title: Synchronized block in Java without main Object
body: <p>I am wondering why does Java require an object in a <code>synchronized</code> block. i.e.:</p>
  
  <pre><code>synchronized(object) {
      // stuff
  }
  </code></pre>
  
  <p>Why can't I use a simple block without specifying any object? For example:</p>
  
  <pre><code>synchronized {
      // stuff
  }
  </code></pre>