com.obergner.hzserver.HazelcastService.java Source code

Introduction

Here is the source code for com.obergner.hzserver.HazelcastService.java

Source

/**
 * Copyright (C) 2012.
 * Olaf Bergner.
 * Hamburg, Germany. olaf.bergner@gmx.de
 * All rights reserved.
 *
 * 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.obergner.hzserver;

import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;

import com.hazelcast.core.Hazelcast;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.SmartLifecycle;

import com.hazelcast.config.Config;
import com.hazelcast.core.HazelcastInstance;
import com.hazelcast.instance.HazelcastInstanceProxy;
import com.yammer.metrics.core.Gauge;
import com.yammer.metrics.core.MetricsRegistry;

/**
 * <p>
 * TODO: Document HazelcastService
 * <p>
 * 
 * @author obergner <a href="olaf.bergner@gmx.de">Olaf Bergner</a>
 * 
 */
public class HazelcastService implements SmartLifecycle {

    private static final String STARTUP_DURATION_GAUGE = "startup-duration-millis";

    private final Logger log = LoggerFactory.getLogger(getClass());

    private final Config configuration;

    private final MetricsRegistry metricsRegistry;

    private volatile HazelcastInstance hazelcastInstance;

    /**
     * @param configuration
     */
    public HazelcastService(final Config configuration, final MetricsRegistry metricsRegistry) {
        this.configuration = checkNotNull(configuration, "Argument 'configuration' must not be null");
        this.metricsRegistry = checkNotNull(metricsRegistry, "Argument 'metricsRegistry' must not be null");
    }

    /**
     * @see org.springframework.context.Lifecycle#start()
     */
    @Override
    public void start() {
        checkState(this.hazelcastInstance == null, "{} has already been started", this);
        this.log.info("Starting {} using ...", this.configuration);

        final long start = System.currentTimeMillis();
        this.hazelcastInstance = Hazelcast.newHazelcastInstance(this.configuration);
        final long startupDuration = System.currentTimeMillis() - start;
        this.metricsRegistry.newGauge(getClass(), STARTUP_DURATION_GAUGE, new Gauge<Long>() {

            @Override
            public Long value() {
                return startupDuration;
            }
        });

        this.log.info("{} started in [{}] ms", this, startupDuration);
    }

    /**
     * @see org.springframework.context.Lifecycle#stop()
     */
    @Override
    public void stop() {
        checkState(this.hazelcastInstance != null, "{} is not running", this);
        this.log.info("Shutting down Hazelcast instance {} ...", this.hazelcastInstance);

        this.metricsRegistry.removeMetric(getClass(), STARTUP_DURATION_GAUGE);
        this.hazelcastInstance.getLifecycleService().shutdown();

        this.log.info("{} shut down", this.hazelcastInstance);

        this.hazelcastInstance = null;
    }

    /**
     * @see org.springframework.context.Lifecycle#isRunning()
     */
    @Override
    public boolean isRunning() {
        return this.hazelcastInstance != null;
    }

    /**
     * @see org.springframework.context.Phased#getPhase()
     */
    @Override
    public int getPhase() {
        return Integer.MAX_VALUE;
    }

    /**
     * @see org.springframework.context.SmartLifecycle#isAutoStartup()
     */
    @Override
    public boolean isAutoStartup() {
        return true;
    }

    /**
     * @see org.springframework.context.SmartLifecycle#stop(java.lang.Runnable)
     */
    @Override
    public void stop(final Runnable callback) {
        stop();
        callback.run();
    }

    /**
     * Exposed solely for testing purposes.
     */
    HazelcastInstance getHazelcastInstance() {
        return this.hazelcastInstance;
    }

    /**
     * @see java.lang.Object#toString()
     */
    @Override
    public String toString() {
        return "HazelcastService@" + this.hashCode() + "[hazelcastInstance: "
                + (this.hazelcastInstance != null ? this.hazelcastInstance.getName() : "<NOT-STARTED>") + "]";
    }
}