One of the systems is deployed at multiple points, and data is transmitted between different points through HTTP. The server side is implemented with SpringMVC, so such requests that are not initiated through pages need to be excluded from the CAS Filter. The initial idea was to use regular expressions in the FilterMapping declaration, but the deployment test was invalid. Google learned from SOF that Servlet does not support regular expressions, as follows:
No, you can't use a regex there. According to the Java Servlet Specification v2.4 (section srv.11.1), the url-path is interpreted as follows: •A string beginning with a ‘/’ character and ending with a ‘/*’ suffix is used for path mapping. •A string beginning with a ‘*.’ prefix is used as an extension mapping. •A string containing only the ’/’ character indicates the "default" servlet of the application. In this case the servlet path is the request URI minus the context path and the path info is null. •All other strings are used for exact matches only. No regexes. Not even complicated wild-cards.
The meaning seems to be that those starting with "/" can only be filtered by the prefix, those starting with "*" can only be filtered by the suffix, and other strings can only be completely matched, regular and even complex wildcards are not supported. Since Servlet does not support it, it has to find another way. Other methods that come to mind are:
- 1. Customize the Filter, and then refer to the Filter of CAS itself;
- 2. Strip the request to transfer data from MVC.
Because the functions of CAS permission verification, login, and logout are intercepted by multiple filters, the modification is more complicated and has potential risks. So in the end, I chose to write a separate Servlet to implement the function of receiving data.
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