What is Java – Key Features of Java Programming

Java is a powerful programming language which is widely used for developing applications across different domains. It stands out in the market due to its some unique features that make it robust, secure, and efficient. In this article, we will explore everything about the java language like history, features, Editions, and advantages of using Java.

History of Java

• Developed By: James Gosling
• Original Company: Sun Microsystems
• Current Owner: Oracle Corporation
• Original Project Name: Oak (later renamed to Java due to trademark issues)
• First Release: 23 January 1996

Editions Of Java

• When Java was originally released in 1996, it was just Java and no such thing as “editions” was there.
• But as use of Java increased , then in 1999 , SUN categorized it into 3 editions called J2SE,J2EE and J2ME .
• Later on in 2006 they changed the naming and called them JSE,JEE and JME.
• These editions were named based on the kind of application which can be developed by learning that edition.

JSE(Java Standard Edition)

• This is the most basic version of Java and it provides us core concepts of Java language like the data types , operators, arrays, methods , OOP , GUI (Graphical User Interface ) etc.
• Since it teaches us core concepts of Java that is why many people call it CORE JAVA , although SUN never gave this name.
• Later on in 2006 they changed the naming and called them JSE,JEE and JME.
• Used for developing desktop applications like calculators, media player, IDE etc

JSE(Java Standard Edition)

• The Java EE which stands for Java Enterprise Edition is built on top of the Java SE platform and is a collection of libraries used for building “enterprise applications” (usually web applications).
• In simple terms we can say JEE is used for developing applications which run on servers.
• Some popular applications developed using JEE are amazon.in, alibaba.com, irctc.co.in, ideacellular.com, airtel.in etc

JME(Java Micro Edition)

• Java ME is the slimmer version of Java targeted towards small devices such as mobile phones.
• Generally people tend to think of the micro edition as the mobile edition, while in reality, the micro edition is used not just for mobile phones, but for all kinds of devices, such as television sets, printers, smartcards and more.
• But as smartphone technology arrived the use of JME has reduced as Android has superseded it.

Following are the key features of Java that make it the preferred choice for developers.

• 1. Platform Independent

  One of the most popular features of Java is its platform independence.

• What is a Platform?

  A platform is the combination of an operating system (OS) and hardware (CPU) where an application runs. Now being platform independent means that an application developed and compiled over one platform can be executed over any other platform without any change in the code

  For Example Windows 8 + Intel Core i5, Linux + AMD A6, and Mac + Intel Core i3.

  • Java uses the concepts of bytecode and JVM (Java Virtual Machine) to achieve platform independence.
  • Bytecode: Whenever we compile a java program , the compiler never generates machine code. Rather it generates a machine independent code called the “bytecode”.
  • JVM: This bytecode is not directly understandable by the platform(OS & CPU). Here, the JVM comes into picture. The JVM translates bytecode into platform-specific machine code and executes it.

  Thus, any platform with a JVM can run a Java application without requiring any changes to the code. This is encapsulated in Java’s slogan: “Write Once, Run Anywhere” (WORA).

• 2. Automatic Memory Management

  Java simplifies memory management by introducing automatic garbage collection

  • In languages like C and C++ any dynamic memory which the programmer allocates using malloc( ) or new has to be deallocated by himself using free( ) or delete
  • But Java uses runtime automatic garbage collection feature where the JVM itself deallocates any dynamic memory which our program allocated
  • This not only reduces memory leaks but also allows developers to focus more on application logic.

• 3. Secure

  When it comes to security, Java is always the first choice. It enables us to develop virus free, temper free systems.

  Key Features:

  • No Explicit Pointers: Unlike C/C++, Java does not allow direct memory access using pointers, It does not allow a programmer to explicitly create pointers.
  • Java Runtime Environment: Java program always runs in Java runtime environment with almost null interaction with system OS, hence it is more secure.
  • Exception Handling: Java enforces strict coding rules, and violations are promptly detected and handled by the JVM through exceptions.

  These features make Java ideal for building virus-free and tamper-proof systems.

• 4. Robust

  Java has very strict rules which every program must compulsorily follow and if these rules are violated then JVM kills/terminates the code by generating “Exception”

  • Exception Handling Mechanism: Effective handling of runtime errors.
  • Strong Memory Management: Automatic garbage collection and no manual deallocation of memory.
  • Type Safety: Strict type checking during compile-time and runtime ensures fewer bugs.

  To understand java’s robustness , guess the output of the following C/C++ code:

  
  int arr[5];
  int i;
  
  for(i = 0; i <= 9; i++) {
      arr[i] = i + 1;
  }
  
  // Unpredictable, after i is 5
  
  

  • The previous code might show uncertain behaviour in C/C++ i.e. if memory is available after arr[4] , then the code will run , otherwise it will generate error at runtime.
  • On the other hand if in java this code is executed, the JVM will kill the application as soon as it finds the statement arr[5]=. . .
  • Reason is that in java we are not allowed to access any array beyond it’s upper/lower index

• 5. object-Oriented

  Java is a purely object-oriented language, means it supports all important concepts of OOPs like Encapsulation, Inheritance, Polymorphism and Abstraction.

• 6. Multithreaded

  Java supports multithreading , which allows the concurrent execution of multiple parts of a program. In simple terms it means that we can execute more than one part of the same program simultaneously. To understand this feature consider the code given below:

  
  main()
  {
  clrscr();
  factorial(5);
  prime(8);
  evenodd(4);
  }
  
  

  • In the previous sample code all 4 functions clrscr(),factorial(),prime() and evenodd() are independent of each other but still they will run sequentially i.e. one after the other.
  • This can be improved in java by using a multithreading feature so that all of these functions can run together.
  • Reduced execution time , full utilization of CPU

  Examples of Multithreading in Real-Life Applications:

  -> A browser running multiple tabs simultaneously.

  -> A media player performing multiple tasks like:

  • Moving a slider.
  • Showing elapsed time.
  • Adjusting volume.
  • Adding or removing songs.
  • Playing the audio

  Java’s multithreading capabilities make it highly suitable for applications requiring parallel processing.

• 7. Simple

  • Java borrows most of it’s syntax from C/C++ languages
  • Moreover it has inherited the best points from these languages and dropped others.
  • Like , it has removed pointers, multiple inheritance etc as developers of java language found these features to be security threat and confusing.
  • Thus if we have basic understanding of C/C++ languages it is very easy to learn Java

  These features collectively make Java programs resilient and reliable.

• Conclusion

  Java’s features like platform independence, automatic memory management, security, robustness, simplicity, object-oriented design, and multithreading make it a good for software development.

  These characteristics ensure that Java remains a top choice for building reliable, scalable, and efficient applications across a variety of platforms and industries.

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