What is java?
Java is a high level programming language created by James Gosling for Sun Microsystems in 1995.It was originally designed to use on digital mobile devices, such as cell phones.But later it created more interaction to use over internet which lead to the creation of many interactive webpages. so java became one of the best programming languages to use in both offline and online applications.It is fast,secure and reliable. There are many applications and websites that will
work only with the help of java.
It is used widely for two main reasons
•It can adopt to any changing environments and for different purpose
•For implementing refinements and to gain improvements in the art of programming
Evolution of java:
Java was conceived by James Gosling, Patrick Naughton, Chris Warth, Ed Frank, and Mike Sheridan at Sun Microsystems, Inc. in 1991. It took nearly 18 months to develop the first working version. This language was initially called “Oak,” but was renamed “Java” in 1995.The main cause was the need of platform-independent language so that we can create many softwares which is to be embedded in various electronic devices like remote controlled devices, microwave ovens,etc. As you can see many different types of CPUs are used as controllers.The major drawback with most of the programming languages is that they are designed in sauch a manner that it can be compiled only for a specific target. Although it is possible to compile a c++ program in different type of cpu, it requires a full c++ compiler targeted to that cpu.But the problem is that compilers are more expensive and time consuming to create.
Inorder to overcome these backlogs we need a feasible and more cost efficient solution.So Gosling and others began to and the result of their effort led to the creation of java.
Editions of Java Technology:
Java SE- Java SE or the Java Standard Edition helps in creating server applications,applets and even desktop applications. The applications which are developed by using this allows programs to run in almost all operating systems.
JEE-JEE or Java Enterprise Edition helps in working with web applications,component models and supports Service Oriented Architecture(SOA).
JME-JME or Java Micro Edition is used for the development of software for the devices like PDA's,mobile phones,TV set-top boxes and game programming.
•Linux 7.1 or Windows xp/7/8/10 operating system
•Pentium 200-MHz computer with a minimum of 64 MB of RAM (128MB RAM recommended).
•Java JDK 8 or any updated version of java
•Notepad or any other text editor
some of the popular java editors which can be used are
Java-Object Oriented Programming:
Object-oriented programming (OOP) is at the core of Java.An object-oriented program can be
characterized as data controlling access to code. In fact, all Java programs are to be atleast
some extent object-oriented. OOP is more needed for Java so that it is best to understand its
basic principles before you begin writing even simple Java programs.
An essential element of object-oriented programming is abstraction. Everyone manage all their
complexities through abstraction. For example, people do not think of a computer as a set of
hundreds of individual parts. Instead they think of it as a well-defined object with its own
unique behavior. They can ignore the details of how the cpu and the processor work. Instead,
they are free to utilize the object as a whole.
Likewise abstraction is a process in which all the implementation details will be kept hidden from the user and only the
functionality will be known to the user.In other words, the user will know the information of what work does the
object performs but not how that work is performed.
Encapsulation is the mechanism of binding code and data together which manipulates and
keeps both safe from any other interference and illegal usage. One way to think about encapsulation
is as a protective wrapper that prevents the code and data from being arbitrarily accessed
by other code defined outside the wrapper. Accessing of the code and data inside the wrapper
is fully controlled by a well-defined interface.
Inheritance is the process of acquiring the properties of one object to the other object.
Since it also supports the concept of hierarchical classification it is more important in java.
Inheritance interacts with encapsulation as well.
The concept of polymorphism is often defined as “one
interface, multiple methods”, which means that it is possible to perform a group of related activities under a
generic interface.This helps in reducing complexity in the specification of general class of action.