/*
 * @(#)Object.java	1.50 01/12/03
 *
 * Copyright 2002 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package org.omg.CORBA;

/**
 * The definition for a CORBA object reference.
 * <p>
 * A CORBA object reference is a handle for a particular
 * CORBA object implemented by a server. A CORBA object reference
 * identifies the same CORBA object each time the reference is used to invoke
 * a method on the object.
 * A CORBA object may have multiple, distinct object references.
 * <p>
 * The <code>org.omg.CORBA.Object</code> interface is the root of
 * the inheritance hierarchy for all CORBA object references in the Java
 * programming language, analogous to <code>java.rmi.Remote</code>
 * for RMI remote objects.
 * <p>
 * A CORBA object may be either local or remote.
 * If it is a local object (that is, running in the same
 * VM as the client), invocations may be directly serviced by
 * the object instance, and the object reference could point to the actual
 * instance of the object implementation class.
 * If a CORBA object is a remote object (that is, running in a different
 * VM from the client), the object reference points to a stub (proxy) which uses the
 * ORB machinery to make a remote invocation on the server where the object
 * implementation resides.
 * <p>
 * Default implementations of the methods in the interface
 * <code>org.omg.CORBA.Object</code>
 * are provided in the class <code>org.omg.CORBA.portable.ObjectImpl</code>,
 * which is the base class for stubs and object implementations.
 * <p>
 * @see org.omg.CORBA.portable.ObjectImpl
 */

public interface Object {

    /**
     * Checks whether this object is an instance of a class that
     * implements the given interface.
     *
     * @param repositoryIdentifier the interface to check against
     * @return <code>true</code> if this object reference is an instance
     *         of a class that implements the interface;
     *         <code>false</code> otherwise
     */
    boolean _is_a(String repositoryIdentifier);


    /**
     * Determines whether the two object references are equivalent,
     * so far as the ORB can easily determine. Two object references are equivalent
     * if they are identical. Two distinct object references which in fact refer to
     * the same object are also equivalent. However, ORBs are not required
     * to attempt determination of whether two distinct object references
     * refer to the same object, since such determination could be impractically
     * expensive.
     * @param other the other object reference with which to check for equivalence
     * @return <code>true</code> if this object reference is known to be
     *         equivalent to the given object reference.
     *         Note that <code>false</code> indicates only that the two
     *         object references are distinct, not necessarily that
     *         they reference distinct objects.
     */
    boolean _is_equivalent(org.omg.CORBA.Object other);


    /**
     * Determines whether the server object for this object reference has been
     * destroyed.
     * @return <code>true</code> if the ORB knows authoritatively that the
     *         server object does not exist; <code>false</code> otherwise
     */
    boolean _non_existent();


    /**
     * Returns an ORB-internal identifier for this object reference.
     * This is a hash identifier, which does
     * not change during the lifetime of the object reference, and so
     * neither will any hash function of that identifier change. The value returned
     * is not guaranteed to be unique; in other words, another object
     * reference may have the same hash value.
     * If two object references hash differently,
     * then they are distinct object references; however, both may still refer
     * to the same CORBA object.
     *
     * @param maximum the upper bound on the hash value returned by the ORB
     * @return the ORB-internal hash identifier for this object reference
     */
    int _hash(int maximum);


    /**
     * Returns a duplicate of this CORBA object reference.
     * The server object implementation is not involved in creating
     * the duplicate, and the implementation cannot distinguish whether
     * the original object reference or a duplicate was used to make a request.
     * <P>
     * Note that this method is not very useful in the Java platform,
     * since memory management is handled by the VM.
     * It is included for compliance with the CORBA APIs.
     * <P>
     * The method <code>_duplicate</code> may return this object reference itself.
     *
     * @return a duplicate of this object reference or this object reference
     *         itself
     */
    org.omg.CORBA.Object _duplicate();


    /**
     * Signals that the caller is done using this object reference, so
     * internal ORB resources associated with this object reference can be
     * released. Note that the object implementation is not involved in
     * this operation, and other references to the same object are not affected.
     */
    void _release();


