====== Handling the Trailing Slash in URL ======
For now, if you use @RequestMapping, @GetMapping, @PostMapping, ... you will see that if you accidentally added a trailing slash "/" in the URL, you will get a 404 HTTP error.

To handling this problem, we need to add a path matching configurer.

  - Write a WebConfiguration class with @Configuration annotation that implements WebMvcConfigurer.
  - @Override that method ''public void configurePathMatch(PathMatchConfigurer configurer){...}''
  - The method looks like:<code>
@Override
public void configurePathMatch(PathMatchConfigurer configurer){
   configurer.setUseTrailingSlashMatch(true);
}
</code>


To manipulate the URL, you can chain this configurer with ''setPathHelper(...)'', or ''setUrlPathHelper(...)'' with your own implementation of ''PathMatcher'' or ''UrlPathHelper''.