Let org.apache.commons.io.filefilter classes work with

java.nio.file.Files.walk* APIs.

Also: AccumulatorPathVisitor does not track directories properly.

Author: Gary Gregory

pom.xml

@@ -308,6 +308,8 @@ file comparators, endian transformation classes, and much more.
     <spotbugs.plugin.version>4.1.3</spotbugs.plugin.version>
     <spotbugs.impl.version>4.1.3</spotbugs.impl.version>    
     <japicmp.skip>false</japicmp.skip>
+    <!-- generate report even if there are binary incompatible changes -->
+    <commons.japicmp.breakBuildOnBinaryIncompatibleModifications>false</commons.japicmp.breakBuildOnBinaryIncompatibleModifications>
     <jacoco.skip>${env.JACOCO_SKIP}</jacoco.skip>
     <commons.release.isDistModule>true</commons.release.isDistModule>
     <commons.releaseManagerName>Gary Gregory</commons.releaseManagerName>    
@@ -437,6 +439,22 @@ file comparators, endian transformation classes, and much more.
           <excludeFilterFile>${basedir}/spotbugs-exclude-filter.xml</excludeFilterFile>
         </configuration>
       </plugin>
+      <plugin>
+        <groupId>com.github.siom79.japicmp</groupId>
+        <artifactId>japicmp-maven-plugin</artifactId>
+        <configuration>
+          <parameter>
+            <overrideCompatibilityChangeParameters>
+              <overrideCompatibilityChangeParameter>
+                <compatibilityChange>METHOD_NEW_DEFAULT</compatibilityChange>
+                <binaryCompatible>true</binaryCompatible>
+                <sourceCompatible>true</sourceCompatible>
+                <semanticVersionLevel>PATCH</semanticVersionLevel>
+              </overrideCompatibilityChangeParameter>
+            </overrideCompatibilityChangeParameters>
+          </parameter>
+        </configuration>
+      </plugin>
     </plugins>
   </build>
 
@@ -459,6 +477,22 @@ file comparators, endian transformation classes, and much more.
           <excludeFilterFile>${basedir}/spotbugs-exclude-filter.xml</excludeFilterFile>
         </configuration>
       </plugin>
+      <plugin>
+        <groupId>com.github.siom79.japicmp</groupId>
+        <artifactId>japicmp-maven-plugin</artifactId>
+        <configuration>
+          <parameter>
+            <overrideCompatibilityChangeParameters>
+              <overrideCompatibilityChangeParameter>
+                <compatibilityChange>METHOD_NEW_DEFAULT</compatibilityChange>
+                <binaryCompatible>true</binaryCompatible>
+                <sourceCompatible>true</sourceCompatible>
+                <semanticVersionLevel>PATCH</semanticVersionLevel>
+              </overrideCompatibilityChangeParameter>
+            </overrideCompatibilityChangeParameters>
+          </parameter>
+        </configuration>
+      </plugin>    
     </plugins>
   </reporting>
   <profiles>

src/changes/changes.xml

@@ -63,10 +63,16 @@ The <action> type attribute can be add,update,fix,remove.
       <action dev="ggregory" type="fix" due-to="Michiel Kalkman">
         FileUtils#copyDirectory(File, File, FileFilter, preserveFileDate) clean up #163.
       </action>
+      <action dev="ggregory" type="fix" due-to="Michiel Kalkman">
+        AccumulatorPathVisitor does not track directories properly.
+      </action>
       <!-- ADD -->
       <action dev="ggregory" type="add" due-to="Gary Gregory">
         Add FileSystemProviders class.
       </action>
+      <action dev="ggregory" type="add" due-to="Gary Gregory">
+        Let org.apache.commons.io.filefilter classes work with java.nio.file.Files.walk* APIs.
+      </action>
       <!-- UPDATES -->
       <action dev="ggregory" type="update" due-to="Dependabot">
         Update junit-jupiter from 5.6.2 to 5.7.0 #153.

src/main/java/org/apache/commons/io/file/AccumulatorPathVisitor.java

@@ -19,7 +19,6 @@
 
 import java.io.IOException;
 import java.nio.file.FileVisitResult;
-import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.attribute.BasicFileAttributes;
 import java.util.ArrayList;
@@ -28,12 +27,34 @@
 import java.util.Objects;
 
 import org.apache.commons.io.file.Counters.PathCounters;
+import org.apache.commons.io.filefilter.PathFilter;
 
 /**
  * Accumulates normalized paths during visitation.
  * <p>
  * Use with care on large file trees as each visited Path element is remembered.
  * </p>
+ * <h2>Example</h2>
+ *
+ * <pre>
+ * Path dir = Paths.get(".");
+ * // We are interested in files older than one day
+ * long cutoff = System.currentTimeMillis() - (24 * 60 * 60 * 1000);
+ * AccumulatorPathVisitor visitor = AccumulatorPathVisitor.withLongCounters(new AgeFileFilter(cutoff));
+ * //
+ * // Walk one dir
+ * Files.walkFileTree(dir, Collections.emptySet(), 1, visitor);
+ * System.out.println(visitor.getPathCounters());
+ * System.out.println(visitor.getFileList());
+ * //
+ * visitor.getPathCounters().reset();
+ * //
+ * // Walk dir tree
+ * Files.walkFileTree(dir, visitor);
+ * System.out.println(visitor.getPathCounters());
+ * System.out.println(visitor.getDirList());
+ * System.out.println(visitor.getFileList());
+ * </pre>
  *
  * @since 2.7
  */
@@ -57,19 +78,65 @@ public static AccumulatorPathVisitor withLongCounters() {
         return new AccumulatorPathVisitor(Counters.longPathCounters());
     }
 
