Features of Java | Object Oriented Programming in Java

TASK 1
1.1 Features of Java Programming Language
A. Object-oriented
 Java programming is object-oriented programming language.
 Like C++ java provides most of the object oriented features (Daniel
Liang, 2012).
 Java is pure OOP. Language. (While C++ is semi object oriented)
B. Multithreaded
 Java provides integrated support for multithreaded programming
(Daniel Liang, 2012).
 Architecture-neutral:
 Java is not tied to a specific machine or operating system architecture.
 Machine Independent i.e. Java is independent of hardware
(http://www.c 4learn.com/java/java-characteristics-features/, April
2016).
C. Robust
Java encourages error-free programming by being strictly typed and
performing run-time checks.
D. Interpreted
 Java supports cross-platform code through the use of Java bytecode.
Bytecode can be interpreted on any platform by JVM.
E. High performance
 Byte-codes are highly optimized.

 JVM can executed them much faster (Daniel Liang, 2012).
F. Simple
 Java is Easy to write and more readable and eye catching.
 Java has a concise, cohesive set of features that makes it easy to learn
and use.
 Most of the concepts are drew from C++ thus making Java learning
simpler Y. (Daniel Liang, 2012).
1.2 The Role of Java Virtual Machine (JVM)
A Java virtual machine (JVM) is an abstract computing machine that
enables a computer to run a Java program. There are three notions of the
JVM: specification, implementation, and instance. The specification is a
document that formally describes what is required of a JVM
implementation. Having a single specification ensures all implementations
are interoperable. A JVM implementation is a computer program that meets
the requirements of the JVM specification. An instance of a JVM is an
implementation running in a process that executes a computer program
compiled into Java bytecode (https://en.wikipedia.org
/wiki/Java_virtual_machine, April 2016).
Java Virtual Machines operate on Java bytecode, which is normally (but not
necessarily) generated from Java source code; a JVM can also be used to
implement programming languages other than Java. For example, Ada
source code can be compiled to Java bytecode, which may then be executed
by a JVM. JVMs can also be released by other companies besides Sun (the
developer of Java) - JVMs using the "Java" trademark may be developed by
other companies as long as they adhere to the JVM specification published
by Sun (and related contractual obligations). The JVM is a crucial
component of the Java Platform. Because JVMs are available for many
hardware and software platforms, Java can be both middleware and a

platform in its own right - hence the trademark write once, run anywhere.
The use of the same bytecode for all platforms allows Java to be described
as "compile once, run anywhere", as opposed to "write once, compile
anywhere", which describes cross-platform compiled languages. The JVM
also enables such features as Automated Exception Handling that provides
'root-cause' debugging information for every software error (exception)
independent of the source code. The JVM is distributed along with a set of
standard class libraries that implement the Java API (Application
Programming Interface). An application programming interface is what a
computer system, library or application provides in order to allow data
exchange between them. They are bundled together as the Java Runtime
Environment (http://www.answers.com/Q/ What_is_the_role_of_JVM_in_Java,
April 2016).
TASK 2
LSB USE-CASE DIAGRAM

Fig 2. Source:
http://www.agilemodeling.com/artifacts/useCaseDiagram.htm, April 2016