001/* Reference.java -- 002 Copyright (C) 2000, 2001, 2005, 2006 Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038 039package javax.naming; 040 041import java.io.Serializable; 042import java.util.Enumeration; 043import java.util.Vector; 044 045/** 046 * This class represents a reference to an object that is located outside of the 047 * naming/directory system. 048 * 049 * @see Referenceable 050 * 051 * @author Tom Tromey (tromey@redhat.com) 052 */ 053public class Reference implements Cloneable, Serializable 054{ 055 private static final long serialVersionUID = - 1673475790065791735L; 056 057 /** 058 * The list of addresses, stored in this reference. The object may be 059 * have by several different addresses. 060 */ 061 protected Vector<RefAddr> addrs; 062 063 /** 064 * The name of the class factory to create an instance of the object, 065 * referenced by this reference. 066 */ 067 protected String classFactory; 068 069 /** 070 * The location, from where the class factory should be loaded. 071 */ 072 protected String classFactoryLocation; 073 074 /** 075 * The name of the class of the object, to that this reference refers. 076 */ 077 protected String className; 078 079 /** 080 * Create a new reference that is referencting to the object of the 081 * specified class. 082 */ 083 public Reference (String className) 084 { 085 this.className = className; 086 addrs = new Vector<RefAddr> (); 087 } 088 089 /** 090 * Create a new reference that is referencing to the object of the 091 * specified class with the given address. 092 */ 093 public Reference (String className, RefAddr addr) 094 { 095 this.className = className; 096 addrs = new Vector<RefAddr> (); 097 addrs.add (addr); 098 } 099 100 /** 101 * Create a new reference that is referencing to the object of the 102 * specified class, specifying the class and location of the factory that 103 * produces these objects. 104 * 105 * @param className the object class name 106 * @param factoryClassName the object factory class name 107 * @param factoryLocation the object factory location 108 */ 109 public Reference (String className, String factoryClassName, 110 String factoryLocation) 111 { 112 this.className = className; 113 this.classFactory = factoryClassName; 114 this.classFactoryLocation = factoryLocation; 115 addrs = new Vector<RefAddr> (); 116 } 117 118 /** 119 * Create a new reference that is referencing to the object of the 120 * specified class, specifying the class and location of the factory that 121 * produces these objects and also the address of this object. 122 * 123 * @param className the object class name 124 * @param addr the address of the object 125 * @param factoryClassName the object factory class name 126 * @param factoryLocation the object factory location 127 */ 128 public Reference (String className, RefAddr addr, 129 String factoryClassName, String factoryLocation) 130 { 131 this.className = className; 132 this.classFactory = factoryClassName; 133 this.classFactoryLocation = factoryLocation; 134 addrs = new Vector<RefAddr> (); 135 addrs.add (addr); 136 } 137 138 /** 139 * Add the new address for this object at the given position of the 140 * address list. 141 */ 142 public void add (int posn, RefAddr addr) 143 { 144 addrs.add (posn, addr); 145 } 146 147 /** 148 * Appends the new object address to the end of the address list. 149 */ 150 public void add (RefAddr addr) 151 { 152 addrs.add (addr); 153 } 154 155 /** 156 * Removes all defined addresses of the object. 157 */ 158 public void clear () 159 { 160 addrs.clear (); 161 } 162 163 public Object clone () 164 { 165 Reference r = new Reference (className, classFactory, 166 classFactoryLocation); 167 r.addrs = (Vector<RefAddr>) addrs.clone (); 168 return r; 169 } 170 171 // Convenience function. 172 private boolean equals (String a, String b) 173 { 174 return (a == null) ? (b == null) : a.equals (b); 175 } 176 177 /** 178 * Compares two addresses for equality, by value. 179 */ 180 public boolean equals (Object obj) 181 { 182 if (! (obj instanceof Reference)) 183 return false; 184 Reference r = (Reference) obj; 185 return (equals (classFactory, r.classFactory) 186 && equals (classFactoryLocation, r.classFactoryLocation) 187 && equals (className, r.className) 188 && addrs.equals (r.addrs)); 189 } 190 191 /** 192 * Get the address of this object at the given position. 193 */ 194 public RefAddr get (int posn) 195 { 196 return addrs.get (posn); 197 } 198 199 /** 200 * Get the given type of address for this object. 201 * 202 * @param addrType the needed type of address 203 * 204 * @return the address of this object, having the specified type. If there 205 * is no address of such type, null is returned. 206 */ 207 public RefAddr get (String addrType) 208 { 209 for (int i = 0; i < addrs.size (); ++i) 210 { 211 RefAddr r = addrs.get (i); 212 if (addrType.equals (r.getType ())) 213 return r; 214 } 215 return null; 216 } 217 218 /** 219 * Get the enumeration over all defined addresses of the object. 220 */ 221 public Enumeration<RefAddr> getAll () 222 { 223 return addrs.elements (); 224 } 225 226 /** 227 * Get the name of the class of the referenced object. 228 * 229 * @see #className 230 */ 231 public String getClassName () 232 { 233 return className; 234 } 235 236 /** 237 * Get the location of the factory class of the referenced object. 238 * 239 * @see #classFactoryLocation 240 */ 241 public String getFactoryClassLocation () 242 { 243 return classFactoryLocation; 244 } 245 246 /** 247 * Get the name of the factory class of the referenced object 248 * 249 * @see #classFactory 250 */ 251 public String getFactoryClassName () 252 { 253 return classFactory; 254 } 255 256 /** 257 * Get the hashcode of this reference. 258 * 259 * @return the sum of the hash codes of the addresses. 260 */ 261 public int hashCode () 262 { 263 // The spec says the hash code is the sum of the hash codes of the 264 // addresses. It does not mention the other fields. 265 int h = 0; 266 for (int i = 0; i < addrs.size (); ++i) 267 h += addrs.get (i).hashCode (); 268 return h; 269 } 270 271 /** 272 * Remove the address at the given position. 273 * 274 * @param posn the position of the address to remove 275 * 276 * @return the removed address 277 */ 278 public Object remove (int posn) 279 { 280 return addrs.remove (posn); 281 } 282 283 /** 284 * Return the number of the defined addresses. 285 */ 286 public int size () 287 { 288 return addrs.size (); 289 } 290 291 /** 292 * Return the string representation. 293 */ 294 public String toString () 295 { 296 String x = getClass ().toString () + "["; 297 for (int i = 0; i < addrs.size (); ++i) 298 { 299 if (i > 0) 300 x += ","; 301 x += addrs.get (i).toString (); 302 } 303 return x + "]"; 304 } 305 306}