怎样将保存在数据库中BLOB类型的图片输出到浏览器上?

<%@ page contentType="text/html; charset=gbk" %>
<%@ page import="java.io.*"%>
<%@ page import="java.sql.*, javax.sql.*" %>
<%@ page import="java.util.*"%>
<%@ page import="java.math.*"%>

<%
String photo_no = request.getParameter("photo_no");

//mysql连接
Class.forName("com.mysql.jdbc.Driver").newInstance();
String URL="jdbc:mysql://localhost:3306/job?user=root&password=111111";
Connection con = DriverManager.getConnection(URL);

//oracle连接
//String URL="jdbc:oracle:thin@localhost:1521:orcl2";
//user="system";
//password="manager";
//Connection con = DriverManager.getConnection(URL,user,password);

try{
// 准备语句执行对象
Statement stmt = con.createStatement();

String sql = " SELECT * FROM PHOTO WHERE photo_no = "+ phot