how to populate a nevigation bar from a data base - html

Question

i tried to populate a dynamic navigation bar using data base.there are maintab and subtab tables.
i tried by this code but did not work :
<nav id="bb" class="navbar navbar-default">
<div class="container-fluid">
<div class="navbar-header">
<button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1">
<span class="sr-only">Toggle navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
<a class="navbar-brand" href="#">home</a>
</div>
<div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
<ul class="nav navbar-nav">
<c:if test="${not empty SubtabsList}">
<c:forEach var="maintab" items="${MaintabsList}">
<li>${maintab.description}</li>
<ul class="dropdown-menu" role="menu">
<c:forEach var="subtab" items="${SubtabsList}">
<c:if test="${subtab.maintab.maiTabId eq maintab.maiTabId}">
<li>${subtab.description}</li>
</c:if>
</ul>
</c:forEach>
</c:forEach>
</c:if>
</ul>
</div>
</div>
</nav>
the sample reffering nevigation bar is as follows : i want auto generate this nevigation bar by data base.but unable to include Dropdown <span class="caret"></span>
in proper place.
<!-- <nav id="bb" class="navbar navbar-default"> -->
<!-- <div class="container-fluid"> -->
<!-- Brand and toggle get grouped for better mobile display -->
<!-- <div class="navbar-header"> -->
<!-- <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1"> -->
<!-- <span class="sr-only">Toggle navigation</span> -->
<!-- <span class="icon-bar"></span> -->
<!-- <span class="icon-bar"></span> -->
<!-- <span class="icon-bar"></span> -->
<!-- </button> -->
<!-- <a class="navbar-brand" href="#">Brand</a> -->
<!-- </div> -->
<!-- Collect the nav links, forms, and other content for toggling -->
<!-- <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1"> -->
<!-- <ul class="nav navbar-nav"> -->
<!-- <li class="active">Link <span class="sr-only">(current)</span></li> -->
<!-- <li>Link</li> -->
<!-- <li class="dropdown"> -->
<!-- Dropdown <span class="caret"></span> -->
<!-- <ul class="dropdown-menu" role="menu"> -->
<!-- <li>Action</li> -->
<!-- <li>Another action</li> -->
<!-- <li>Something else here</li> -->
<!-- <li class="divider"></li> -->
<!-- <li>Separated link</li> -->
<!-- <li class="divider"></li> -->
<!-- <li>One more separated link</li> -->
<!-- </ul> -->
<!-- </li> -->
<!-- </ul> -->
<!-- </div>/.navbar-collapse -->
<!-- </div>/.container-fluid -->
<!-- </nav> -->

Answer 1

<nav id="bb" class="navbar navbar-default">
<div class="container-fluid">
<div class="navbar-header">
<button type="button" class="navbar-toggle collapsed"
data-toggle="collapse" data-target="#bs-example-navbar-collapse-1">
<span class="sr-only">Toggle navigation</span> <span
class="icon-bar"></span> <span class="icon-bar"></span> <span
class="icon-bar"></span>
</button>
<a class="navbar-brand" href="#">home</a>
</div>
<div class="collapse navbar-collapse"
id="bs-example-navbar-collapse-1">
<ul class="nav navbar-nav">
<c:if test="${not empty SubtabsList}">
<c:forEach var="maintab" items="${MaintabsList}">
<li class="dropdown"><a href="#" class="dropdown-toggle"
data-toggle="dropdown" role="button" aria-expanded="false">${maintab.description}
<span class="caret"></span>
</a>
<ul class="dropdown-menu" role="menu">
<c:forEach var="subtab" items="${SubtabsList}">
<c:if test="${subtab.maintab.maiTabId == maintab.maiTabId}">
<li>${subtab.description}</li>
</c:if>
</c:forEach>
</ul></li>
</c:forEach>
</c:if>
</ul>
</div>
</div>
</nav>