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 DelegatingProviderImpl extends InetAddressResolverProvider {
33 
34     public static volatile boolean changeReverseLookupAddress;
35     public static volatile Throwable lastReverseLookupThrowable;
36 
37     @Override
38     public InetAddressResolver get(Configuration configuration) {
39         System.out.println("The following provider will be used by current test:" +
40                 this.getClass().getCanonicalName());
41         return new InetAddressResolver() {
42             @Override
43             public Stream<InetAddress> lookupAddresses(String host, LookupPolicy lookupPolicy) throws UnknownHostException {
44                 return configuration.builtinResolver().lookupAddresses(host, lookupPolicy);
45             }
46 
47             @Override
48             public String lookupHostName(byte[] addr) throws UnknownHostException {
49                 try {
50                     if (!changeReverseLookupAddress) {
51                         return configuration.builtinResolver().lookupHostName(addr);
52                     } else {
53                         // Deliberately supply address bytes array with wrong size
54                         return configuration.builtinResolver().lookupHostName(new byte[]{1, 2, 3});
55                     }
56                 } catch (Throwable t) {
57                     lastReverseLookupThrowable = t;
58                     throw t;
59                 }
60             }
61         };
62     }
63 
64     @Override
65     public String name() {
66         return "DelegatingProvider";
67     }
68 }