struts实现下载文件关键代码

//下载生成的文件到客户端
response.setHeader("pragma","no-cache");
response.setHeader("cache-control","no-cache");
response.setDateHeader("Expires",0);
//设置编码
request.setCharacterEncoding("UTF-8");

String fileName ="bossXML.zip";//request.getParameter("fileName");
//取到文件
File file = new File("d:/" + fileName);
response.reset();
//response.setContentType("application/octet-stream;charset=UTF-8");
response.setContentType("application/octet-stream;charset=GBK");//解决在弹出文件下载框不能打开文件的问题

//一定要对fileName进行encode
//response.addHeader("Content-Disposition", "attachment; filename=" + java.net.URLEncoder.encode(fileName, "UTF-8"));
response.addHeader("Content-Disposition", "attachment; filename=" + new String(fileName.getBytes("GBK"),"ISO8859-1"));//解决在弹出文件下载框不能打开文件的问题
response.setContentLength((int) file.length());

byte[] buffer = new byte[4096];
BufferedOutputStream output = null;
BufferedInputStream input = null;

// 写缓冲区：
try {
output = new BufferedOutputStream(response.getOutputStream());
input = new BufferedInputStream(new FileInputStream(file));

int n = (-1);
while ((n = input.read(buffer, 0, 4096)) > -1) {
output.write(buffer, 0, n);
}
response.flushBuffer();
}
catch (Exception e) {
}
finally {
if (input != null) input.close();
if (output != null) output.close();
}
return null;
}