Returns a URL to the resource that is mapped to a specified path. The path must begin
with a "/" and is interpreted as relative to the current context root.
This method allows the servlet container to make a resource available to servlets from any source.
Resources can be located on a local or remote file system, in a database, or in a .war file.
The servlet container must implement the URL handlers and URLConnection objects that are necessary to access the resource.
This method returns null if no resource is mapped to the pathname.
Some containers may allow writing to the URL returned by this method using the methods of the URL class.
The resource content is returned directly, so be aware that requesting a .jsp page returns the JSP source code. Use a
RequestDispatcher instead to include results of an execution.
This method has a different purpose than java.lang.Class.getResource, which looks up resources based on a class loader. This
method does not use class loaders.