This class is the starting context for performing naming operations.
All naming operations are relative to a context.
The initial context implements the Context interface and
provides the starting point for resolution of names.
When the initial context is constructed, its environment
is initialized with properties defined in the environment parameter
passed to the constructor, and in any
application resource files.
In addition, a small number of standard JNDI properties may
be specified as system properties or as applet parameters
(through the use of Context.APPLET
).
These special properties are listed in the field detail sections of the
Context and
LdapContext
interface documentation.
JNDI determines each property's value by merging
the values from the following two sources, in order:
-
The first occurrence of the property from the constructor's
environment parameter and (for appropriate properties) the applet
parameters and system properties.
-
The application resource files (jndi.properties).
For each property found in both of these two sources, or in
more than one application resource file, the property's value
is determined as follows. If the property is
one of the standard JNDI properties that specify a list of JNDI
factories (see
Context),
all of the values are
concatenated into a single colon-separated list. For other
properties, only the first value found is used.
The initial context implementation is determined at runtime.
The default policy uses the environment property
"java.naming.factory.initial
",
which contains the class name of the initial context factory.
An exception to this policy is made when resolving URL strings, as described
below.
When a URL string (a String of the form
scheme_id:rest_of_name) is passed as a name parameter to
any method, a URL context factory for handling that scheme is
located and used to resolve the URL. If no such factory is found,
the initial context specified by
"java.naming.factory.initial" is used. Similarly, when a
CompositeName object whose first component is a URL string is
passed as a name parameter to any method, a URL context factory is
located and used to resolve the first name component.
See NamingManager.getURLContext()
for a description of how URL
context factories are located.
This default policy of locating the initial context and URL context
factories may be overridden
by calling
NamingManager.setInitialContextFactoryBuilder().
NoInitialContextException is thrown when an initial context cannot
be instantiated. This exception can be thrown during any interaction
with the InitialContext, not only when the InitialContext is constructed.
For example, the implementation of the initial context might lazily
retrieve the context only when actual methods are invoked on it.
The application should not have any dependency on when the existence
of an initial context is determined.
When the environment property "java.naming.factory.initial" is
non-null, the InitialContext constructor will attempt to create the
initial context specified therein. At that time, the initial context factory
involved might throw an exception if a problem is encountered. However,
it is provider implementation-dependent when it verifies and indicates
to the users of the initial context any environment property- or
connection- related problems. It can do so lazily--delaying until
an operation is performed on the context, or eagerly, at the time
the context is constructed.
An InitialContext instance is not synchronized against concurrent
access by multiple threads. Multiple threads each manipulating a
different InitialContext instance need not synchronize.
Threads that need to access a single InitialContext instance
concurrently should synchronize amongst themselves and provide the
necessary locking.