sample.GemFireCacheServerReadyBeanPostProcessor.java Source code

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Here is the source code for sample.GemFireCacheServerReadyBeanPostProcessor.java

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/*
 * Copyright 2014-2016 the original author or authors.
 *
 * 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 sample;

import java.io.IOException;
import java.net.Socket;
import java.util.Properties;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;

import javax.annotation.Resource;

import com.gemstone.gemfire.cache.client.Pool;
import com.gemstone.gemfire.management.membership.ClientMembership;
import com.gemstone.gemfire.management.membership.ClientMembershipEvent;
import com.gemstone.gemfire.management.membership.ClientMembershipListenerAdapter;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.data.gemfire.client.PoolFactoryBean;
import org.springframework.session.data.gemfire.support.GemFireUtils;
import org.springframework.util.Assert;

public class GemFireCacheServerReadyBeanPostProcessor implements BeanPostProcessor {

    static final long DEFAULT_WAIT_DURATION = TimeUnit.SECONDS.toMillis(20);
    static final long DEFAULT_WAIT_INTERVAL = 500L;

    static final CountDownLatch latch = new CountDownLatch(1);

    static final String DEFAULT_SERVER_HOST = "localhost";

    @Value("${spring.session.data.gemfire.port:${application.gemfire.client-server.port}}")
    int port;

    // tag::class[]
    static {
        ClientMembership.registerClientMembershipListener(new ClientMembershipListenerAdapter() {
            public void memberJoined(final ClientMembershipEvent event) {
                if (!event.isClient()) {
                    latch.countDown();
                }
            }
        });
    }

    @SuppressWarnings("all")
    @Resource(name = "applicationProperties")
    private Properties applicationProperties;

    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        if (bean instanceof PoolFactoryBean || bean instanceof Pool) {
            String host = getServerHost(DEFAULT_SERVER_HOST);
            Assert.isTrue(waitForCacheServerToStart(host, this.port),
                    String.format("GemFire Server failed to start [host: '%1$s', port: %2$d]%n", host, this.port));
        }

        return bean;
    }

    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
        if (bean instanceof PoolFactoryBean || bean instanceof Pool) {
            try {
                latch.await(DEFAULT_WAIT_DURATION, TimeUnit.MILLISECONDS);
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
            }
        }

        return bean;
    }
    // tag::end[]

    interface Condition {
        boolean evaluate();
    }

    String getServerHost(String defaultServerHost) {
        return this.applicationProperties.getProperty("application.gemfire.client-server.host", defaultServerHost);
    }

    boolean waitForCacheServerToStart(String host, int port) {
        return waitForCacheServerToStart(host, port, DEFAULT_WAIT_DURATION);
    }

    /* (non-Javadoc) */
    boolean waitForCacheServerToStart(final String host, final int port, long duration) {
        return waitOnCondition(new Condition() {
            AtomicBoolean connected = new AtomicBoolean(false);

            public boolean evaluate() {
                Socket socket = null;

                try {
                    // NOTE: this code is not intended to be an atomic, compound action (a
                    // possible race condition);
                    // opening another connection (at the expense of using system
                    // resources) after connectivity
                    // has already been established is not detrimental in this use case
                    if (!connected.get()) {
                        socket = new Socket(host, port);
                        connected.set(true);
                    }
                } catch (IOException ignore) {
                } finally {
                    GemFireUtils.close(socket);
                }

                return connected.get();
            }
        }, duration);
    }

    boolean waitOnCondition(Condition condition) {
        return waitOnCondition(condition, DEFAULT_WAIT_DURATION);
    }

    @SuppressWarnings("all")
    boolean waitOnCondition(Condition condition, long duration) {
        final long timeout = (System.currentTimeMillis() + duration);

        try {
            while (!condition.evaluate() && System.currentTimeMillis() < timeout) {
                synchronized (condition) {
                    TimeUnit.MILLISECONDS.timedWait(condition, DEFAULT_WAIT_INTERVAL);
                }
            }
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        }

        return condition.evaluate();
    }

}