Delegate (Java SE 9 & JDK 9 )
Keywords: org.omg.CORBA.portable.Delegate class

Module java.corba
Package org.omg.CORBA.portable

## Class Delegate

- java.lang.Object
- - org.omg.CORBA.portable.Delegate

- Direct Known Subclasses:
    `Delegate`

      public abstract class Delegate
      extends Object

  Specifies a portable API for ORB-vendor-specific implementation of the org.omg.CORBA.Object methods. Each stub (proxy) contains a delegate object, to which all org.omg.CORBA.Object methods are forwarded. This allows a stub generated by one vendor's ORB to work with the delegate from another vendor's ORB.
  See Also:
    `Object`

- - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `Delegate​()` |

  - ### Method Summary

    All Methods Instance Methods Abstract Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `abstract Request` | `create_request​(Object obj, Context ctx, String operation, NVList arg_list, NamedValue result)` | Creates a Request instance for use in the Dynamic Invocation Interface.
    `abstract Request` | `create_request​(Object obj, Context ctx, String operation, NVList arg_list, NamedValue result, ExceptionList exclist, ContextList ctxlist)` | Creates a Request instance for use in the Dynamic Invocation Interface.
    `abstract Object` | `duplicate​(Object obj)` | Returns a duplicate of the object reference provided.
    `boolean` | `equals​(Object self, Object obj)` | Provides the implementation to override the equals(java.lang.Object obj) method of the delegating CORBA object.
    `DomainManager[]` | `get_domain_managers​(Object self)` | Retrieves the `DomainManagers` of this object.
    `abstract Object` | `get_interface_def​(Object self)` | Return an InterfaceDef for the object reference provided.
    `Policy` | `get_policy​(Object self, int policy_type)` | Returns the `Policy` object of the specified type which applies to this object.
    `abstract int` | `hash​(Object obj, int max)` | Returns an ORB-internal identifier (hashcode) for this object reference.
    `int` | `hashCode​(Object self)` | Provides the implementation to override the hashCode() method of the delegating CORBA object.
    `InputStream` | `invoke​(Object self, OutputStream output)` | invoke is called by a stub to invoke an operation.
    `abstract boolean` | `is_a​(Object obj, String repository_id)` | Checks if the object reference is an instance of the given interface.
    `abstract boolean` | `is_equivalent​(Object obj, Object other)` | Determines if the two object references are equivalent.
    `boolean` | `is_local​(Object self)` | Returns true if this object is implemented by a local servant.
    `abstract boolean` | `non_existent​(Object obj)` | Determines whether the server object for the object reference has been destroyed.
    `ORB` | `orb​(Object obj)` | Provides a reference to the orb associated with its parameter.
    `abstract void` | `release​(Object obj)` | Releases resources associated with the object reference provided.
    `void` | `releaseReply​(Object self, InputStream input)` | releaseReply may optionally be called by a stub to release a reply stream back to the ORB when the unmarshaling has completed.
    `abstract Request` | `request​(Object obj, String operation)` | Creates a Request instance for use in the Dynamic Invocation Interface.
    `OutputStream` | `request​(Object self, String operation, boolean responseExpected)` | request is called by a stub to obtain an OutputStream for marshaling arguments.
    `void` | `servant_postinvoke​(Object self, ServantObject servant)` | servant_postinvoke() is invoked by the local stub after the operation has been invoked on the local servant.
    `ServantObject` | `servant_preinvoke​(Object self, String operation, Class expectedType)` | Returns a Java reference to the servant which should be used for this request. servant_preinvoke() is invoked by a local stub.
    `Object` | `set_policy_override​(Object self, Policy[] policies, SetOverrideType set_add)` | Associates the policies passed in with a newly created object reference that it returns.
    `String` | `toString​(Object self)` | Provides the implementation to override the toString() method of the delegating CORBA object.

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### Delegate

          public Delegate​()

  - ### Method Detail

    - #### get_interface_def

          public abstract Object get_interface_def​(Object self)

      Return an InterfaceDef for the object reference provided.
      Parameters:
        `self` - The object reference whose InterfaceDef needs to be returned
      Returns:
        the InterfaceDef

    - #### duplicate

          public abstract Object duplicate​(Object obj)

      Returns a duplicate of the object reference provided.
      Parameters:
        `obj` - The object reference whose duplicate needs to be returned
      Returns:
        the duplicate object reference

    - #### release

          public abstract void release​(Object obj)

      Releases resources associated with the object reference provided.
      Parameters:
        `obj` - The object reference whose resources need to be released

    - #### is_a

          public abstract boolean is_a​(Object obj,
                                       String repository_id)

