Basic File Handling

Basic file handling in Java involves reading from and writing to files. Java provides several classes for file handling, including `File`, `FileInputStream`, `FileOutputStream`, `BufferedReader`, and `BufferedWriter`. Let's explore how to perform basic file handling operations in Java:

1. Reading from a File

Using `FileInputStream` and `BufferedReader`

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;

public class ReadFromFile {
    public static void main(String[] args) {
        try (FileInputStream fis = new FileInputStream("example.txt");
             BufferedReader br = new BufferedReader(new InputStreamReader(fis))) {

            String line;

            while ((line = br.readLine()) != null) {
                System.out.println(line);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

2. Writing to a File

Using `FileOutputStream` and `BufferedWriter`

import java.io.BufferedWriter;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;

public class WriteToFile {
    public static void main(String[] args) {
        try (FileOutputStream fos = new FileOutputStream("output.txt");
             BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(fos))) {
            String content = "Hello, world!";
            bw.write(content);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

3. Checking if a File Exists

import java.io.File;

public class FileExists {
    public static void main(String[] args) {
        File file = new File("example.txt");

        if (file.exists()) {
            System.out.println("File exists.");
        } else {
            System.out.println("File does not exist.");
        }
    }
}

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("File deleted successfully.");
        } else {
            System.out.println("Failed to delete the file.");
        }
    }
}

Conclusion

Basic file handling in Java involves reading from and writing to files using classes like `FileInputStream`, `FileOutputStream`, `BufferedReader`, and `BufferedWriter`. Additionally, you can perform operations like checking if a file exists and deleting a file using the `File` class. Understanding these basic file handling operations is essential for working with files in Java applications.