The concept of Write-once-run-anywhere (known as the Platform independent) is one of the important key feature of java language that makes java as the most powerful language.
Java Features
Platform Independent
The concept of Write-once-run-anywhere
(known as the Platform independent) is one of the important key feature of java
language that makes java as the most powerful language. Not even a single
language is idle to this feature but java is more closer to this feature. The
programs written on one platform can run on any platform provided the platform
must have the JVM.
Simple
There are various features that makes
the java as a simple language. Programs are easy to write and debug because java
does not use the pointers explicitly. It is much harder to write the java
programs that can crash the system but we can not say about the other
programming languages. Java provides the bug free system due to the strong
memory management. It also has the automatic memory allocation and deallocation
system.
Object Oriented
To be an Object Oriented
language, any language must follow at least the four characteristics.
- Inheritance : It is the process of creating the new classes and using the behavior of the existing classes by extending them just to reuse the existing code and adding the additional features as needed.
- Encapsulation:
: It is the mechanism of combining the
information and providing the abstraction.
- Polymorphism:
: As the name suggest one name multiple
form, Polymorphism is the way of providing the different functionality by
the
functions having the same name based on the signatures of the methods. - Dynamic binding : Sometimes we don't have the knowledge of objects about their specific types while writing our code. It is the way of providing the maximum functionality to a program about the specific type at runtime.
As the languages like Objective C, C++ fulfills the above four characteristics yet they are not fully object oriented languages because they are structured as well as object oriented languages. But in case of java, it is a fully Object Oriented language because object is at the outer most level of data structure in java. No stand alone methods, constants, and variables are there in java. Everything in java is object even the primitive data types can also be converted into object by using the wrapper class.
Robust
Java has the strong memory allocation
and automatic garbage collection mechanism. It provides the powerful exception
handling and type checking mechanism as
compare to other programming languages. Compiler checks the program whether there any
error and interpreter checks any run time error and makes the system
secure from crash. All of the above features makes the java language robust.
Distributed
The widely used protocols like HTTP and FTP are
developed in java. Internet programmers can call
functions on these protocols and can get access the files from any remote
machine on the
internet rather than writing codes on their local system.
Portable
The feature Write-once-run-anywhere makes the java language portable provided that the system must
have interpreter for the JVM. Java also have the standard data size irrespective
of operating system or the processor. These features makes the java as a
portable language.
Dynamic
While executing the java program the
user can get the required files dynamically from a local drive or from a
computer thousands of miles away from the user just by connecting with the
Internet.
Secure
Java does not use memory pointers
explicitly. All the programs in java are run under an area known as the sand
box. Security manager determines the accessibility options of a class like
reading and writing a file to the local disk. Java uses the public key
encryption system to allow the java applications to transmit over the internet
in the secure encrypted form. The bytecode Verifier checks the classes after
loading.
Performance
Java uses native code usage, and
lightweight process called threads. In the beginning interpretation of
bytecode resulted the performance slow but the advance version of JVM uses the
adaptive and just in time compilation technique that improves the performance.
Multithreaded
As we all know several features of Java like Secure, Robust, Portable, dynamic
etc; you will be more delighted to know another feature of Java which is Multithreaded.
Java is also a Multithreaded programming language. Multithreading means a
single program having different threads executing independently at the same
time. Multiple threads execute instructions according to the program code in a
process or a program. Multithreading works the similar way as multiple processes
run on one computer.
Multithreading programming is a very interesting concept in Java. In
multithreaded programs not even a single thread disturbs the execution of other
thread. Threads are obtained from the pool of available ready to run threads and
they run on the system CPUs. This is how Multithreading works in Java which you
will soon come to know in details in later chapters.
Interpreted
We all know that Java is an interpreted language as well. With an
interpreted language such as Java, programs run directly from the source code.
The interpreter program reads the source code and translates it on the fly into
computations. Thus, Java as an interpreted language depends on an interpreter
program.
The versatility of being platform independent makes Java to outshine from
other languages. The source code to be written and distributed is platform
independent.
Another advantage of Java as an interpreted language is its error debugging
quality. Due to this any error occurring in the program gets traced. This is how
it is different to work with Java.
Architecture Neutral
The term architectural neutral seems to be weird, but yes Java is an
architectural neutral language as well. The growing popularity of networks makes
developers think distributed. In the world of network it is essential that the
applications must be able to migrate easily to different computer systems. Not
only to computer systems but to a wide variety of hardware architecture and
Operating system architectures as well. The Java compiler does this by
generating byte code instructions, to be easily interpreted on any machine and
to be easily translated into native machine code on the fly. The compiler
generates an architecture-neutral object file format to enable a Java
application to execute anywhere on the network and then the compiled code is
executed on many processors, given the presence of the Java runtime system. Hence
Java was designed to support applications on network. This feature of Java has
thrived the programming language.