Connecting to mysql from eclipse
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    Connection con = null;
    try{
        Class.forName("com.mysql.jdbc.Driver").newInstance();
        con = DriverManager.getConnection("jdbc:mysql//localhost:3306/try", "root", "password");
    }catch(Exception e){
        e.printStackTrace();
    }
    if(request.getParameter("select1")!=null){
        PrintWriter out = response.getWriter();
        String select1  = (String) request.getParameter("select1");
        int no = Integer.parseInt(select1);
        String query = "SELECT * FROM try.try where id='"+no+"'";
        out.print("<option>---select one---</option>");
        try{
            Statement stmt = (Statement) con.createStatement();
            ResultSet rs = stmt.executeQuery(query);
            while(rs.next()){
                out.print("<option>"+rs.getString("output")+"</option>");
            }
        }catch(Exception e){
            e.printStackTrace();
        }
    }

}

jdbc:mysql://localhost:3306/try
          ^-- you missed the colon here