Hashtable implementation with arraylist in java

Below is the implementation of Hashtable & Array list in java

<%
//Declare hashtable & arraylist

Hashtable ht_data = new Hashtable();
ArrayList al_data = null;

try {   


StringBuffer SEL_SQL = new StringBuffer("SELECT id,name, ");
SEL_SQL.append("nvl(to_char(DOB,'DD-MM-YYYY'),'NA')DOB");
SEL_SQL.append(" FROM EMPLOYEE WHERE ID=6587)");

Statement stmt = con.createStatement();
       
ResultSet rs = stmt.executeQuery(SEL_SQL.toString());

    while (rs.next()) {   
   
        al_data = new ArrayList();
        al_data.add(rs.getString("id"));
        al_data.add(rs.getString("name"));
        al_data.add(rs.getString("DOB"));   
       
        ht_maindata.put(i, al_maindata);
       
    }//WHILE LOOP END
   
%>   
    <table width="682" border="1" align="center" cellpadding="0" cellspacing="2" class="table_bgcolor" id="content">
    <tr height="30">
        <th class="normal">ID</th>
        <th class="normal">NAME</th>
        <th class="normal">DOB</th>
     </tr>
   
   
<%   
   
    if (ht_data.size() > 0) {
                for (int s = 0; s < ht_data.size(); s++) {

                    ArrayList al = (ArrayList) ht_data.get(s);
%>               
                   
        <tr height="30">
        <td class="normal"><%=index%></td>
        <td class="normal"><%=al.get(0)%></td>
        <td class="normal"><%=al.get(1)%></td>
        <td class="normal"><%=al.get(2)%></td>
        </tr>       
<%       
        }//for
       
        //if
        }//try
        catch(Exception e)
        {
        System.out.println(e.getMessage());
        finally
        {
        try{
        connection.close();
        }
       
        catch(Exception e)
        {
        System.out.println(e.getMessage());
        }
       
        }//catch
%>