| /* |
| * Copyright (c) 1996, 2014, 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.server; |
| |
| import java.rmi.Remote; |
| import java.rmi.NoSuchObjectException; |
| import java.lang.reflect.Proxy; |
| import sun.rmi.server.Util; |
| |
| /** |
| * The <code>RemoteObject</code> class implements the |
| * <code>java.lang.Object</code> behavior for remote objects. |
| * <code>RemoteObject</code> provides the remote semantics of Object by |
| * implementing methods for hashCode, equals, and toString. |
| * |
| * @author Ann Wollrath |
| * @author Laird Dornin |
| * @author Peter Jones |
| * @since 1.1 |
| */ |
| public abstract class RemoteObject implements Remote, java.io.Serializable { |
| |
| /** The object's remote reference. */ |
| transient protected RemoteRef ref; |
| |
| /** indicate compatibility with JDK 1.1.x version of class */ |
| private static final long serialVersionUID = -3215090123894869218L; |
| |
| /** |
| * Creates a remote object. |
| */ |
| protected RemoteObject() { |
| ref = null; |
| } |
| |
| /** |
| * Creates a remote object, initialized with the specified remote |
| * reference. |
| * @param newref remote reference |
| */ |
| protected RemoteObject(RemoteRef newref) { |
| ref = newref; |
| } |
| |
| /** |
| * Returns the remote reference for the remote object. |
| * |
| * <p>Note: The object returned from this method may be an instance of |
| * an implementation-specific class. The <code>RemoteObject</code> |
| * class ensures serialization portability of its instances' remote |
| * references through the behavior of its custom |
| * <code>writeObject</code> and <code>readObject</code> methods. An |
| * instance of <code>RemoteRef</code> should not be serialized outside |
| * of its <code>RemoteObject</code> wrapper instance or the result may |
| * be unportable. |
| * |
| * @return remote reference for the remote object |
| * @since 1.2 |
| */ |
| public RemoteRef getRef() { |
| return ref; |
| } |
| |
| /** |
| * Returns the stub for the remote object <code>obj</code> passed |
| * as a parameter. This operation is only valid <i>after</i> |
| * the object has been exported. |
| * @param obj the remote object whose stub is needed |
| * @return the stub for the remote object, <code>obj</code>. |
| * @exception NoSuchObjectException if the stub for the |
| * remote object could not be found. |
| * @since 1.2 |
| */ |
| @SuppressWarnings("deprecation") |
| public static Remote toStub(Remote obj) throws NoSuchObjectException { |
| if (obj instanceof RemoteStub || |
| (obj != null && |
| Proxy.isProxyClass(obj.getClass()) && |
| Proxy.getInvocationHandler(obj) instanceof |
| RemoteObjectInvocationHandler)) |
| { |
| return obj; |
| } else { |
| return sun.rmi.transport.ObjectTable.getStub(obj); |
| } |
| } |
| |
| /** |
| * Returns a hashcode for a remote object. Two remote object stubs |
| * that refer to the same remote object will have the same hash code |
| * (in order to support remote objects as keys in hash tables). |
| * |
| * @see java.util.Hashtable |
| */ |
| public int hashCode() { |
| return (ref == null) ? super.hashCode() : ref.remoteHashCode(); |
| } |
| |
| /** |
| * Compares two remote objects for equality. |
| * Returns a boolean that indicates whether this remote object is |
| * equivalent to the specified Object. This method is used when a |
| * remote object is stored in a hashtable. |
| * If the specified Object is not itself an instance of RemoteObject, |
| * then this method delegates by returning the result of invoking the |
| * <code>equals</code> method of its parameter with this remote object |
| * as the argument. |
| * @param obj the Object to compare with |
| * @return true if these Objects are equal; false otherwise. |
| * @see java.util.Hashtable |
| */ |
| public boolean equals(Object obj) { |
| if (obj instanceof RemoteObject) { |
| if (ref == null) { |
