FileReader in Java

FileReader class in Java is used to read character data from files. FileReader class is available in the java.io package.

Contents hide

1 What is FileReader ?

2 FileReader Constructors

3 FileReader Methods

3.1 int read()

3.2 int read(char[] cbuf )

3.3 void close()

4 Using FileReader

5 Similar Java Tutorials

What is FileReader ?

The FileReader class in Java is designed to read character data from files sequentially. FileReader class extends InputStreamReader. FileReder class provide a simple option to access files as a stream of characters.

FileReader Constructors

FileReader fileReader = new FileReader(String fileName);

FileReader fileReader = new FileReader(File f);

FileReader Methods

int read()

public int read()
 throws java.io.IOException

This method reads a single character from the file and returns the equivalent UNICODE value of the character. If there is no next character available then this method returns -1. This method returns the UNICODE value (int). At the time of printing the character, we have to perform typecasting.

int read(char[] cbuf )

public int read(     @NotNull  char[] cbuf ) throws java.io.IOException

This method reads characters into an array. and returns the number of character reads.

void close()

public void close()
 throws java.io.IOException

This method is used to close the FileReader and release any resource associated with it. This method should be called when the FileReader is no longer needed.

Using FileReader

package file;

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

public class FileReaderExample {
    public static void main(String[] args) throws IOException {
        FileReader fileReader = new FileReader("java.txt");
        int character;
        while ((character=fileReader.read()) != -1){
            System.out.println((char)character);

        }
    }
}

Note- By using FileReader class we can read data from the file character by character which is not convenient for the programer. To overcome this problem we can use BufferReader.