J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2002 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package sun.net.dns; |
| 27 | |
| 28 | import java.util.List; |
| 29 | import java.io.IOException; |
| 30 | |
| 31 | /** |
| 32 | * The configuration of the client resolver. |
| 33 | * |
| 34 | * <p>A ResolverConfiguration is a singleton that represents the |
| 35 | * configuration of the client resolver. The ResolverConfiguration |
| 36 | * is opened by invoking the {@link #open() open} method. |
| 37 | * |
| 38 | * @since 1.4 |
| 39 | */ |
| 40 | |
| 41 | public abstract class ResolverConfiguration { |
| 42 | |
| 43 | private static final Object lock = new Object(); |
| 44 | |
| 45 | private static ResolverConfiguration provider; |
| 46 | |
| 47 | protected ResolverConfiguration() { } |
| 48 | |
| 49 | /** |
| 50 | * Opens the resolver configuration. |
| 51 | * |
| 52 | * @return the resolver configuration |
| 53 | */ |
| 54 | public static ResolverConfiguration open() { |
| 55 | synchronized (lock) { |
| 56 | if (provider == null) { |
| 57 | provider = new sun.net.dns.ResolverConfigurationImpl(); |
| 58 | } |
| 59 | return provider; |
| 60 | } |
| 61 | } |
| 62 | |
| 63 | /** |
| 64 | * Returns a list corresponding to the domain search path. The |
| 65 | * list is ordered by the search order used for host name lookup. |
| 66 | * Each element in the list returns a {@link java.lang.String} |
| 67 | * containing a domain name or suffix. |
| 68 | * |
| 69 | * @return list of domain names |
| 70 | */ |
| 71 | public abstract List searchlist(); |
| 72 | |
| 73 | /** |
| 74 | * Returns a list of name servers used for host name lookup. |
| 75 | * Each element in the list returns a {@link java.lang.String} |
| 76 | * containing the textual representation of the IP address of |
| 77 | * the name server. |
| 78 | * |
| 79 | * @return list of the name servers |
| 80 | */ |
| 81 | public abstract List nameservers(); |
| 82 | |
| 83 | |
| 84 | /** |
| 85 | * Options representing certain resolver variables of |
| 86 | * a {@link ResolverConfiguration}. |
| 87 | */ |
| 88 | public static abstract class Options { |
| 89 | |
| 90 | /** |
| 91 | * Returns the maximum number of attempts the resolver |
| 92 | * will connect to each name server before giving up |
| 93 | * and returning an error. |
| 94 | * |
| 95 | * @return the resolver attempts value or -1 is unknown |
| 96 | */ |
| 97 | public int attempts() { |
| 98 | return -1; |
| 99 | } |
| 100 | |
| 101 | /** |
| 102 | * Returns the basic retransmit timeout, in milliseconds, |
| 103 | * used by the resolver. The resolver will typically use |
| 104 | * an exponential backoff algorithm where the timeout is |
| 105 | * doubled for every retransmit attempt. The basic |
| 106 | * retransmit timeout, returned here, is the initial |
| 107 | * timeout for the exponential backoff algorithm. |
| 108 | * |
| 109 | * @return the basic retransmit timeout value or -1 |
| 110 | * if unknown |
| 111 | */ |
| 112 | public int retrans() { |
| 113 | return -1; |
| 114 | } |
| 115 | } |
| 116 | |
| 117 | /** |
| 118 | * Returns the {@link #Options} for the resolver. |
| 119 | * |
| 120 | * @return options for the resolver |
| 121 | */ |
| 122 | public abstract Options options(); |
| 123 | } |