Class NVList

public abstract class NVList
extends Object

A modifiable list containing NamedValue objects.

The class NVList is used as follows:

• to describe arguments for a Request object in the Dynamic Invocation Interface and the Dynamic Skeleton Interface
• to describe context values in a Context object

Each NamedValue object consists of the following:

• a name, which is a String object
• a value, as an Any object
• an argument mode flag

An NVList object may be created using one of the following ORB methods:

1. org.omg.CORBA.ORB.create_list

   org.omg.CORBA.NVList nv = orb.create_list(3);

   The variable nv represents a newly-created NVList object. The argument is a memory-management hint to the orb and does not imply the actual length of the list. If, for example, you want to use an NVList object in a request, and the method being invoked takes three parameters, you might optimize by supplying 3 to the method create_list. Note that the new NVList will not necessarily have a length of 3; it could have a length of 2 or 4, for instance. Note also that you can add any number of NamedValue objects to this list regardless of its original length.
2. org.omg.CORBA.ORB.create_operation_list

   org.omg.CORBA.NVList nv = orb.create_operation_list(myOperationDef);

   The variable nv represents a newly-created NVList object that contains descriptions of the arguments to the method described in the given OperationDef object.

The methods in the class NVList all deal with the NamedValue objects in the list. There are three methods for adding a NamedValue object, a method for getting the count of NamedValue objects in the list, a method for retrieving a NamedValue object at a given index, and a method for removing a NamedValue object at a given index.

Constructors

NVList

public NVList()

Methods

count

public abstract int count()

Returns the number of NamedValue objects that have been added to this NVList object.

Returns:

an int indicating the number of NamedValue objects in this NVList.

add

public abstract NamedValue add(int flags)

Creates a new NamedValue object initialized with the given flag and adds it to the end of this NVList object. The flag can be any one of the argument passing modes: ARG_IN.value, ARG_OUT.value, or ARG_INOUT.value.

Parameters:

flags - one of the argument mode flags

Returns:

the newly-created NamedValue object

add_item

public abstract NamedValue add_item(String item_name,
                                    int flags)

Creates a new NamedValue object initialized with the given name and flag, and adds it to the end of this NVList object. The flag can be any one of the argument passing modes: ARG_IN.value, ARG_OUT.value, or ARG_INOUT.value.

Parameters:

item_name - the name for the new NamedValue object

flags - one of the argument mode flags

Returns:

the newly-created NamedValue object

add_value

public abstract NamedValue add_value(String item_name,
                                     Any val,
                                     int flags)

Creates a new NamedValue object initialized with the given name, value, and flag, and adds it to the end of this NVList object.

Parameters:

item_name - the name for the new NamedValue object

val - an Any object containing the value for the new NamedValue object

flags - one of the following argument passing modes: ARG_IN.value, ARG_OUT.value, or ARG_INOUT.value

Returns:

the newly created NamedValue object

item

public abstract NamedValue item(int index)
                         throws Bounds

Retrieves the NamedValue object at the given index.

Parameters:

index - the index of the desired NamedValue object, which must be between zero and the length of the list minus one, inclusive. The first item is at index zero.

Returns:

the NamedValue object at the given index

Throws:

Bounds - if the index is greater than or equal to number of NamedValue objects

remove

public abstract void remove(int index)
                     throws Bounds

Removes the NamedValue object at the given index. Note that the indices of all NamedValue objects following the one removed are shifted down by one.

Parameters:

index - the index of the NamedValue object to be removed, which must be between zero and the length of the list minus one, inclusive. The first item is at index zero.

Throws:

Bounds - if the index is greater than or equal to number of NamedValue objects in the list