1 |
/* PortableRemoteObject.java -- |
/* PortableRemoteObject.java -- |
2 |
Copyright (C) 2002, 2004 Free Software Foundation, Inc. |
Copyright (C) 2004, 2004, 2005 Free Software Foundation, Inc. |
3 |
|
|
4 |
This file is part of GNU Classpath. |
This file is part of GNU Classpath. |
5 |
|
|
39 |
package javax.rmi; |
package javax.rmi; |
40 |
|
|
41 |
import gnu.javax.rmi.CORBA.DelegateFactory; |
import gnu.javax.rmi.CORBA.DelegateFactory; |
42 |
import gnu.javax.rmi.CORBA.GetDelegateInstanceException; |
|
43 |
|
import org.omg.CORBA.BAD_PARAM; |
44 |
|
import org.omg.CORBA.ORB; |
45 |
|
import org.omg.CORBA.portable.ObjectImpl; |
46 |
|
import org.omg.PortableServer.POA; |
47 |
|
import org.omg.PortableServer.Servant; |
48 |
|
|
49 |
import java.rmi.NoSuchObjectException; |
import java.rmi.NoSuchObjectException; |
50 |
import java.rmi.Remote; |
import java.rmi.Remote; |
51 |
import java.rmi.RemoteException; |
import java.rmi.RemoteException; |
52 |
|
|
53 |
import javax.rmi.CORBA.PortableRemoteObjectDelegate; |
import javax.rmi.CORBA.PortableRemoteObjectDelegate; |
54 |
|
import javax.rmi.CORBA.Stub; |
55 |
|
import javax.rmi.CORBA.Tie; |
56 |
|
import javax.rmi.CORBA.Util; |
57 |
|
|
58 |
|
/** |
59 |
|
* <p> |
60 |
|
* An utility class for RMI/IDL server side object implementations. Server side |
61 |
|
* implementation objects may inherit from this class, but this is not |
62 |
|
* mandatory, as the needed methds are static. Server side implementations may |
63 |
|
* choose to inherit from {@link ObjectImpl} or {@link Servant} instead. |
64 |
|
* </p> |
65 |
|
* <p> |
66 |
|
* The functionality of methods in this class is forwarded to the enclosed |
67 |
|
* PortableRemoteObjectDelegate. This delegate can be altered by setting the |
68 |
|
* system property "javax.rmi.CORBA.PortableRemoteObjectClass" to the name of |
69 |
|
* the alternative class that must implement |
70 |
|
* {@link PortableRemoteObjectDelegate}. |
71 |
|
* </p> |
72 |
|
* |
73 |
|
* @author Audrius Meskauskas (AudriusA@Bioinformatics.org) |
74 |
|
*/ |
75 |
public class PortableRemoteObject |
public class PortableRemoteObject |
|
implements Remote /* why doc doesn't say should implement Remote */ |
|
76 |
{ |
{ |
77 |
|
/** |
78 |
private static PortableRemoteObjectDelegate delegate; |
* A delegate where the functionality is forwarded. |
79 |
static |
*/ |
80 |
{ |
static PortableRemoteObjectDelegate delegate = (PortableRemoteObjectDelegate) DelegateFactory.getInstance(DelegateFactory.PORTABLE_REMOTE_OBJECT); |
81 |
try |
|
82 |
{ |
/** |
83 |
delegate = (PortableRemoteObjectDelegate)DelegateFactory.getInstance |
* The protected constructor calls {@link exportObject} (this). |
84 |
("PortableRemoteObject"); |
* |
85 |
} |
* @throws RemoteException if the exportObject(this) throws one. |
86 |
catch(GetDelegateInstanceException e) |
*/ |
|
{ |
|
|
e.printStackTrace(); |
|
|
delegate = null; |
|
|
} |
|
|
} |
|
|
|
|
87 |
protected PortableRemoteObject() |
protected PortableRemoteObject() |
88 |
throws RemoteException |
throws RemoteException |
89 |
{ |
{ |
90 |
if(delegate != null) |
exportObject((Remote) this); |
|
exportObject((Remote)this); |
|
91 |
} |
} |
92 |
|
|
93 |
|
/** |
94 |
|
* <p> |
95 |
|
* Makes the remote object <code>a_target</code> ready for remote |
96 |
|
* communication using the same communications runtime as for the passed |
97 |
|
* <code>a_source</code> parameter. The a_target is connected to the same |
