Services

Pretty much everything (events, permissions, etc.) is handled through services. All services are accessed through the service manager:

import org.spongepowered.api.Sponge;

Sponge.getServiceManager().provide(EventManager.class);

If you need to get an object reference to something, just get it off the service manager.

Service Guidelines

• Services should be registered during the POST_INITIALIZATION game state at the latest.
• Services should be fully operational by the SERVER_ABOUT_TO_START game state.

You can read more about game states on the Plugin Lifecycle page.

Note

It is a good practice to register services as soon as possible so that other plugins can note that the service will be provided.

Providing your own service

Your plugin can provide the implementation for a core interface like PermissionService, or for a custom interface that is not part of SpongeAPI (e.g. economy, web server):

Sponge.getServiceManager().setProvider(Object plugin, Class<T> service, T provider);

The provider object has to implement the service interface or class.

Designing the API this way makes Sponge extremely modular.

Note

Plugins should provide options to not install their providers if the plugin is not dedicated to a single function.

Example: Providing a simple warp service

The first step is optional, but recommended. You specify the public methods of your service class in an interface:

import org.spongepowered.api.world.Location;
import org.spongepowered.api.world.World;
import java.util.Optional;

public interface WarpService {
    void setWarp(String name, Location<World> location);
    Optional<Location<World>> getWarp(String name);
}

Now you can write the class that implements your interface:

import java.util.HashMap;

public class SimpleWarpService implements WarpService {
    HashMap<String, Location<World>> warpMap = new HashMap<String, Location<World>>();

    @Override
    public Optional<Location<World>> getWarp(String name) {
        if(!warpMap.containsKey(name)) {
            return Optional.empty();
        } else {
            return Optional.of(warpMap.get(name));
        }
    }

    @Override
    public void setWarp(String name, Location<World> location) {
        warpMap.put(name, location);
    }
}

Now we can register a new instance of the class in the service manager. We are using the interface WarpService.class as the service key.

This makes it possible for other plugin developers to write their own implementation of your service (that implements the interface) and replace your version.

PluginContainer plugin = ...;

Sponge.getServiceManager().setProvider(plugin, WarpService.class, new SimpleWarpService());

Other plugins can now access your service through the service manager:

Sponge.getServiceManager().provide(WarpService.class);

Tip

If you don’t want to use interfaces, just replace the service key with your class (SimpleWarpService.class in the example).