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 package impl;
25 
26 import java.net.InetAddress;
27 import java.net.UnknownHostException;
28 import java.net.spi.InetAddressResolver;
29 import java.net.spi.InetAddressResolverProvider;
30 import java.util.stream.Stream;
31 
32 public class WithBootstrapResolverUsageProvider extends InetAddressResolverProvider {
33 
34     public static volatile long numberOfGetCalls;
35 
36     @Override
37     public InetAddressResolver get(Configuration configuration) {
38         numberOfGetCalls++;
39         System.out.println("The following provider will be used by current test:" +
40                 this.getClass().getCanonicalName());
41         System.out.println("InetAddressResolverProvider::get() called " + numberOfGetCalls + " times");
42 
43         // We use different names to avoid InetAddress-level caching
44         doLookup("foo" + numberOfGetCalls + ".A.org");
45 
46         // We need second call to test how InetAddress internals maintain reference to a bootstrap resolver
47         doLookup("foo" + numberOfGetCalls + ".B.org");
48 
49         return new InetAddressResolver() {
50             @Override
51             public Stream<InetAddress> lookupByName(String host, LookupPolicy lookupPolicy)
52                     throws UnknownHostException {
53                 return Stream.of(InetAddress.getByAddress(host, new byte[]{127, 0, 2, 1}));
54             }
55 
56             @Override
57             public String lookupByAddress(byte[] addr) throws UnknownHostException {
58                 return configuration.builtinResolver().lookupByAddress(addr);
59             }
60         };
61     }
62 
63     // Perform an InetAddress resolution lookup operation
64     private static void doLookup(String hostName) {
65         try {
66             InetAddress.getByName(hostName);
67         } catch (UnknownHostException e) {
68             // Ignore UHE since the bootstrap resolver is used here
69         }
70     }
71 
72     @Override
73     public String name() {
74         return "WithBootstrapResolverUsageProvider";
75     }
76 }