📂 Java File Handling – Read, Write, Create & Delete Files with Ease (2025)

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🧲 Introduction – Why Learn Java File Handling?

In real-world applications, reading and writing files is a core requirement—whether it’s saving user data, logs, configuration, or reports. Java’s java.io and java.nio packages provide robust tools to manage file operations.

🎯 In this guide, you’ll learn:

• How to create and write to files
• How to read content from files
• How to delete files using Java
• Best practices for file handling

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📌 Topics Covered

🔢 Topic	📘 Description
Java Files	Introduction to file management in Java
Java Create/Write Files	Creating and writing text into files
Java Read Files	Reading content line-by-line
Java Delete Files	Deleting existing files using File.delete()

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📁 Java Files – File Class Overview

Java provides the File class (from java.io) to represent file and directory pathnames.

🧪 Example: Checking if a file exists

import java.io.File;

public class FileCheck {
  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.");
    }
  }
}

🔍 Line-by-Line Explanation:

• File file = new File(...) → Represents a file or path
• file.exists() → Checks if the file physically exists

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📝 Java Create/Write Files – FileWriter

You can use FileWriter or BufferedWriter to create and write to files.

🧪 Example:

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

public class WriteFile {
  public static void main(String[] args) {
    try {
      FileWriter writer = new FileWriter("output.txt");
      writer.write("Welcome to Java File Handling!");
      writer.close();
      System.out.println("Successfully written to the file.");
    } catch (IOException e) {
      System.out.println("An error occurred.");
    }
  }
}

🔍 Line-by-Line Explanation:

• FileWriter writer = new FileWriter(...) → Creates or opens the file
• writer.write(...) → Writes content
• writer.close() → Closes the file (important for saving data)

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📖 Java Read Files – FileReader/BufferedReader

Java supports reading files using FileReader, BufferedReader, or Scanner.

🧪 Example (BufferedReader):

import java.io.*;

public class ReadFile {
  public static void main(String[] args) {
    try {
      BufferedReader reader = new BufferedReader(new FileReader("output.txt"));
      String line;
      while ((line = reader.readLine()) != null) {
        System.out.println(line);
      }
      reader.close();
    } catch (IOException e) {
      System.out.println("Unable to read file.");
    }
  }
}

🔍 Line-by-Line Explanation:

• BufferedReader + FileReader → Opens file for reading
• readLine() → Reads each line until the end (null)
• reader.close() → Frees up system resources

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🗑️ Java Delete Files – File.delete()

Use the delete() method to remove a file.

🧪 Example:

import java.io.File;

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

🔍 Line-by-Line Explanation:

• file.delete() → Attempts to delete the specified file
• Returns true if successful, false otherwise

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📌 Summary – Recap & Next Steps

File handling in Java is essential for applications involving persistent storage, reporting, and configuration.

🔍 Key Takeaways:

• Use File, FileWriter, and BufferedReader for file manipulation
• Always close streams to avoid memory leaks
• Always handle exceptions using try-catch blocks
• File.delete() allows cleanup of unneeded files

⚙️ What’s Next?

• Learn about serialization for writing objects to files
• Use java.nio.file.Files for advanced file operations
• Try writing a log system or file-based database

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❓ Frequently Asked Questions (FAQs)

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❓ What is the difference between FileWriter and BufferedWriter?
✅ FileWriter writes directly, while BufferedWriter buffers content before writing, improving performance for large files.

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❓ Can I append data to a file instead of overwriting?
✅ Yes! Use new FileWriter("file.txt", true) to enable append mode.

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❓ What happens if the file doesn’t exist when reading?
❌ Java throws a FileNotFoundException, which must be handled using try-catch.

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❓ Is it necessary to close the file after writing?
✅ Absolutely. Not closing the file may result in unsaved data or resource leaks.

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❓ Can I delete a directory using File.delete()?
✅ Only if the directory is empty. Use Files.delete(Path) for more advanced deletion.

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