1 /*
 2  * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
 3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 4  *
 5  * This code is free software; you can redistribute it and/or modify it
 6  * under the terms of the GNU General Public License version 2 only, as
 7  * published by the Free Software Foundation.
 8  *
 9  * This code is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * version 2 for more details (a copy is included in the LICENSE file that
13  * accompanied this code).
14  *
15  * You should have received a copy of the GNU General Public License version
16  * 2 along with this work; if not, write to the Free Software Foundation,
17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18  *
19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20  * or visit www.oracle.com if you need additional information or have any
21  * questions.
22  */
23 
24 import org.testng.annotations.BeforeTest;
25 import org.testng.annotations.Test;
26 
27 import java.lang.reflect.Field;
28 import java.net.InetAddress;
29 import java.net.UnknownHostException;
30 import java.net.spi.InetAddressResolver;
31 
32 import static org.testng.Assert.*;
33 
34 /*
35  * @test
36  * @summary white-box test to check that the built-in resolver
37  *  is used by default.
38  * @modules java.base/java.net:open
39  * @run testng/othervm BuiltInResolverTest
40  */
41 
42 public class BuiltInResolverTest {
43 
44     private Field builtInResolverField, resolverField;
45 
46     @BeforeTest
47     public void beforeTest() throws NoSuchFieldException {
48         Class<InetAddress> inetAddressClass = InetAddress.class;
49         // Needs to happen for InetAddress.resolver to be initialized
50         try {
51             InetAddress.getByName("test");
52         } catch (UnknownHostException e) {
53             // Do nothing, only want to assign resolver
54         }
55         builtInResolverField = inetAddressClass.getDeclaredField("BUILTIN_RESOLVER");
56         builtInResolverField.setAccessible(true);
57         resolverField = inetAddressClass.getDeclaredField("resolver");
58         resolverField.setAccessible(true);
59     }
60 
61     @Test
62     public void testDefaultNSContext() throws IllegalAccessException {
63         // Test that the resolver used by default is the BUILTIN_RESOLVER
64         Object defaultResolverObject = builtInResolverField.get(InetAddressResolver.class);
65         Object usedResolverObject = resolverField.get(InetAddressResolver.class);
66 
67         assertTrue(defaultResolverObject == usedResolverObject);
68 
69         String defaultClassName = defaultResolverObject.getClass().getCanonicalName();
70         String currentClassName = usedResolverObject.getClass().getCanonicalName();
71 
72         assertNotNull(defaultClassName, "defaultClassName not set");
73         assertNotNull(currentClassName, "currentClassName name not set");
74 
75         assertEquals(currentClassName, defaultClassName,
76                 "BUILTIN_RESOLVER resolver was not used.");
77         System.err.println("Resolver used by default is the built-in resolver");
78     }
79 }