98 |
|
* ORB (and, if applicable, to the same {@link POA}) as the a_source. |
99 |
|
* |
100 |
|
* @param a_target the target to connect to ORB, must be an instance of either |
101 |
|
* {@link ObjectImpl} (Stubs and old-style ties) or {@link Tie}. |
102 |
|
* |
103 |
|
* @param a_source the object, providing the connection information, must be |
104 |
|
* an instance of either {@link ObjectImpl} (Stubs and old-style ties) or |
105 |
|
* {@link Servant} (the next-generation Ties supporting {@link POA}). |
106 |
|
* |
107 |
|
* @throws RemoteException if the target is already connected to another ORB. |
108 |
|
*/ |
109 |
public static void connect(Remote target, Remote source) |
public static void connect(Remote target, Remote source) |
110 |
throws RemoteException |
throws RemoteException |
111 |
{ |
{ |
112 |
if(delegate != null) |
delegate.connect(target, source); |
|
delegate.connect(target, source); |
|
113 |
} |
} |
114 |
|
|
115 |
public static void exportObject(Remote obj) |
/** |
116 |
|
* <p> |
117 |
|
* Makes a server object ready for remote calls. The subclasses of |
118 |
|
* PortableRemoteObject do not need to call this method, as it is called by |
119 |
|
* the constructor. |
120 |
|
* </p> |
121 |
|
* <p> |
122 |
|
* This method only creates a tie object and caches it for future usage. The |
123 |
|
* created tie does not have a delegate or an ORB associated. |
124 |
|
* </p> |
125 |
|
* |
126 |
|
* @param object the object to export. |
127 |
|
* |
128 |
|
* @throws RemoteException if export fails due any reason. |
129 |
|
*/ |
130 |
|
public static void exportObject(Remote object) |
131 |
throws RemoteException |
throws RemoteException |
132 |
{ |
{ |
133 |
if(delegate != null) |
delegate.exportObject(object); |
|
delegate.exportObject(obj); |
|
134 |
} |
} |
135 |
|
|
136 |
public static Object narrow(Object narrowFrom, Class narrowTo) |
/** |
137 |
|
* Narrows the passed object to conform to the given interface or IDL type. In |
138 |
|
* RMI-IIOP, this method replaces the narrow(org.omg.CORBA.Object) method that |
139 |
|
* was present in the CORBA Helpers. This method frequently returns different |
140 |
|
* instance and cannot be replaced by the direct cast. The typical narrowing |
141 |
|
* cases (all supported by GNU Classpath) are: |
142 |
|
* <ul> |
143 |
|
* <li>A CORBA object (for instance, returned by the |
144 |
|
* {@link ORB#string_to_object} or from the naming service) can be narrowed |
145 |
|
* into interface, derived from Remote. The method will try to locate an |
146 |
|
* appropriate {@link Stub} by the name pattern (_*_Stub). If the object being |
147 |
|
* narrowed is connected to an ORB, the returned instance will inherit that |
148 |
|
* connection, representing the same remote (or local) object, but now with |
149 |
|
* the possibility to invoke remote methods. </li> |
150 |
|
* <li>A CORBA object may be directly narrowed into the appropriate |
151 |
|
* {@link Stub} class, if it is and passed as a second parameter. This allows |
152 |
|
* to use non-standard stubs without parameterless constructors.</li> |
153 |
|
* <li>Any two classes, derived from the {@link ObjectImpl} (may be Stub's) |
154 |
|
* can be narrowed one into another (a delegate is transferred). </li> |
155 |
|
* <li>An implementation of Remote can be narrowed into {@link Tie} that can |
156 |
|
* later connected to an ORB, making the methods accessible remotely. The |
157 |
|
