8169068: Add a new method: java.net.Authenticator.getDefault()

Reviewed-by: chegar

jdk/src/java.base/share/classes/java/net/Authenticator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2016, 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
@@ -130,6 +130,35 @@ class Authenticator {
         theAuthenticator = a;
     }
 
+    /**
+     * Gets the default authenticator.
+     * First, if there is a security manager, its {@code checkPermission}
+     * method is called with a
+     * {@code NetPermission("requestPasswordAuthentication")} permission.
+     * This may result in a java.lang.SecurityException.
+     * Then the default authenticator, if set, is returned.
+     * Otherwise, {@code null} is returned.
+     *
+     * @return The default authenticator, if set, {@code null} otherwise.
+     *
+     * @throws SecurityException
+     *        if a security manager exists and its
+     *        {@code checkPermission} method doesn't allow
+     *        requesting password authentication.
+     * @since 9
+     * @see SecurityManager#checkPermission
+     * @see java.net.NetPermission
+     */
+    public static Authenticator getDefault() {
+        SecurityManager sm = System.getSecurityManager();
+        if (sm != null) {
+            NetPermission requestPermission
+                = new NetPermission("requestPasswordAuthentication");
+            sm.checkPermission(requestPermission);
+        }
+        return theAuthenticator;
+    }
+
     /**
      * Ask the authenticator that has been registered with the system
      * for a password.

jdk/test/java/net/Authenticator/GetAuthenticatorTest.java

@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2016, 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.
+ */
+import java.lang.ref.Reference;
+import java.net.Authenticator;
+import java.net.NetPermission;
+import java.net.PasswordAuthentication;
+import java.security.AccessControlException;
+
+/**
+ * @test
+ * @bug 8169068
+ * @summary  Basic test for Authenticator.getDefault()
+ * @run main/othervm GetAuthenticatorTest
+ */
+public class GetAuthenticatorTest {
+
+    static final class MyAuthenticator extends Authenticator {
+
+        MyAuthenticator () {
+            super ();
+        }
+
+        @Override
+        public PasswordAuthentication getPasswordAuthentication () {
+            System.out.println ("Auth called");
+            return (new PasswordAuthentication ("user",
+                        "passwordNotCheckedAnyway".toCharArray()));
+        }
+
+    }
+
+    public static void main (String args[]) throws Exception {
+        Authenticator defaultAuth = Authenticator.getDefault();
+        if (defaultAuth != null) {
+            throw new RuntimeException("Unexpected authenticator: null expected");
+        }
+        MyAuthenticator auth = new MyAuthenticator();
+        Authenticator.setDefault(auth);
+        defaultAuth = Authenticator.getDefault();
+        if (defaultAuth != auth) {
+            throw new RuntimeException("Unexpected authenticator: auth expected");
+        }
+        System.setSecurityManager(new SecurityManager());
+        try {
+            defaultAuth = Authenticator.getDefault();
+            throw new RuntimeException("Expected security exception not raised");
+        } catch (AccessControlException s) {
+            System.out.println("Got expected exception: " + s);
+            if (!s.getPermission().equals(new NetPermission("requestPasswordAuthentication"))) {
+                throw new RuntimeException("Unexpected permission check: " + s.getPermission());
+            }
+        }
+        System.out.println("Test passed with default authenticator "
+                           + defaultAuth);
+    }
+}