| /* |
| * Copyright (c) 1997, 2005, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package java.rmi.activation; |
| |
| import java.io.IOException; |
| import java.io.InvalidObjectException; |
| import java.io.ObjectInputStream; |
| import java.io.ObjectOutputStream; |
| import java.io.Serializable; |
| import java.lang.reflect.InvocationHandler; |
| import java.lang.reflect.Proxy; |
| import java.rmi.MarshalledObject; |
| import java.rmi.Remote; |
| import java.rmi.RemoteException; |
| import java.rmi.UnmarshalException; |
| import java.rmi.server.RemoteObject; |
| import java.rmi.server.RemoteObjectInvocationHandler; |
| import java.rmi.server.RemoteRef; |
| import java.rmi.server.UID; |
| |
| /** |
| * Activation makes use of special identifiers to denote remote |
| * objects that can be activated over time. An activation identifier |
| * (an instance of the class <code>ActivationID</code>) contains several |
| * pieces of information needed for activating an object: |
| * <ul> |
| * <li> a remote reference to the object's activator (a {@link |
| * java.rmi.server.RemoteRef RemoteRef} |
| * instance), and |
| * <li> a unique identifier (a {@link java.rmi.server.UID UID} |
| * instance) for the object. </ul> <p> |
| * |
| * An activation identifier for an object can be obtained by registering |
| * an object with the activation system. Registration is accomplished |
| * in a few ways: <ul> |
| * <li>via the <code>Activatable.register</code> method |
| * <li>via the first <code>Activatable</code> constructor (that takes |
| * three arguments and both registers and exports the object, and |
| * <li>via the first <code>Activatable.exportObject</code> method |
| * that takes the activation descriptor, object and port as arguments; |
| * this method both registers and exports the object. </ul> |
| * |
| * @author Ann Wollrath |
| * @see Activatable |
| * @since 1.2 |
| */ |
| public class ActivationID implements Serializable { |
| /** |
| * the object's activator |
| */ |
| private transient Activator activator; |
| |
| /** |
| * the object's unique id |
| */ |
| private transient UID uid = new UID(); |
| |
| /** indicate compatibility with the Java 2 SDK v1.2 version of class */ |
| private static final long serialVersionUID = -4608673054848209235L; |
| |
| /** |
| * The constructor for <code>ActivationID</code> takes a single |
| * argument, activator, that specifies a remote reference to the |
| * activator responsible for activating the object associated with |
| * this identifier. An instance of <code>ActivationID</code> is globally |
| * unique. |
| * |
| * @param activator reference to the activator responsible for |
| * activating the object |
| * @since 1.2 |
| */ |
| public ActivationID(Activator activator) { |
| this.activator = activator; |
| } |
| |
| /** |
| * Activate the object for this id. |
| * |
| * @param force if true, forces the activator to contact the group |
| * when activating the object (instead of returning a cached reference); |
| * if false, returning a cached value is acceptable. |
| * @return the reference to the active remote object |
| * @exception ActivationException if activation fails |
| * @exception UnknownObjectException if the object is unknown |
| * @exception RemoteException if remote call fails |
| * @since 1.2 |
| */ |
| public Remote activate(boolean force) |
| throws ActivationException, UnknownObjectException, RemoteException |
| { |
| try { |
| MarshalledObject<? extends Remote> mobj = |
| activator.activate(this, force); |
| return mobj.get(); |
| } catch (RemoteException e) { |
| throw e; |
| } catch (IOException e) { |
| throw new UnmarshalException("activation failed", e); |
| } catch (ClassNotFoundException e) { |
| throw new UnmarshalException("activation failed", e); |
| } |
| |
| } |
| |
| /** |
| * Returns a hashcode for the activation id. Two identifiers that |
| * refer to the same remote object will have the same hash code. |
| * |
| * @see java.util.Hashtable |
| * @since 1.2 |
| */ |
| public int hashCode() { |
| return uid.hashCode(); |
| } |
| |
| /** |
| * Compares two activation ids for content equality. |
| * Returns true if both of the following conditions are true: |
| * 1) the unique identifiers equivalent (by content), and |
| * 2) the activator specified in each identifier |
| * refers to the same remote object. |
| * |
| * @param obj the Object to compare with |
| * @return true if these Objects are equal; false otherwise. |
| * @see java.util.Hashtable |
| * @since 1.2 |
| */ |
| public boolean equals(Object obj) { |
| if (obj instanceof ActivationID) { |
| ActivationID id = (ActivationID) obj; |
| return (uid.equals(id.uid) && activator.equals(id.activator)); |
| } else { |
| return false; |
| } |
| } |
| |
| /** |
| * <code>writeObject</code> for custom serialization. |
| * |
| * <p>This method writes this object's serialized form for |
| * this class as follows: |
| * |
| * <p>The <code>writeObject</code> method is invoked on |
| * <code>out</code> passing this object's unique identifier |
| * (a {@link java.rmi.server.UID UID} instance) as the argument. |
