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:
<HTML> <HEAD> <TITLE> 图像测试 </TITLE> </HEAD> <BODY> <TABLE> <TR> <TD>图像测试</TD> </TR> <TR> <TD><img src="show.jsp?photo_no=2"></TD> </TR> </TABLE> </BODY> </HTML>