001/* Servant.java -- 002 Copyright (C) 2005 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 org.omg.PortableServer; 040 041import org.omg.CORBA.BAD_OPERATION; 042import org.omg.CORBA.BAD_INV_ORDER; 043import org.omg.CORBA.NO_IMPLEMENT; 044import org.omg.CORBA.OBJECT_NOT_EXIST; 045import org.omg.CORBA.ORB; 046import org.omg.PortableServer.POAPackage.ServantNotActive; 047import org.omg.PortableServer.POAPackage.WrongPolicy; 048import org.omg.PortableServer.portable.Delegate; 049 050import gnu.CORBA.Minor; 051import gnu.CORBA.Poa.ORB_1_4; 052import gnu.CORBA.Poa.gnuPOA; 053 054/** 055 * <p> 056 * The servant is responsible for handling the method invocation on the 057 * target object. It can be one servant per object, or the same servant can 058 * support several (possibly all) objects, associated with the given POA. 059 * </p> <p> 060 * Till JDK 1.3 inclusive, a typical IDL to java compiler generates an 061 * implementation base (name pattern _*ImplBase.java) that is derived from the 062 * {@link org.omg.CORBA.portable.ObjectImpl}. Since JDK 1.4 the implementation 063 * base is derived from the Servant, also having a different name pattern 064 * (*POA.java). This suffix may be confusing, as the servant itself is 065 * <i>not</i> POA nor it is derived from it. 066 * </p><p> 067 * In both cases, the implementation base also inherits an interface, containing 068 * definitions of the application specific methods. The application programmer 069 * writes a child of the implementation base, implementing these methods 070 * for the application-specific functionality. The ObjectImpl is connected 071 * directly to the ORB. The Servant is connected to POA that can be obtained 072 * from the ORB. 073 * </p><p> 074 * If the servant is connected to more than one object, the exact object 075 * being currently served can be identified with {@link #_object_id}. 076 * </p><p> 077 * The derivativ of Servant, being directly connected to serve requests, 078 * must inherit either from {@link org.omg.CORBA.portable.InvokeHandler} 079 * or from {@link org.omg.PortableServer.DynamicImplementation}). 080 * </p><p> 081 * The Servant type is a CORBA <code>native</code> type. 082 * </p> 083 * 084 * @see POA#servant_to_reference(Servant) 085 * 086 * @author Audrius Meskauskas, Lithuania (AudriusA@Bioinformatics.org) 087 */ 088public abstract class Servant 089{ 090 /** 091 * The delegate, where calls to some Servant methods are forwarded. 092 */ 093 private Delegate delegate; 094 095 /** 096 * Get the repository ids of all interfaces, supported by the 097 * CORBA object, identified by the passed Id. In the typical code the 098 * passed parameters are ignored, returning an array of repository ids, 099 * supported by the servant implementation. 100 * 101 * @param poa a POA of the given object. 102 * @param object_ID the object Id of the given object. 103 * 104 * @return an array, containing the repository ids. 105 */ 106 public abstract String[] _all_interfaces(POA poa, byte[] object_ID); 107 108 /** 109 * Get the delegate, where calls to some Servant methods are forwarded. 110 */ 111 public final Delegate _get_delegate() 112 { 113 if (delegate == null) { 114 throw new BAD_INV_ORDER 115 ("The Servant has not been associated with an ORBinstance"); 116 } 117 return delegate; 118 } 119 120 /** 121 * Get the interface repository definition <code>InterfaceDef</code> for this 122 * Object. By default, forwards request to the delegate. 123 * 124 * @specnote The interface repository is officially not implemented up till 125 * JDK 1.5 inclusive. The delegate throws NO_IMPLEMENT, always. 126 */ 127 public org.omg.CORBA.Object _get_interface_def() 128 { 129 throw new NO_IMPLEMENT(); 130 } 131 132 /** 133 * Checks if the passed servant is an instance of the given CORBA IDL type. 134 * By default, forwards the requet to the delegate. 135 * 136 * @param repository_id a repository ID, representing an IDL type for that the 137 * servant must be checked. 138 * 139 * @return true if the servant is an instance of the given type, false 140 * otherwise. 141 */ 142 public boolean _is_a(String repository_id) 143 { 144 return delegate.is_a(this, repository_id); 145 } 146 147 /** 148 * Determines if the server object for this reference has already 149 * been destroyed. By default, forwards request to the delegate. 