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用JSP从数据库中读取图片并显示在网页上

2008-02-23 07:51:46来源：互联网阅读 ()

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();
}
%>