Pass variable to a method in JSP Java

I have a Vector Method which returns value from the database to a JSP combobox. The Method has an Input Variable String which is stored in the session. I need to Pass the Value from the Session to the method invocation in the JSP but I am not getting the values from the Database.

Here is my method:

public Vector getHostel(String campus) throws IOException{
   Vector v = new Vector();
   Connection conn;
    try{
     conn =  db.getDbConnection();
     String sql = "select * from hostel_master where campus_code = ?";
     PreparedStatement ps = conn.prepareStatement(sql);
     ps.setString(1, campus);
     ResultSet rs = ps.executeQuery();
       while(rs.next()){
         String host = rs.getString(1);
         v.add(host)
       }
    }catch(Exception asd){
      System.out.println(asd.getMessage());
    }
    return v;
}

And My JSP file extract:

<jsp:useBean id = "obj" class="com.app.dao.HostelsDao" scope = "page"/>
<% String campus = (String)session.getAttribute("campus_code");%> <%-- I really hate this --%>

<option selected value = "SELECT">SELECT</option>
<c:forEach var = "item" items = "${obj.getHostel(campus)}">
<option>${item}</option>
</c:forEach>

I am not getting anything in my select list but when I pass the Value directly I am getting correct output. I need this value to vary depending on the campus_code value in the session.

Solution

Rather than the EL call to obj.getHostel(campus), in your DAO you could have class property and setter for campus_code.

You could then set the value using a <c:set target="${obj}" property="campusCode"> after the useBean tag. You would then just change your DAO method getHostel(campus) to a simple getter getHostels() which can be accessed with ${obj.hostels}.

The session can be accessed in JSTL with the implicit session object: ${session} so you should be able to do ${session.campus_code} or ${session["campus_code"]} rather than using the scriptlet.