* Remote being narrowed normally provides a local implementation, but you can |
158 |
|
* also narrow remote Stub, creating "forwarding Tie".</li> |
159 |
|
* <li>null is narrowed into null regardless of the second parameter.</li> |
160 |
|
* <li>A {@link Tie} can be narrowed into Remote, representing the |
161 |
|
* implementation for this Tie (if one is set).</li> |
162 |
|
* </ul> |
163 |
|
* |
164 |
|
* @param object the object like CORBA Object, Stub or Remote that must be |
165 |
|
* narrowed to the given interface. |
166 |
|
* |
167 |
|
* @param narrowToInstaceOf the class of the interface to that the object must |
168 |
|
* be narrowed. |
169 |
|
* |
170 |
|
* @return On success, an object of type narrowTo or null, if narrowFrom = |
171 |
|
* null. |
172 |
|
* |
173 |
|
* @throws ClassCastException if no narrowing is possible. |
174 |
|
*/ |
175 |
|
public static Object narrow(Object object, Class narrowToInstaceOf) |
176 |
throws ClassCastException |
throws ClassCastException |
177 |
{ |
{ |
178 |
if(delegate != null) |
return delegate.narrow(object, narrowToInstaceOf); |
|
return delegate.narrow(narrowFrom, narrowTo); |
|
|
else |
|
|
return null; |
|
179 |
} |
} |
180 |
|
|
181 |
public static Remote toStub(Remote obj) |
/** |
182 |
|
* <p> |
183 |
|
* Takes a server implementation object (name pattern *imp) and returns a stub |
184 |
|
* object that can be used to access that server object (target), name |
185 |
|
* (pattern _*_Stub). |
186 |
|
* |
187 |
|
* The returned stub is not connected to any ORB and must be explicitly |
188 |
|
* connected using {@link #connect}. |
189 |
|
* </p> |
190 |
|
* <p> |
191 |
|
* The method signature prevents it from returning stubs that does not |
192 |
|
* implement Remote (ClassCastException will be thrown). |
193 |
|
* </p> |
194 |
|
* |
195 |
|
* @param target a server side object implementation. |
196 |
|
* @return a stub object that can be used to access that server object. |
197 |
|
* |
198 |
|
* @throws NoSuchObjectException if a stub class cannot be located by supposed |
199 |
|
* name pattern, or an instance of stub fails to be instantiated. |
200 |
|
* |
201 |
|
* @throws ClassCastException if the stub class can be located, but it does |
202 |
|
* not inherit from Remote. |
203 |
|
* |
204 |
|
* @throws BAD_PARAM if the name of the passed class does not match the |
205 |
|
* implementation name pattern (does not end by 'Impl'). |
206 |
|
*/ |
207 |
|
public static Remote toStub(Remote targetImpl) |
208 |
throws NoSuchObjectException |
throws NoSuchObjectException |
209 |
{ |
{ |
210 |
if(delegate != null) |
return delegate.toStub(targetImpl); |
|
return delegate.toStub(obj); |
|
|
else |
|
|
return null; |
|
211 |
} |
} |
212 |
|
|
213 |
public static void unexportObject(Remote obj) |
/** |
214 |
|
* Deregister a currently exported server object from the ORB runtimes. The |
215 |
|
* object to becomes available for garbage collection. This is usually |
216 |
|
* impemented via {@link Util#unexportObject} |
217 |
|
* |
218 |
|
* @param object the object to unexport. |
219 |
|
* |
220 |
|
* @throws NoSuchObjectException if the passed object is not currently |
221 |
|
* exported. |
222 |
|
*/ |
223 |
|
public static void unexportObject(Remote object) |
224 |
throws NoSuchObjectException |
throws NoSuchObjectException |
225 |
{ |
{ |
226 |
if(delegate != null) |
delegate.unexportObject(object); |
|
delegate.unexportObject(obj); |
|
227 |
} |
} |
228 |
|
} |
|
} |
|