6865748: (file) SimpleFileVisitor methods ignore null arguments

Reviewed-by: sherman

src/share/classes/java/nio/file/SimpleFileVisitor.java

@@ -47,6 +47,14 @@ public class SimpleFileVisitor<T> implements FileVisitor<T> {
     protected SimpleFileVisitor() {
     }
 
+    /**
+     * Throws NullPointerException if obj is null.
+     */
+    private static void checkNotNull(Object obj) {
+        if (obj == null)
+            throw new NullPointerException();
+    }
+
     /**
      * Invoked for a directory before entries in the directory are visited.
      *
@@ -55,6 +63,7 @@ public class SimpleFileVisitor<T> implements FileVisitor<T> {
      */
     @Override
     public FileVisitResult preVisitDirectory(T dir) {
+        checkNotNull(dir);
         return FileVisitResult.CONTINUE;
     }
 
@@ -70,6 +79,8 @@ public class SimpleFileVisitor<T> implements FileVisitor<T> {
      */
     @Override
     public FileVisitResult preVisitDirectoryFailed(T dir, IOException exc) {
+        checkNotNull(dir);
+        checkNotNull(exc);
         throw new IOError(exc);
     }
 
@@ -81,6 +92,8 @@ public class SimpleFileVisitor<T> implements FileVisitor<T> {
      */
     @Override
     public FileVisitResult visitFile(T file, BasicFileAttributes attrs) {
+        checkNotNull(file);
+        checkNotNull(attrs);
         return FileVisitResult.CONTINUE;
     }
 
@@ -96,6 +109,8 @@ public class SimpleFileVisitor<T> implements FileVisitor<T> {
      */
     @Override
     public FileVisitResult visitFileFailed(T file, IOException exc) {
+        checkNotNull(file);
+        checkNotNull(exc);
         throw new IOError(exc);
     }
 
@@ -114,6 +129,7 @@ public class SimpleFileVisitor<T> implements FileVisitor<T> {
      */
     @Override
     public FileVisitResult postVisitDirectory(T dir, IOException exc) {
+        checkNotNull(dir);
         if (exc != null)
             throw new IOError(exc);
         return FileVisitResult.CONTINUE;

test/java/nio/file/Files/Misc.java

@@ -22,13 +22,14 @@
  */
 
 /* @test
- * @bug 4313887 6838333
+ * @bug 4313887 6838333 6865748
  * @summary Unit test for java.nio.file.Files for miscellenous cases not
  *   covered by other tests
  * @library ..
  */
 
 import java.nio.file.*;
+import java.nio.file.attribute.Attributes;
 import java.io.IOException;
 import java.util.*;
 
@@ -113,5 +114,29 @@ public class Misc {
             npeExpected();
         } catch (NullPointerException e) {
         }
+
+        SimpleFileVisitor<Path> visitor = new SimpleFileVisitor<Path>() { };
+        boolean ranTheGauntlet = false;
+        try { visitor.preVisitDirectory(null);
+        } catch (NullPointerException x0) {
+        try { visitor.preVisitDirectoryFailed(null, new IOException());
+        } catch (NullPointerException x1) {
+        try { visitor.preVisitDirectoryFailed(dir, null);
+        } catch (NullPointerException x2) {
+        try { visitor.visitFile(null, Attributes.readBasicFileAttributes(Paths.get(".")));
+        } catch (NullPointerException x3) {
+        try {  visitor.visitFile(dir, null);
+        } catch (NullPointerException x4) {
+        try { visitor.visitFileFailed(null, new IOException());
+        } catch (NullPointerException x5) {
+        try { visitor.visitFileFailed(dir, null);
+        } catch (NullPointerException x6) {
+        try { visitor.postVisitDirectory(null, new IOException());
+        } catch (NullPointerException x7) {
+            // if we get here then all visit* methods threw NPE as expected
+            ranTheGauntlet = true;
+        }}}}}}}}
+        if (!ranTheGauntlet)
+            throw new RuntimeException("A visit method did not throw NPE");
     }
 }