ContentDisposition 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rfc2616 http://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：

1.  
    
2.  
   disposition := "Content-Disposition" ":"
3.  
   disposition-type
4.  
   *(";" disposition-parm)
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   disposition-type := "inline"
6.  
   / "attachment"
7.  
   / extension-token
8.  
   ; values are not case-sensitive
9.  
   disposition-parm := filename-parm / parameter
10.  
    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

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   File file = new File("rfc1806.txt");
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   String filename = file.getName();
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   response.setHeader("Content-Type","text/plain");
4.  
   response.addHeader("Content-Disposition","inline;filename=" + new String(filename.getBytes(),"utf-8"));
5.  
   response.addHeader("Content-Length","" + file.length());

attachment：弹出对话框让用户下载

1.  
   File file = new File("rfc1806.txt");
2.  
   String filename = file.getName();
3.  
   response.setHeader("Content-Type","text/plain");
4.  
   response.addHeader("Content-Disposition","attachment;filename=" + new String(filename.getBytes(),"utf-8"));
5.  
   response.addHeader("Content-Length","" + file.length());