io.vertx.core.Verticle Maven / Gradle / Ivy
/*
* Copyright (c) 2011-2019 Contributors to the Eclipse Foundation
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
* which is available at https://www.apache.org/licenses/LICENSE-2.0.
*
* SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
*/
package io.vertx.core;
/**
* A verticle is a piece of code that can be deployed by Vert.x.
*
* Use of verticles with Vert.x is entirely optional, but if you use them they provide an actor-like
* deployment and concurrency model, out of the box.
*
* Vert.x does not provide a strict actor implementation, but there are significant similarities.
*
* You can think of verticle instances as a bit like actors in the Actor Model. A typical verticle-based Vert.x application
* will be composed of many verticle instances in each Vert.x instance.
*
* The verticles communicate with each other by sending messages over the {@link io.vertx.core.eventbus.EventBus}.
*
* @author Tim Fox
*/
public interface Verticle {
/**
* Get a reference to the Vert.x instance that deployed this verticle
*
* @return A reference to the Vert.x instance
*/
Vertx getVertx();
/**
* Initialise the verticle with the Vert.x instance and the context.
*
* This method is called by Vert.x when the instance is deployed. You do not call it yourself.
*
* @param vertx the Vert.x instance
* @param context the context
*/
void init(Vertx vertx, Context context);
/**
* Start the verticle instance.
*
* Vert.x calls this method when deploying the instance. You do not call it yourself.
*
* A promise is passed into the method, and when deployment is complete the verticle should either call
* {@link io.vertx.core.Promise#complete} or {@link io.vertx.core.Promise#fail} the future.
*
* @param startPromise the future
*/
void start(Promise startPromise) throws Exception;
/**
* Stop the verticle instance.
*
* Vert.x calls this method when un-deploying the instance. You do not call it yourself.
*
* A promise is passed into the method, and when un-deployment is complete the verticle should either call
* {@link io.vertx.core.Promise#complete} or {@link io.vertx.core.Promise#fail} the future.
*
* @param stopPromise the future
*/
void stop(Promise stopPromise) throws Exception;
}