A client to communicate with a Minecraft server using the RCON (remote control) interface. Contains both a Java client to be used in other projects, as well as a command-line application.

Modify your server.properties to include the following properties:

enable-rcon=true
rcon.password=<your password>
rcon.port=<1-65535>

The default port is 25575.

Add the following Maven dependency:

<dependency>
  <groupId>com.github.t9t.minecraft-rcon-client</groupId>
  <artifactId>minecraft-rcon-client</artifactId>
  <version>1.0.0</version>
</dependency>

Be sure to use the latest version. Check The Maven Central Repository to see which that is.

Use the client in your code as follows:

import com.github.t9t.minecraftrconclient.RconClient;

public class Teleporter {
  public void teleport(String player, int x, int y, int z) {
    try (RconClient client = RconClient.open("localhost", 25575, "hunter2")) {
      client.sendCommand(String.format("say Teleporting player %s to (%d, %d, %d)", player, x, y, z));
      client.sendCommand(String.format("teleport %s %d %d %d", player, x, y, z));
    }
  }
}

Note that a connection is only opened when open() is called and when the connection becomes broken (eg. because of a network failure), no attempt is made to re-establish the connection when sendCommand() is called.

You can download the JAR from The Maven Central Repository, at com.github.t9t.minecraft-rcon-client:minecraft-rcon-client, by clicking jar in the Download column on the right. Be sure to fetch the latest version.

The command-line application supports to modes: it can either send a list of specified commands to server and quit immediately, or it can be started as an interactive terminal to type in and send commands. In general, the usage is:

java -jar minecraft-rcon-client-<version>.jar <host[:port]> <password> <-t|commands>

The port number is optional. When omitted, the default of 25575 will be used.

Specify a list of commands as arguments separated by spaces. Please take care to understand how to write arguments which contain spaces for your particular terminal. For example:

skankhunt42@battlestation:~$ export PLAYER=skankhunt42 COORDS='0 200 0'
skankhunt42@battlestation:~$ java -jar minecraft-rcon-client-1.0.0.jar localhost:12587 hunter2 \
  "say Teleporting $PLAYER to ($COORDS)" \
  "teleport $PLAYER $COORDS"
> say Teleporting skankhunt42 to (0 200 0)
< (empty response)
> teleport skankhunt42 0 200 0
< (empty response)
skankhunt42@battlestation:~$ 

Just use -t instead of any commands. You will be presented with an interactive terminal where you can type a command. Press Enter to send the command. The response will be displayed. In a lot of cases when a command was successfully sent and executed, the server will return with an empty response however, in which case the client shows (empty response), so as not to confuse the user.

To exit the terminal write \quit, use your terminal's keyboard shortcut to send an end-of-file (^D on most terminals), or use ^C.

For example:

skankhunt42@battlestation:~$ java -jar minecraft-rcon-client-1.0.0.jar localhost:12587 hunter2 -t
> say Teleporting skankhunt42 to (0 200 0)
< (empty response)
> teleport skankhunt42 0 200 0
< (empty response)
> \quit
skankhunt42@battlestation:~$  

• Page describing the Minecraft RCON protocol: http://wiki.vg/RCON
• Minecraft server.properties documentation: http://minecraft.gamepedia.com/Server.properties