Merge pull request #53 from nastiausenko/feature/original-link-redirect

Update Javadoc for link cache and redirect controller

src/main/java/com/linkurlshorter/urlshortener/redirect/LinkCache.java

@@ -7,20 +7,47 @@
 import java.util.HashMap;
 import java.util.Map;
 
+/**
+ * Component class for caching links to optimize redirection performance.
+ *
+ * <p>This class provides a simple in-memory cache for storing links by their short links.
+ * It allows for quick retrieval of links based on short links, reducing the need for repeated
+ * database queries during redirection requests.
+ *
+ * @author Egor Sivenko
+ */
 @Component
 @RequiredArgsConstructor
 public class LinkCache {
 
     private final Map<String, Link> cache = new HashMap<>();
 
+    /**
+     * Checks if the cache contains the specified short link.
+     *
+     * @param shortLink the short link to check for in the cache
+     * @return true if the cache contains the short link, false otherwise
+     */
     public boolean containsShortLink(String shortLink) {
         return cache.containsKey(shortLink);
     }
 
+    /**
+     * Retrieves the link associated with the specified short link from the cache.
+     *
+     * @param shortLink the short link to retrieve the associated link for
+     * @return the link associated with the short link, or null if not found in the cache
+     */
     public Link getByShortLink(String shortLink) {
         return cache.get(shortLink);
     }
 
+    /**
+     * Puts a new link into the cache with the specified short link.
+     *
+     * @param shortLink the short link to use as the cache key
+     * @param link      the link to be cached
+     */
     public void putLink(String shortLink, Link link) {
         cache.put(shortLink, link);
     }

src/main/java/com/linkurlshorter/urlshortener/redirect/LinkRedirectController.java

@@ -15,10 +15,10 @@
  * Controller class for handling link redirection requests.
  *
  * <p>This class provides an endpoint for redirecting short links to their corresponding long links.
- * When a request is made with a short link, the controller fetches the corresponding long link
- * from the database using the {@link LinkService#findByShortLink(String)}, updates link statistics,
- * and redirects the user to the long link.
- * Additionally, it updates the link's expiration time to extend its validity.
+ * It first checks if the short link is cached in {@link LinkCache}. If the short link is found in the cache,
+ * it retrieves the link directly from the cache; otherwise, it queries the {@link LinkService} to fetch
+ * the link from the database. After retrieving the link, it updates its statistics and expiration time,
+ * caches the link for future requests and redirects the user to the corresponding long link.
  *
  * @author Egor Sivenko
  * @see org.springframework.web.servlet.view.RedirectView
@@ -27,12 +27,8 @@
 @RequiredArgsConstructor
 public class LinkRedirectController {
 
-    /**
-     * The service responsible for managing links
-     */
-    private final LinkService linkService;
-
     private final LinkCache linkCache;
+    private final LinkService linkService;
 
     /**
      * Redirects a request with a short link to its corresponding long link.
@@ -50,14 +46,25 @@ public RedirectView redirectToOriginalLink(@PathVariable("shortLink") String sho
         return redirectToLongLink(link);
     }
 
+    /**
+     * Updates the link statistics, expiration time, and caches the link.
+     *
+     * @param link the link to be updated
+     */
     private void updateLinkStats(Link link) {
         link.setStatistics(link.getStatistics() + 1);
         link.setExpirationTime(LocalDateTime.now().plusMonths(1));
 
-        linkService.update(link);
+        linkService.save(link);
         linkCache.putLink(link.getShortLink(), link);
     }
 
+    /**
+     * Redirects to the long link.
+     *
+     * @param link the link to redirect to
+     * @return a RedirectView object directing the user to the long link
+     */
     private RedirectView redirectToLongLink(Link link) {
         RedirectView redirectView = new RedirectView();
         redirectView.setUrl(link.getLongLink());