Add utilities to detect and replace broken links V2

Author: barsh404error

application/src/main/java/org/togetherjava/tjbot/features/utils/LinkDetection.java

@@ -17,9 +17,13 @@
  * Utility class to detect links.
  */
 public class LinkDetection {
-    private static final HttpClient HTTP_CLIENT = HttpClient.newHttpClient();
+    private static final HttpClient HTTP_CLIENT =
+            HttpClient.newBuilder().followRedirects(HttpClient.Redirect.NORMAL).build();
 
-    private static final Set<LinkFilter> DEFAULT_FILTERS =
+    /**
+     * Default filters used when extracting links: skip suppressed URLs and non-http schemes.
+     */
+    private static final Set<LinkFilter> DEFAULT_EXTRACT_FILTERS =
             Set.of(LinkFilter.SUPPRESSED, LinkFilter.NON_HTTP_SCHEME);
 
     /**
@@ -78,23 +82,22 @@ public static boolean containsLink(String content) {
      * </ul>
      *
      * <p>
-     * The method first performs an HTTP {@code HEAD} request and falls back to an HTTP {@code GET}
-     * request if the {@code HEAD} request indicates a failure.
-     * </p>
-     *
-     * <p>
      * Notes:
      * <ul>
      * <li>Status code {@code 200} is considered valid, even if the response body is empty</li>
      * <li>The response body content is not inspected</li>
      * </ul>
      *
-     * @param url the URL to check (must be a valid {@link URI})
+     * @param url the URL to check
      * @return a future completing with {@code true} if the link is broken
      * @throws IllegalArgumentException if the given URL is not a valid URI
      */
 
+
     public static CompletableFuture<Boolean> isLinkBroken(String url) {
+        // Quick check with HEAD "cheaper". If HEAD indicates failure some servers don't implement
+        // HEAD properly,
+        // fall back to GET to confirm the resource status.
         HttpRequest headCheckRequest = HttpRequest.newBuilder(URI.create(url))
             .method("HEAD", HttpRequest.BodyPublishers.noBody())
             .build();
@@ -104,7 +107,7 @@ public static CompletableFuture<Boolean> isLinkBroken(String url) {
                 int status = response.statusCode();
                 return status < 200 || status >= 400;
             })
-            .exceptionally(ignored -> true)
+            .exceptionally(_ -> true)
             .thenCompose(result -> {
                 if (!result) {
                     return CompletableFuture.completedFuture(false);
@@ -127,7 +130,7 @@ public static CompletableFuture<Boolean> isLinkBroken(String url) {
      *
      * <p>
      * Example:
-     * 
+     *
      * <pre>{@code
      * replaceDeadLinks("""
      *         Test
@@ -138,19 +141,19 @@ public static CompletableFuture<Boolean> isLinkBroken(String url) {
      *
      * <p>
      * Results in:
-     * 
+     *
      * <pre>{@code
      * Test
      * broken
      * http://workinglink/1
      * }</pre>
      *
-     * @param text the input text containing URLs (must not be {@code null})
-     * @param replacement the string to replace broken links with (must not be {@code null})
+     * @param text the input text containing URLs
+     * @param replacement the string to replace broken links with
      * @return a future containing the modified text
      */
     public static CompletableFuture<String> replaceDeadLinks(String text, String replacement) {
-        List<String> links = extractLinks(text, DEFAULT_FILTERS);
+        List<String> links = extractLinks(text, DEFAULT_EXTRACT_FILTERS);
 
         if (links.isEmpty()) {
             return CompletableFuture.completedFuture(text);
@@ -164,16 +167,20 @@ public static CompletableFuture<String> replaceDeadLinks(String text, String rep
 
 
         return CompletableFuture.allOf(deadLinkFutures.toArray(CompletableFuture[]::new))
-            .thenApply(ignored -> deadLinkFutures.stream()
+            .thenApply(_ -> deadLinkFutures.stream()
                 .map(CompletableFuture::join)
                 .flatMap(Optional::stream)
                 .toList())
             .thenApply(deadLinks -> {
-                String result = text;
+                StringBuilder sb = new StringBuilder(text);
                 for (String deadLink : deadLinks) {
-                    result = result.replace(deadLink, replacement);
+                    int idx = sb.indexOf(deadLink);
+                    while (idx != -1) {
+                        sb.replace(idx, idx + deadLink.length(), replacement);
+                        idx = sb.indexOf(deadLink, idx + replacement.length());
+                    }
                 }
-                return result;
+                return sb.toString();
             });
     }