Java web 文件下载

/**
     * 下载文件
     * @param msg
     */
    public boolean printOutFile(String fileFullName,String fileName) {
        if (fileFullName == null || "".equals(fileFullName)) {
            return false;
        }
        File file=new File(fileFullName);
        if(!file.exists()){
            return false;
        }
        try {
            HttpServletResponse response=ServletActionContext.getResponse();
            response.setContentType("application/octet-stream");
            response.addHeader("Content-Disposition", "attachment;filename="+URLEncoder.encode(fileName, "UTF-8"));
            response.addHeader("Content-Length", file.length()+"");
            response.setContentLength(((Long)file.length()).intValue());
            
            ServletOutputStream os=response.getOutputStream();
            FileInputStream fis=new FileInputStream(file);
            
            int size=0;
            byte[] buffer=new byte[4096];
            while((size=fis.read(buffer))!=-1){
                os.write(buffer,0,size);
            }
            os.flush();
            os.close();
            fis.close();
            return true;
            
        } catch (IOException e) {
            e.printStackTrace();
        }
        return false;
    }