In CQ, ResourceResolver class can be used for resolving a Request into a Sling Resource. However, given a random URL served by a CQ instance, how do you figure out the corresponding Sling Resource of the given URL as a result of Resource Mapping definition?

Let's assume we have some Resource Mapping rules (mapping definition) set up on our Author node via /etc/map so that a sample request to, 

In CQ, let's say we want to expose some sort of REST API for our internal clients, but don't want these API's accessible by the public. For example, say we'd like the said JSP to be available internally (inside firewall), and to be invoked via the web. The API's responsibility is to clear Dispatcher cache via curl command behind the scene.

Tail recursive saves stack memory.

A recursive function is said to be tail-recursive if there is nothing to do after the function returns except returning its value. In this case, instead of allocating a stack frame for each call, the compiler can rework the code to simply reuse the current stack frame, meaning a tail-recursive function will only use a single stack frame as opposed to hundreds or even thousands of stack frame as in the case of regular recursive calls.

Also, in a tail-recursive case, with each evaluation of the recursive call, the solution (e.g., a running total) is updated through parameter. A smart compiler can make Tail Recursion as efficient as iteration normally is.

We'll see an tail-recursion implementation of Fibonacci at the end of this post. Using Fibonacci as an example, a Fibonacci sequence: [f(0)...f(n)]=[0, 1, 1, 2, 3, 5, 8, 13, ...]