Files Read/Write

Reading Files:

1. Using BufferedReader (Older Approach):

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

public class ReadFileExample {
    public static void main(String[] args) {
        try (BufferedReader reader = new BufferedReader(new FileReader("path/to/your/file.txt"))) {
            String line;
            while ((line = reader.readLine()) != null) {
                System.out.println(line);
            }
        } catch (IOException e) {
            System.out.println("An error occurred while reading the file.");
            e.printStackTrace();
        }
    }
}

In this example, the BufferedReader is used to read the file line by line.

2. Using Files.readAllLines (Java 7 and later):

import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.io.IOException;
import java.util.List;

public class ReadFileWithNIOExample {
    public static void main(String[] args) {
        try {
            Path path = Paths.get("path/to/your/file.txt");
            List<String> lines = Files.readAllLines(path);

            for (String line : lines) {
                System.out.println(line);
            }
        } catch (IOException e) {
            System.out.println("An error occurred while reading the file.");
            e.printStackTrace();
        }
    }
}

This example uses the Files.readAllLines method to read all lines of the file into a list of strings.

Writing Files:

1. Using BufferedWriter (Older Approach):

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

public class WriteFileExample {
    public static void main(String[] args) {
        try (BufferedWriter writer = new BufferedWriter(new FileWriter("path/to/your/output.txt"))) {
            writer.write("Hello, World!");
            writer.newLine();
            writer.write("This is a new line.");
        } catch (IOException e) {
            System.out.println("An error occurred while writing to the file.");
            e.printStackTrace();
        }
    }
}

This example uses the BufferedWriter to write text to a file.

2. Using Files.write (Java 7 and later):

import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.io.IOException;
import java.util.Arrays;

public class WriteFileWithNIOExample {
    public static void main(String[] args) {
        try {
            Path path = Paths.get("path/to/your/output.txt");
            Files.write(path, Arrays.asList("Hello, World!", "This is a new line."));
        } catch (IOException e) {
            System.out.println("An error occurred while writing to the file.");
            e.printStackTrace();
        }
    }
}

The Files.write method is used to write lines of text to a file.

Note:

• Always close resources (such as BufferedReader or BufferedWriter) using try-with-resources or explicitly in a finally block to ensure proper resource management.
• Make sure to handle exceptions appropriately, especially when working with file I/O, as file operations may throw IOException.

Choose the approach that fits your requirements and the Java version you are using. The java.nio.file package provides a more modern and flexible API for file operations in Java 7 and later.