用JSP从数据库中读取图片并显示在网页上

环境：mysql+tomcat: 

<1>先在mysql下建立如下的table. 并insert图像. 
mysql.sql文件如下: 

CREATE TABLE photo ( 
photo_no int(6) unsigned NOT NULL auto_increment, 
image blob, 
PRIMARY KEY (`photo_no`) 
) 

<2>把show.jsp放在tomcat的任意目录下. show.jsp作用:从数据库中读出blob,并产生image/jpg. 

show.jsp文件如下: 

<%@ 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 = "+ photo_no; 
ResultSet rs = stmt.executeQuery(sql); 
if (rs.next()) { 
Blob b = rs.getBlob("photo_image"); 
long size = b.length(); 
//out.print(size); 
byte[] bs = b.getBytes(1, (int)size); 
response.setContentType("image/jpeg"); 
OutputStream outs = response.getOutputStream(); 
outs.write(bs); 
outs.flush(); 
rs.close(); 
} 
else { 
rs.close(); 
response.sendRedirect("./images/error.gif"); 
} 
} 
finally{ 
con.close(); 
} 
%> 

<3>把如下文件放在show.jsp的同一目录下. 
index.html文件如下: 

	

		图像测试