      Checks if the object reference is an instance of the given interface.
      Parameters:
        `obj` - The object reference to be checked.
        `repository_id` - The repository identifier of the interface to check against.
      Returns:
        true if the object reference supports the interface

    - #### non_existent

          public abstract boolean non_existent​(Object obj)

      Determines whether the server object for the object reference has been destroyed.
      Parameters:
        `obj` - The object reference which delegated to this delegate.
      Returns:
        true if the ORB knows authoritatively that the server object does not exist, false otherwise

    - #### is_equivalent

          public abstract boolean is_equivalent​(Object obj,
                                                Object other)

      Determines if the two object references are equivalent.
      Parameters:
        `obj` - The object reference which delegated to this delegate.
        `other` - The object reference to check equivalence against.
      Returns:
        true if the objects are CORBA-equivalent.

    - #### hash

          public abstract int hash​(Object obj,
                                   int max)

      Returns an ORB-internal identifier (hashcode) for this object reference.
      Parameters:
        `obj` - The object reference which delegated to this delegate.
        `max` - specifies an upper bound on the hash value returned by the ORB.
      Returns:
        ORB-internal hash identifier for object reference

    - #### request

          public abstract Request request​(Object obj,
                                          String operation)

      Creates a Request instance for use in the Dynamic Invocation Interface.
      Parameters:
        `obj` - The object reference which delegated to this delegate.
        `operation` - The name of the operation to be invoked using the Request instance.
      Returns:
        the created Request instance

    - #### create_request

          public abstract Request create_request​(Object obj,
                                                 Context ctx,
                                                 String operation,
                                                 NVList arg_list,
                                                 NamedValue result)

      Creates a Request instance for use in the Dynamic Invocation Interface.
      Parameters:
        `obj` - The object reference which delegated to this delegate.
        `ctx` - The context to be used.
        `operation` - The name of the operation to be invoked.
        `arg_list` - The arguments to the operation in the form of an NVList.
        `result` - A container for the result as a NamedValue.
      Returns:
        The created Request object.

    - #### create_request

          public abstract Request create_request​(Object obj,
                                                 Context ctx,
                                                 String operation,
                                                 NVList arg_list,
                                                 NamedValue result,
                                                 ExceptionList exclist,
                                                 ContextList ctxlist)

      Creates a Request instance for use in the Dynamic Invocation Interface.
      Parameters:
        `obj` - The object reference which delegated to this delegate.
        `ctx` - The context to be used.
        `operation` - The name of the operation to be invoked.
        `arg_list` - The arguments to the operation in the form of an NVList.
        `result` - A container for the result as a NamedValue.
        `exclist` - A list of possible exceptions the operation can throw.
        `ctxlist` - A list of context strings that need to be resolved and sent with the Request.
      Returns:
        The created Request object.

    - #### orb

          public ORB orb​(Object obj)

      Provides a reference to the orb associated with its parameter.
      Parameters:
        `obj` - the object reference which delegated to this delegate.
      Returns:
        the associated orb.
      See Also:
        `portable` package comments for unimplemented features

    - #### get_policy

          public Policy get_policy​(Object self,
                                   int policy_type)

      Returns the `Policy` object of the specified type which applies to this object.
      Parameters:
        `self` - The object reference which delegated to this delegate.
        `policy_type` - The type of policy to be obtained.
      Returns:
        A `Policy` object of the type specified by the policy_type parameter.
      Throws:
        `BAD_PARAM` - raised 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.
      See Also:
        `portable` package comments for unimplemented features

    - #### get_domain_managers

          public DomainManager[] get_domain_managers​(Object self)

      Retrieves the `DomainManagers` 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.
      Parameters:
        `self` - The object reference which delegated to this delegate.
      Returns:
        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.
      See Also:
        `portable` package comments for unimplemented features

    - #### set_policy_override

          public Object set_policy_override​(Object self,
                                            Policy[] policies,
                                            SetOverrideType set_add)

      Associates the policies passed in with a newly created object reference that it returns. Only certain policies that pertain to the invocation of an operation at the client end can be overridden using this operation. Attempts to override any other policy will result in the raising of the CORBA::NO_PERMISSION exception.
      Parameters:
        `self` - The object reference which delegated to this delegate.
        `policies` - A sequence of references to Policy objects.
        `set_add` - Indicates whether these policies should be added onto any otheroverrides that already exist (ADD_OVERRIDE) in the object reference, or they should be added to a clean override free object reference (SET_OVERRIDE).
      Returns:
        A new object reference with the new policies associated with it.
      See Also:
        `portable` package comments for unimplemented features

    - #### is_local

          public boolean is_local​(Object self)

      Returns true if this object is implemented by a local servant.
      Parameters:
        `self` - The object reference which delegated to this delegate.
      Returns:
        true only if the servant incarnating this object is located in this Java VM. Return false if the servant is not local or the ORB does not support local stubs for this particular servant. The default behavior of is_local() is to return false.

