title: What is chain.doFilter doing in Filter.doFilter method?
body: <p>In a <a href="https://docs.oracle.com/javaee/7/api/javax/servlet/Filter.html#doFilter-javax.servlet.ServletRequest-javax.servlet.ServletResponse-javax.servlet.FilterChain-" rel="noreferrer"><code>Filter.doFilter</code></a> method I made this call <a href="https://docs.oracle.com/javaee/7/api/javax/servlet/FilterChain.html#doFilter-javax.servlet.ServletRequest-javax.servlet.ServletResponse-" rel="noreferrer"><code>chain.doFilter</code></a>.</p>
  
  <p>What is <code>doFilter</code> doing inside a <code>doFilter</code>? Isn't it a recursive call?</p>