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CORBA.locatorClass


Contents

CORBA.locatorClass.locatorClass()
CORBA.locatorClass.lookUp()



Synopsis:

Class locatorClass is a conceptually abstract base class which defines the interface to a location server. OrbixWeb uses the installed locator to find a target object in the distributed system when _bind() is called with a null host name.

The default locator, provided by OrbixWeb, searches for the target object of a _bind() call in the manner described in Chapter 24, "Locators" of the OrbixWeb Programming Guide.

Programmers may override the default locator by defining and implementing a derived class of CORBA.locatorClass as described in Chapter 24, "Locators" of the OrbixWeb Programming Guide.

OrbixWeb:

Notes:

OrbixWeb specific.



CORBA.locatorClass.locatorClass()


Synopsis:

Description:

Default constructor. Direct instances of locatorClass cannot be created: the constructor is protected to enforce this. The derived classes of locatorClass will normally have public constructors.

Notes:

OrbixWeb specific.



CORBA.locatorClass.lookUp()


Synopsis:

Description:

Searches for a server. This method is called on the locator object referenced by _CORBA.locator when _bind() is called with a null host name. Any parameters to _bind() are passed to lookUp().

Parameters:



     ServiceName
    
The name of the server being sought.

     MaxHops
    
In the default locator, this is interpreted as the maximum number of machines to search for the required server.

An interpretation similar to this one should be retained in a user-defined locator if it is to be used without changing client code that explicitly calls lookUp().

     ctx
    
This allows a client to pass extra information to the locator: for example, constraints on how to search for the server. The context parameter can be used to define properties to be used when deciding between a set of servers with the same name.

The Context passed to lookUp() originates in the Context value passed by the application programmer to a _bind() call.

The default locator ignores this parameter.

Return Value:

The default locator returns a list of names of hosts on which that server is registered in the Implementation Repository. The default implementation of the locator randomises the sequence before returning it. An empty sequence is returned if no host names can be found for the specified server.

Notes:

OrbixWeb specific.



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