org.omg.DynamicAny (Java Platform SE 8 )
Keywords: org.omg.DynamicAny package
Date: 2015-11-18

# Package org.omg.DynamicAny

Provides classes and interfaces that enable traversal of the data value associated with an `any` at runtime, and extraction of the primitive constituents of the data value.

See: Description

- Interface Summary
  Interface | Description
  --- | ---
  DynAny | Any values can be dynamically interpreted (traversed) and constructed through DynAny objects.
  DynAnyFactory | DynAny objects can be created by invoking operations on the DynAnyFactory object.
  DynAnyFactoryOperations | DynAny objects can be created by invoking operations on the DynAnyFactory object.
  DynAnyOperations | Any values can be dynamically interpreted (traversed) and constructed through DynAny objects.
  DynArray | DynArray objects support the manipulation of IDL arrays.
  DynArrayOperations | DynArray objects support the manipulation of IDL arrays.
  DynEnum | DynEnum objects support the manipulation of IDL enumerated values.
  DynEnumOperations | DynEnum objects support the manipulation of IDL enumerated values.
  DynFixed | DynFixed objects support the manipulation of IDL fixed values.
  DynFixedOperations | DynFixed objects support the manipulation of IDL fixed values.
  DynSequence | DynSequence objects support the manipulation of IDL sequences.
  DynSequenceOperations | DynSequence objects support the manipulation of IDL sequences.
  DynStruct | DynStruct objects support the manipulation of IDL struct and exception values.
  DynStructOperations | DynStruct objects support the manipulation of IDL struct and exception values.
  DynUnion | DynUnion objects support the manipulation of IDL unions.
  DynUnionOperations | DynUnion objects support the manipulation of IDL unions.
  DynValue | DynValue objects support the manipulation of IDL non-boxed value types.
  DynValueBox | DynValueBox objects support the manipulation of IDL boxed value types.
  DynValueBoxOperations | DynValueBox objects support the manipulation of IDL boxed value types.
  DynValueCommon | DynValueCommon provides operations supported by both the DynValue and DynValueBox interfaces.
  DynValueCommonOperations | DynValueCommon provides operations supported by both the DynValue and DynValueBox interfaces.
  DynValueOperations | DynValue objects support the manipulation of IDL non-boxed value types.

- Class Summary
  Class | Description
  --- | ---
  _DynAnyFactoryStub | DynAny objects can be created by invoking operations on the DynAnyFactory object.
  _DynAnyStub | Any values can be dynamically interpreted (traversed) and constructed through DynAny objects.
  _DynArrayStub | DynArray objects support the manipulation of IDL arrays.
  _DynEnumStub | DynEnum objects support the manipulation of IDL enumerated values.
  _DynFixedStub | DynFixed objects support the manipulation of IDL fixed values.
  _DynSequenceStub | DynSequence objects support the manipulation of IDL sequences.
  _DynStructStub | DynStruct objects support the manipulation of IDL struct and exception values.
  _DynUnionStub | DynUnion objects support the manipulation of IDL unions.
  _DynValueStub | DynValue objects support the manipulation of IDL non-boxed value types.
  AnySeqHelper | org/omg/DynamicAny/AnySeqHelper.java .
  DynAnyFactoryHelper | DynAny objects can be created by invoking operations on the DynAnyFactory object.
  DynAnyHelper | Any values can be dynamically interpreted (traversed) and constructed through DynAny objects.
  DynAnySeqHelper | org/omg/DynamicAny/DynAnySeqHelper.java .
  DynArrayHelper | DynArray objects support the manipulation of IDL arrays.
  DynEnumHelper | DynEnum objects support the manipulation of IDL enumerated values.
  DynFixedHelper | DynFixed objects support the manipulation of IDL fixed values.
  DynSequenceHelper | DynSequence objects support the manipulation of IDL sequences.
  DynStructHelper | DynStruct objects support the manipulation of IDL struct and exception values.
  DynUnionHelper | DynUnion objects support the manipulation of IDL unions.
  DynValueHelper | DynValue objects support the manipulation of IDL non-boxed value types.
  FieldNameHelper | org/omg/DynamicAny/FieldNameHelper.java .
  NameDynAnyPair | org/omg/DynamicAny/NameDynAnyPair.java .
  NameDynAnyPairHelper | org/omg/DynamicAny/NameDynAnyPairHelper.java .
  NameDynAnyPairSeqHelper | org/omg/DynamicAny/NameDynAnyPairSeqHelper.java .
  NameValuePair | org/omg/DynamicAny/NameValuePair.java .
  NameValuePairHelper | org/omg/DynamicAny/NameValuePairHelper.java .
  NameValuePairSeqHelper | org/omg/DynamicAny/NameValuePairSeqHelper.java .

## Package org.omg.DynamicAny Description

Provides classes and interfaces that enable traversal of the data value associated with an `any` at runtime, and extraction of the primitive constituents of the data value.

An `any` can be passed to a program that doesn't have any static information for the type of the `any` (code generated for the type by an IDL compiler has not been compiled with the object implementation). As a result, the object receiving the `any` does not have a portable method of using it.

`DynAny`s enable traversal of the data value associated with an `any` at runtime, and extraction of the primitive constituents of the data value. This is especially helpful for writing powerful generic servers (bridges, event channels supporting filtering). Similarly, this facility enables the construction of an `any` at runtime, without having static knowledge of its type. This is especially helpful for writing generic clients (bridges, browsers, debuggers, user interface tools).

