Replace filterPath pattern '/*' with empty string

[fschrogl]

A filterPath pattern of '/*' is now replaced with an empty string. This matches the behavior of methods getFilterPathFromAnnotation() and getFilterPathFromConfig().

I'm not sure if it's a bug, but I noticed the different beahvior when initializing Wicket in a Spring Boot application. When using a @webfilter("/") annotation or the init parameter filterMappingUrlPattern="/" Wicket works as expected, but when doing the same programmatically with wicketFilter.setFilterPath("/") the path gets internally rewritten to "/" and Wicket than only handles HTTP requests to the root path.

[martin-g]

bq. wicketFilter.setFilterPath("/") the path gets internally rewritten to "/"

Is something missing here ? The values are the same - "/", so I do not understand what is rewritten.
Can you please provide your Spring Boot configuration related to WicketFilter that breaks your app ? I also have Spring Boot based app and I can try it locally to verify the problem..
Thanks!

[fschrogl]

I tried to initialize Wicket using WicketFilter class and three different approaches (one after another). That's where I noticed the different behavior (at least that's how I understand it).

(1) Using setFilterPath method

@Bean
public FilterRegistrationBean<WicketFilter> initWicketFilterByGetter() {
  WicketFilter wicketFilter = new WicketFilter(new MyWicketApplication());
  // filterPath '/' works for all paths
  // filterPath '/*' only works for root path
  wicketFilter.setFilterPath("/");
  return new FilterRegistrationBean<>(wicketFilter);
}

(2) Using init params

@Bean
public FilterRegistrationBean<WicketFilter> initWicketFilterByInitParam() {
  WicketFilter wicketFilter = new WicketFilter(new MyWicketApplication());
  FilterRegistrationBean<WicketFilter> wicketFilterRegistrationBean = new FilterRegistrationBean<>(wicketFilter);
  // Using '/*' works for all paths, using '/' leads to an exception
  wicketFilterRegistrationBean.addInitParameter(WicketFilter.FILTER_MAPPING_PARAM, "/*");
  return wicketFilterRegistrationBean;
}

(3) Using @WebFilter annotation on a custom filter and @ServletComponentScan for Spring Boot

// /* works, / doesn't work
@WebFilter(value = "/*", initParams = @WebInitParam(name = "applicationClassName", value = "package.MyWicketApplication"))
public static class MyWicketFilter extends WicketFilter {  }

In approach (1) I have to use / while in approaches (2) and (3) I have to use /* to achieve the same outcome.

[klopfdreh]

Just my thoughts:

/* - maps every path - root paths and sub paths to the specific filter
/ - maps only the root path but not every sub path

So from my understanding they aren't the same and shouldn't be mixed up.

https://stackoverflow.com/questions/4140448/difference-between-and-in-servlet-mapping-url-pattern

Maybe we should inspect this a bit more to achieve the right handling.

WDTY?

[klopfdreh]

@martin-g what do you thing of extracting the lines:

https://github.com/apache/wicket/blob/master/wicket-core/src/main/java/org/apache/wicket/protocol/http/WicketFilter.java#L583

to

https://github.com/apache/wicket/blob/master/wicket-core/src/main/java/org/apache/wicket/protocol/http/WicketFilter.java#L599

into a method and call this method within getFilterPath and getFilterPathFromConfig?

[solomax]

This PR seems to be inactive for too long :(
I guess it can be dropped? :)