mysql query based on jQuery variables in jsp page

<%@ page import = "java.util.*,java.io.*,java.sql.*" %>
<!DOCTYPE html>
<html>
<head>
  <title>SASG v1.0</title>
  <link rel="stylesheet" href="main1.css"/>
  <script type="text/javascript" src="jquery-3.3.1.js"></script>
</head>
<body>
<script>
    function subject_list()
    {
        var course = $('#course-cb option:selected').text();
        var stream = $('#stream-cb option:selected').text();
        var year = $('#year-cb option:selected').text();
        <%
            try
            {

                Class.forName("com.mysql.jdbc.Driver");
                Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/timetabledb","root","`");
                Statement stmt = con.createStatement();
                String query = "select * from subjects";
                ResultSet rs = stmt.executeQuery(query);
                for(int i=0;rs.next();i++)
                {
        %>

        $('#tbl').append('<tr><td><input type="checkbox"></input></td><td><%=rs.getString("subject_code")%></td><td><%=rs.getString("subject_name")%></td><td><%=rs.getString("subject_code")%></td><td><%=rs.getString("subject_code")%></td><td><%=rs.getString("subject_code")%></td><td><%=rs.getString("subject_code")%></td><td><%=rs.getString("subject_code")%></td><td><%=rs.getString("subject_code")%></td></tr>');

        <%
                }
             }
            catch(Exception e)
            {

            }
        %>
    }
    function change()
    {
        var selectedItem = $('#course-cb option:selected').text();
        if(selectedItem=="B.Tech")
        {
            $('#stream-cb').find('option').remove().end();
            $('#stream-cb').append($("<option></option>").attr("value","BT").text("BioTechnology"));
            $('#stream-cb').append($("<option></option>").attr("value","CH").text("Chemical Engineering"));
            $('#stream-cb').append($("<option></option>").attr("value","EE").text("Electrical Engineering"));
            $('#stream-cb').append($("<option></option>").attr("value","IT").text("Information Technology"));
            $('#stream-cb').append($("<option></option>").attr("value","CSE").text("Computer Science & Engineering"));
            $('#stream-cb').append($("<option></option>").attr("value","CE").text("Civil Engineering"));
            $('#stream-cb').append($("<option></option>").attr("value","ECE").text("Electronics & Communications Engineering"));
            $('#stream-cb').append($("<option></option>").attr("value","ME").text("Mechanical Engineering"));

            $('#year-cb').find('option').remove().end();
            $('#year-cb').append($("<option></option>").attr("value","1").text("1"));
            $('#year-cb').append($("<option></option>").attr("value","2").text("2"));
            $('#year-cb').append($("<option></option>").attr("value","3").text("3"));
            $('#year-cb').append($("<option></option>").attr("value","4").text("4"));
        }
        if(selectedItem=="B.Pharm")
        {
            $('#stream-cb').find('option').remove().end();
            $('#stream-cb').append($("<option></option>").attr("value","P").text("Pharmacy"));

            $('#year-cb').find('option').remove().end();
            $('#year-cb').append($("<option></option>").attr("value","1").text("1"));
            $('#year-cb').append($("<option></option>").attr("value","2").text("2"));
            $('#year-cb').append($("<option></option>").attr("value","3").text("3"));
            $('#year-cb').append($("<option></option>").attr("value","4").text("4"));
        }
        if(selectedItem=="M.Tech")
        {
            $('#stream-cb').find('option').remove().end();
            $('#stream-cb').append($("<option></option>").attr("value","BT").text("BioTechnology"));
            $('#stream-cb').append($("<option></option>").attr("value","ECE").text("Electronics & Communications Engineering"));
            $('#stream-cb').append($("<option></option>").attr("value","CSE").text("Computer Science & Engineering"));
            $('#stream-cb').append($("<option></option>").attr("value","TE").text("Thermal Engineering"));

            $('#year-cb').find('option').remove().end();
            $('#year-cb').append($("<option></option>").attr("value","1").text("1"));
            $('#year-cb').append($("<option></option>").attr("value","2").text("2"));
        }
        if(selectedItem=="M.B.A.")
        {
            $('#stream-cb').find('option').remove().end();
            $('#stream-cb').append($("<option></option>").attr("value","BA").text("Business Administration"));

            $('#year-cb').find('option').remove().end();
            $('#year-cb').append($("<option></option>").attr("value","1").text("1"));
            $('#year-cb').append($("<option></option>").attr("value","2").text("2"));
        }
        if(selectedItem=="M.C.A.")
        {
            $('#stream-cb').find('option').remove().end();
            $('#stream-cb').append($("<option></option>").attr("value","INT").text("Integrated (2-Year)"));
            $('#stream-cb').append($("<option></option>").attr("value","INT").text("Regular (3-Year)"));            

            $('#year-cb').find('option').remove().end();
            $('#year-cb').append($("<option></option>").attr("value","1").text("1"));
            $('#year-cb').append($("<option></option>").attr("value","2").text("2"));
            $('#year-cb').append($("<option></option>").attr("value","3").text("3"));
        }
        if(selectedItem=="M.Pharm")
        {
            $('#stream-cb').find('option').remove().end();
            $('#stream-cb').append($("<option></option>").attr("value","PH").text("Pharmacology"));
            $('#stream-cb').append($("<option></option>").attr("value","PH").text("Pharmaceutics"));

            $('#year-cb').find('option').remove().end();
            $('#year-cb').append($("<option></option>").attr("value","1").text("1"));
            $('#year-cb').append($("<option></option>").attr("value","2").text("2"));
        }
    }
</script>
    <div id="head">
        <p>Assign Subjects & Faculty</p>
    </div>
    <div id="details">
        <span id="course">
            <select id="course-cb" onchange="change();">
                <option value="" selected hidden>--Choose course--</option>
                <option value="B.Tech">B.Tech</option>
                <option value="M.B.A.">M.B.A.</option>
                <option value="B.Pharm">B.Pharm</option>
                <option value="M.Pharm">M.Pharm</option>
                <option value="M.Tech">M.Tech</option>
                <option value="M.C.A.">M.C.A.</option>
            </select>
        </span>
        <span id="stream">
            <select id="stream-cb">
                <option value="" selected hidden>--Choose stream--</option>
            </select>
        </span>
        <span id="year">
            <select id="year-cb">
                <option value="" selected hidden>--Choose year--</option>
            </select>
        </span>
        <span>
            <button name="subject_gen" onclick="subject_list();">List Out Subjects</button>
        </span>
    </div>
    <br>
    <div>
        <table id="tbl" border=1 cellspacing=3>
            <tr>
                <th rowspan=2>Select</th>
                <th rowspan=2>Subject Code</th>
                <th rowspan=2>Subject Name</th>
                <th colspan=6>Assigned Faculties</th>
            </tr>
            <tr>
                <th>A</th>
                <th>B</th>
                <th>C</th>
                <th>D</th>
                <th>E</th>
                <th>F</th>
            </tr>
        </table>
    </div>
</body>
</html>

this is my jsp page, i want to execute a MySQL query using JDBC code with values selected in three drop down menus in same page, how could I do the same. I've tried but it always generates an error saying somewhat like, "Insert a semi-colon". I'm totally confused, please help.

In the function named subject_list(), the 3 variables declared have to be used in the query.