150 * 151 * @return true if the object has been destroyed, false otherwise. 152 */ 153 public boolean _non_existent() 154 { 155 return delegate.non_existent(this); 156 } 157 158 /** 159 * Returns the ORB that is directly associated with the given servant. 160 * In this implementation, the method is overridden to return 161 */ 162 public final ORB _orb() 163 { 164 return delegate.orb(this); 165 } 166 167 /** 168 * Returns the root POA of the ORB instance, associated with this servant. 169 * It is the same POA that would be returned by resolving the initial 170 * reference "RootPOA" for that orb. By default, forwards request to the 171 * delegate. 172 * 173 * @see ORB#resolve_initial_references 174 */ 175 public POA _default_POA() 176 { 177 return delegate == null ? null : delegate.default_POA(this); 178 } 179 180 /** 181 * Return the invocation target object identifier as a byte array. 182 * This is typically used when the same servant serves multiple objects, 183 * and the object id can encapsulated the whole description of the 184 * object. 185 * 186 * This method returns correct values even when the same 187 * servant serves several objects in parallel threads. The ORB maintains the 188 * thread to invocation data map for all calls that are currently being 189 * processed. 190 */ 191 public final byte[] _object_id() 192 { 193 if (delegate != null) 194 return delegate.object_id(this); 195 else 196 throw new OBJECT_NOT_EXIST(); 197 } 198 199 /** 200 * Get POA that is directly associated with the given servant. 201 * By default, forwards request to the delegate. 202 */ 203 public final POA _poa() 204 { 205 return delegate.poa(this); 206 } 207 208 /** 209 * Set the delegate for this servant. 210 */ 211 public final void _set_delegate(Delegate a_delegate) 212 { 213 delegate = a_delegate; 214 } 215 216 /** 217 * Obtains the CORBA object reference that is a current invocation target for 218 * the given servant. This is important when the same servant serves 219 * multiple objects. If the servant is not yet connected to the passed 220 * orb, the method will try to connect it to that orb on POA, returned 221 * by the method {@link #_default_POA}. That method can be overridden to 222 * get poa where the object must be automatically connected when 223 * calling this method. 224 * 225 * @param an_orb the ORB with relate to that the object is requested. 226 */ 227 public final org.omg.CORBA.Object _this_object(ORB an_orb) 228 { 229 if (delegate != null) 230 return delegate.this_object(this); 231 else 232 { 233 if (an_orb instanceof ORB_1_4) 234 { 235 ORB_1_4 m_orb = (ORB_1_4) an_orb; 236 237 gnuPOA dp = (gnuPOA) _default_POA(); 238 if (dp == null) 239 dp = m_orb.rootPOA; 240 241 try 242 { 243 return dp.servant_to_reference(this); 244 } 245 catch (WrongPolicy unexp) 246 { 247 BAD_OPERATION bad = new BAD_OPERATION(); 248 bad.minor = Minor.Policy; 249 bad.initCause(unexp); 250 throw bad; 251 } 252 catch (ServantNotActive ex) 253 { 254 try 255 { 256 return dp.id_to_reference(dp.activate_object(this)); 257 } 258 catch (Exception unexp) 259 { 260 unexp.initCause(ex); 261 262 BAD_OPERATION bad = new BAD_OPERATION(); 263 bad.minor = Minor.Activation; 264 bad.initCause(unexp); 265 throw bad; 266 } 267 } 268 } 269 } 270 throw new OBJECT_NOT_EXIST(); 271 } 272 273 /** 274 * Obtains the CORBA object reference that is a current invocation target for 275 * the given servant. This is important when the same servant serves 276 * multiple objects. This method required the servant to be connected 277 * to a single orb, and a delegate set. 278 * 279 * This method returns correct values even when the same 280 * servant serves several objects in parallel threads. The ORB maintains the 281 * thread to invocation data map for all calls that are currently being 282 * processed. 283 */ 284 public final org.omg.CORBA.Object _this_object() 285 { 286 if (delegate != null) 287 return _this_object(_orb()); 288 else 289 { 290 POA def = _default_POA(); 291 if (def instanceof gnuPOA) 292 return _this_object(((gnuPOA) def).orb()); 293 } 294 throw new OBJECT_NOT_EXIST(); 295 } 296}