CODEWITHSUNDEEP
jsp
Shimul
Shimul

Reputation: 469

How to write and call user defined function properly in JSP?

I come from PHP, where declaring and using user defined function is much easier than JSP (I think). In PHP, I separate the HTML template into several parts using PHP function (in a *.php file) and call them when required, as like as follow:

require_once 'resource.php';
load_header($title);
load_navbar($title);
<!--Other content goes here-->
load_footer();

In resource.php all of the above function contains the required code.

Now in JSP, I want to do the same thing. So I write a function in JSP as like as follow:

<%
int login = 0;
if( session.getAttribute("username") != null ) {
    login = 1;
} else {
    login = 0;
}
%>

<%!
    public static void load_navbar(String title) {
%>
    <nav class="navbar navbar-inverse navbar-static-top">
  <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" aria-expanded="false">
        <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 navbar-left">
        <li class="active left-margin"><a href="#"> <i class='fa fa-fw fa-home'></i>&nbsp;Home</a> </li>
      </ul>
      <ul class="nav navbar-nav navbar-right">
        <%
            if( login == 0 ) {      
        %>
        <li><a href="#">Login</a></li>
        <%              
            } else if( login == 1 ) {
        %>
                <li><a href="#">Logout</a></li>
        <%
            }
        %>
      </ul>
    </div><!-- /.navbar-collapse -->
  </div><!-- /.container-fluid -->
</nav>
<%!
}
%>

To include the the file in my target page, I write the following line of code:

<jsp:include page="include/navbar.jsp"></jsp:include>

But the problem is, All the code inside load_navbar() function is automatically added to my page without calling the function. I want to load the code when the function is called. i.e:

<body>
    <%! load_navbar("Title goes here"); %>
</body>

Can anyone help me to fix the issue?
Thanks

Upvotes: 0

Views: 377

Answers (1)

Harold
Harold

Reputation: 76

The jsp:include will make a request to include/navbar.jsp and append the response to the JSP using jsp:include. For your case, you want to use <%@ include file="include/navbar.jsp" %>. In this case, the content of the navbar.jsp will be added, during the translation phase, to the JSP file using the include directive.

Upvotes: 1

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