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ReferralException.javaAPI DocJava SE 5 API6637Fri Aug 26 14:57:40 BST 2005javax.naming

ReferralException

public abstract class ReferralException extends NamingException
This abstract class is used to represent a referral exception, which is generated in response to a referral such as that returned by LDAP v3 servers.

A service provider provides a subclass of ReferralException by providing implementations for getReferralInfo() and getReferralContext() (and appropriate constructors and/or corresponding "set" methods).

The following code sample shows how ReferralException can be used. 

while (true) {
try {
bindings = ctx.listBindings(name);
while (bindings.hasMore()) {
b = bindings.next();
...
}
break;
} catch (ReferralException e) {
ctx = e.getReferralContext();
}
}

ReferralException is an abstract class. Concrete implementations determine its synchronization and serialization properties.

An environment parameter passed to the getReferralContext() method is owned by the caller. The service provider will not modify the object or keep a reference to it, but may keep a reference to a clone of it.

author
Rosanna Lee
author
Scott Seligman
version
1.11 04/07/16
since
1.3

Fields Summary
private static final long
serialVersionUID
Use serialVersionUID from JNDI 1.1.1 for interoperability
Constructors Summary
protected ReferralException(String explanation)
Constructs a new instance of ReferralException using the explanation supplied. All other fields are set to null.

param
explanation Additional detail about this exception. Can be null.
see
java.lang.Throwable#getMessage

	super(explanation);
protected ReferralException()
Constructs a new instance of ReferralException. All fields are set to null.

	super();
Methods Summary
public abstract javax.naming.ContextgetReferralContext()
Retrieves the context at which to continue the method. Regardless of whether a referral is encountered directly during a context operation, or indirectly, for example, during a search enumeration, the referral exception should provide a context at which to continue the operation. The referral context is created using the environment properties of the context that threw the ReferralException.

To continue the operation, the client program should re-invoke the method using the same arguments as the original invocation.

return
The non-null context at which to continue the method.
exception
NamingException If a naming exception was encountered. Call either retryReferral() or skipReferral() to continue processing referrals.

public abstract javax.naming.ContextgetReferralContext(java.util.Hashtable env)
Retrieves the context at which to continue the method using
environment properties.
Regardless of whether a referral is encountered directly during a
context operation, or indirectly, for example, during a search
enumeration, the referral exception should provide a context
at which to continue the operation.


The referral context is created using env as its environment
properties.
This method should be used instead of the no-arg overloaded form
when the caller needs to use different environment properties for
the referral context. It might need to do this, for example, when
it needs to supply different authentication information to the referred
server in order to create the referral context.


To continue the operation, the client program should re-invoke
the method using the same arguments as the original invocation.
param
env The possibly null environment to use when retrieving the
referral context. If null, no environment properties will be used.
return
The non-null context at which to continue the method.
exception
NamingException If a naming exception was encountered.
Call either retryReferral() or skipReferral()
to continue processing referrals.
public abstract java.lang.ObjectgetReferralInfo()
Retrieves information (such as URLs) related to this referral.
The program may examine or display this information
to the user to determine whether to continue with the referral,
or to determine additional information needs to be supplied in order
to continue with the referral.
return
Non-null referral information related to this referral.
public abstract voidretryReferral()
Retries the referral currently being processed.
A call to this method should be followed by a call to
getReferralContext to allow the current
referral to be retried.
The following code fragment shows a typical usage pattern.

} catch (ReferralException e) {
while (true) {
try {
ctx = e.getReferralContext(env);
break;
} catch (NamingException ne) {
if (! shallIRetry()) {
return;
}
// modify environment properties (env), if necessary
e.retryReferral();
}
}
}

public abstract booleanskipReferral()
Discards the referral about to be processed.
A call to this method should be followed by a call to
getReferralContext to allow the processing of
other referrals to continue.
The following code fragment shows a typical usage pattern.

} catch (ReferralException e) {
if (!shallIFollow(e.getReferralInfo())) {
if (!e.skipReferral()) {
return;
}
}
ctx = e.getReferralContext();
}

return
true If more referral processing is pending; false otherwise.