Skip to main content

Socket (TCP & UDP) communication in Java

Socket communication in Java enables communication between two endpoints over a network. There are two main types of sockets: TCP sockets and UDP sockets. Let's explain both types with examples: TCP Socket Communication: 1. **Server Side**:    - The server creates a `ServerSocket` object to listen for incoming connections on a specific port.    - When a client connects, the server accepts the connection and creates a `Socket` object to communicate with the client.    - The server reads from and writes to the socket's input and output streams to communicate with the client. import java.io.*; import java.net.*; public class TCPServer {     public static void main(String[] args) throws IOException {         ServerSocket serverSocket = new ServerSocket(12345);         System.out.println("Server started. Waiting for client...");         Socket clientSocket = serverSocket.accept();         System.out.println("Client connected.");         BufferedReader in = new Bu

this keyword

 In Java, the "this" keyword is a reference variable that refers to the current object. It is used within the instance methods of a class to refer to the current instance of the class. The primary purposes of the "this" keyword are:


1. Distinguishing Instance Variables: When an instance method has parameters or local variables with the same names as instance variables, using "this" helps to differentiate between the instance variables and local variables. For example:

    public class MyClass {

        // Instance variable

        private int myValue;


        // Constructor with a parameter

        public MyClass(int myValue) {

            // Using "this" to distinguish instance variable

            this.myValue = myValue;

        }


        // Method using "this" to access instance variable

        public void printValue() {

            System.out.println("Instance variable value: " + this.myValue);

        }

    }


    In the above example, "this.myValue" explicitly refers to the instance variable "myValue."


2. Invoking Current Object's Method: The "this" keyword is often used to invoke other methods of the current object. For example:

    public class MyClass {

        private int value;


        public void setValue(int value) {

            // Using "this" to invoke another method

            this.value = validateValue(value);

        }


        private int validateValue(int value) {

            // Some validation logic

            return value * 2;

        }

    }


    Here, "this.value" is used to call the private method `validateValue` within the same class.


3. Passing Current Object as a Parameter: The "this" keyword can be used to pass the current object as a parameter to other methods. For example:

    public class MyClass {

        private int value;


        public void setValue(int value) {

            // Passing current object using "this"

            HelperClass.processValue(this, value);

        }

    }


    class HelperClass {

        public static void processValue(MyClass obj, int value) {

            // Processing logic

            obj.value = value;

        }

    }


    In this case, the current object (`this`) is passed to the `HelperClass.processValue` method.


In summary, the "this" keyword in Java is a reference to the current object and is commonly used for disambiguating instance variables, invoking other methods of the current object, and passing the current object as a parameter to other methods.

Comments

Popular posts from this blog

Method Overloading in Java

Method Overloading in Java Method Overloading  is a feature in Java that allows a class to have multiple methods with the same name but different parameter lists. The methods can have a different number or types of parameters. The decision on which method to invoke is made by the compiler based on the arguments provided during the method call.  Example: public class Calculator {     // Method to add two integers     public int add(int a, int b) {         return a + b;     }     // Method to add three integers     public int add(int a, int b, int c) {         return a + b + c;     }     // Method to add two doubles     public double add(double a, double b) {         return a + b;     }     // Method to concatenate two strings     public String concatenate(String str1, String str2) {         return str1 + str2;     } } Method Overloading in Action: public class Main {     public static void main(String[] args) {         Calculator calculator = new Calculator();         // Overloaded meth

Java Runtime Environment (JRE)

Definition : Java Runtime Environment (JRE) is a set of software tools and libraries that enables the execution of Java applications. It provides the necessary runtime support for Java programs to run on various devices and platforms. Components of Java Runtime Environment (JRE): Java Virtual Machine (JVM): Definition: The JVM is a crucial component of the JRE responsible for executing Java bytecode. Functionality: It interprets Java bytecode or, in some cases, uses Just-In-Time (JIT) compilation to translate bytecode into native machine code for improved performance. Importance: JVM abstracts the underlying hardware, allowing Java programs to be platform-independent. Class Libraries: Definition: JRE includes a set of precompiled classes and methods that Java applications can utilize. Functionality: These classes cover a wide range of functionalities, from basic data structures to networking. Importance: Class libraries provide a foundation for developers, offering reusable code