From 207951a8074901323829d6ef8387a3dddfb56cef Mon Sep 17 00:00:00 2001
From: Juri Duval <27741935+Mulgish@users.noreply.github.com>
Date: Sat, 22 Nov 2025 23:41:00 +0000
Subject: [PATCH] Switch to Java NIO for readDirInternal

---
 .../vertx/core/file/impl/FileSystemImpl.java  | 39 ++++++++-----------
 1 file changed, 17 insertions(+), 22 deletions(-)

diff --git a/vertx-core/src/main/java/io/vertx/core/file/impl/FileSystemImpl.java b/vertx-core/src/main/java/io/vertx/core/file/impl/FileSystemImpl.java
index 3b26f87cceb..c714a373f7a 100644
--- a/vertx-core/src/main/java/io/vertx/core/file/impl/FileSystemImpl.java
+++ b/vertx-core/src/main/java/io/vertx/core/file/impl/FileSystemImpl.java
@@ -25,10 +25,10 @@
 import io.vertx.core.internal.VertxInternal;
 
 import java.io.File;
-import java.io.FilenameFilter;
 import java.io.IOException;
 import java.io.RandomAccessFile;
 import java.nio.file.CopyOption;
+import java.nio.file.DirectoryStream;
 import java.nio.file.FileAlreadyExistsException;
 import java.nio.file.FileStore;
 import java.nio.file.FileVisitOption;
@@ -531,7 +531,7 @@ public Void perform() {
             raf.setLength(len);
           }
         } catch (IOException e) {
-          throw new FileSystemException(getFileAccessErrorMessage("truncate", p) ,e);
+          throw new FileSystemException(getFileAccessErrorMessage("truncate", p), e);
         }
         return null;
       }
@@ -840,27 +840,13 @@ public List<String> perform() {
           if (!file.isDirectory()) {
             throw new FileSystemException("Cannot read directory " + file + ". It's not a directory");
           } else {
-            FilenameFilter fnFilter;
-            if (filter != null) {
-              fnFilter = new FilenameFilter() {
-                public boolean accept(File dir, String name) {
-                  return Pattern.matches(filter, name);
-                }
-              };
-            } else {
-              fnFilter = null;
-            }
-            File[] files;
-            if (fnFilter == null) {
-              files = file.listFiles();
-            } else {
-              files = file.listFiles(fnFilter);
-            }
-            List<String> ret = new ArrayList<>(files.length);
-            for (File f : files) {
-              ret.add(f.getCanonicalPath());
+            try (DirectoryStream<Path> pathStream = Files.newDirectoryStream(file.toPath(), directoryFilterInternal(filter))) {
+              List<String> ret = new ArrayList<>();
+              for (final Path path : pathStream) {
+                ret.add(path.toRealPath().toString());
+              }
+              return ret;
             }
-            return ret;
           }
         } catch (IOException e) {
           throw new FileSystemException(getFolderAccessErrorMessage("read", p), e);
@@ -869,6 +855,15 @@ public boolean accept(File dir, String name) {
     };
   }
 
+  private static DirectoryStream.Filter<Path> directoryFilterInternal(String filter) {
+    if (filter == null) {
+      return entry -> true;
+    } else {
+      Pattern filePattern = Pattern.compile(filter);
+      return entry -> filePattern.matcher(entry.getFileName().toString()).matches();
+    }
+  }
+
   private BlockingAction<Buffer> readFileInternal(String path) {
     Objects.requireNonNull(path);
     return new BlockingAction<Buffer>() {