`Any` values can be dynamically interpreted (traversed) and constructed through `DynAny` objects. A `DynAny` object is associated with a data value which corresponds to a copy of the value inserted into an `Any`. A `DynAny` object may be viewed as an ordered collection of component `DynAny`s. For `DynAny`s representing a basic type, such as `long`, or a type without components, such as an empty exception, the ordered collection of components is empty.

Each `DynAny` object maintains the notion of a current position into its collection of component `DynAny`s. The current position is identified by an index value that runs from 0 to n-1, where n is the number of components. The special index value -1 indicates a current position that points nowhere. For values that cannot have a current position (such as an empty exception), the index value is fixed at -1. If a `DynAny` is initialized with a value that has components, the index is initialized to 0. After creation of an uninitialized `DynAny` (that is, a `DynAny` that has no value but a `TypeCode` that permits components), the current position depends on the type of value represented by the `DynAny`. (The current position is set to 0 or -1, depending on whether the new `DynAny` gets default values for its components.)

The iteration operations `rewind`, `seek`, and `next` can be used to change the current position and the `current_component` operation returns the component at the current position. The `component_count` operation returns the number of components of a `DynAny`. Collectively, these operations enable iteration over the components of a `DynAny`, for example, to (recursively) examine its contents.

A constructed `DynAny` object is a `DynAny` object associated with a constructed type. There is a different interface, inheriting from the `DynAny` interface, associated with each kind of constructed type in IDL (fixed, enum, struct, sequence, union, array, exception, and value type). A constructed `DynAny` object exports operations that enable the creation of new `DynAny` objects, each of them associated with a component of the constructed data value. As an example, a `DynStruct` is associated with a `struct` value. This means that the `DynStruct` may be seen as owning an ordered collection of components, one for each structure member. The `DynStruct` object exports operations that enable the creation of new `DynAny` objects, each of them associated with a member of the `struct`.

If a `DynAny` object has been obtained from another (constructed) `DynAny` object, such as a `DynAny` representing a structure member that was created from a `DynStruct`, the member `DynAny` is logically contained in the `DynStruct`. Calling an `insert` or `get` operation leaves the current position unchanged. Destroying a top-level `DynAny` object (one that was not obtained as a component of another `DynAny`) also destroys any component `DynAny` objects obtained from it. Destroying a non-top level `DynAny` object does nothing. Invoking operations on a destroyed top-level `DynAny` or any of its descendants raises OBJECT_NOT_EXIST. If the programmer wants to destroy a `DynAny` object but still wants to manipulate some component of the data value associated with it, then he or she should first create a `DynAny` for the component and, after that, make a copy of the created `DynAny` object.

The behavior of `DynAny` objects has been defined in order to enable efficient implementations in terms of allocated memory space and speed of access. `DynAny` objects are intended to be used for traversing values extracted from `any`s or constructing values of `any`s at runtime. Their use for other purposes is not recommended.

## Handling DynAny objects

`Insert` and `get` operations are necessary to handle basic `DynAny` objects but are also helpful to handle constructed `DynAny` objects. Inserting a basic data type value into a constructed `DynAny` object implies initializing the current component of the constructed data value associated with the `DynAny` object. For example, invoking `insert_boolean` on a `DynStruct` implies inserting a `boolean` data value at the current position of the associated `struct` data value. A type is consistent for inserting or extracting a value if its `TypeCode` is equivalent to the `TypeCode` contained in the `DynAny` or, if the `DynAny` has components, is equivalent to the `TypeCode` of the `DynAny` at the current position.

Basic operations include:

- insert_boolean, get_boolean
- insert_char, get_char
- insert_short, get_short
- insert_ushort, get_ushort
- insert_long, get_long
- insert_ulong, get_ulong
- insert_double, get_double
- insert_string, get_string
- insert_reference, get_reference
- insert_typecode, get_typecode
- insert_longlong, get_longlong
- insert_ulonglong, get_ulonglong
- insert_longdouble, get_longdouble
- insert_wchar, get_wchar
- insert_wstring, get_wstring
- insert_any, get_any
- insert_dyn_any, get_dyn_any
- insert_val, get_val
- insert_octet, get_octet
- insert_float, get_float
- get_value
- get_as_string
- get_as_ulong
- get_members
- get_members_as_dyn_any
- get_discriminator
- get_length
- get_elements
- get_elements_as_dyn_any
- get_boxed_value
- get_boxed_value_as_dyn_any

`DynAny` and `DynAnyFactory` objects are intended to be local to the process in which they are created and used. This means that references to `DynAny` and `DynAnyFactory` objects cannot be exported to other processes, or externalized with `ORB.object_to_string()`. If any attempt is made to do so, the offending operation will raise a MARSHAL system exception. Since their interfaces are specified in IDL, `DynAny` objects export operations defined in the standard `org.omg.CORBA.Object` interface. However, any attempt to invoke operations exported through the `Object` interface may raise the standard NO_IMPLEMENT exception. An attempt to use a `DynAny` object with the DII may raise the NO_IMPLEMENT exception.

### Package Specification

For a precise list of supported sections of official specifications with which the Java[tm] Platform, Standard Edition 6 ORB complies, see Official Specifications for CORBA support in Java[tm] SE 6.

Since:
  1.4

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