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SnappyData store based off Pivotal GemFireXD
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/*
 * Copyright (c) 2010-2015 Pivotal Software, Inc. 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. See accompanying
 * LICENSE file.
 */
package quickstart;

import java.util.Arrays;

import com.gemstone.gemfire.cache.Cache;
import com.gemstone.gemfire.cache.CacheFactory;
import com.gemstone.gemfire.cache.ExpirationAttributes;
import com.gemstone.gemfire.cache.Region;

/**
 * Each data region can be configured to expire entries that have not been
 * accessed recently or that have not been updated recently. You can configure
 * eviction to remove the data and its key (destruction) or just the data
 * (invalidation). Please refer to the quickstart guide for instructions on how
 * to run this example.
 * 
 * 
 * @author GemStone Systems, Inc.
 * @since 4.1.1
 */
public class DataExpiration {

  public static void main(String[] args) throws Exception {

    System.out.println("This example shows entry expiration.");
    System.out.println();
    System.out.println("Connecting to the distributed system and creating the cache.");
    // Create the cache which causes the cache-xml-file to be parsed
    Cache cache = new CacheFactory()
        .set("name", "DataExpiration")
        .set("cache-xml-file", "xml/DataExpiration.xml")
        .create();

    // Get the exampleRegion
    Region exampleRegion = cache.getRegion("exampleRegion");
    System.out.println();
    System.out.println("Example region \"" + exampleRegion.getFullPath() + "\" created in cache.");

    // Get the EntryIdleTimeout setting from the region attributes
    ExpirationAttributes expirationAttr = exampleRegion.getAttributes().getEntryIdleTimeout();

    System.out.println();
    System.out.println("The region \"" + exampleRegion.getFullPath() + "\" is configured to");
    System.out.println(expirationAttr.getAction() + " any cache entry that is idle for ");
    System.out.println(expirationAttr.getTimeout() + " seconds.");

    int idleTime = expirationAttr.getTimeout();

    System.out.println();
    System.out.println("Putting entry: key1 => value1");
    exampleRegion.put("key1", "value1");
    System.out.println("Putting entry: key2 => value2");
    exampleRegion.put("key2", "value2");
    System.out.println("Putting entry: key3 => value3");
    exampleRegion.put("key3", "value3");

    System.out.println();
    System.out.println("The cache now contains:");
    printRegionContents(exampleRegion);

    System.out.println();
    System.out.println("Before the idle time expiration, access two of the entries...");
    Thread.sleep((idleTime - 1) * 1000);

    // Get key1 to prevent it from expiring
    System.out.println("Getting entry: key1 => " + exampleRegion.get("key1"));

    // Update key2 to prevent it from expiring
    System.out.println("Putting entry: key2 => value2000");
    System.out.println();
    exampleRegion.put("key2", "value2000");

    System.out.println("Next, the listener should report on an expiration action... ");
    System.out.println();

    // Sleep past expiration
    Thread.sleep((idleTime / 2) * 1000);

    System.out.println("After the expiration timeout, the cache contains:");
    printRegionContents(exampleRegion);

    System.out.println();
    System.out.println("Closing the cache and disconnecting.");
    cache.close();
  }

  private static void printRegionContents(Region region) {
    Object[] keys = region.keySet().toArray();
    Arrays.sort(keys);

    for (Object key : keys) {
      System.out.println("    " + key + " => " + region.get(key));
    }
  }
}