Solved Remove From Database

Hey,

I made a banning plugin that uses a database. When I ban someone it works fine but I can't unban them. (Using UUIDS)Here is my unban method:

Code:

    public void unbanPlayer(Player p) {
        try {
            PreparedStatement statement = connection.prepareStatement("delete from users where uuid='" + p.getUniqueId() + "';");
            statement.executeUpdate();
            statement.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        

Here is where I use the method:
And yes, I returned onCommand boolean.

Code:java

 if (cmd.getName().equalsIgnoreCase("unban")) {
if (sender.hasPermission("punishment.use")) {
if (args.length < 1) {
sender.sendMessage(ChatColor.GREEN + "/unban <player>");
return true;
}
 
Player player = Bukkit.getPlayer(args[0]);
 
mysql.unbanPlayer(player);
return true;
}
And, yes, I returned the boolean.
}

And the error:

Code:

>unban macboinc1
[09:51:09 WARN]: java.lang.NullPointerException
[09:51:09 WARN]:        at me.macboinc1.punishment.MySQL.unbanPlayer(MySQL.java:
51)
[09:51:09 WARN]:        at me.macboinc1.punishment.Punishment.onCommand(Punishme
nt.java:74)
[09:51:09 WARN]:        at org.bukkit.command.PluginCommand.execute(PluginComman
d.java:44)
[09:51:09 WARN]:        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCo
mmandMap.java:180)
[09:51:09 WARN]:        at org.bukkit.craftbukkit.v1_7_R3.CraftServer.dispatchCo
mmand(CraftServer.java:701)
[09:51:09 WARN]:        at org.bukkit.craftbukkit.v1_7_R3.CraftServer.dispatchSe
rverCommand(CraftServer.java:688)
[09:51:09 WARN]:        at net.minecraft.server.v1_7_R3.DedicatedServer.aB(Dedic
atedServer.java:296)
[09:51:09 WARN]:        at net.minecraft.server.v1_7_R3.DedicatedServer.v(Dedica
tedServer.java:261)
[09:51:09 WARN]:        at net.minecraft.server.v1_7_R3.MinecraftServer.u(Minecr
aftServer.java:558)
[09:51:09 WARN]:        at net.minecraft.server.v1_7_R3.MinecraftServer.run(Mine
craftServer.java:469)
[09:51:09 WARN]:        at net.minecraft.server.v1_7_R3.ThreadServerApplication.
run(SourceFile:628)
>unban macboinc1
[09:51:11 WARN]: java.lang.NullPointerException
[09:51:11 WARN]:        at me.macboinc1.punishment.MySQL.unbanPlayer(MySQL.java:
51)
[09:51:11 WARN]:        at me.macboinc1.punishment.Punishment.onCommand(Punishme
nt.java:74)
[09:51:11 WARN]:        at org.bukkit.command.PluginCommand.execute(PluginComman
d.java:44)
[09:51:11 WARN]:        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCo
mmandMap.java:180)
[09:51:11 WARN]:        at org.bukkit.craftbukkit.v1_7_R3.CraftServer.dispatchCo
mmand(CraftServer.java:701)
[09:51:11 WARN]:        at org.bukkit.craftbukkit.v1_7_R3.CraftServer.dispatchSe
rverCommand(CraftServer.java:688)
[09:51:11 WARN]:        at net.minecraft.server.v1_7_R3.DedicatedServer.aB(Dedic
atedServer.java:296)
[09:51:11 WARN]:        at net.minecraft.server.v1_7_R3.DedicatedServer.v(Dedica
tedServer.java:261)
[09:51:11 WARN]:        at net.minecraft.server.v1_7_R3.MinecraftServer.u(Minecr
aftServer.java:558)
[09:51:11 WARN]:        at net.minecraft.server.v1_7_R3.MinecraftServer.run(Mine
craftServer.java:469)
[09:51:11 WARN]:        at net.minecraft.server.v1_7_R3.ThreadServerApplication.
run(SourceFile:628)
>

Please help!
-Mac

 

First, I just want to point out that I have no idea how you got that code to not throw errors. On to the error, can you tell me what's on line 51 of the MySQL class?

 

Sorry for the pasting error on the unbanplayer method,the computer derped out, anyways, this is what is on line 51:

Code:java

PreparedStatement statement = connection.prepareStatement("delete from users where uuid='" + p.getUniqueId() + "';");

 

Can you show us where you initialize your "connection" variable? It's probably null, hence the NullPointerException.

 

private Connection connection;

Oh, I see the problem now, just, how would I fix this?

Code:java

package me.macboinc1.punishment;
 
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
 
import org.bukkit.entity.Player;
 
public class MySQL {
 
    private Connection connection;
 
    public MySQL(String ip, String userName, String password, String db) {
        try {
            Class.forName("com.mysql.jdbc.Driver");
            connection = DriverManager.getConnection("jdbc:mysql://" + ip + "/" + db + "?user=" + userName + "&password=" + password);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
 
    public String getBannedReason(Player p) {
        try {
            PreparedStatement statement = connection.prepareStatement("select reason from users where uuid='" + p.getUniqueId() + "'");
            ResultSet result = statement.executeQuery();
 
            if (result.next()) {
                return result.getString("reason");
            } else {
                return null;
            }
        } catch (Exception e) {
            e.printStackTrace();
            return "[[Failed to connect]]";
        }
    }
 
    public void banPlayer(Player p, String reason) {
        try {
            PreparedStatement statement = connection.prepareStatement("insert into users (uuid, reason)\nvalues ('" + p.getUniqueId() + "', '" + reason + "');");
            statement.executeUpdate();
            statement.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
 
    public void unbanPlayer(Player p) {
        try {
            PreparedStatement statement = connection.prepareStatement("delete from users where uuid='" + p.getUniqueId() + "';");
            statement.executeUpdate();
            statement.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
 
    }
}

The ban function works, just the unban one doesn't.

Wizehh

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

 

macboinc
Why not just use a boolean, toggle it for "banned".

 

Yes, I removed the check if the player is null because if the player is banned, they are offline, and I can't do that only if they're online. If I had to do this I would need to query the database.

 

I honestly cannot comprehend that sentence. Can you please reiterate that in a more clear manner?

 

If I do that, it will say that they are not online.

So I can't unban them.

http://imgur.com/eV0DctL

No because he is banned

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

 

I can't write an in-depth explanation since I'm using a mobile device, but just change all your Player variables to type OfflinePlayer.

 

So instead of Player type 'OfflinePlayer'?