请教如何用jsp下载图片

请问怎么用jsp下载图片


在网上查过一些 比较零碎的资料

2种方案

1)不用第三方库
2)smartupload


我想要比较完整的代码



谢谢

[解决办法]
SF,帮你顶起来.让更多人看到来帮助你.
[解决办法]
写个servlet 重定向输出文件流就可以了 ,代码放在jsp 中也可以

Java code

import java.io.FileInputStream;import java.io.IOException;import java.io.OutputStream;import java.net.URLEncoder;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;public class DownloadFileServlet extends HttpServlet {    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        String filename=request.getParameter("filename");        response.reset();        response.setContentType("application/x-download");        UploadFile upload = new UploadFile();        String filepath = upload.getDownloadFilePath();        String filenamedownload = filepath + java.io.File.separator + filename;        String filenamedisplay = java.net.URLEncoder.encode(filename, "UTF-8");        filenamedisplay = URLEncoder.encode(filenamedisplay, "UTF-8");        response.addHeader("Content-Disposition", "attachment;filename=" + filenamedisplay);        OutputStream output = null;        FileInputStream fis = null;        try {            output = response.getOutputStream();            fis = new FileInputStream(filenamedownload);            byte[] b = new byte[1024];            int i = 0;            while ((i = fis.read(b)) > 0) {                output.write(b, 0, i);            }            output.flush();        } catch (Exception e) {            System.out.println("Close the download file windows!");        } finally {            if (fis != null) {                fis.close();                fis = null;            }            if (output != null) {                output.close();                output = null;            }        }    }}