springmvc下载文件

可以跨域下载

    /**
     * 音频下载
     */
    @RequestMapping("/audio/download")
    public void downloadFile(HttpServletRequest request, HttpServletResponse response) throws IOException {
        //String id = request.getParameter("id");
        String filePath = ServletRequestUtils.getStringParameter(request, "filePath", ""); //
        String fileName = ServletRequestUtils.getStringParameter(request, "fileName", ""); //
        String destUrl = filePath;
        //System.out.println("--------------"+filePath); 

        String fileFormat=filePath.substring(filePath.lastIndexOf("."));
        String name=fileName.trim()+fileFormat;
        //File f = new File(filePath);
        //response.setHeader("Content-Disposition", "attachment; filename="+java.net.URLEncoder.encode(f.getName(),"UTF-8"));
        //System.out.println("--------------"+f.getName());

        // 建立链接
        URL url = new URL(destUrl);
        HttpURLConnection httpUrl = (HttpURLConnection) url.openConnection();
        // 连接指定的资源
        httpUrl.connect();
        // 获取网络输入流
        BufferedInputStream bis = new BufferedInputStream(httpUrl.getInputStream());  

        response.setContentType("application/x-msdownload");
        response.setHeader("Content-Disposition", "attachment; filename="+java.net.URLEncoder.encode(name,"UTF-8"));
        OutputStream out = response.getOutputStream();
        byte[] buf = new byte[1024];
        if (destUrl != null) {
            BufferedInputStream br = bis;
            int len = 0;
            while ((len = br.read(buf)) > 0){
                out.write(buf, 0, len);
            }
            br.close();
        }
        out.flush();
        out.close();  

    } 

页面主要代码：

<div class="txt-2" style="padding-left:6px;float:none;">
			    <a href="/wxj/audio/download?filePath=${(contentJson.audiolink)!''}&fileName=${(course.title)!''}" class="btn btn-info">下　载</a>
			</div>