Skip to main content

Posts

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();   ...
Post a Comment
Read more

The Comparable and Comparator interfaces in Java

 The Comparable and Comparator interfaces in Java are both used for sorting objects, but they serve different purposes and provide different mechanisms for comparison. Comparable Interface: 1. Purpose:    - The Comparable interface is used to define the natural ordering of objects. It enables objects of a class to be compared to one another based on a predefined criterion.    - Objects that implement Comparable can be sorted automatically based on their natural ordering. 2. Method:    - The Comparable interface contains a single method, `compareTo(Object obj)`, which compares the current object with another object of the same type.    - The `compareTo` method returns a negative integer, zero, or a positive integer depending on whether the current object is less than, equal to, or greater than the specified object. 3. Usage:    - Comparable is typically implemented by the class of the objects being sorted.    - It defines t...
Post a Comment
Read more

Introduction to JCF

The Java Collections Framework (JCF) is a fundamental part of the Java programming language, providing a unified architecture for representing and manipulating collections of objects. Introduced in Java 2, it offers a set of interfaces and classes to handle common data structures efficiently. Here's an overview of the key aspects of the Java Collections Framework: 1. Interfaces:    - The framework includes several core interfaces such as `Collection`, `List`, `Set`, `Queue`, and `Map`.    - These interfaces define common operations and behaviors for collections, such as adding, removing, and iterating over elements. 2. Implementations:    - Along with interfaces, the JCF provides various implementations of these interfaces, each optimized for different use cases.    - Examples include `ArrayList`, `LinkedList`, and `Vector` for lists, `HashSet`, `TreeSet`, and `LinkedHashSet` for sets, and `HashMap`, `TreeMap`, and `LinkedHashMap` for maps. 3. Uti...
Post a Comment
Read more

Creating Files and Directories

File I/O Classes: Creating Files and Directories 1. File Class:    - Represents a file or directory path.    - Provides methods for creating new files and directories.    File file = new File("newFile.txt");    try {        if (file.createNewFile()) {            System.out.println("File created: " + file.getName());        } else {            System.out.println("File already exists.");        }    } catch (IOException e) {        System.out.println("An error occurred.");        e.printStackTrace();    } 2. mkdir() Method:    - Creates a directory.    File directory = new File("newDirectory");    if (directory.mkdir()) {        System.out.println("Directory created: " + directory.getName());    } else {   ...
Post a Comment
Read more

File I/O Classes Writing

File I/O Classes Writing 1. FileOutputStream:    - Writes raw bytes to a file output stream.    - Suitable for writing binary data to files.        try (FileOutputStream fos = new FileOutputStream("output.txt")) {        String data = "Hello, world!";        byte[] bytes = data.getBytes();        fos.write(bytes);    } catch (IOException e) {        e.printStackTrace();    } 2. BufferedWriter:    - Writes text to a character-output stream efficiently by buffering characters.        try (BufferedWriter bw = new BufferedWriter(new FileWriter("output.txt"))) {        String data = "Hello, world!";        bw.write(data);    } catch (IOException e) {        e.printStackTrace();    } 3. FileWriter:    - Writes character files using the d...
Post a Comment
Read more

File I/O Classes Reading

File I/O Classes Reading  1. File Class:    - Represents a file or directory path in the file system.    - Provides methods for file manipulation and querying file attributes.        File file = new File("example.txt");    if (file.exists()) {        System.out.println("File exists!");    } else {        System.out.println("File does not exist!");    } 2. FileInputStream:    - Reads raw bytes from a file input stream.    - Suitable for reading binary data from files.        try (FileInputStream fis = new FileInputStream("example.txt")) {        int byteRead;        while ((byteRead = fis.read()) != -1) {            System.out.print((char) byteRead);        }    } catch (IOException e) {        e.printStackTrace(); ...
Post a Comment
Read more

Object Streams

 Object streams in Java are used to serialize and deserialize objects, allowing them to be written to and read from streams. Here are some notes and examples on object streams: 1. Object Streams:    - Object streams allow for the serialization and deserialization of Java objects.    - They provide a convenient way to persist Java objects to files or transmit them over networks. 2. ObjectInputStream and ObjectOutputStream:    - `ObjectInputStream` and `ObjectOutputStream` are classes in Java used for reading and writing objects to streams.    - These classes wrap byte streams and provide methods like `readObject()` and `writeObject()`.    Example (Writing Objects to ObjectOutputStream):    import java.io.*;    public class ObjectOutputStreamExample {        public static void main(String[] args) throws IOException {            ObjectOutputStream oos = new ObjectOut...
Post a Comment
Read more

Data Streams

Data Streams in Java with examples: 1. Data Streams:    - Data streams are used for reading and writing primitive data types and strings from and to a source.    - They are more efficient than byte streams when working with primitive data types. 2. DataInputStream and DataOutputStream:    - `DataInputStream` and `DataOutputStream` are classes in Java that provide methods for reading and writing primitive data types and strings.    - These classes wrap byte streams and provide methods like `readInt()`, `writeDouble()`, `readUTF()`, etc.    Example (Writing to a DataOutputStream):    import java.io.*;    public class DataOutputStreamExample {        public static void main(String[] args) throws IOException {            DataOutputStream dos = new DataOutputStream(new FileOutputStream("data.txt"));            dos.writeInt(42);     ...
Post a Comment
Read more