FileUtils.listFiles() does not list matching files if File parameter is

a symbolic link.

Author: Gary Gregory

src/changes/changes.xml

@@ -77,6 +77,9 @@ The <action> type attribute can be add,update,fix,remove.
       <action issue="IO-726" dev="ggregory" type="fix" due-to="shollander, Gary Gregory">
         Add MemoryMappedInputStream. #215.
       </action>
+      <action issue="IO-749" dev="ggregory" type="fix" due-to="haihuiyang, Gary Gregory">
+        FileUtils.listFiles() does not list matching files if File parameter is a symbolic link.
+      </action>
       <!-- ADD -->
       <action dev="ggregory" type="add" due-to="Gary Gregory">
         Add BrokenReader.INSTANCE.

src/main/java/org/apache/commons/io/FileUtils.java

@@ -55,9 +55,11 @@
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Date;
+import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Objects;
+import java.util.Set;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 import java.util.zip.CRC32;
@@ -2175,13 +2177,15 @@ public static LineIterator lineIterator(final File file, final String charsetNam
     }
 
     private static AccumulatorPathVisitor listAccumulate(final File directory, final IOFileFilter fileFilter,
-        final IOFileFilter dirFilter) throws IOException {
+        final IOFileFilter dirFilter, FileVisitOption... options) throws IOException {
         final boolean isDirFilterSet = dirFilter != null;
         final FileEqualsFileFilter rootDirFilter = new FileEqualsFileFilter(directory);
         final PathFilter dirPathFilter = isDirFilterSet ? rootDirFilter.or(dirFilter) : rootDirFilter;
         final AccumulatorPathVisitor visitor = new AccumulatorPathVisitor(Counters.noopPathCounters(), fileFilter,
             dirPathFilter);
-        Files.walkFileTree(directory.toPath(), Collections.emptySet(), toMaxDepth(isDirFilterSet), visitor);
+        Set<FileVisitOption> optionSet = new HashSet<>();
+        Collections.addAll(optionSet, options);
+        Files.walkFileTree(directory.toPath(), optionSet, toMaxDepth(isDirFilterSet), visitor);
         return visitor;
     }
 
@@ -2237,7 +2241,7 @@ private static File[] listFiles(final File directory, final FileFilter fileFilte
     public static Collection<File> listFiles(
         final File directory, final IOFileFilter fileFilter, final IOFileFilter dirFilter) {
         try {
-            final AccumulatorPathVisitor visitor = listAccumulate(directory, fileFilter, dirFilter);
+            final AccumulatorPathVisitor visitor = listAccumulate(directory, fileFilter, dirFilter, FileVisitOption.FOLLOW_LINKS);
             return visitor.getFileList().stream().map(Path::toFile).collect(Collectors.toList());
         } catch (final IOException e) {
             throw UncheckedIOExceptions.create(directory, e);
@@ -2284,7 +2288,7 @@ public static Collection<File> listFiles(final File directory, final String[] ex
     public static Collection<File> listFilesAndDirs(
         final File directory, final IOFileFilter fileFilter, final IOFileFilter dirFilter) {
         try {
-            final AccumulatorPathVisitor visitor = listAccumulate(directory, fileFilter, dirFilter);
+            final AccumulatorPathVisitor visitor = listAccumulate(directory, fileFilter, dirFilter, FileVisitOption.FOLLOW_LINKS);
             final List<Path> list = visitor.getFileList();
             list.addAll(visitor.getDirList());
             return list.stream().map(Path::toFile).collect(Collectors.toList());