+    /**
+     * Creates a new instance configured with a long {@link PathCounters}.
+     *
+     * @param pathFilter Filters files to accumulate and count.
+     * @return a new instance configured with a long {@link PathCounters}.
+     * @since 2.9.0
+     */
+    public static AccumulatorPathVisitor withLongCounters(final PathFilter pathFilter) {
+        return new AccumulatorPathVisitor(Counters.longPathCounters(), pathFilter);
+    }
+
+    /**
+     * Creates a new instance configured with a BigInteger {@link PathCounters}.
+     *
+     * @param pathFilter Filters files to accumulate and count.
+     * @return a new instance configured with a long {@link PathCounters}.
+     * @since 2.9.0
+     */
+    public static AccumulatorPathVisitor withBigIntegerCounters(final PathFilter pathFilter) {
+        return new AccumulatorPathVisitor(Counters.bigIntegerPathCounters(), pathFilter);
+    }
+
     private final List<Path> dirList = new ArrayList<>();
 
     private final List<Path> fileList = new ArrayList<>();
 
     /**
      * Constructs a new instance.
      *
+     * @since 2.9.0
+     */
+    public AccumulatorPathVisitor() {
+        super(Counters.noopPathCounters());
+    }
+
+    /**
+     * Constructs a new instance that counts file system elements.
+     *
      * @param pathCounter How to count path visits.
      */
     public AccumulatorPathVisitor(final PathCounters pathCounter) {
         super(pathCounter);
     }
 
+    /**
+     * Constructs a new instance.
+     *
+     * @param pathCounter How to count path visits.
+     * @param pathFilter Filters which paths to count.
+     * @since 2.9.0
+     */
+    public AccumulatorPathVisitor(final PathCounters pathCounter, final PathFilter pathFilter) {
+        super(pathCounter, pathFilter);
+    }
+
+    private void add(final List<Path> list, final Path dir) {
+        list.add(dir.normalize());
+    }
+
     @Override
     public boolean equals(final Object obj) {
         if (this == obj) {
@@ -111,6 +178,12 @@ public int hashCode() {
         return result;
     }
 
+    @Override
+    public FileVisitResult postVisitDirectory(final Path dir, final IOException exc) throws IOException {
+        add(dirList, dir);
+        return super.postVisitDirectory(dir, exc);
+    }
+
     /**
      * Relativizes each directory path with {@link Path#relativize(Path)} against the given {@code parent}, optionally
      * sorting the result.
@@ -120,7 +193,8 @@ public int hashCode() {
      * @param comparator How to sort, null uses default sorting.
      * @return A new list
      */
-    public List<Path> relativizeDirectories(final Path parent, final boolean sort, final Comparator<? super Path> comparator) {
+    public List<Path> relativizeDirectories(final Path parent, final boolean sort,
+        final Comparator<? super Path> comparator) {
         return PathUtils.relativize(getDirList(), parent, sort, comparator);
     }
 
@@ -133,13 +207,14 @@ public List<Path> relativizeDirectories(final Path parent, final boolean sort, f
      * @param comparator How to sort, null uses default sorting.
      * @return A new list
      */
-    public List<Path> relativizeFiles(final Path parent, final boolean sort, final Comparator<? super Path> comparator) {
+    public List<Path> relativizeFiles(final Path parent, final boolean sort,
+        final Comparator<? super Path> comparator) {
         return PathUtils.relativize(getFileList(), parent, sort, comparator);
     }
 
     @Override
     public FileVisitResult visitFile(final Path file, final BasicFileAttributes attributes) throws IOException {
-        ((Files.isDirectory(file)) ? dirList : fileList).add(file.normalize());
+        add(fileList, file);
         return super.visitFile(file, attributes);
     }
 

src/main/java/org/apache/commons/io/file/CopyDirectoryVisitor.java

@@ -27,6 +27,7 @@
 import java.util.Objects;
 
 import org.apache.commons.io.file.Counters.PathCounters;
+import org.apache.commons.io.filefilter.PathFilter;
 
 /**
  * Copies a source directory to a target directory.
@@ -35,8 +36,6 @@
  */
 public class CopyDirectoryVisitor extends CountingPathVisitor {
 
-    private static final CopyOption[] EMPTY_COPY_OPTIONS = new CopyOption[0];
-
     private final CopyOption[] copyOptions;
     private final Path sourceDirectory;
     private final Path targetDirectory;
@@ -54,7 +53,25 @@ public CopyDirectoryVisitor(final PathCounters pathCounter, final Path sourceDir
         super(pathCounter);
         this.sourceDirectory = sourceDirectory;
         this.targetDirectory = targetDirectory;
-        this.copyOptions = copyOptions == null ? EMPTY_COPY_OPTIONS : copyOptions.clone();
+        this.copyOptions = copyOptions == null ? PathUtils.EMPTY_COPY_OPTIONS : copyOptions.clone();
+    }
+
+    /**
+     * Constructs a new visitor that deletes files except for the files and directories explicitly given.
+     *
+     * @param pathCounter How to count visits.
+     * @param pathFilter How to filter paths.
+     * @param sourceDirectory The source directory
+     * @param targetDirectory The target directory
+     * @param copyOptions Specifies how the copying should be done.
+     * @since 2.9.0
+     */
+    public CopyDirectoryVisitor(final PathCounters pathCounter, final PathFilter pathFilter, final Path sourceDirectory, final Path targetDirectory,
+        final CopyOption... copyOptions) {
+        super(pathCounter, pathFilter);
+        this.sourceDirectory = sourceDirectory;
+        this.targetDirectory = targetDirectory;
+        this.copyOptions = copyOptions == null ? PathUtils.EMPTY_COPY_OPTIONS : copyOptions.clone();
     }
 
     /**