    /**
     * Obtains an <code>InterfaceDef</code> for the object implementation
     * referenced by this object reference.
     * The <code>InterfaceDef</code> object
     * may be used to introspect on the methods, attributes, and other
     * type information for the object referred to by this object reference.
     *
     * @return the <code>InterfaceDef</code> object in the Interface Repository
     *         which provides type information about the object referred to by
     *         this object reference
     */
    org.omg.CORBA.Object _get_interface_def();



    /**
     * Creates a <code>Request</code> instance for use in the
     * Dynamic Invocation Interface.
     *
     * @param operation  the name of the method to be invoked using the
     *		              <code>Request</code> instance
     * @return the newly-created <code>Request</code> instance
     */
    Request _request(String operation);



    /**
     * Creates a <code>Request</code> instance initialized with the
     * given context, method name, list of arguments, and container
     * for the method's return value.
     *
     * @param ctx			a <code>Context</code> object containing
     *                     a list of properties
     * @param operation    the name of the method to be invoked
     * @param arg_list		an <code>NVList</code> containing the actual arguments
     *                     to the method being invoked
     * @param result		a <code>NamedValue</code> object to serve as a
     *                     container for the method's return value
     * @return			the newly-created <code>Request</code> object
     *
     * @see Request
     * @see NVList
     * @see NamedValue
     */

    Request _create_request(Context ctx,
			    String operation,
			    NVList arg_list,
			    NamedValue result);

    /**
     * Creates a <code>Request</code> instance initialized with the
     * given context, method name, list of arguments, container
     * for the method's return value, list of possible exceptions,
     * and list of context strings needing to be resolved.
     *
     * @param ctx			a <code>Context</code> object containing
     *                     a list of properties
     * @param operation    the name of the method to be invoked
     * @param arg_list		an <code>NVList</code> containing the actual arguments
     *                     to the method being invoked
     * @param result		a <code>NamedValue</code> object to serve as a
     *                     container for the method's return value
     * @param exclist		an <code>ExceptionList</code> object containing a
     *                     list of possible exceptions the method can throw
     * @param ctxlist		a <code>ContextList</code> object containing a list of
     *                     context strings that need to be resolved and sent with the
     * 			     	<code>Request</code> instance
     * @return			the newly-created <code>Request</code> object
     *
     * @see Request
     * @see NVList
     * @see NamedValue
     * @see ExceptionList
     * @see ContextList
     */

    Request _create_request(Context ctx,
			    String operation,
			    NVList arg_list,
			    NamedValue result,
			    ExceptionList exclist,
			    ContextList ctxlist);




    /**
     * Returns the <code>Policy</code> object of the specified type 
     * which applies to this object.
     * 
     * @param policy_type the type of policy to be obtained
     * @return A <code>Policy</code> object of the type specified by 
     *         the policy_type parameter
     * @exception org.omg.CORBA.BAD_PARAM when the value of policy type 
     * is not valid either because the specified type is not supported by this 
     * ORB or because a policy object of that type is not associated with this 
     * Object
     */
    Policy _get_policy(int policy_type);


    /**
     * Retrieves the <code>DomainManagers</code> of this object.
     * This allows administration services (and applications) to retrieve the 
     * domain managers, and hence the security and other policies applicable 
     * to individual objects that are members of the domain.
     * 
     * @return the list of immediately enclosing domain managers of this object.
     *  At least one domain manager is always returned in the list since by 
     * default each object is associated with at least one domain manager at 
     * creation.
     */
    DomainManager[] _get_domain_managers();


    /**
     * Returns a new <code>Object</code> with the given policies
	 * either replacing any existing policies in this
	 * <code>Object</code> or with the given policies added 
	 * to the existing ones, depending on the value of the
	 * given <code>SetOverrideType</code> object.
	 * 
	 * @param policies an array of <code>Policy</code> objects containing
	 *                 the policies to be added or to be used as replacements
	 * @param set_add either <code>SetOverrideType.SET_OVERRIDE</code>, indicating
	 *                that the given policies will replace any existing ones, or
	 *                <code>SetOverrideType.ADD_OVERRIDE</code>, indicating that
	 *                the given policies should be added to any existing ones
	 * @return a new <code>Object</code> with the given policies replacing
	 *         or added to those in this <code>Object</code>
     */
    org.omg.CORBA.Object _set_policy_override(Policy[] policies,
                                              SetOverrideType set_add);


}
