NVList.java revision 608:7e06bf1dcb09 
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25
26package org.omg.CORBA;
27
28/**
29 * A modifiable list containing <code>NamedValue</code> objects.
30 * <P>
31 * The class <code>NVList</code> is used as follows:
32 * <UL>
33 * <LI>to describe arguments for a <code>Request</code> object
34 * in the Dynamic Invocation Interface and
35 * the Dynamic Skeleton Interface
36 * <LI>to describe context values in a <code>Context</code> object
37 * </UL>
38 * <P>
39 * Each <code>NamedValue</code> object consists of the following:
40 * <UL>
41 * <LI>a name, which is a <code>String</code> object
42 * <LI>a value, as an <code>Any</code> object
43 * <LI>an argument mode flag
44 * </UL>
45 * <P>
46 * An <code>NVList</code> object
47 * may be created using one of the following
48 * <code>ORB</code> methods:
49 * <OL>
50 * <LI><code>org.omg.CORBA.ORB.create_list</code>
51 * <PRE>
52 *    org.omg.CORBA.NVList nv = orb.create_list(3);
53 * </PRE>
54 * The variable <code>nv</code> represents a newly-created
55 * <code>NVList</code> object.  The argument is a memory-management
56 * hint to the orb and does not imply the actual length of the list.
57 * If, for example, you want to use an <code>NVList</code> object
58 * in a request, and the method being invoked takes three parameters,
59 * you might optimize by supplying 3 to the method
60 * <code>create_list</code>.  Note that the new <code>NVList</code>
61 * will not necessarily have a length of 3; it
62 * could have a length of 2 or 4, for instance.
63 * Note also that you can add any number of
64 * <code>NamedValue</code> objects to this list regardless of
65 * its original length.
66 * <P>
67 * <LI><code>org.omg.CORBA.ORB.create_operation_list</code>
68 * <PRE>
69 *    org.omg.CORBA.NVList nv = orb.create_operation_list(myOperationDef);
70 * </PRE>
71 * The variable <code>nv</code> represents a newly-created
72 * <code>NVList</code> object that contains descriptions of the
73 * arguments to the method described in the given
74 * <code>OperationDef</code> object.
75 * </OL>
76 * <P>
77 * The methods in the class <code>NVList</code> all deal with
78 * the <code>NamedValue</code> objects in the list.
79 * There are three methods for adding a <code>NamedValue</code> object,
80 * a method for getting the count of <code>NamedValue</code> objects in
81 * the list, a method for retrieving a <code>NamedValue</code> object
82 * at a given index, and a method for removing a <code>NamedValue</code> object
83 * at a given index.
84 *
85 * @see org.omg.CORBA.Request
86 * @see org.omg.CORBA.ServerRequest
87 * @see org.omg.CORBA.NamedValue
88 * @see org.omg.CORBA.Context
89 *
90 * @since       JDK1.2
91 */
92
93public abstract class NVList {
94
95    /**
96     * Returns the number of <code>NamedValue</code> objects that have
97     * been added to this <code>NVList</code> object.
98     *
99     * @return                  an <code>int</code> indicating the number of
100     * <code>NamedValue</code> objects in this <code>NVList</code>.
101     */
102
103    public abstract int count();
104
105    /**
106     * Creates a new <code>NamedValue</code> object initialized with the given flag
107     * and adds it to the end of this <code>NVList</code> object.
108     * The flag can be any one of the argument passing modes:
109     * <code>ARG_IN.value</code>, <code>ARG_OUT.value</code>, or
110     * <code>ARG_INOUT.value</code>.
111     *
112     * @param flags             one of the argument mode flags
113     * @return                  the newly-created <code>NamedValue</code> object
114     */
115
116    public abstract NamedValue add(int flags);
117
118    /**
119     * Creates a new <code>NamedValue</code> object initialized with the
120     * given name and flag,
121     * and adds it to the end of this <code>NVList</code> object.
122     * The flag can be any one of the argument passing modes:
123     * <code>ARG_IN.value</code>, <code>ARG_OUT.value</code>, or
124     * <code>ARG_INOUT.value</code>.
125     *
126     * @param item_name the name for the new <code>NamedValue</code> object
127     * @param flags             one of the argument mode flags
128     * @return                  the newly-created <code>NamedValue</code> object
129     */
130
131    public abstract NamedValue add_item(String item_name, int flags);
132
133    /**
134     * Creates a new <code>NamedValue</code> object initialized with the
135     * given name, value, and flag,
136     * and adds it to the end of this <code>NVList</code> object.
137     *
138     * @param item_name the name for the new <code>NamedValue</code> object
139     * @param val         an <code>Any</code> object containing the  value
140     *                    for the new <code>NamedValue</code> object
141     * @param flags       one of the following argument passing modes:
142     *                    <code>ARG_IN.value</code>, <code>ARG_OUT.value</code>, or
143     *                    <code>ARG_INOUT.value</code>
144     * @return            the newly created <code>NamedValue</code> object
145     */
146
147    public abstract NamedValue add_value(String item_name, Any val, int flags);
148
149    /**
150     * Retrieves the <code>NamedValue</code> object at the given index.
151     *
152     * @param index             the index of the desired <code>NamedValue</code> object,
153     *                    which must be between zero and the length of the list
154     *                    minus one, inclusive.  The first item is at index zero.
155     * @return                  the <code>NamedValue</code> object at the given index
156     * @exception org.omg.CORBA.Bounds  if the index is greater than
157     *                          or equal to number of <code>NamedValue</code> objects
158     */
159
160    public abstract NamedValue item(int index) throws org.omg.CORBA.Bounds;
161
162    /**
163     * Removes the <code>NamedValue</code> object at the given index.
164     * Note that the indices of all <code>NamedValue</code> objects following
165     * the one removed are shifted down by one.
166     *
167     * @param index             the index of the <code>NamedValue</code> object to be
168     *                    removed, which must be between zero and the length
169     *                    of the list minus one, inclusive.
170     *                    The first item is at index zero.
171     * @exception org.omg.CORBA.Bounds  if the index is greater than
172     *                          or equal to number of <code>NamedValue</code> objects in
173     *                the list
174     */
175
176    public abstract void remove(int index) throws org.omg.CORBA.Bounds;
177
178}
179