Avoid NPE in

org.apache.commons.io.filefilter.WildcardFilter.accept(File)

Internal refactoring

Author: garydgregory

src/changes/changes.xml

@@ -68,6 +68,7 @@ The <action> type attribute can be add,update,fix,remove.
       <action dev="ggregory" type="fix"                due-to="Gary Gregory">Fix SpotBugs [ERROR] Medium: Shared primitive variable "propagateClose" in one thread may not yield the value of the most recent write from another thread [org.apache.commons.io.input.BoundedInputStream] At BoundedInputStream.java:[line 555] AT_STALE_THREAD_WRITE_OF_PRIMITIVE.</action>
       <action dev="ggregory" type="fix"                due-to="maxxedev, Piotr P. Karwasz, Gary Gregory">QueueInputStream reads all but the first byte without waiting. #748.</action> 
       <action dev="ggregory" type="fix"                due-to="Gary Gregory">Javadoc fixes and improvements.</action>
+      <action dev="ggregory" type="fix"                due-to="Gary Gregory">Avoid NPE in org.apache.commons.io.filefilter.WildcardFilter.accept(File).</action>
       <!-- ADD -->
       <action dev="ggregory" type="add" issue="IO-875" due-to="Pierre Baumard, Gary Gregory">Add org.apache.commons.io.file.CountingPathVisitor.accept(Path, BasicFileAttributes) #743.</action>
       <action dev="ggregory" type="add" due-to="Gary Gregory">Add org.apache.commons.io.Charsets.isAlias(Charset, String).</action>

src/main/java/org/apache/commons/io/filefilter/AbstractFileFilter.java

@@ -136,6 +136,14 @@ protected FileVisitResult handle(final Throwable t) {
         return FileVisitResult.TERMINATE;
     }
 
+    boolean isDirectory(final File file) {
+        return file != null && file.isDirectory();
+    }
+
+    boolean isFile(final File file) {
+        return file != null && file.isFile();
+    }
+
     @Override
     public FileVisitResult postVisitDirectory(final Path dir, final IOException exc) throws IOException {
         return FileVisitResult.CONTINUE;

src/main/java/org/apache/commons/io/filefilter/DirectoryFileFilter.java

@@ -97,7 +97,7 @@ protected DirectoryFileFilter() {
      */
     @Override
     public boolean accept(final File file) {
-        return file != null && file.isDirectory();
+        return isDirectory(file);
     }
 
     /**

src/main/java/org/apache/commons/io/filefilter/FileFileFilter.java

@@ -97,7 +97,7 @@ protected FileFileFilter() {
      */
     @Override
     public boolean accept(final File file) {
-        return file != null && file.isFile();
+        return isFile(file);
     }
 
     /**

src/main/java/org/apache/commons/io/filefilter/MagicNumberFileFilter.java

@@ -258,7 +258,7 @@ public MagicNumberFileFilter(final String magicNumber, final long offset) {
      */
     @Override
     public boolean accept(final File file) {
-        if (file != null && file.isFile() && file.canRead()) {
+        if (isFile(file) && file.canRead()) {
             try {
                 return RandomAccessFileMode.READ_ONLY.apply(file.toPath(),
                         raf -> Arrays.equals(magicNumbers, RandomAccessFiles.read(raf, byteOffset, magicNumbers.length)));

src/main/java/org/apache/commons/io/filefilter/WildcardFilter.java

@@ -132,7 +132,7 @@ public WildcardFilter(final String... wildcards) {
      */
     @Override
     public boolean accept(final File file) {
-        if (file.isDirectory()) {
+        if (isDirectory(file)) {
             return false;
         }
         return Stream.of(wildcards).anyMatch(wildcard -> FilenameUtils.wildcardMatch(file.getName(), wildcard));