Overview

The version of Java supported is Java OpenJDK 14.0.1

Each turn your source code will be compiled within a new sandbox, by default no information is shared or persisted between turns, if you wish to persist data then you should use the User Data field within the API.

Input - Standard Input (STDIN)

Within Java you can use InputStreamReader to capture the STDIN input

String inputString, outputString;
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
try {
    inputString = br.readLine();
} catch (IOException ioe) {
    System.out.println(ioe);
}

Ouput - Standard Outout (STDOUT)

Within Java you can simply use System.out.println() to return your CSV based instructions to BotWars.

System.out.println("5:5-M-N,12:12-D");

Example Bot

import java.io.*;
public class Main {
    public static void main (String[] args) {
        String inputString, outputString;
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        try {
            inputString = br.readLine();
        } catch (IOException ioe) {
            System.out.println(ioe);
        }

        // Bot Logic...

        System.out.println("5:5-M-N,12:12-D");
    }
}