Object Oriented Programming Using 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 the default sorting behavior for objects of that class. Comparato

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. Utilities:    - The framework offers u

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 {        System.out.println("Directory already exists.");    } 3. mkdirs() Method:    - Creates a directory and its parent directories if they do not exist.    File directories = new File("newDirectories/childDirect

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 default character encoding.        try (FileWriter fw = new FileWriter("output.txt")) {        String data = "Hello, world!";        fw.write(data);    } catch (IOException e) {        e.printStackTra

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();    } 3. BufferedReader:    - Reads text from a character-input stream efficiently by buffering characters.        try (BufferedReader br = new BufferedReader(new FileReader("example.txt"))) {        String line;        while (

 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 ObjectOutputStream(new FileOutputStream("objects.ser"));            Person person = new Person("John", 30);      

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);            dos.writeDouble(3.14);            dos.writeUTF("Hello, world!");            dos.close();        }    }    Example (Reading from a Data