Filter mapping servlet with url pattern **

Question

The difference between * and ** should be : * matches until "/" while ** matches every path including "/" . I noticed that for filter mapping in web xml "/*" is working even for paths with multiple "/" eg :

<filter>
    <filter-name>loginFilter</filter-name>
    <filter-class>..LoginFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>loginFilter</filter-name>
    <url-pattern>/test/*</url-pattern>
</filter-mapping>

this will match /test/...../....

so is this specific to filter mapping ? is servlet mapping the same or it works with ** ?

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This mapping is done in project's (Spring Data ) web.xml not the tomcat , I'm not sure if it's different.

I have also tried tomcat web.xml and it seems "/*" will work for all paths with "/" , the question will be when "/**" is applicable ?

Answer 1

Ant-style patterns with "**" do not work in a web.xml file. See the Servlet specification chapter "12.2 Specification of Mappings" for details on what mappings are allowed. The options are rather limited. The '*' character is used in prefix mapping and extension mapping only. In all other cases it is interpreted literally (for exact matching).