File Reading in Java Using FileReader: Step-by-Step Guide with Examples

📘 File Reading in Java (Using FileReader Class)

What is File Reading in Java?

File Reading in Java is the process of reading data from a file stored on the system. Java provides the FileReader class (not “File Reading”) inside the java.io package to read character-based data from files.

📦 FileReader Class

The FileReader class is used to read text data from a file character by character.

📌 Package

java.io

🧱 Constructor of FileReader

FileReader(String filePath) throws FileNotFoundException

• Opens a file located at the given file path.
• Internally creates an input stream to read data from the file.
• Throws FileNotFoundException if the file does not exist.

🛠️ Methods of FileReader

Method.               Description

int read().    Reads one character at a time and returns its ASCII (Unicode) value

void close().   Closes the input stream and releases system resources

🔄 How File Reading Works (Step by Step)

1. Create a FileReader object

     When the object is created, the operating system opens an input stream for the file.

2. Read data using read() method

     Reads one character at a time.

     Returns the ASCII value of the character.

     Returns -1 when the end of the file is reached.

3. Use a loop to read the entire file

      Since read() reads only one character, it must be used inside a loop.

4. Close the file using close()

     Closing the stream is mandatory to avoid memory leaks.

💡 Example: Reading a File in Java

import java.io.FileReader;

import java.io.IOException;

public class FileReadingExample {

    public static void main(String[] args) throws IOException {

        FileReader fr = new FileReader("example.txt");

        int ch;

        while ((ch = fr.read()) != -1) {

            System.out.print((char) ch);

        }

        fr.close();

    }

}

🌍 Real-Life Example

• Think of FileReader like reading a book letter by letter:
• Opening the book → Creating FileReader object
• Reading each letter → read() method
• Finishing the book → read() returns -1
• Closing the book → close() method

⭐ Key Points to Remember

• FileReader reads character-based data
• Reads one character at a time
• Must use a loop to read full content
• Always close the file after reading
• Returns -1 at end of file