1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://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,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package libcore.io;
18
19import java.net.UnknownHostException;
20import libcore.io.OsConstants;
21
22/**
23 * An unchecked exception thrown when the {@link Os} {@code getaddrinfo} or {@code getnameinfo}
24 * methods fail. This exception contains the native error value, for comparison against the
25 * {@code GAI_} constants in {@link OsConstants}, should sophisticated
26 * callers need to adjust their behavior based on the exact failure.
27 */
28public final class GaiException extends RuntimeException {
29    private final String functionName;
30    public final int error;
31
32    public GaiException(String functionName, int error) {
33        this.functionName = functionName;
34        this.error = error;
35    }
36
37    public GaiException(String functionName, int error, Throwable cause) {
38        super(cause);
39        this.functionName = functionName;
40        this.error = error;
41    }
42
43    /**
44     * Converts the stashed function name and error value to a human-readable string.
45     * We do this here rather than in the constructor so that callers only pay for
46     * this if they need it.
47     */
48    @Override public String getMessage() {
49        String gaiName = OsConstants.gaiName(error);
50        if (gaiName == null) {
51            gaiName = "GAI_ error " + error;
52        }
53        String description = Libcore.os.gai_strerror(error);
54        return functionName + " failed: " + gaiName + " (" + description + ")";
55    }
56
57    public UnknownHostException rethrowAsUnknownHostException(String detailMessage) throws UnknownHostException {
58        UnknownHostException newException = new UnknownHostException(detailMessage);
59        newException.initCause(this);
60        throw newException;
61    }
62
63    public UnknownHostException rethrowAsUnknownHostException() throws UnknownHostException {
64        throw rethrowAsUnknownHostException(getMessage());
65    }
66}
67