7179567: JCK8 tests: api/java_net/URLClassLoader/index.html#Ctor3 failed with NPE

6445180: URLClassLoader does not describe the behavior of several methods with respect to null arguments

Document when a NPE will be thrown by URLClassLoader constructors, newInstance(), findClass(), and getPermissions().

Reviewed-by: alanb, mduigou, chegar, dholmes, jrose

jdk/src/share/classes/java/net/URLClassLoader.java

@@ -25,21 +25,30 @@
 
 package java.net;
 
-import java.io.*;
+import java.io.Closeable;
-import java.util.*;
+import java.io.File;
-import java.util.jar.Manifest;
+import java.io.FilePermission;
-import java.util.jar.JarFile;
+import java.io.IOException;
-import java.util.jar.Attributes;
+import java.io.InputStream;
-import java.util.jar.Attributes.Name;
-import java.security.CodeSigner;
-import java.security.PrivilegedAction;
-import java.security.PrivilegedExceptionAction;
-import java.security.AccessController;
 import java.security.AccessControlContext;
-import java.security.SecureClassLoader;
+import java.security.AccessController;
+import java.security.CodeSigner;
 import java.security.CodeSource;
 import java.security.Permission;
 import java.security.PermissionCollection;
+import java.security.PrivilegedAction;
+import java.security.PrivilegedExceptionAction;
+import java.security.SecureClassLoader;
+import java.util.Enumeration;
+import java.util.List;
+import java.util.NoSuchElementException;
+import java.util.Objects;
+import java.util.Set;
+import java.util.WeakHashMap;
+import java.util.jar.Attributes;
+import java.util.jar.Attributes.Name;
+import java.util.jar.JarFile;
+import java.util.jar.Manifest;
 import sun.misc.Resource;
 import sun.misc.URLClassPath;
 import sun.net.www.ParseUtil;
@@ -84,6 +93,7 @@ public class URLClassLoader extends SecureClassLoader implements Closeable {
      * @exception  SecurityException  if a security manager exists and its
      *             {@code checkCreateClassLoader} method doesn't allow
      *             creation of a class loader.
+     * @exception  NullPointerException if {@code urls} is {@code null}.
      * @see SecurityManager#checkCreateClassLoader
      */
     public URLClassLoader(URL[] urls, ClassLoader parent) {
@@ -127,6 +137,7 @@ public class URLClassLoader extends SecureClassLoader implements Closeable {
      * @exception  SecurityException  if a security manager exists and its
      *             {@code checkCreateClassLoader} method doesn't allow
      *             creation of a class loader.
+     * @exception  NullPointerException if {@code urls} is {@code null}.
      * @see SecurityManager#checkCreateClassLoader
      */
     public URLClassLoader(URL[] urls) {
@@ -169,6 +180,7 @@ public class URLClassLoader extends SecureClassLoader implements Closeable {
      * @exception  SecurityException  if a security manager exists and its
      *             {@code checkCreateClassLoader} method doesn't allow
      *             creation of a class loader.
+     * @exception  NullPointerException if {@code urls} is {@code null}.
      * @see SecurityManager#checkCreateClassLoader
      */
     public URLClassLoader(URL[] urls, ClassLoader parent,
@@ -260,13 +272,13 @@ public class URLClassLoader extends SecureClassLoader implements Closeable {
     * and errors are not caught. Calling close on an already closed
     * loader has no effect.
     * <p>
-    * @throws IOException if closing any file opened by this class loader
+    * @exception IOException if closing any file opened by this class loader
     * resulted in an IOException. Any such exceptions are caught internally.
     * If only one is caught, then it is re-thrown. If more than one exception
     * is caught, then the second and following exceptions are added
     * as suppressed exceptions of the first one caught, which is then re-thrown.
     *
-    * @throws SecurityException if a security manager is set, and it denies
+    * @exception SecurityException if a security manager is set, and it denies
     *   {@link RuntimePermission}{@code ("closeClassLoader")}
     *
     * @since 1.7
@@ -339,6 +351,7 @@ public class URLClassLoader extends SecureClassLoader implements Closeable {
      * @return the resulting class
      * @exception ClassNotFoundException if the class could not be found,
      *            or if the loader is closed.
+     * @exception NullPointerException if {@code name} is {@code null}.
      */
     protected Class<?> findClass(final String name)
          throws ClassNotFoundException
@@ -621,6 +634,7 @@ public class URLClassLoader extends SecureClassLoader implements Closeable {
      * If the protocol is not "file", then permission
      * to connect to and accept connections from the URL's host is granted.
      * @param codesource the codesource
+     * @exception NullPointerException if {@code codesource} is {@code null}.
      * @return the permissions granted to the codesource
      */
     protected PermissionCollection getPermissions(CodeSource codesource)
@@ -700,6 +714,7 @@ public class URLClassLoader extends SecureClassLoader implements Closeable {
      *
      * @param urls the URLs to search for classes and resources
      * @param parent the parent class loader for delegation
+     * @exception  NullPointerException if {@code urls} is {@code null}.
      * @return the resulting class loader
      */
     public static URLClassLoader newInstance(final URL[] urls,
@@ -725,6 +740,7 @@ public class URLClassLoader extends SecureClassLoader implements Closeable {
      * loading the class.
      *
      * @param urls the URLs to search for classes and resources
+     * @exception  NullPointerException if {@code urls} is {@code null}.
      * @return the resulting class loader
      */
     public static URLClassLoader newInstance(final URL[] urls) {

jdk/src/share/classes/javax/management/remote/rmi/NoCallStackClassLoader.java

@@ -120,6 +120,7 @@ class NoCallStackClassLoader extends ClassLoader {
      */
     @Override
     protected Class<?> findClass(String name) throws ClassNotFoundException {
+        // Note: classNames is guaranteed by the constructor to be non-null.
         for (int i = 0; i < classNames.length; i++) {
             if (name.equals(classNames[i])) {
                 return defineClass(classNames[i], byteCodes[i], 0,

