📁 Java File Handling

 

📘 1. Introduction to File Handling in Java

File handling in Java allows programmers to store, retrieve, and manipulate data in files stored on the disk. This is achieved using classes from the java.io and java.nio packages.

📁 2. File Class Overview

Java provides a File class in the java.io package to represent the pathnames of files and directories.

📘 1. Creating a File

import java.io.File;
import java.io.IOException;

public class CreateFile {
    public static void main(String[] args) {
        try {
            File file = new File("example.txt");
            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. Writing to a File

import java.io.FileWriter;
import java.io.IOException;

public class WriteToFile {
    public static void main(String[] args) {
        try {
            FileWriter writer = new FileWriter("example.txt");
            writer.write("Hello, this is a file handling example.");
            writer.close();
            System.out.println("Successfully wrote to the file.");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

📖 3. Reading from a File

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;

public class ReadFile {
    public static void main(String[] args) {
        try {
            File file = new File("example.txt");
            Scanner reader = new Scanner(file);
            while (reader.hasNextLine()) {
                String data = reader.nextLine();
                System.out.println(data);
            }
            reader.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }
}

❌ 4. Deleting a File

import java.io.File;

public class DeleteFile {
    public static void main(String[] args) {
        File file = new File("example.txt");
        if (file.delete()) {
            System.out.println("Deleted the file: " + file.getName());
        } else {
            System.out.println("Failed to delete the file.");
        }
    }
}

📂 5. File Info

File file = new File("example.txt");

System.out.println("File name: " + file.getName());
System.out.println("Absolute path: " + file.getAbsolutePath());
System.out.println("Writable: " + file.canWrite());
System.out.println("Readable: " + file.canRead());
System.out.println("File size in bytes: " + file.length());