| * |
| * <p>Next, the {@link |
| * java.rmi.server.RemoteRef#getRefClass(java.io.ObjectOutput) |
| * getRefClass} method is invoked on the activator's |
| * <code>RemoteRef</code> instance to obtain its external ref |
| * type name. Next, the <code>writeUTF</code> method is |
| * invoked on <code>out</code> with the value returned by |
| * <code>getRefClass</code>, and then the |
| * <code>writeExternal</code> method is invoked on the |
| * <code>RemoteRef</code> instance passing <code>out</code> |
| * as the argument. |
| * |
| * @serialData The serialized data for this class comprises a |
| * <code>java.rmi.server.UID</code> (written with |
| * <code>ObjectOutput.writeObject</code>) followed by the |
| * external ref type name of the activator's |
| * <code>RemoteRef</code> instance (a string written with |
| * <code>ObjectOutput.writeUTF</code>), followed by the |
| * external form of the <code>RemoteRef</code> instance as |
| * written by its <code>writeExternal</code> method. |
| * |
| * <p>The external ref type name of the |
| * <code>RemoteRef</Code> instance is |
| * determined using the definitions of external ref type |
| * names specified in the {@link java.rmi.server.RemoteObject |
| * RemoteObject} <code>writeObject</code> method |
| * <b>serialData</b> specification. Similarly, the data |
| * written by the <code>writeExternal</code> method and read |
| * by the <code>readExternal</code> method of |
| * <code>RemoteRef</code> implementation classes |
| * corresponding to each of the defined external ref type |
| * names is specified in the {@link |
| * java.rmi.server.RemoteObject RemoteObject} |
| * <code>writeObject</code> method <b>serialData</b> |
| * specification. |
| **/ |
| private void writeObject(ObjectOutputStream out) |
| throws IOException, ClassNotFoundException |
| { |
| out.writeObject(uid); |
| |
| RemoteRef ref; |
| if (activator instanceof RemoteObject) { |
| ref = ((RemoteObject) activator).getRef(); |
| } else if (Proxy.isProxyClass(activator.getClass())) { |
| InvocationHandler handler = Proxy.getInvocationHandler(activator); |
| if (!(handler instanceof RemoteObjectInvocationHandler)) { |
| throw new InvalidObjectException( |
| "unexpected invocation handler"); |
| } |
| ref = ((RemoteObjectInvocationHandler) handler).getRef(); |
| |
| } else { |
| throw new InvalidObjectException("unexpected activator type"); |
| } |
| out.writeUTF(ref.getRefClass(out)); |
| ref.writeExternal(out); |
| } |
| |
| /** |
| * <code>readObject</code> for custom serialization. |
| * |
| * <p>This method reads this object's serialized form for this |
| * class as follows: |
| * |
| * <p>The <code>readObject</code> method is invoked on |
| * <code>in</code> to read this object's unique identifier |
| * (a {@link java.rmi.server.UID UID} instance). |
| * |
| * <p>Next, the <code>readUTF</code> method is invoked on |
| * <code>in</code> to read the external ref type name of the |
| * <code>RemoteRef</code> instance for this object's |
| * activator. Next, the <code>RemoteRef</code> |
| * instance is created of an implementation-specific class |
| * corresponding to the external ref type name (returned by |
| * <code>readUTF</code>), and the <code>readExternal</code> |
| * method is invoked on that <code>RemoteRef</code> instance |
| * to read the external form corresponding to the external |
| * ref type name. |
| * |
| * <p>Note: If the external ref type name is |
| * <code>"UnicastRef"</code>, <code>"UnicastServerRef"</code>, |
| * <code>"UnicastRef2"</code>, <code>"UnicastServerRef2"</code>, |
| * or <code>"ActivatableRef"</code>, a corresponding |
| * implementation-specific class must be found, and its |
| * <code>readExternal</code> method must read the serial data |
| * for that external ref type name as specified to be written |
| * in the <b>serialData</b> documentation for this class. |
| * If the external ref type name is any other string (of non-zero |
| * length), a <code>ClassNotFoundException</code> will be thrown, |
| * unless the implementation provides an implementation-specific |
| * class corresponding to that external ref type name, in which |
| * case the <code>RemoteRef</code> will be an instance of |
| * that implementation-specific class. |
| */ |
| private void readObject(ObjectInputStream in) |
| throws IOException, ClassNotFoundException |
| { |
| uid = (UID)in.readObject(); |
| |
| try { |
| Class<? extends RemoteRef> refClass = |
| Class.forName(RemoteRef.packagePrefix + "." + in.readUTF()) |
| .asSubclass(RemoteRef.class); |
| RemoteRef ref = refClass.newInstance(); |
| ref.readExternal(in); |
| activator = (Activator) |
| Proxy.newProxyInstance(null, |
| new Class<?>[] { Activator.class }, |
| new RemoteObjectInvocationHandler(ref)); |
| |
| } catch (InstantiationException e) { |
| throw (IOException) |
| new InvalidObjectException( |
| "Unable to create remote reference").initCause(e); |
| } catch (IllegalAccessException e) { |
| throw (IOException) |
| new InvalidObjectException( |
| "Unable to create remote reference").initCause(e); |
| } |
| } |
| } |
