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 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 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.
This constructor will not modify environment or save a reference to it, but may save a clone.
The value of this constant is "java.naming.applet".
The value of this constant is "java.naming.authoritative".
The value of this constant is "java.naming.batchsize".
The value of this constant is "java.naming.dns.url".
The value of this constant is "java.naming.factory.initial".
The value of this constant is "java.naming.language".
The value of this constant is "java.naming.factory.object".
The value of this constant is "java.naming.provider.url".
The value of this constant is "java.naming.referral".
The value of this constant is "java.naming.security.authentication".
The value of this constant is "java.naming.security.credentials".
The value of this constant is "java.naming.security.principal".
The value of this constant is "java.naming.security.protocol".
The value of this constant is "java.naming.factory.state".
The value of this constant is "java.naming.factory.url.pkgs".
This method is idempotent: invoking it on a context that has already been closed has no effect. Invoking any other method on a closed context is not allowed, and results in undefined behaviour.
name) relative to this context, and
the name (prefix) of this context relative to one
of its ancestors, this method returns the composition of the
two names using the syntax appropriate for the naming
system(s) involved. That is, if name names an
object relative to this context, the result is the name of the
same object, but relative to the ancestor context. None of the
names may be null.
For example, if this context is named "wiz.com" relative to the initial context, then
composeName("east", "wiz.com")
might return "east.wiz.com".
If instead this context is named "org/research", then
composeName("user/jane", "org/research")
might return "org/research/user/jane" while
composeName("user/jane", "research")
returns "research/user/jane".This method is idempotent. It succeeds even if the terminal atomic name is not bound in the target context, but throws NameNotFoundException if any of the intermediate contexts do not exist.
In a federated naming system, a context from one naming system may be bound to a name in another. One can subsequently look up and perform operations on the foreign context using a composite name. However, an attempt destroy the context using this composite name will fail with NotContextException, because the foreign context is not a "subcontext" of the context in which it is bound. Instead, use unbind() to remove the binding of the foreign context. Destroying the foreign context requires that the destroySubcontext() be performed on a context from the foreign context's "native" naming system.
The equals method implements an equivalence relation
on non-null object references:
x, x.equals(x) should return
true.
x and y, x.equals(y)
should return true if and only if
y.equals(x) returns true.
x, y, and z, if
x.equals(y) returns true and
y.equals(z) returns true, then
x.equals(z) should return true.
x and y, multiple invocations of
x.equals(y) consistently return true
or consistently return false, provided no
information used in equals comparisons on the
objects is modified.
x,
x.equals(null) should return false.
The equals method for class Object implements
the most discriminating possible equivalence relation on objects;
that is, for any non-null reference values x and
y, this method returns true if and only
if x and y refer to the same object
(x == y has the value true).
Note that it is generally necessary to override the hashCode method whenever this method is overridden, so as to maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.
The caller should not make any changes to the object returned: their effect on the context is undefined. The environment of this context may be changed using addToEnvironment() and removeFromEnvironment().
Many naming services have a notion of a "full name" for objects in their respective namespaces. For example, an LDAP entry has a distinguished name, and a DNS record has a fully qualified name. This method allows the client application to retrieve this name. The string returned by this method is not a JNDI composite name and should not be passed directly to context methods. In naming systems for which the notion of full name does not make sense, OperationNotSupportedException is thrown.
java.util.Hashtable.
The general contract of hashCode is:
hashCode method on each of
the two objects must produce the same integer result.
As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the JavaTM programming language.)
If a binding is added to or removed from this context, its effect on an enumeration previously returned is undefined.
If a binding is added to or removed from this context, its effect on an enumeration previously returned is undefined.
wait methods.
The awakened thread will not be able to proceed until the current thread relinquishes the lock on this object. The awakened thread will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened thread enjoys no reliable privilege or disadvantage in being the next thread to lock this object.
This method should only be called by a thread that is the owner of this object's monitor. A thread becomes the owner of the object's monitor in one of three ways:
synchronized statement
that synchronizes on the object.
Class, by executing a
synchronized static method of that class.
Only one thread at a time can own an object's monitor.
wait methods.
The awakened threads will not be able to proceed until the current thread relinquishes the lock on this object. The awakened threads will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened threads enjoy no reliable privilege or disadvantage in being the next thread to lock this object.
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.
If the object is a DirContext, any existing attributes associated with the name are replaced with those of the object. Otherwise, any existing attributes associated with the name remain unchanged.
toString method returns a string that
"textually represents" this object. The result should
be a concise but informative representation that is easy for a
person to read.
It is recommended that all subclasses override this method.
The toString method for class Object
returns a string consisting of the name of the class of which the
object is an instance, the at-sign character `@', and
the unsigned hexadecimal representation of the hash code of the
object. In other words, this method returns a string equal to the
value of:
getClass().getName() + '@' + Integer.toHexString(hashCode())
name
from the target context--that named by all but the terminal
atomic part of name.
This method is idempotent. It succeeds even if the terminal atomic name is not bound in the target context, but throws NameNotFoundException if any of the intermediate contexts do not exist.
Any attributes associated with the name are removed. Intermediate contexts are not changed.
The current thread must own this object's monitor. The thread
releases ownership of this monitor and waits until another thread
notifies threads waiting on this object's monitor to wake up
either through a call to the notify method or the
notifyAll method. The thread then waits until it can
re-obtain ownership of the monitor and resumes execution.
As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:
synchronized (obj) {
while (<condition does not hold>)
obj.wait();
... // Perform action appropriate to condition
}
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.The current thread must own this object's monitor.
This method causes the current thread (call it T) to place itself in the wait set for this object and then to relinquish any and all synchronization claims on this object. Thread T becomes disabled for thread scheduling purposes and lies dormant until one of four things happens:
A thread can also wake up without being notified, interrupted, or timing out, a so-called spurious wakeup. While this will rarely occur in practice, applications must guard against it by testing for the condition that should have caused the thread to be awakened, and continuing to wait if the condition is not satisfied. In other words, waits should always occur in loops, like this one:
synchronized (obj) {
while (<condition does not hold>)
obj.wait(timeout);
... // Perform action appropriate to condition
}
(For more information on this topic, see Section 3.2.3 in Doug Lea's
"Concurrent Programming in Java (Second Edition)" (Addison-Wesley,
2000), or Item 50 in Joshua Bloch's "Effective Java Programming
Language Guide" (Addison-Wesley, 2001).
If the current thread is interrupted by another thread while it is waiting, then an InterruptedException is thrown. This exception is not thrown until the lock status of this object has been restored as described above.
Note that the wait method, as it places the current thread into the wait set for this object, unlocks only this object; any other objects on which the current thread may be synchronized remain locked while the thread waits.
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.
This method is similar to the wait method of one
argument, but it allows finer control over the amount of time to
wait for a notification before giving up. The amount of real time,
measured in nanoseconds, is given by:
1000000*timeout+nanos
In all other respects, this method does the same thing as the method of one argument. In particular, wait(0, 0) means the same thing as wait(0).
The current thread must own this object's monitor. The thread releases ownership of this monitor and waits until either of the following two conditions has occurred:
notify method
or the notifyAll method.
timeout
milliseconds plus nanos nanoseconds arguments, has
elapsed.
The thread then waits until it can re-obtain ownership of the monitor and resumes execution.
As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:
synchronized (obj) {
while (<condition does not hold>)
obj.wait(timeout, nanos);
... // Perform action appropriate to condition
}
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.