Java Features

Java is a high-level, object-oriented programming language. It is known for its platform independence, reliability, and security. Java Programming language follows the "Write Once, Run Anywhere" principle. It provides various features like portability, robustness, simplicity, multithreading, and high performance, which makes it a popular choice for beginners as well as for developers.

In this article, we are going to discuss the important features of Java programming language.

1. Simple Syntax

Java syntax is very straight forward and very easy to learn. Java removes complex features like pointers and multiple inheritance, which makes it more beginner friendly.

Example: Basic Java Program

// Java program to Demonstrate the Basic Syntax
import java.io.*;

class Geeks {
    public static void main(String[] args)
    {
        System.out.println("GeeksForGeeks!");
    }
}

GeeksForGeeks!

Explanation: The program starts with the main method, which is the entry point of any Java application. The System.out.println statement prints "GeeksForGeeks!" to the console. The import java.io.*; statement includes input-output functionalities, though it is not explicitly used in this simple program.

2. Object Oriented

Java is a pure object-oriented language. It supports core OOP concepts like

• Class
• Objects
• Inheritance
• Encapsulation
• Abstraction
• Polymorphism

Example: The below Java program demonstrates the basic concepts of oops.

// Java program to demonstrate the basic concepts of oops
// like class, object, Constructor and method
import java.io.*;

class Student {
    int age;
    String name;
    public Student(int age, String name)
    {
        this.age = age;
        this.name = name;
    }
  
    // This method display the details of the student
    void display()
    {
        System.out.println("Name is: " + name);
        System.out.println("Age is: " + age);      
    }
}

class Geeks {
    public static void main(String[] args)
    {
        Student student = new Student(22, "GFG");
        student.display();
    }
}

Name is: GFG
Age is: 22

Explanation: The Student class is defined with two attributes: age and name. A constructor is used to initialize these attributes when an object of the Student class is created. The display method prints the student's details. In the main method, an object of the Student class is created, and the display method is called to show the output

3. Platform Independent

Java is platform-independent because of Java Virtual Machine (JVM).

• When we write Java code, it is first compiled by the compiler and then converted into bytecode (which is platform-independent).
• This byte code can run on any platform which has JVM installed.

4. Interpreted

Java code is not directly executed by the computer. It is first compiled into bytecode. This byte code is then understand by the JVM. This enables Java to run on any platform without rewriting code.

5. Scalable

Java is able to handle both small and large-scale applications, features like multithreading and distributed computing allows developers to manage loads more efficiently.

6. Portable

Java Byte code can be executed on any platform with the help of JVM. This means once we write and compile our code, it can be used on different kind of devices without any changes, making Java programs portable and easy to use anywhere.

7. Secured and Robust

Java ensures reliability through early error detection, runtime checks, and exception handling. Java has built-in security features, like preventing the use of pointers and providing a security manager, which help create safe, tamper-proof applications.

8. Memory Management

Memory management in Java is automatically handled by the Java Virtual Machine (JVM).

• Java garbage collector reclaim memory from objects that are no longer needed.
• Memory for objects are allocated in the heap
• Method calls and local variables are stored in the stack.

9. High Performance

Java is faster than old interpreted languages. Java program is first converted into bytecode which is faster than interpreted code. It is slower than fully compiled languages like C or C++ because of interpretation and JIT compilation process. Java performance is improve with the help of Just-In-Time (JIT) compilation, which makes it faster than many interpreted languages but not as fast as fully compiled languages.

10. Multithreading

Multithreading in Java allows multiple threads to run at the same time.

• It improves CPU utilization and enhancing performance in applications that require concurrent task execution.
• Multithreading is especially important for interactive and high-performance applications, such as games and real-time systems.
• Java provides build in support for managing multiple threads. A thread is known as the smallest unit of execution within a process.

Example: Basic Multithreadig in Java

// Java program to demonstrate multithreading
class MyThread extends Thread {
  
    public void run() {
      
        System.out.println("Thread is running...");
    }
}

public class Geeks {
  
    public static void main(String[] args) {
        MyThread thread = new MyThread();
      
        // Starts the thread
        thread.start();  
    }
}

Thread is running...

Explanation: The MyThread class extends the Thread class and overrides the run method. In the main method, an object of MyThread is created, and the start method is called to begin the execution of the thread. The run method is executed in a separate thread, printing "Thread is running..." to the console.

11. Rich Standard Library

Java provides various pre-built tools and libraries which is known as Java API. Java API is used to cover tasks like file handling, networking, database connectivity (JDBC), security, etc. With the help of these libraries developers save a lot of time and ready to use solutions and can also build a powerful application.

12. Functional Programming Features

Since Java 8, the language has introduced functional programming features such as:

• lambda expression allows you to write shorter, more readable code by using inline expressions instead of traditional methods.
• Stream API allows data to be processed efficiently, supporting operations like filtering, mapping, and reducing data without the need for complex loops.
• Functional interfaces contain just one method, are designed to work seamlessly with lambda expressions, making the code more flexible and reusable.

Example:

// Java program demonstrating lambda expressions
interface Lambda {
  
    int operate(int a, int b);
}

public class Geeks {
  
    public static void main(String[] args) {
      
        // Lambda expression
        Lambda add = (a, b) -> a + b;  
        System.out.println("Addition: " + add.operate(2, 3));
    }
}

Addition: 5

Explanation: A functional interface Lambda is defined with a single method operate. A lambda expression (a, b) -> a + b is used to implement the operate method. The main method calls the operate method using the lambda expression and prints the result.

13. Integration with Other Technologies

Java can also works with other technologies and languages, including C/C++ with the help of Java Native Interface (JNI). Java works well with web technologies and web services (RESTful & SOAP), JDBC for database connectivity. Java is the main language for Android development. This flexibility of java enables developers to create scalable and powerful applications for various domains.

14. Support for Mobile and Web Application

Java offers support for both web and mobile applications.

• For web development: Java offers technologies like JSP and Servlets, along with frameworks like Spring and Springboot, which makes it easier to build web applications.
• For mobile development: Java is the main language for Android app development. The Android SDK uses special version of Java and its various tools to build mobile apps for Android devices.

15. Documentation and Community Support

Java provide documentation which includes guides, API references, and tutorials for easy learning. Java has a large and active global community contributing to open-source projects, and resources. This community support helps developers solve problems and stay updated with new advancements.