Java Read and Write File

To read from and write to a file in Java, you can use classes like FileInputStream, FileOutputStream, BufferedReader, and BufferedWriter. Here's an example that demonstrates reading from one file and writing to another:

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class ReadWriteFileExample {
    public static void main(String[] args) {
        // File paths
        String inputFile = "input.txt";
        String outputFile = "output.txt";

        try {
            // Create a BufferedReader to read from input file
            BufferedReader reader = new BufferedReader(new FileReader(inputFile));

            // Create a BufferedWriter to write to output file
            BufferedWriter writer = new BufferedWriter(new FileWriter(outputFile));

            // Read input file line by line and write to output file
            String line;
            while ((line = reader.readLine()) != null) {
                // Write each line to output file
                writer.write(line);
                // Write a new line after each line in output file
                writer.newLine();
            }

            // Close reader and writer
            reader.close();
            writer.close();

            System.out.println("File reading and writing completed successfully!");
        } catch (IOException e) {
            System.out.println("An error occurred: " + e.getMessage());
        }
    }
}

In this example:

• We create a BufferedReader to read from the input file and a BufferedWriter to write to the output file.
• We read each line from the input file using the readLine() method and write it to the output file using the write() method.
• We use the newLine() method to add a newline character after each line in the output file.
• Finally, we close both the reader and writer to release system resources.