Modify the look of the navbar by adding .navbar-inverse.
<!DOCTYPE HTML>
<html>
<head>
<link href="http://java2s.com/style/bootstrap.min.css" rel="stylesheet">
<!--from ww w . ja va 2 s.c om-->
<script src="http://java2s.com/style/jquery-1.8.0.min.js"></script>
<script src="http://java2s.com/style/bootstrap.min.js"></script>
</head>
<body style='margin: 20px;'>
<div class="navbar navbar-inverse">
<div class="container">
<button type="button" class="navbar-toggle" data-toggle="collapse"
data-target=".navbar-inverse-collapse">
<span class="icon-bar"></span> <span class="icon-bar"></span> <span
class="icon-bar"></span>
</button>
<a class="navbar-brand" href="#">Title</a>
<div class="nav-collapse collapse navbar-inverse-collapse">
<ul class="nav navbar-nav">
<li class="active"><a href="#">Home</a></li>
<li><a href="#">Link</a></li>
<li><a href="#">Link</a></li>
<li class="dropdown"><a href="#" class="dropdown-toggle"
data-toggle="dropdown">Dropdown <b class="caret"></b></a>
<ul class="dropdown-menu">
<li><a href="#">Action</a></li>
<li><a href="#">Another action</a></li>
<li><a href="#">Something else here</a></li>
<li class="divider"></li>
<li class="dropdown-header">Dropdown header</li>
<li><a href="#">Separated link</a></li>
<li><a href="#">One more separated link</a></li>
</ul></li>
</ul>
<form class="navbar-form pull-left" action="">
<input type="text" class="form-control col-lg-8"
placeholder="Search">
</form>
<ul class="nav navbar-nav pull-right">
<li><a href="#">Link</a></li>
<li class="dropdown"><a href="#" class="dropdown-toggle"
data-toggle="dropdown">Dropdown <b class="caret"></b></a>
<ul class="dropdown-menu">
<li><a href="#">Action</a></li>
<li><a href="#">Another action</a></li>
<li><a href="#">Something else here</a></li>
<li class="divider"></li>
<li><a href="#">Separated link</a></li>
</ul></li>
</ul>
</div>
<!-- /.nav-collapse -->
</div>
<!-- /.container -->
</div>
</body>
</html>