HttpServerAnnouncerModule.java

/**
 * Copyright (C) 2012 Ness Computing, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.nesscomputing.service.discovery.testing.server;


import com.google.common.base.Preconditions;
import com.google.inject.AbstractModule;
import com.google.inject.Inject;
import com.google.inject.name.Named;
import com.nesscomputing.httpserver.HttpConnector;
import com.nesscomputing.httpserver.HttpServer;
import com.nesscomputing.lifecycle.LifecycleStage;
import com.nesscomputing.lifecycle.guice.OnStage;
import com.nesscomputing.service.discovery.announce.ServiceAnnouncementFactory;
import com.nesscomputing.service.discovery.client.DiscoveryClient;
import com.nesscomputing.service.discovery.client.ServiceInformation;

class HttpServerAnnouncerModule extends AbstractModule {

    @Override
    protected void configure() {
        bind (Announcer.class).asEagerSingleton();
        bind (ServiceAnnouncementFactory.class);
    }


    static class Announcer {
        private final HttpServer httpServer;
        private final DiscoveryClient discoveryClient;
        private ServiceInformation serviceInfo;
        private final String serviceName;

        @Inject
        Announcer(HttpServer httpServer, DiscoveryClient discoveryClient, @Named("SERVICE") String serviceName) {
            this.httpServer = httpServer;
            this.discoveryClient = discoveryClient;
            this.serviceName = serviceName;
        }

        @OnStage(LifecycleStage.ANNOUNCE)
        public void announce() {
            final HttpConnector connector = httpServer.getConnectors().get("internal-http");
            Preconditions.checkState(connector != null, "could not find internal http connector!");

            serviceInfo = ServiceInformation.forService(serviceName, null, "http", "localhost", connector.getPort());
            discoveryClient.announce(serviceInfo);
        }

        @OnStage(LifecycleStage.STOP)
        public void unannounce() {
            if (serviceInfo != null) {
                discoveryClient.unannounce(serviceInfo);
                serviceInfo = null;
            }
        }
    }
}