public class

RegistryContextFactory

extends Object
implements InitialContextFactory ObjectFactory
java.lang.Object
   ↳ com.sun.jndi.rmi.registry.RegistryContextFactory

Class Overview

A RegistryContextFactory takes an RMI registry reference, and creates the corresponding RMI object or registry context. In addition, it serves as the initial context factory when using an RMI registry as an initial context.

When an initial context is being created, the environment property "java.naming.provider.url" should contain the RMI URL of the appropriate registry. Otherwise, the default URL "rmi:" is used.

An RMI registry reference contains one or more StringRefAddrs of type "URL", each containing a single RMI URL. Other addresses are ignored. Multiple URLs represent alternative addresses for the same logical resource. The order of the addresses is not significant.

Summary

Constants
String ADDRESS_TYPE The type of each address in an RMI registry reference.
Public Constructors
RegistryContextFactory()
Public Methods
Context getInitialContext(Hashtable<?, ?> env)
Creates an Initial Context for beginning name resolution.
Object getObjectInstance(Object ref, Name name, Context nameCtx, Hashtable<?, ?> env)
Creates an object using the location or reference information specified.
[Expand]
Inherited Methods
From class java.lang.Object
From interface javax.naming.spi.InitialContextFactory
From interface javax.naming.spi.ObjectFactory

Constants

public static final String ADDRESS_TYPE

The type of each address in an RMI registry reference.

Constant Value: "URL"

Public Constructors

public RegistryContextFactory ()

Public Methods

public Context getInitialContext (Hashtable<?, ?> env)

Creates an Initial Context for beginning name resolution. Special requirements of this context are supplied using environment.

The environment parameter is owned by the caller. The implementation will not modify the object or keep a reference to it, although it may keep a reference to a clone or copy.

Parameters
env The possibly null environment specifying information to be used in the creation of the initial context.
Returns
  • A non-null initial context object that implements the Context interface.

public Object getObjectInstance (Object ref, Name name, Context nameCtx, Hashtable<?, ?> env)

Creates an object using the location or reference information specified.

Special requirements of this object are supplied using environment. An example of such an environment property is user identity information.

NamingManager.getObjectInstance() successively loads in object factories and invokes this method on them until one produces a non-null answer. When an exception is thrown by an object factory, the exception is passed on to the caller of NamingManager.getObjectInstance() (and no search is made for other factories that may produce a non-null answer). An object factory should only throw an exception if it is sure that it is the only intended factory and that no other object factories should be tried. If this factory cannot create an object using the arguments supplied, it should return null.

A URL context factory is a special ObjectFactory that creates contexts for resolving URLs or objects whose locations are specified by URLs. The getObjectInstance() method of a URL context factory will obey the following rules.

  1. If obj is null, create a context for resolving URLs of the scheme associated with this factory. The resulting context is not tied to a specific URL: it is able to handle arbitrary URLs with this factory's scheme id. For example, invoking getObjectInstance() with obj set to null on an LDAP URL context factory would return a context that can resolve LDAP URLs such as "ldap://ldap.wiz.com/o=wiz,c=us" and "ldap://ldap.umich.edu/o=umich,c=us".
  2. If obj is a URL string, create an object (typically a context) identified by the URL. For example, suppose this is an LDAP URL context factory. If obj is "ldap://ldap.wiz.com/o=wiz,c=us", getObjectInstance() would return the context named by the distinguished name "o=wiz, c=us" at the LDAP server ldap.wiz.com. This context can then be used to resolve LDAP names (such as "cn=George") relative to that context.
  3. If obj is an array of URL strings, the assumption is that the URLs are equivalent in terms of the context to which they refer. Verification of whether the URLs are, or need to be, equivalent is up to the context factory. The order of the URLs in the array is not significant. The object returned by getObjectInstance() is like that of the single URL case. It is the object named by the URLs.
  4. If obj is of any other type, the behavior of getObjectInstance() is determined by the context factory implementation.

The name and environment parameters are owned by the caller. The implementation will not modify these objects or keep references to them, although it may keep references to clones or copies.

Name and Context Parameters.     The name and nameCtx parameters may optionally be used to specify the name of the object being created. name is the name of the object, relative to context nameCtx. If there are several possible contexts from which the object could be named -- as will often be the case -- it is up to the caller to select one. A good rule of thumb is to select the "deepest" context available. If nameCtx is null, name is relative to the default initial context. If no name is being specified, the name parameter should be null. If a factory uses nameCtx it should synchronize its use against concurrent access, since context implementations are not guaranteed to be thread-safe.

Parameters
ref The possibly null object containing location or reference information that can be used in creating an object.
name The name of this object relative to nameCtx, or null if no name is specified.
nameCtx The context relative to which the name parameter is specified, or null if name is relative to the default initial context.
env The possibly null environment that is used in creating the object.
Returns
  • The object created; null if an object cannot be created.