1 /*
2 * Copyright 2023 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License,
5 * version 2.0 (the "License"); you may not use this file except in compliance
6 * with the License. You may obtain a copy of the License at:
7 *
8 * https://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations
14 * under the License.
15 */
16
17 package io.netty.resolver.dns;
18
19 import io.netty.handler.codec.dns.DnsResponseCode;
20 import io.netty.util.internal.ThrowableUtil;
21
22 import java.net.UnknownHostException;
23
24 /**
25 * A metadata carrier exception, to propagate {@link DnsResponseCode} information as an enrichment
26 * within the {@link UnknownHostException} cause.
27 */
28 public final class DnsErrorCauseException extends RuntimeException {
29
30 private static final long serialVersionUID = 7485145036717494533L;
31
32 private final DnsResponseCode code;
33
34 private DnsErrorCauseException(String message, DnsResponseCode code, boolean shared) {
35 super(message, null, false, true);
36 this.code = code;
37 assert shared;
38 }
39
40 // Override fillInStackTrace() so we not populate the backtrace via a native call and so leak the
41 // Classloader.
42 @Override
43 public Throwable fillInStackTrace() {
44 return this;
45 }
46
47 /**
48 * Returns the DNS error-code that caused the {@link UnknownHostException}.
49 *
50 * @return the DNS error-code that caused the {@link UnknownHostException}.
51 */
52 public DnsResponseCode getCode() {
53 return code;
54 }
55
56 static DnsErrorCauseException newStatic(String message, DnsResponseCode code, Class<?> clazz, String method) {
57 final DnsErrorCauseException exception = new DnsErrorCauseException(message, code, true);
58 return ThrowableUtil.unknownStackTrace(exception, clazz, method);
59 }
60 }