J2EE Interview questions and answers

221. What is parsed entity 

A general entity that contains XML and therefore is
parsed when inserted into the XML document, as opposed
to an unparsed entity. 

222. What is parser 

A module that reads in XML data from an input source
and breaks it into chunks so that your program knows
when it is working with a tag, an attribute, or
element data. A nonvalidating parser ensures that the
XML data is well formed but does not verify that it is
valid. See also validating parser. 


223. What is passivation 

The process of transferring an enterprise bean from
memory to secondary storage. See activation. 

224. What is persistence 

The protocol for transferring the state of an entity
bean between its instance variables and an underlying
database. 

225. What is persistent field 

A virtual field of an entity bean that has
container-managed persistence; it is stored in a
database. 


226. What is POA 

Portable Object Adapter. A CORBA standard for building
server-side applications that are portable across
heterogeneous ORBs. 

227. What is point-to-point messaging system 

A messaging system built on the concept of message
queues. Each message is addressed to a specific queue;
clients extract messages from the queues established
to hold their messages. 


229. What is primary key 

An object that uniquely identifies an entity bean
within a home. 

230. What is principal 

The identity assigned to a user as a result of
authentication.