J2EE Interview questions and answers

261. What is role mapping

The process of associating the groups or principals
(or both), recognized by the container with security
roles specified in the deployment descriptor. Security
roles must be mapped by the deployer before a
component is installed in the server.

262. What is role (security)

An abstract logical grouping of users that is defined
by the application assembler. When an application is
deployed, the roles are mapped to security identities,
such as principals or groups, in the operational
environment. In the J2EE server authentication
service, a role is an abstract name for permission to
access a particular set of resources. A role can be
compared to a key that can open a lock. Many people
might have a copy of the key; the lock doesn't care
who you are, only that you have the right key.



263. What is rollback

The point in a transaction when all updates to any
resources involved in the transaction are reversed.

264. What is root

The outermost element in an XML document. The element
that contains all other elements.

265. What is SAX

Abbreviation of Simple API for XML.

266. What is Simple API for XML

An event-driven interface in which the parser invokes
one of several methods supplied by the caller when a
parsing event occurs. Events include recognizing an
XML tag, finding an error, encountering a reference to
an external entity, or processing a DTD specification.




267. What is schema

A database-inspired method for specifying constraints
on XML documents using an XML-based language. Schemas
address deficiencies in DTDs, such as the inability to
put constraints on the kinds of data that can occur in
a particular field. Because schemas are founded on
XML, they are hierarchical. Thus it is easier to
create an unambiguous specification, and it is
possible to determine the scope over which a comment
is meant to apply.

268. What is Secure Socket Layer (SSL)

A technology that allows Web browsers and Web servers
to communicate over a secured connection.

267. What is security attributes

A set of properties associated with a principal.
Security attributes can be associated with a principal
by an authentication protocol or by a J2EE product
provider or both.



268. What is security constraint

A declarative way to annotate the intended protection
of Web content. A security constraint consists of a
Web resource collection, an authorization constraint,
and a user data constraint.

269. What is security context

An object that encapsulates the shared state
information regarding security between two entities.

270. What is security permission

A mechanism defined by J2SE, and used by the J2EE
platform to express the programming restrictions
imposed on application component developers.