jdk/src/share/classes/sun/applet/AppletClassLoader.java

@@ -239,6 +239,7 @@ public class AppletClassLoader extends URLClassLoader {
      * the "localhost".
      *
      * @param codesource the codesource
+     * @throws NullPointerException if {@code codesource} is {@code null}.
      * @return the permissions granted to the codesource
      */
     protected PermissionCollection getPermissions(CodeSource codesource)

jdk/test/java/net/URLClassLoader/NullURLTest.java

@@ -0,0 +1,175 @@
+/*
+ * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 7179567
+ * @summary Test that URLClassLoader public constructors and factory methods
+ * throw NullPointerException when appropriate.
+ *
+ * Tests whether URLClassLoader public constructors and factory methods throw
+ * appropriate NullPointerExceptions for 1) a null URL array parameter, and
+ * 2) a non-null URL array containing a null element.
+ */
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.util.jar.JarFile;
+
+public class NullURLTest {
+    JarFile jarFile;
+
+    public static void main(String[] args) throws Throwable {
+        new NullURLTest();
+    }
+
+    NullURLTest() throws Throwable {
+        File local = new File(System.getProperty("test.src", "."), "jars");
+        String path = "jar:file:"
+                + local.getPath()
+                + "/class_path_test.jar!/Foo.class";
+
+        URL validURL = new URL(path);
+        URL[] validURLArray = new URL[] { validURL, validURL };
+        URL[] invalidURLArray = new URL[] { validURL, null };
+
+        int failures = 0;
+        URLClassLoader loader;
+
+        try {
+            loader = new URLClassLoader(validURLArray);
+        } catch (Throwable t) {
+            System.err.println("URLClassLoader(validURLArray) threw " + t);
+            failures++;
+        }
+        try {
+            loader = new URLClassLoader(null);
+            System.err.println("URLClassLoader(null) did not throw NPE");
+            failures++;
+        } catch (NullPointerException e) {
+            // expected
+        }
+        // This section should be uncommented if 8026517 is fixed.
+//        try {
+//            loader = new URLClassLoader(invalidURLArray);
+//            System.err.println("URLClassLoader(invalidURLArray) did not throw NPE");
+//            failures++;
+//        } catch (NullPointerException e) {
+//            // expected
+//        }
+
+        try {
+            loader = new URLClassLoader(validURLArray, null);
+        } catch (Throwable t) {
+            System.err.println("URLClassLoader(validURLArray, null) threw " + t);
+            failures++;
+        }
+        try {
+            loader = new URLClassLoader(null, null);
+            System.err.println("URLClassLoader(null, null) did not throw NPE");
+            failures++;
+        } catch (NullPointerException e) {
+            // expected
+        }
+        // This section should be uncommented if 8026517 is fixed.
+//        try {
+//            loader = new URLClassLoader(invalidURLArray, null);
+//            System.err.println("URLClassLoader(invalidURLArray, null) did not throw NPE");
+//            failures++;
+//        } catch (NullPointerException e) {
+//            // expected
+//        }
+
+        try {
+            loader = new URLClassLoader(validURLArray, null, null);
+        } catch (Throwable t) {
+            System.err.println("URLClassLoader(validURLArray, null, null) threw " + t);
+            failures++;
+        }
+        try {
+            loader = new URLClassLoader(null, null, null);
+            System.err.println("URLClassLoader(null, null, null) did not throw NPE");
+            failures++;
+        } catch (NullPointerException e) {
+            // expected
+        }
+        // This section should be uncommented if 8026517 is fixed.
+//        try {
+//            loader = new URLClassLoader(invalidURLArray, null, null);
+//            System.err.println("URLClassLoader(invalidURLArray, null, null) did not throw NPE");
+//            failures++;
+//        } catch (NullPointerException e) {
+//            // expected
+//        }
+
+        try {
+            loader = URLClassLoader.newInstance(validURLArray);
+        } catch (Throwable t) {
+            System.err.println("URLClassLoader.newInstance(validURLArray) threw " + t);
+            failures++;
+        }
+        try {
+            loader = URLClassLoader.newInstance(null);
+            System.err.println("URLClassLoader.newInstance(null) did not throw NPE");
+            failures++;
+        } catch (NullPointerException e) {
+            // expected
+        }
+        // This section should be uncommented if 8026517 is fixed.
+//        try {
+//            loader = URLClassLoader.newInstance(invalidURLArray);
+//            System.err.println("URLClassLoader.newInstance(invalidURLArray) did not throw NPE");
+//            failures++;
+//        } catch (NullPointerException e) {
+//            // expected
+//        }
+
+        try {
+            loader = URLClassLoader.newInstance(validURLArray, null);
+        } catch (Throwable t) {
+            System.err.println("URLClassLoader.newInstance(validURLArray, null) threw " + t);
+            failures++;
+        }
+        try {
+            loader = URLClassLoader.newInstance(null, null);
+            System.err.println("URLClassLoader.newInstance(null, null) did not throw NPE");
+            failures++;
+        } catch (NullPointerException e) {
+            // expected
+        }
+        // This section should be uncommented if 8026517 is fixed.
+//        try {
+//            loader = URLClassLoader.newInstance(invalidURLArray, null);
+//            System.err.println("URLClassLoader.newInstance(invalidURLArray, null) did not throw NPE");
+//            failures++;
+//        } catch (NullPointerException e) {
+//            // expected
+//        }
+
+        if (failures != 0) {
+            throw new Exception("URLClassLoader NullURLTest had "+failures+" failures!");
+        }
+    }
+}