java 下载文件功能代码例子

public static void down(HttpServletRequest request,
HttpServletResponse
response) throws Exception {


String name="aaa.*";//文件名
String uploadPath =
UploadFileHelper.getRepositoryPath()+"//";//文件来源

String
filePath = name;
String fileName = name;


if
(request.getHeader("User-Agent").toLowerCase().indexOf("firefox")
> 0){
fileName =
new String(fileName.getBytes("UTF-8"),
"ISO8859-1");//firefox浏览器
}else {

if (request.getHeader("User-Agent").toUpperCase().indexOf("MSIE")
> 0){

fileName = URLEncoder.encode(fileName,
"UTF-8");//IE浏览器

}
}

response.setContentType("text/plain");

response.setHeader("Location",fileName);

response.reset();
response.setHeader("Cache-Control",
"max-age=0" );
response.setHeader("Content-Disposition",
"attachment; filename=" + fileName);
BufferedInputStream bis = null;
BufferedOutputStream bos =
null;
OutputStream fos = null;
InputStream fis = null;
filePath = uploadPath +
filePath;
fis = new
FileInputStream(filePath);

bis = new BufferedInputStream(fis);

fos = response.getOutputStream();

bos = new BufferedOutputStream(fos);

int bytesRead = 0;

byte[] buffer = new byte[5 * 1024];

while ((bytesRead = bis.read(buffer)) != -1) {

bos.write(buffer, 0, bytesRead);// 将文件发送到客户端

}

bos.close();

bis.close();

fos.close();

fis.close();

}