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QUESTION: What is a JavaBean? (asked
by Lifescan inc)
ANSWER: JavaBeans are reusable software
components written in the Java
programming language, designed to be
manipulated visually by a software
development environment, like JBuilder
or VisualAge for Java. They are similar
to Microsoft’s ActiveX components, but
designed to be platform-neutral, running
anywhere there is a Java Virtual Machine
(JVM).
QUESTION: What are the seven
layers(OSI model) of networking? (asked
by Caspio.com)
ANSWER: 1.Physical, 2.Data Link,
3.Network, 4.Transport, 5.Session,
6.Presentation and 7.Application Layers.
QUESTION: What are some advantages
and disadvantages of Java Sockets?
(asked by Arashsoft.com)
ANSWER:
Advantages of Java Sockets:
Sockets are flexible and sufficient.
Efficient socket based programming can
be easily implemented for general
communications.
Sockets cause low network traffic.
Unlike HTML forms and CGI scripts that
generate and transfer whole web pages
for each new request, Java applets can
send only necessary updated information.
Disadvantages of Java Sockets:
Security restrictions are sometimes
overbearing because a Java applet
running in a Web browser is only able to
establish connections to the machine
where it came from, and to nowhere else
on the network
Despite all of the useful and helpful
Java features, Socket based
communications allows only to send
packets of raw data between
applications. Both the client-side and
server-side have to provide mechanisms
to make the data useful in any way.
Since the data formats and protocols
remain application specific, the re-use
of socket based implementations is
limited.
QUESTION: What is the difference
between a NULL pointer and a void
pointer? (asked by Lifescan inc)
ANSWER: A NULL pointer is a pointer of
any type whose value is zero. A void
pointer is a pointer to an object of an
unknown type, and is guaranteed to have
enough bits to hold a pointer to any
object. A void pointer is not guaranteed
to have enough bits to point to a
function (though in general practice it
does).
QUESTION: What is encapsulation
technique? (asked by Microsoft)
ANSWER: Hiding data within the class and
making it available only through the
methods. This technique is used to
protect your class against accidental
changes to fields, which might leave the
class in an inconsistent state.
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