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 *

 * 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

 * particular file as subject to the "Classpath" exception as provided

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

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 * 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,

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package org.omg.CORBA;

/**

 * An object containing the information necessary for

 * invoking a method.  This class is

 * the cornerstone of the ORB Dynamic

 * Invocation Interface (DII), which allows dynamic creation and

 * invocation of requests.

 * A server cannot tell the difference between a client

 * invocation using a client stub and a request using the DII.

 * <P>

 * A <code>Request</code> object consists of:

 * <UL>

 * <LI>the name of the operation to be invoked

 * <LI>an <code>NVList</code> containing arguments for the operation.<BR>

 * Each item in the list is a <code>NamedValue</code> object, which has three

 * parts:

 *  <OL>

 *    <LI>the name of the argument

 *    <LI>the value of the argument (as an <code>Any</code> object)

 *    <LI>the argument mode flag indicating whether the argument is

 *        for input, output, or both

 *  </OL>

 * </UL>

 * <P>

 * <code>Request</code> objects may also contain additional information,

 * depending on how an operation was defined in the original IDL

 * interface definition.  For example, where appropriate, they may contain

 * a <code>NamedValue</code> object to hold the return value or exception,

 * a context, a list of possible exceptions, and a list of

 * context strings that need to be resolved.

 * <P>

 * New <code>Request</code> objects are created using one of the

 * <code>create_request</code> methods in the <code>Object</code> class.

 * In other words, a <code>create_request</code> method is performed on the

 * object which is to be invoked.

 *

 * @see org.omg.CORBA.NamedValue

 *

 */

public abstract class Request {

    /**

     * Retrieves the the target object reference.

     *

     * @return                  the object reference that points to the

     *                    object implementation for the method

     *                    to be invoked

     */

    public abstract org.omg.CORBA.Object target();

    /**

     * Retrieves the name of the method to be invoked.

     *

     * @return                  the name of the method to be invoked

     */

    public abstract String operation();

    /**

     * Retrieves the <code>NVList</code> object containing the arguments

     * to the method being invoked.  The elements in the list are

     * <code>NamedValue</code> objects, with each one describing an argument

     * to the method.

     *

     * @return  the <code>NVList</code> object containing the arguments

     *                  for the method

     *

     */

    public abstract NVList arguments();

    /**

     * Retrieves the <code>NamedValue</code> object containing the return

     * value for the method.

     *

     * @return          the <code>NamedValue</code> object containing the result

     *                          of the method

     */

    public abstract NamedValue result();

    /**

     * Retrieves the <code>Environment</code> object for this request.

     * It contains the exception that the method being invoked has

     * thrown (after the invocation returns).

     *

     *

     * @return  the <code>Environment</code> object for this request

     */

    public abstract Environment env();

    /**

     * Retrieves the <code>ExceptionList</code> object for this request.

     * This list contains <code>TypeCode</code> objects describing the

     * exceptions that may be thrown by the method being invoked.

     *

     * @return  the <code>ExceptionList</code> object describing the exceptions

     *            that may be thrown by the method being invoked

     */

    public abstract ExceptionList exceptions();

    /**

     * Retrieves the <code>ContextList</code> object for this request.

     * This list contains context <code>String</code>s that need to

     * be resolved and sent with the invocation.

     *

     *

     * @return                  the list of context strings whose values

     *                          need to be resolved and sent with the

     *                          invocation.

     */

    public abstract ContextList contexts();

    /**

     * Retrieves the <code>Context</code> object for this request.

     * This is a list of properties giving information about the

     * client, the environment, or the circumstances of this request.

     *

     * @return          the <code>Context</code> object that is to be used

     *                          to resolve any context strings whose

     *                          values need to be sent with the invocation

     */

    public abstract Context ctx();

    /**

     * Sets this request's <code>Context</code> object to the one given.

     *

     * @param c         the new <code>Context</code> object to be used for

     *                          resolving context strings

     */

    public abstract void ctx(Context c);

    /**

     * Creates an input argument and adds it to this <code>Request</code>

     * object.

     *

     * @return          an <code>Any</code> object that contains the

     *                value and typecode for the input argument added

     */

    public abstract Any add_in_arg();

    /**

     * Creates an input argument with the given name and adds it to

     * this <code>Request</code> object.

     *

     * @param name              the name of the argument being added

     * @return          an <code>Any</code> object that contains the

     *                value and typecode for the input argument added

     */

    public abstract Any add_named_in_arg(String name);

    /**

     * Adds an input/output argument to this <code>Request</code> object.

     *

     * @return          an <code>Any</code> object that contains the

     *                value and typecode for the input/output argument added

     */

    public abstract Any add_inout_arg();

    /**

     * Adds an input/output argument with the given name to this

     * <code>Request</code> object.

     *

     * @param name              the name of the argument being added

     * @return          an <code>Any</code> object that contains the

     *                value and typecode for the input/output argument added

     */

    public abstract Any add_named_inout_arg(String name);

    /**

     * Adds an output argument to this <code>Request</code> object.

     *

     * @return          an <code>Any</code> object that contains the

     *                value and typecode for the output argument added

     */

    public abstract Any add_out_arg();

    /**

     * Adds an output argument with the given name to this

     * <code>Request</code> object.

     *

     * @param name              the name of the argument being added

     * @return          an <code>Any</code> object that contains the

     *                value and typecode for the output argument added

     */

    public abstract Any add_named_out_arg(String name);

    /**

     * Sets the typecode for the return

     * value of the method.

     *

     * @param tc                        the <code>TypeCode</code> object containing type information

     *                   for the return value

     */

    public abstract void set_return_type(TypeCode tc);

    /**

     * Returns the <code>Any</code> object that contains the value for the

     * result of the method.

     *

     * @return                  an <code>Any</code> object containing the value and

     *                   typecode for the return value

     */

    public abstract Any return_value();

    /**

     * Makes a synchronous invocation using the

     * information in the <code>Request</code> object. Exception information is

     * placed into the <code>Request</code> object's environment object.

     */

    public abstract void invoke();

    /**

     * Makes a oneway invocation on the

     * request. In other words, it does not expect or wait for a

     * response. Note that this can be used even if the operation was

     * not declared as oneway in the IDL declaration. No response or

     * exception information is returned.

     */

    public abstract void send_oneway();

    /**

     * Makes an asynchronous invocation on

     * the request. In other words, it does not wait for a response before it

     * returns to the user. The user can then later use the methods

     * <code>poll_response</code> and <code>get_response</code> to get

     * the result or exception information for the invocation.

     */

    public abstract void send_deferred();

    /**

     * Allows the user to determine

     * whether a response has been received for the invocation triggered

     * earlier with the <code>send_deferred</code> method.

     *

     * @return          <code>true</code> if the method response has

     *                          been received; <code>false</code> otherwise

     */

    public abstract boolean poll_response();

    /**

     * Allows the user to access the

     * response for the invocation triggered earlier with the

     * <code>send_deferred</code> method.

     *

     * @exception WrongTransaction  if the method <code>get_response</code> was invoked

     * from a different transaction's scope than the one from which the

     * request was originally sent. See the OMG Transaction Service specification

     * for details.

     */

    public abstract void get_response() throws WrongTransaction;

};