Java Files

📁 Java Files

Java provides several classes to work with files, mainly from these packages:

  • java.io.File

  • java.io.FileWriter

  • java.util.Scanner

  • java.nio.file.Files (modern approach)

You can perform tasks like:

✔ Create a file
✔ Write to a file
✔ Read from a file
✔ Get file information
✔ Delete a file

📝 1. Creating a File

You can use the File class and its createNewFile() method.

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.”);
}
}
}

✍️ 2. Writing to a File

Use FileWriter to write text.

import java.io.FileWriter;
import java.io.IOException;public class WriteFile {
public static void main(String[] args) {
try {
FileWriter writer = new FileWriter(“example.txt”);
writer.write(“Hello Java File Handling!”);
writer.close();
System.out.println(“Successfully wrote to the file.”);
} catch (IOException e) {
System.out.println(“Error writing to file.”);
}
}
}

📖 3. Reading a File

Use a Scanner to read text from a file.

import java.io.File;
import java.util.Scanner;public class ReadFile {
public static void main(String[] args) {
try {
File file = new File(“example.txt”);
Scanner scanner = new Scanner(file);while(scanner.hasNextLine()) {
System.out.println(scanner.nextLine());
}

scanner.close();

} catch (Exception e) {
System.out.println(“File not found.”);
}
}
}

🔍 4. Get File Information

You can also check file properties:

import java.io.File;

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

if (file.exists()) {
System.out.println(“Name: “ + file.getName());
System.out.println(“Path: “ + file.getAbsolutePath());
System.out.println(“Readable: “ + file.canRead());
System.out.println(“Writable: “ + file.canWrite());
System.out.println(“Size: “ + file.length() + ” bytes”);
} else {
System.out.println(“File does not exist.”);
}
}
}

❌ 5. Delete 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: “ + file.getName());
} else {
System.out.println(“Failed to delete the file.”);
}
}
}

🚀 Modern Approach (Java NIO)

Since Java 7, the Files class provides easy file handling.

📘 Write File (NIO)

import java.nio.file.Files;
import java.nio.file.Paths;
import java.io.IOException;public class NioWrite {
public static void main(String[] args) throws IOException {
Files.write(Paths.get(“nio.txt”), “Hello from NIO!”.getBytes());
}
}

📗 Read File (NIO)

import java.nio.file.Files;
import java.nio.file.Paths;
import java.io.IOException;public class NioRead {
public static void main(String[] args) throws IOException {
String content = Files.readString(Paths.get(“nio.txt”));
System.out.println(content);
}
}

🧠 Summary Table

Operation Old Way (java.io) New Way (java.nio)
Create file File class Files.createFile
Write FileWriter Files.write
Read Scanner/FileReader Files.readString
Delete File.delete() Files.delete

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