J2EE Interview Questions
By Ramakrishna on Apr 7, 2009 in J2EE Interview Question
Q) What is J2EE
Rep) Java 2 Platform, Enterprise Edition.
Q) What is J2EE application
Rep) Any deployable unit of J2EE functionality. This can be
a single J2EE module or a group of modules packaged
into an EAR file along with a J2EE application
deployment descriptor. J2EE applications are typically
engineered to be distributed across multiple computing
tiers.
Q) What is J2EE component
Rep) A self-contained functional software unit supported by
a container and configurable at deployment time. The
J2EE specification defines the following J2EE
components: Application clients and applets are
components that run on the client. Java servlet and
JavaServer Pages (JSP) technology components are Web
components that run on the server. Enterprise
JavaBeans (EJB) components (enterprise beans) are
business components that run on the server. J2EE
components are written in the Java programming
language and are compiled in the same way as any
program in the language. The difference between J2EE
components and “standard” Java classes is that J2EE
components are assembled into a J2EE application,
verified to be well formed and in compliance with the
J2EE specification, and deployed to production, where
they are run and managed by the J2EE server or client
container.
Q) What is J2EE module
Rep) A software unit that consists of one or more J2EE
components of the same container type and one
deployment descriptor of that type. There are four
types of modules: EJB, Web, application client, and
resource adapter. Modules can be deployed as
stand-alone units or can be assembled into a J2EE
application.
Q) What is J2EE product
Rep) An implementation that conforms to the J2EE platform
specification.
Q) What is J2EE product provider
Rep) A vendor that supplies a J2EE product.
Q) What is J2EE server
Rep) The runtime portion of a J2EE product. A J2EE server
provides EJB or Web containers or both.
Q) What is J2ME
Rep) Abbreviate of Java 2 Platform, Micro Edition.
Q) What is J2SE
Rep) Abbreviate of Java 2 Platform, Standard Edition.
Q) What is JAR
Rep) Java archive. A platform-independent file format that
permits many files to be aggregated into one file.
Q) What is Java 2 Platform, Enterprise Edition(J2EE)
Rep) An environment for developing and deploying enterprise
applications. The J2EE platform consists of a set of
services, application programming interfaces (APIs),
and protocols that provide the functionality for
developing multitiered, Web-based applications.
Q) What is Java 2 Platform, Micro Edition (J2ME)
Rep) A highly optimized Java runtime environment targeting
a wide range of consumer products, including pagers,
cellular phones, screen phones, digital set-top boxes,
and car navigation systems.
Q) What is Java 2 Platform, Standard Edition (J2SE)
Rep) The core Java technology platform.
Q) What is Java API for XML Processing (JAXP)
Rep) An API for processing XML documents. JAXP leverages
the parser standards SAX and DOM so that you can
choose to parse your data as a stream of events or to
build a tree-structured representation of it. JAXP
supports the XSLT standard, giving you control over
the presentation of the data and enabling you to
convert the data to other XML documents or to other
formats, such as HTML. JAXP provides namespace
support, allowing you to work with schema that might
otherwise have naming conflicts.
Q) What is Java API for XML Registries (JAXR)
Rep) An API for accessing various kinds of XML registries.
Q) What is Java API for XML-based RPC (JAX-RPC)
Rep) An API for building Web services and clients that use
remote procedure calls and XML
Q) What is Java IDL
Rep) A technology that provides CORBA interoperability and
connectivity capabilities for the J2EE platform. These
capabilities enable J2EE applications to invoke
operations on remote network services using the Object
Management Group IDL and IIOP.
Q) What is Java Message Service (JMS)
Rep) An API for invoking operations on enterprise messaging
systems.
Q) What is Java Naming and Directory Interface (JNDI)
Rep) An API that provides naming and directory
functionality.
Q) What is Java Secure Socket Extension (JSSE)
Rep) A set of packages that enable secure Internet
communications.
Q) What is Java Transaction API (JTA)
Rep) An API that allows applications and J2EE servers to
access transactions.
Q) What is Java Transaction Service (JTS)
Rep) Specifies the implementation of a transaction manager
that supports JTA and implements the Java mapping of
the Object Management Group Object Transaction Service
1.1 specification at the level below the API.
Q) What is JavaBeans component
Rep) A Java class that can be manipulated by tools and
composed into applications. A JavaBeans component must
adhere to certain property and event interface
conventions.
Q) What is JavaMail
Rep) An API for sending and receiving email.
Q) What is JavaServer Faces Technology
Rep) A framework for building server-side user interfaces
for Web applications written in the Java programming
language.
Q) What is JavaServer Faces conversion model
Rep) A mechanism for converting between string-based markup
generated by JavaServer Faces UI components and
server-side Java objects.
Q) What is JavaServer Faces event and listener model
Rep) A mechanism for determining how events emitted by
JavaServer Faces UI components are handled. This model
is based on the JavaBeans component event and listener
model.
Q) What is JavaServer Faces _expression language
Rep) A simple _expression language used by a JavaServer
Faces UI component tag attributes to bind the
associated component to a bean property or to bind the
associated component’s value to a method or an
external data source, such as a bean property. Unlike
JSP EL expressions, JavaServer Faces EL expressions
are evaluated by the JavaServer Faces implementation
rather than by the Web container.
Q) What is JavaServer Faces navigation model
Rep) A mechanism for defining the sequence in which pages
in a JavaServer Faces application are displayed.
Q) What is JavaServer Faces UI component
Rep) A user interface control that outputs data to a client
or allows a user to input data to a JavaServer Faces
application.
Q) What is JavaServer Faces UI component class
Rep) A JavaServer Faces class that defines the behavior and
properties of a JavaServer Faces UI component.
Q) What is JavaServer Faces validation model
Rep) A mechanism for validating the data a user inputs to a
JavaServer Faces UI component.
Q) What is JavaServer Pages (JSP)
Rep) An extensible Web technology that uses static data,
JSP elements, and server-side Java objects to generate
dynamic content for a client. Typically the static
data is HTML or XML elements, and in many cases the
client is a Web browser.
Q) What is JavaServer Pages Standard Tag Library(JSTL)
Rep) A tag library that encapsulates core functionality
common to many JSP applications. JSTL has support for
common, structural tasks such as iteration and
conditionals, tags for manipulating XML documents,
internationalization and locale-specific formatting
tags, SQL tags, and functions.
Q) What is JAXR client
Rep) A client program that uses the JAXR API to access a
business registry via a JAXR provider.