    - #### servant_preinvoke

          public ServantObject servant_preinvoke​(Object self,
                                                 String operation,
                                                 Class expectedType)

      Returns a Java reference to the servant which should be used for this request. servant_preinvoke() is invoked by a local stub. If a ServantObject object is returned, then its servant field has been set to an object of the expected type (Note: the object may or may not be the actual servant instance). The local stub may cast the servant field to the expected type, and then invoke the operation directly. The ServantRequest object is valid for only one invocation, and cannot be used for more than one invocation.
      Parameters:
        `self` - The object reference which delegated to this delegate.
        `operation` - a string containing the operation name. The operation name corresponds to the operation name as it would be encoded in a GIOP request.
        `expectedType` - a Class object representing the expected type of the servant. The expected type is the Class object associated with the operations class of the stub's interface (e.g. A stub for an interface Foo, would pass the Class object for the FooOperations interface).
      Returns:
        a ServantObject object. The method may return a null value if it does not wish to support this optimization (e.g. due to security, transactions, etc). The method must return null if the servant is not of the expected type.

    - #### servant_postinvoke

          public void servant_postinvoke​(Object self,
                                         ServantObject servant)

      servant_postinvoke() is invoked by the local stub after the operation has been invoked on the local servant. This method must be called if servant_preinvoke() returned a non-null value, even if an exception was thrown by the servant's method. For this reason, the call to servant_postinvoke() should be placed in a Java finally clause.
      Parameters:
        `self` - The object reference which delegated to this delegate.
        `servant` - the instance of the ServantObject returned from the servant_preinvoke() method.

    - #### request

          public OutputStream request​(Object self,
                                      String operation,
                                      boolean responseExpected)

      request is called by a stub to obtain an OutputStream for marshaling arguments. The stub must supply the operation name, and indicate if a response is expected (i.e is this a oneway call).
      Parameters:
        `self` - The object reference which delegated to this delegate.
        `operation` - a string containing the operation name. The operation name corresponds to the operation name as it would be encoded in a GIOP request.
        `responseExpected` - false if the operation is a one way operation, and true otherwise.
      Returns:
        OutputStream the OutputStream into which request arguments can be marshaled.
      See Also:
        `portable` package comments for unimplemented features

    - #### invoke

          public InputStream invoke​(Object self,
                                    OutputStream output)
                             throws ApplicationException,
                                    RemarshalException

      invoke is called by a stub to invoke an operation. The stub provides an OutputStream that was previously returned by a request() call. invoke returns an InputStream which contains the marshaled reply. If an exception occurs, invoke may throw an ApplicationException object which contains an InputStream from which the user exception state may be unmarshaled.
      Parameters:
        `self` - The object reference which delegated to this delegate.
        `output` - the OutputStream which contains marshaled arguments
      Returns:
        input the InputStream from which reply parameters can be unmarshaled.
      Throws:
        `ApplicationException` - thrown when implementation throws (upon invocation) an exception defined as part of its remote method definition.
        `RemarshalException` - thrown when remarshalling fails.
      See Also:
        `portable` package comments for unimplemented features

    - #### releaseReply

          public void releaseReply​(Object self,
                                   InputStream input)

      releaseReply may optionally be called by a stub to release a reply stream back to the ORB when the unmarshaling has completed. The stub passes the InputStream returned by invoke() or ApplicationException.getInputStream(). A null value may also be passed to releaseReply, in which case the method is a noop.
      Parameters:
        `self` - The object reference which delegated to this delegate.
        `input` - the InputStream returned from invoke().
      See Also:
        `portable` package comments for unimplemented features

    - #### toString

          public String toString​(Object self)

      Provides the implementation to override the toString() method of the delegating CORBA object.
      Parameters:
        `self` - the object reference that delegated to this delegate
      Returns:
        a `String` object that represents the object reference that delegated to this `Delegate` object

    - #### hashCode

          public int hashCode​(Object self)

      Provides the implementation to override the hashCode() method of the delegating CORBA object.
      Parameters:
        `self` - the object reference that delegated to this delegate
      Returns:
        an `int` that represents the hashcode for the object reference that delegated to this `Delegate` object

    - #### equals

          public boolean equals​(Object self,
                                Object obj)

      Provides the implementation to override the equals(java.lang.Object obj) method of the delegating CORBA object.
      Parameters:
        `self` - the object reference that delegated to this delegate
        `obj` - the `Object` with which to compare
      Returns:
        `true` if `obj` equals `self`; `false` otherwise