文件下载实现

java代码：
@RequestMapping(value = "/download")
@ResponseBody
public void download(HttpServletRequest request,
HttpServletResponse response) throws FileNotFoundException {
//获取服务器端文件保存路径
String realPath = request.getSession().getServletContext().getRealPath("/");
String path = realPath+"文件.txt";
//下载
try {
// path是指欲下载的文件的路径。
File file = new File(path);
// 取得文件名。
String filename = file.getName();
// 取得文件的后缀名。
String ext = filename.substring(filename.lastIndexOf(".") + 1).toUpperCase();

// 以流的形式下载文件。
InputStream fis = new BufferedInputStream(new FileInputStream(path));
byte[] buffer = new byte[fis.available()];
fis.read(buffer);
fis.close();
// 清空response
response.reset();
// 设置response的Header
response.addHeader("Content-Disposition", "attachment;filename=" + new String(filename.getBytes("gb2312"),"ISO8859-1"));
response.addHeader("Content-Length", "" + file.length());
OutputStream toClient = new BufferedOutputStream(response.getOutputStream());
response.setContentType("application/octet-stream");
toClient.write(buffer);
toClient.flush();
toClient.close();
} catch (IOException ex) {
ex.printStackTrace();
}

}
请求方法：window.location.href = encodeURI("forecast/download");

这样不用使用a标签来请求 直接在js中调用即可