jsp下拉列表标签

<form action="submit.jsp" method="post">
    <label for="cars">Choose a car:</label>
    <select id="cars" name="cars">
        <option value="volvo">Volvo</option>
        <option value="saab">Saab</option>
        <option value="mercedes">Mercedes</option>
        <option value="audi">Audi</option>
    </select>
    <input type="submit" value="Submit">
</form>

<%@ page import="java.sql.*" %>
<%
    Connection conn = null;
    Statement stmt = null;
    ResultSet rs = null;
    try {
        Class.forName("com.mysql.jdbc.Driver");
        conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "username", "password");
        stmt = conn.createStatement();
        rs = stmt.executeQuery("SELECT brand FROM cars ORDER BY brand");
%>
<form action="submit.jsp" method="post">
    <label for="cars">Choose a car:</label>
    <select id="cars" name="cars">
        <% while (rs.next()) { %>
            <option value="<%= rs.getString("brand") %>"><%= rs.getString("brand") %></option>
        <% } %>
    </select>
    <input type="submit" value="Submit">
</form>
<%
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        if (rs != null) rs.close();
        if (stmt != null) stmt.close();
        if (conn != null) conn.close();
    }
%>