Content-Disposition 响应头，设置文件在浏览器打开还是下载(pdf文件在浏览器预览功能)图片预览功能浏览器下载功能

Content-Disposition 属性是作为对下载文件的一个标识字段，在rfc2616http://www.rfc-editor.org/rfc/rfc2616.pdf章节19.5 Additional Features中

有介绍，具体介绍请看http://www.rfc-editor.org/rfc/rfc1806.txt

字段介绍如下：

disposition :="Content-Disposition"":"

disposition-type

*(";"disposition-parm)

disposition-type:="inline"

/"attachment"

                  / extension-token 

; values are notcase-sensitive

disposition-parm := filename-parm / parameter 

filename-parm :="filename""="value;

Content-Disposition属性有两种类型：inline 和 attachment

inline ：将文件内容直接显示在页面

Filefile=newFile("rfc1806.txt");

Stringfilename=file.getName();

response.setHeader("Content-Type","text/plain");

response.addHeader("Content-Disposition","inline;filename="+newString(filename.getBytes(),"utf-8"));

response.addHeader("Content-Length",""+ file.length());

attachment：弹出对话框让用户下载

Filefile=newFile("rfc1806.txt");

Stringfilename=file.getName();

response.setHeader("Content-Type","text/plain");

response.addHeader("Content-Disposition","attachment;filename="+newString(filename.getBytes(),"utf-8"));

response.addHeader("Content-Length",""+ file.length());