distributedlog-service/src/main/java/org/apache/bookkeeper/stats/ServletReporter.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.bookkeeper.stats;

import com.codahale.metrics.MetricRegistry;
import com.codahale.metrics.health.HealthCheckRegistry;
import com.codahale.metrics.servlets.AdminServlet;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.servlet.ServletContextHandler;
import org.eclipse.jetty.servlet.ServletHolder;

/**
 * Starts a jetty server on a configurable port to export stats.
 */
public class ServletReporter {

    private final MetricRegistry metricRegistry;
    private final HealthCheckRegistry healthCheckRegistry;
    private final int port;
    private final Server jettyServer;

    public ServletReporter(MetricRegistry metricRegistry,
                           HealthCheckRegistry healthCheckRegistry,
                           int port) {
        this.metricRegistry = metricRegistry;
        this.healthCheckRegistry = healthCheckRegistry;
        this.port = port;
        this.jettyServer = new Server(port);
    }

    public void start() throws Exception {
        ServletContextHandler context = new ServletContextHandler(ServletContextHandler.SESSIONS);
        context.setContextPath("/");
        jettyServer.setHandler(context);

        context.addEventListener(new HealthCheckServletContextListener(healthCheckRegistry));
        context.addEventListener(new MetricsServletContextListener(metricRegistry));
        context.addServlet(new ServletHolder(new AdminServlet()), "/*");

        jettyServer.start();
    }

    public void stop() throws Exception {
        jettyServer.stop();
    }

}