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    <p>You could do the following:</p> <ul> <li>Let the shutdown hook set some AtomicBoolean (or volatile boolean) "keepRunning" to false</li> <li>(Optionally, <code>.interrupt</code> the working threads if they wait for data in some blocking call)</li> <li>Wait for the working threads (executing <code>writeBatch</code> in your case) to finish, by calling the <code>Thread.join()</code> method on the working threads.</li> <li>Terminate the program</li> </ul> <p>Some sketchy code:</p> <ul> <li>Add a <code>static volatile boolean keepRunning = true;</code></li> <li><p>In <em>run()</em> you change to</p> <pre><code>for (int i = 0; i &lt; N &amp;&amp; keepRunning; ++i) writeBatch(pw, i); </code></pre></li> <li><p>In <em>main()</em> you add:</p> <pre><code>final Thread mainThread = Thread.currentThread(); Runtime.getRuntime().addShutdownHook(new Thread() { public void run() { keepRunning = false; mainThread.join(); } }); </code></pre></li> </ul> <p>That's roughly how I do a graceful "reject all clients upon hitting Control-C" in terminal.</p> <hr> <p>From <a href="http://download.oracle.com/javase/7/docs/api/java/lang/Runtime.html#addShutdownHook%28java.lang.Thread%29" rel="noreferrer">the docs</a>:</p> <blockquote> <p>When the virtual machine begins its shutdown sequence it will start all registered shutdown hooks in some unspecified order and let them run concurrently. <strong>When all the hooks have finished it will then run all uninvoked finalizers if finalization-on-exit has been enabled. Finally, the virtual machine will halt.</strong></p> </blockquote> <p>That is, a shutdown hook keeps the JVM running until the hook has terminated (returned from the <em>run()</em>-method.</p>
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    1. COAh -- so if I understand right, the gist of what you're saying is that the shutdown hook has an opportunity to communicate with other currently-running threads, and to hold off the VM shutdown (e.g. by using Thread.join()) until it is satisfied that a quick cleanup has been completed. That's the point I was missing. thanks!
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    2. COYes. You got it. Updated the answer with a few sentences from the docs.
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    3. COSorry in advance,but shouldnt GracefulShutdownTest1 implement Runnable?
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