This project demonstrates basic file handling operations in Java using the NIO (New I/O) package. It allows a user to create, read, write, append, modify, and delete text files dynamically through a console-based interactive menu.

Developed using IntelliJ IDEA, this program is ideal for learning file I/O operations, text manipulation, and exception handling in Java.

🧩 Features Function Description 📝 Write File Create a new text file and write user-provided lines. ➕ Append Line Add a new line of text to an existing file. 📖 Read File Display file content line by line with numbering. 🔍 Search & Replace Find and replace a word or phrase within the file. 🔄 Replace Specific Line Find a line containing specific text and replace it. 🗑️ Delete File Delete the selected file. ❌ Exit Safely close the program. 🧠 Technical Concepts Used

Java NIO (java.nio.file) package for efficient file handling (Files, Paths, StandardOpenOption, Path, etc.)

Exception Handling for safe file operations (try-with-resources, IOException handling)

Scanner class for dynamic user input

List for text line manipulation

Menu-driven console interface

UTF-8 character encoding for compatibility

⚙️ Requirements Tool Version Java JDK 17 or later IDE IntelliJ IDEA (Community or Ultimate Edition) Operating System Windows / macOS / Linux 🧭 How to Run the Project (Step-by-Step)

Open IntelliJ IDEA

Create a new Java project named FileOperationsDemo.

Add the source file

Create a new Java Class → Name it FileOperationsDemo.

Copy and paste the full program code (with comments) provided.

Run the Program

Click the green ▶️ Run button or press Shift + F10.

Interact via the Console

A menu will appear where you can select different file operations.

🧪 Example Run === JAVA FILE OPERATIONS DEMO === Working Directory: C:\Users\User\IdeaProjects\FileOperationsDemo\demo_files

Choose an operation: 1 - Write new file 2 - Append line 3 - Read file 4 - Search & Replace text 5 - Replace specific line 6 - Delete file 7 - Exit Enter your choice: 1

Enter text lines (press ENTER on empty line to finish): Hello, this is a demo file. This program shows Java file operations.

✅ File created and written successfully!

💡 Author

Name: Nishant Tiwari Role: Intern / Java Developer Organization: CodTEch Solutions IDE Used: IntelliJ IDEA Language: Java (JDK 17)

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✅ A menu-driven Java application demonstrating:

Reading and writing text files

Modifying content

Handling user input dynamically

Clear inline documentation and README file