The Character Streams FileReader - RameshMF/java-io-guide GitHub Wiki

The FileReader class creates a Reader that you can use to read the contents of a file. FileReader is meant for reading streams of characters. For reading streams of raw bytes, consider using a FileInputStream.

FileReader Constructors

• FileReader(File file) - Creates a new FileReader, given the File to read from.
• FileReader(FileDescriptor fd) - Creates a new FileReader, given the FileDescriptor to read from.
• FileReader(String fileName) - Creates a new FileReader, given the name of the file to read from.

FileReader Class Methods

• int read() - It is used to return a character in ASCII form. It returns -1 at the end of file.
• void close() - It is used to close the FileReader class.

FileReader Class Example

The following example shows how to read lines from a file and display them on the standard output device. It reads its own source file, which must be in the current directory.

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

/**
 * The class demonstrate the usage of FileReader class methods.
 * @author javaguides.net
 *
 */
class FileReaderDemo {
	public static void main(String args[]) {
		try (FileReader fr = new FileReader("FileReaderDemo.java")) {
			int c;
			// Read and display the file.
			while ((c = fr.read()) != -1)
				System.out.print((char) c);
		} catch (IOException e) {
			System.out.println("I/O Error: " + e);
		}
	}
}

Note that this program reads its own source file, which must be in the current directory and produces below output:

package com.javaguides.javaio.book;

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

class FileReaderDemo {
	public static void main(String args[]) {
		try (FileReader fr = new FileReader("FileReaderDemo.java")) {
			int c;
			// Read and display the file.
			while ((c = fr.read()) != -1)
				System.out.print((char) c);
		} catch (IOException e) {
			System.out.println("I/O Error: " + e);
		}
	}
}

Reference

FileReader