| return obj == this; |
| } else { |
| return ref.remoteEquals(((RemoteObject)obj).ref); |
| } |
| } else if (obj != null) { |
| /* |
| * Fix for 4099660: if object is not an instance of RemoteObject, |
| * use the result of its equals method, to support symmetry is a |
| * remote object implementation class that does not extend |
| * RemoteObject wishes to support equality with its stub objects. |
| */ |
| return obj.equals(this); |
| } else { |
| return false; |
| } |
| } |
| |
| /** |
| * Returns a String that represents the value of this remote object. |
| */ |
| public String toString() { |
| String classname = Util.getUnqualifiedName(getClass()); |
| return (ref == null) ? classname : |
| classname + "[" + ref.remoteToString() + "]"; |
| } |
| |
| /** |
| * <code>writeObject</code> for custom serialization. |
| * |
| * <p>This method writes this object's serialized form for this class |
| * as follows: |
| * |
| * <p>The {@link RemoteRef#getRefClass(java.io.ObjectOutput) getRefClass} |
| * method is invoked on this object's <code>ref</code> field |
| * to obtain its external ref type name. |
| * If the value returned by <code>getRefClass</code> was |
| * a non-<code>null</code> string of length greater than zero, |
| * 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 |
| * this object's <code>ref</code> field passing <code>out</code> |
| * as the argument; otherwise, |
| * the <code>writeUTF</code> method is invoked on <code>out</code> |
| * with a zero-length string (<code>""</code>), and then |
| * the <code>writeObject</code> method is invoked on <code>out</code> |
| * passing this object's <code>ref</code> field as the argument. |
| * |
| * @serialData |
| * |
| * The serialized data for this class comprises a string (written with |
| * <code>ObjectOutput.writeUTF</code>) that is either the external |
| * ref type name of the contained <code>RemoteRef</code> instance |
| * (the <code>ref</code> field) or a zero-length string, followed by |
| * either the external form of the <code>ref</code> field as written by |
| * its <code>writeExternal</code> method if the string was of non-zero |
| * length, or the serialized form of the <code>ref</code> field as |
| * written by passing it to the serialization stream's |
| * <code>writeObject</code> if the string was of zero length. |
| * |
| * <p>If this object is an instance of |
| * {@link RemoteStub} or {@link RemoteObjectInvocationHandler} |
| * that was returned from any of |
| * the <code>UnicastRemoteObject.exportObject</code> methods |
| * and custom socket factories are not used, |
| * the external ref type name is <code>"UnicastRef"</code>. |
| * |
| * If this object is an instance of |
| * <code>RemoteStub</code> or <code>RemoteObjectInvocationHandler</code> |
| * that was returned from any of |
| * the <code>UnicastRemoteObject.exportObject</code> methods |
| * and custom socket factories are used, |
| * the external ref type name is <code>"UnicastRef2"</code>. |
| * |
| * If this object is an instance of |
| * <code>RemoteStub</code> or <code>RemoteObjectInvocationHandler</code> |
| * that was returned from any of |
| * the <code>java.rmi.activation.Activatable.exportObject</code> methods, |
| * the external ref type name is <code>"ActivatableRef"</code>. |
| * |
| * If this object is an instance of |
| * <code>RemoteStub</code> or <code>RemoteObjectInvocationHandler</code> |
| * that was returned from |
| * the <code>RemoteObject.toStub</code> method (and the argument passed |
| * to <code>toStub</code> was not itself a <code>RemoteStub</code>), |
| * the external ref type name is a function of how the remote object |
| * passed to <code>toStub</code> was exported, as described above. |
| * |
| * If this object is an instance of |
| * <code>RemoteStub</code> or <code>RemoteObjectInvocationHandler</code> |
