title: Gracefull shutdown for Spring boot Application
body: <p>I am running a spring-boot application and everything is good except when i try to close it. I got error on the below code </p>
  
  <pre><code>    while (true) {
          try {
              if(level2List == null)
                  break;
              CDR cdr = level2List.poll(2, TimeUnit.SECONDS);
  </code></pre>
  
  <p>The error is generated on the last line , spring boot is shutting down  level2List before the 2 second wait is done  as below </p>
  
  <pre><code>2015-05-29 17:32:15.758  INFO 27390 --- [       Thread-1] ationConfigEmbeddedWebApplicationContext : Closing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@358ee631: startup date [Fri May 29 17:31:17 GMT 2015]; root of context hierarchy
  2015-05-29 17:32:15.765  INFO 27390 --- [       Thread-1] o.s.j.e.a.AnnotationMBeanExporter        : Unregistering JMX-exposed beans on shutdown
  2015-05-29 17:32:15.766  INFO 27390 --- [       Thread-1] o.s.j.e.a.AnnotationMBeanExporter        : Unregistering JMX-exposed beans
  2015-05-29 17:32:15.780  INFO 27390 --- [       Thread-1] o.s.c.ehcache.EhCacheManagerFactoryBean  : Shutting down EhCache CacheManager
  2015-05-29 17:32:15.804  INFO 27390 --- [       Thread-1] o.s.s.concurrent.ThreadPoolTaskExecutor  : Shutting down ExecutorService 'level2ES'
  2015-05-29 17:32:15.815  INFO 27390 --- [       Thread-1] o.s.s.concurrent.ThreadPoolTaskExecutor  : Shutting down ExecutorService 'level1ES'
  2015-05-29 17:32:15.823  INFO 27390 --- [       Thread-1] j.LocalContainerEntityManagerFactoryBean : Closing JPA EntityManagerFactory for persistence unit 'default'
  2015-05-29 17:32:15.825  INFO 27390 --- [       Thread-1] com.jolbox.bonecp.BoneCP                 : Shutting down connection pool...
  2015-05-29 17:32:15.833  INFO 27390 --- [       Thread-1] com.jolbox.bonecp.BoneCP                 : Connection pool has been shutdown.
  2015-05-29 17:32:15.848 ERROR 27390 --- [pool-2-thread-1] c.t.t.c.process.CDRDataBase     : Error
  
  java.lang.InterruptedException: null
          at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.reportInterruptAfterWait(AbstractQueuedSynchronizer.java:2014)
          at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2088)
          at java.util.concurrent.LinkedBlockingQueue.poll(LinkedBlockingQueue.java:467)
          at com.teltacworldwide.tekram.cdrserver.process.CDRDataBaseNative.run(CDRDataBaseNative.java:79)
          at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
          at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
          at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
          at java.lang.reflect.Method.invoke(Method.java:483)
          at org.springframework.scheduling.support.ScheduledMethodRunnable.run(ScheduledMethodRunnable.java:65)
          at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54)
          at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
          at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
          at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
          at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
          at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
          at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
          at java.lang.Thread.run(Thread.java:745)
  </code></pre>
  
  <p>Is there any way to order the shutting down process or to make sure I am not using level2List before shutting it down?</p>
  
  <p>BR
  Shahbour</p>