title: Jetty LoginModule or LoginService
body: <p>I'm involved in a java EE project with very old code. It has own mechanism for authentication and authorization user from a html form. Now I want to port this mechanism in Java EE Login mechanism using</p>
  
  <pre class="lang-xml prettyprint-override"><code>&lt;login-config&gt;
    &lt;auth-method&gt;FORM&lt;/auth-method&gt;
    &lt;realm-name&gt;Test Realm&lt;/realm-name&gt;
    &lt;form-login-config&gt;
       &lt;form-login-page&gt;/logon.html?param=test&lt;/form-login-page&gt;
       &lt;form-error-page&gt;/logonError.html?param=test&lt;/form-error-page&gt;
    &lt;/form-login-config&gt;
  &lt;/login-config&gt;
  </code></pre>
  
  <p>Jetty Document says, one can implement the Interface <code>LoginModule</code> (may use 
   <code>org.eclipse.jetty.jaas.spi.AbstractLoginModule</code>) and use the class <code>JASSLoginService</code> to configure Jetty, s.t. like </p>
  
  <pre class="lang-xml prettyprint-override"><code>&lt;Set name="securityHandler"&gt;
      &lt;New class="org.eclipse.jetty.security.ConstraintSecurityHandler"&gt;
       &lt;Set name="loginService"&gt;
         &lt;New class="org.eclipse.jetty.jaas.JAASLoginService"&gt;
           &lt;Set name="name"&gt;Test JAAS Realm&lt;/Set&gt;
           &lt;Set name="loginModuleName"&gt;xyz&lt;/Set&gt;
         &lt;/New&gt;
       &lt;/Set&gt;
      &lt;/New&gt;
    &lt;/Set&gt;
  </code></pre>
  
  <p>Since I don't want to make the app over-configuration, my question is, instead of using <code>LoginModule</code> with all circumstance of JASS, can I just implement the Interface <code>org.eclipse.jetty.security.LoginService</code> and use it directly in the "securityHandler"?</p>
  
  <p>Environment: Java SE 8/JavaEE7; Jetty 9.2.x; Windows Server</p>