LoginSecurity", "*******", "*******"); 

The error ist plugin but i don't know to fix it.
Can anyone help me?

Sorry for my bad english.