title: What's the difference between Future and FutureTask in Java?
body: <p>Since use <code>ExecutorService</code> can <code>submit</code> a <code>Callable</code> task and return a <code>Future</code>, why need to use <code>FutureTask</code> to wrap <code>Callable</code> task and use the method <code>execute</code>? I feel they both do the same thing.</p>