后台 实现文件的上载 的实现

后台 实现文件的下载 的实现
Ext 实现文件的下载简要步骤：
1）为某个控件编写事件响应代码

//设置相应的头部分response.setContentType("application/x-download");response.setHeader("Content-disposition", "attachment;filename="+filename);//通过流进行连接，提供下载 ，doc_downPath就是要下载文件的路劲OutputStream outputStream = null;FileInputStream fileInputStream = null;outputStream  = response.getOutputStream();fileInputStream = new FileInputStream(doc_downPath);byte[] b = new byte[1024];    int length = 0;    while((length = fileInputStream.read(b)) > 0) {        outputStream.write(b, 0, length);    }    outputStream.flush();    fileInputStream.close();    outputStream.close();