write operation becomes
 possible without blocking. Other than the initial call, <a href="WriteListener.html#onWritePossible()"><code>WriteListener.onWritePossible()</code></a> will only be called
 if and only if this method is called and returns false.</div>
<dl>
<dt><span class="returnLabel">Returns:</span></dt>
<dd><code>true</code> if data can be written without blocking, otherwise returns <code>false</code>.</dd>
<dt><span class="simpleTagLabel">Since:</span></dt>
<dd>Servlet 3.1</dd>
<dt><span class="