title: How does getWriter() function in an HttpServletResponse?
body: <p>In the method <code>service()</code>, we use</p>
  
  <pre><code>PrintWriter out = res.getWriter();
  </code></pre>
  
  <p>Please tell me how it returns the <code>PrintWriter</code> class object, and then makes a connection to the Browser and sends the data to the Browser.</p>