Java 无法从标头中正确获取“用户代理”

`嗨

我试图在servlet过滤器中获取用户的浏览器信息。我使用了一个简单的代码，见下文

String userAgent = request.getHeader("User-Agent");

用户使用的是谷歌浏览器，上面的代码打印如下

Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/42.0.2311.135 Safari/537.36

它打印了所有主要浏览器的名称，而不是在应用程序运行后获取名称。这里怎么了？

这里什么都没有

例如，让我们考虑返回的字符串是

Mozilla/5.0（Windows NT 6.1）AppleWebKit/537.36（KHTML，如Gecko）Chrome/41.0.2228.0 Safari/537.36

那么解释是

ChromeChrome 41.0.2228.0

Mozilla ==> 

MozillaProductSlice. Claims to be a Mozilla based user agent, which is only true for Gecko browsers like Firefox and Netscape. For all other user agents it means 'Mozilla-compatible'. In modern browsers, this is only used for historical reasons. It has no real meaning anymore

5.0 ==> Mozilla version

Windows NT 6.1  ==> Operating System Windows 7 

AppleWebKit  ==> The Web Kit provides a set of core classes to display web content in windows

537.36       ==> Web Kit build
KHTML        ==> Open Source HTML layout engine developed by the KDE project
like Gecko   ==> like Gecko...
Chrome  Name ==> Chrome
41.0.2228.0  ==> Chrome version
Safari       ==> Based on Safari
537.36       ==> Safari build

Description:    Free open-source web browser developed by Google. 
Chromium is the name of the open source project behind Google Chrome, released under the BSD license.

您可以在下面的链接中找到更多信息

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单击页面上的每个链接以获取更多信息

这是Chrome的用户代理字符串。这是不同浏览器使用的所有用户代理字符串的列表。有关更多帮助，请参阅最新浏览器，让服务器认为它可以兼容呈现复杂内容。说来话长。有关更多信息，请参见此。