如何在jsp页面显示存储在数据库的图片

Posted 2020-08-26 写最少的代码

 

1.从数据库中查找图片的二进制数据,把查找出来的数据set到会话中

　　request.getSession().setAttribute("img",图片的二进制数据 );

 

2.把数据write到流里

 1 package cn.jbit.auction.web.servlet;
 2 
 3 import java.io.IOException;
 4 
 5 import javax.servlet.ServletException;
 6 import javax.servlet.http.HttpServlet;
 7 import javax.servlet.http.HttpServletRequest;
 8 import javax.servlet.http.HttpServletResponse;
 9 
10 public class ShowImgServlet extends HttpServlet {
11     private static final long serialVersionUID = 306275585861980357L;
12     public void doGet(HttpServletRequest request, HttpServletResponse response)
13             throws ServletException, IOException {
14         doPost(request, response);
15     }
16 
17     public void doPost(HttpServletRequest request, HttpServletResponse response)
18             throws ServletException, IOException {
19         byte[] imgBytes = (byte[]) request.getSession().getAttribute("img");
20         response.getOutputStream().write(imgBytes);
21     }
22 }

 

3. 更改web.xml文件的配置 (修改<url-pattern>的参数)

<servlet-mapping>
　　<servlet-name>ShowImgServlet</servlet-name>
　　<url-pattern>/auctionImg.jpg</url-pattern>
</servlet-mapping>

 

4.在jsp页面显示

　　<img src="<%=path %>/auctionImg.jpg" width="270" height="185" alt="图片" />