partial.log

[18:45:32 INFO]: Starting minecraft server version 1.10.2
[18:45:32 INFO] [Sponge]: Loading Sponge...
[18:45:33 INFO] [Sponge]: Loading plugins...
[18:45:33 INFO] [Sponge]: Loaded plugin: spongejni 1.0.0-SNAPSHOT (from mods/spongejni-1.0.0-SNAPSHOT.jar)
[18:45:33 INFO] [Sponge]: Initializing plugins...
[18:45:33 INFO]: Loading properties
[18:45:33 INFO]: Default game type: SURVIVAL
[18:45:33 INFO]: Generating keypair
[18:45:33 INFO]: Starting Minecraft server on *:25565
[18:45:33 INFO]: Using default channel type
[18:45:33 INFO] [Sponge]: Successfully loaded and initialized plugins.
[18:45:33 INFO]: Preparing level "world"
[18:45:33 INFO] [Sponge]: Checking for worlds that need to be migrated...
[18:45:33 INFO] [Sponge]: No worlds were found in need of migration.
[18:45:34 INFO] [Sponge]: Loading world [world] (Overworld)
[18:45:34 INFO] [Sponge]: Loading world [DIM-1] (Nether)
[18:45:34 INFO] [Sponge]: Loading world [DIM1] (The End)
[18:45:34 INFO]: Preparing start region for level 0 (world)
[18:45:35 INFO]: Preparing spawn area: 35%
[18:45:35 INFO]: Preparing start region for level -1 (DIM-1)
[18:45:36 INFO]: Preparing start region for level 1 (DIM1)
> The max number of players is 20
Seed for default world is -5095462419283824123
[18:45:36 INFO]: Done (2.872s)! For help, type "help" or "?"
[18:45:36 INFO] [Sponge]: Timings Reset

shim.rs

#[allow(non_snake_case)]
#[no_mangle]
pub extern fn Java_me_kyleclemens_spongejni_SpongeJNIShim_jniShim(env: *mut JNIEnv, this: jobject, game: jobject) -> jboolean {
  // check that game object passed to us by the shim isn't null
  if game.is_null() {
    // return false to shim if it is, indicating an error
    return 0;
  }
  // wrap the game object in a rust struct
  let game = generated_types::Game {
    env: env,
    object: game
  };
  // get the server
  let server = game.get_server();
  // print out the max number of players the server allows
  println!("The max number of players is {}", server.get_max_players());
  // match against Option<world_storage_WorldProperties>
  let world = match server.get_default_world() {
    // if there is a value
    Some(world) => world,
    // if there isn't a value
    None => {
      // print error message
      println!("No default world!");
      // return false to indicate an error
      return 0;
    }
  };
  // print out the default world's seed
  println!("Seed for default world is {}", world.get_seed());
  // return true to the shim, indicating success
  return 1;
}