| * that was originally created via deserialization, |
| * the external ref type name is the same as that which was read |
| * when this object was deserialized. |
| * |
| * <p>If this object is an instance of |
| * <code>java.rmi.server.UnicastRemoteObject</code> that does not |
| * use custom socket factories, |
| * the external ref type name is <code>"UnicastServerRef"</code>. |
| * |
| * If this object is an instance of |
| * <code>UnicastRemoteObject</code> that does |
| * use custom socket factories, |
| * the external ref type name is <code>"UnicastServerRef2"</code>. |
| * |
| * <p>Following is the data that must be written by the |
| * <code>writeExternal</code> method and read by the |
| * <code>readExternal</code> method of <code>RemoteRef</code> |
| * implementation classes that correspond to the each of the |
| * defined external ref type names: |
| * |
| * <p>For <code>"UnicastRef"</code>: |
| * |
| * <ul> |
| * |
| * <li>the hostname of the referenced remote object, |
| * written by {@link java.io.ObjectOutput#writeUTF(String)} |
| * |
| * <li>the port of the referenced remote object, |
| * written by {@link java.io.ObjectOutput#writeInt(int)} |
| * |
| * <li>the data written as a result of calling |
| * {link java.rmi.server.ObjID#write(java.io.ObjectOutput)} |
| * on the <code>ObjID</code> instance contained in the reference |
| * |
| * <li>the boolean value <code>false</code>, |
| * written by {@link java.io.ObjectOutput#writeBoolean(boolean)} |
| * |
| * </ul> |
| * |
| * <p>For <code>"UnicastRef2"</code> with a |
| * <code>null</code> client socket factory: |
| * |
| * <ul> |
| * |
| * <li>the byte value <code>0x00</code> |
| * (indicating <code>null</code> client socket factory), |
| * written by {@link java.io.ObjectOutput#writeByte(int)} |
| * |
| * <li>the hostname of the referenced remote object, |
| * written by {@link java.io.ObjectOutput#writeUTF(String)} |
| * |
| * <li>the port of the referenced remote object, |
| * written by {@link java.io.ObjectOutput#writeInt(int)} |
| * |
| * <li>the data written as a result of calling |
| * {link java.rmi.server.ObjID#write(java.io.ObjectOutput)} |
| * on the <code>ObjID</code> instance contained in the reference |
| * |
| * <li>the boolean value <code>false</code>, |
| * written by {@link java.io.ObjectOutput#writeBoolean(boolean)} |
| * |
| * </ul> |
| * |
| * <p>For <code>"UnicastRef2"</code> with a |
| * non-<code>null</code> client socket factory: |
| * |
| * <ul> |
| * |
| * <li>the byte value <code>0x01</code> |
| * (indicating non-<code>null</code> client socket factory), |
| * written by {@link java.io.ObjectOutput#writeByte(int)} |
| * |
| * <li>the hostname of the referenced remote object, |
| * written by {@link java.io.ObjectOutput#writeUTF(String)} |
| * |
| * <li>the port of the referenced remote object, |
| * written by {@link java.io.ObjectOutput#writeInt(int)} |
| * |
| * <li>a client socket factory (object of type |
| * <code>java.rmi.server.RMIClientSocketFactory</code>), |
| * written by passing it to an invocation of |
| * <code>writeObject</code> on the stream instance |
| * |
| * <li>the data written as a result of calling |
| * {link java.rmi.server.ObjID#write(java.io.ObjectOutput)} |
| * on the <code>ObjID</code> instance contained in the reference |
| * |
| * <li>the boolean value <code>false</code>, |
| * written by {@link java.io.ObjectOutput#writeBoolean(boolean)} |
| * |
| * </ul> |
| * |
| * <p>For <code>"ActivatableRef"</code> with a |
| * <code>null</code> nested remote reference: |
| * |
| * <ul> |
| * |
| * <li>an instance of |
| * <code>java.rmi.activation.ActivationID</code>, |
| * written by passing it to an invocation of |
| * <code>writeObject</code> on the stream instance |
| * |
| * <li>a zero-length string (<code>""</code>), |
| * written by {@link java.io.ObjectOutput#writeUTF(String)} |
| * |
| * </ul> |
| * |
