Shuyi Chen | d7955ce | 2013-05-22 14:51:55 -0700 | [diff] [blame] | 1 | // Copyright (c) 1999-2004 Brian Wellington (bwelling@xbill.org) |
| 2 | |
| 3 | package org.xbill.DNS; |
| 4 | |
| 5 | import java.util.*; |
| 6 | |
| 7 | /** |
| 8 | * The Response from a query to Cache.lookupRecords() or Zone.findRecords() |
| 9 | * @see Cache |
| 10 | * @see Zone |
| 11 | * |
| 12 | * @author Brian Wellington |
| 13 | */ |
| 14 | |
| 15 | public class SetResponse { |
| 16 | |
| 17 | /** |
| 18 | * The Cache contains no information about the requested name/type |
| 19 | */ |
| 20 | static final int UNKNOWN = 0; |
| 21 | |
| 22 | /** |
| 23 | * The Zone does not contain the requested name, or the Cache has |
| 24 | * determined that the name does not exist. |
| 25 | */ |
| 26 | static final int NXDOMAIN = 1; |
| 27 | |
| 28 | /** |
| 29 | * The Zone contains the name, but no data of the requested type, |
| 30 | * or the Cache has determined that the name exists and has no data |
| 31 | * of the requested type. |
| 32 | */ |
| 33 | static final int NXRRSET = 2; |
| 34 | |
| 35 | /** |
| 36 | * A delegation enclosing the requested name was found. |
| 37 | */ |
| 38 | static final int DELEGATION = 3; |
| 39 | |
| 40 | /** |
| 41 | * The Cache/Zone found a CNAME when looking for the name. |
| 42 | * @see CNAMERecord |
| 43 | */ |
| 44 | static final int CNAME = 4; |
| 45 | |
| 46 | /** |
| 47 | * The Cache/Zone found a DNAME when looking for the name. |
| 48 | * @see DNAMERecord |
| 49 | */ |
| 50 | static final int DNAME = 5; |
| 51 | |
| 52 | /** |
| 53 | * The Cache/Zone has successfully answered the question for the |
| 54 | * requested name/type/class. |
| 55 | */ |
| 56 | static final int SUCCESSFUL = 6; |
| 57 | |
| 58 | private static final SetResponse unknown = new SetResponse(UNKNOWN); |
| 59 | private static final SetResponse nxdomain = new SetResponse(NXDOMAIN); |
| 60 | private static final SetResponse nxrrset = new SetResponse(NXRRSET); |
| 61 | |
| 62 | private int type; |
| 63 | private Object data; |
| 64 | |
| 65 | private |
| 66 | SetResponse() {} |
| 67 | |
| 68 | SetResponse(int type, RRset rrset) { |
| 69 | if (type < 0 || type > 6) |
| 70 | throw new IllegalArgumentException("invalid type"); |
| 71 | this.type = type; |
| 72 | this.data = rrset; |
| 73 | } |
| 74 | |
| 75 | SetResponse(int type) { |
| 76 | if (type < 0 || type > 6) |
| 77 | throw new IllegalArgumentException("invalid type"); |
| 78 | this.type = type; |
| 79 | this.data = null; |
| 80 | } |
| 81 | |
| 82 | static SetResponse |
| 83 | ofType(int type) { |
| 84 | switch (type) { |
| 85 | case UNKNOWN: |
| 86 | return unknown; |
| 87 | case NXDOMAIN: |
| 88 | return nxdomain; |
| 89 | case NXRRSET: |
| 90 | return nxrrset; |
| 91 | case DELEGATION: |
| 92 | case CNAME: |
| 93 | case DNAME: |
| 94 | case SUCCESSFUL: |
| 95 | SetResponse sr = new SetResponse(); |
| 96 | sr.type = type; |
| 97 | sr.data = null; |
| 98 | return sr; |
| 99 | default: |
| 100 | throw new IllegalArgumentException("invalid type"); |
| 101 | } |
| 102 | } |
| 103 | |
| 104 | void |
| 105 | addRRset(RRset rrset) { |
| 106 | if (data == null) |
| 107 | data = new ArrayList(); |
| 108 | List l = (List) data; |
| 109 | l.add(rrset); |
| 110 | } |
| 111 | |
| 112 | /** Is the answer to the query unknown? */ |
| 113 | public boolean |
| 114 | isUnknown() { |
| 115 | return (type == UNKNOWN); |
| 116 | } |
| 117 | |
| 118 | /** Is the answer to the query that the name does not exist? */ |
| 119 | public boolean |
| 120 | isNXDOMAIN() { |
| 121 | return (type == NXDOMAIN); |
| 122 | } |
| 123 | |
| 124 | /** Is the answer to the query that the name exists, but the type does not? */ |
| 125 | public boolean |
| 126 | isNXRRSET() { |
| 127 | return (type == NXRRSET); |
| 128 | } |
| 129 | |
| 130 | /** Is the result of the lookup that the name is below a delegation? */ |
| 131 | public boolean |
| 132 | isDelegation() { |
| 133 | return (type == DELEGATION); |
| 134 | } |
| 135 | |
| 136 | /** Is the result of the lookup a CNAME? */ |
| 137 | public boolean |
| 138 | isCNAME() { |
| 139 | return (type == CNAME); |
| 140 | } |
| 141 | |
| 142 | /** Is the result of the lookup a DNAME? */ |
| 143 | public boolean |
| 144 | isDNAME() { |
| 145 | return (type == DNAME); |
| 146 | } |
| 147 | |
| 148 | /** Was the query successful? */ |
| 149 | public boolean |
| 150 | isSuccessful() { |
| 151 | return (type == SUCCESSFUL); |
| 152 | } |
| 153 | |
| 154 | /** If the query was successful, return the answers */ |
| 155 | public RRset [] |
| 156 | answers() { |
| 157 | if (type != SUCCESSFUL) |
| 158 | return null; |
| 159 | List l = (List) data; |
| 160 | return (RRset []) l.toArray(new RRset[l.size()]); |
| 161 | } |
| 162 | |
| 163 | /** |
| 164 | * If the query encountered a CNAME, return it. |
| 165 | */ |
| 166 | public CNAMERecord |
| 167 | getCNAME() { |
| 168 | return (CNAMERecord)((RRset)data).first(); |
| 169 | } |
| 170 | |
| 171 | /** |
| 172 | * If the query encountered a DNAME, return it. |
| 173 | */ |
| 174 | public DNAMERecord |
| 175 | getDNAME() { |
| 176 | return (DNAMERecord)((RRset)data).first(); |
| 177 | } |
| 178 | |
| 179 | /** |
| 180 | * If the query hit a delegation point, return the NS set. |
| 181 | */ |
| 182 | public RRset |
| 183 | getNS() { |
| 184 | return (RRset)data; |
| 185 | } |
| 186 | |
| 187 | /** Prints the value of the SetResponse */ |
| 188 | public String |
| 189 | toString() { |
| 190 | switch (type) { |
| 191 | case UNKNOWN: return "unknown"; |
| 192 | case NXDOMAIN: return "NXDOMAIN"; |
| 193 | case NXRRSET: return "NXRRSET"; |
| 194 | case DELEGATION: return "delegation: " + data; |
| 195 | case CNAME: return "CNAME: " + data; |
| 196 | case DNAME: return "DNAME: " + data; |
| 197 | case SUCCESSFUL: return "successful"; |
| 198 | default: throw new IllegalStateException(); |
| 199 | } |
| 200 | } |
| 201 | |
| 202 | } |