| * <p>For <code>"ActivatableRef"</code> with a |
| * non-<code>null</code> nested remote reference: |
| * |
| * <ul> |
| * |
| * <li>an instance of |
| * <code>java.rmi.activation.ActivationID</code>, |
| * written by passing it to an invocation of |
| * <code>writeObject</code> on the stream instance |
| * |
| * <li>the external ref type name of the nested remote reference, |
| * which must be <code>"UnicastRef2"</code>, |
| * written by {@link java.io.ObjectOutput#writeUTF(String)} |
| * |
| * <li>the external form of the nested remote reference, |
| * written by invoking its <code>writeExternal</code> method |
| * with the stream instance |
| * (see the description of the external form for |
| * <code>"UnicastRef2"</code> above) |
| * |
| * </ul> |
| * |
| * <p>For <code>"UnicastServerRef"</code> and |
| * <code>"UnicastServerRef2"</code>, no data is written by the |
| * <code>writeExternal</code> method or read by the |
| * <code>readExternal</code> method. |
| */ |
| private void writeObject(java.io.ObjectOutputStream out) |
| throws java.io.IOException, java.lang.ClassNotFoundException |
| { |
| if (ref == null) { |
| throw new java.rmi.MarshalException("Invalid remote object"); |
| } else { |
| String refClassName = ref.getRefClass(out); |
| if (refClassName == null || refClassName.length() == 0) { |
| /* |
| * No reference class name specified, so serialize |
| * remote reference. |
| */ |
| out.writeUTF(""); |
| out.writeObject(ref); |
| } else { |
| /* |
| * Built-in reference class specified, so delegate |
| * to reference to write out its external form. |
| */ |
| out.writeUTF(refClassName); |
| 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>readUTF</code> method is invoked on <code>in</code> |
| * to read the external ref type name for the <code>RemoteRef</code> |
| * instance to be filled in to this object's <code>ref</code> field. |
| * If the string returned by <code>readUTF</code> has length zero, |
| * the <code>readObject</code> method is invoked on <code>in</code>, |
| * and than the value returned by <code>readObject</code> is cast to |
| * <code>RemoteRef</code> and this object's <code>ref</code> field is |
| * set to that value. |
| * Otherwise, this object's <code>ref</code> field is set to a |
| * <code>RemoteRef</code> instance that is created of an |
| * implementation-specific class corresponding to the external ref |
| * type name returned by <code>readUTF</code>, and then |
| * the <code>readExternal</code> method is invoked on |
| * this object's <code>ref</code> field. |
| * |
| * <p>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 this object's <code>ref</code> field will be set to an |
| * instance of that implementation-specific class. |
| */ |
| private void readObject(java.io.ObjectInputStream in) |
| throws java.io.IOException, java.lang.ClassNotFoundException |
| { |
| String refClassName = in.readUTF(); |
| if (refClassName == null || refClassName.length() == 0) { |
| /* |
| * No reference class name specified, so construct |
| * remote reference from its serialized form. |
| */ |
| ref = (RemoteRef) in.readObject(); |
| } else { |
| /* |
| * Built-in reference class specified, so delegate to |
| * internal reference class to initialize its fields from |
| * its external form. |
| */ |
| String internalRefClassName = |
| RemoteRef.packagePrefix + "." + refClassName; |
| Class<?> refClass = Class.forName(internalRefClassName); |
| try { |
| @SuppressWarnings("deprecation") |
| Object tmp = refClass.newInstance(); |
| ref = (RemoteRef) tmp; |
| |
| /* |
| * If this step fails, assume we found an internal |
| * class that is not meant to be a serializable ref |
| * type. |
| */ |
| } catch (InstantiationException | IllegalAccessException | ClassCastException e) { |
| throw new ClassNotFoundException(internalRefClassName, e); |
| } |
| ref.readExternal(in); |
| } |
| } |
| } |