FileReader Class

FileReader

This class can be used for reading character data from the file.

Constructors
1. FileReader fr = new FileReader(String name);
2. FileReader fr = new FileReader(File f); 
Important methods

1. int read():

For reading next character from the file. If there is no next character this method returns -1

2. int read(char[] ch):

To read data from the file into char array.

3. void close():

To close FileReader

E.g

package com.ashok.files;

import java.io.File;
import java.io.FileReader;

public class MyFile {
   public static void main(String arg[]) throws Exception {
      File f = new File("Ashok.txt");
      FileReader fr = new FileReader(f);
      System.out.println(fr.read());
      char[] ch2 = new char[(int) (f.length())];
      System.out.println(ch2.length);
      fr.read(ch2);
      for (char ch1 : ch2) {
         System.out.print(ch1);
      }
   }
}
Output
97
40
Hai
How are you
abcaHai
How are you
abc

The usage of FileReader and FileWriter is in efficient because

  • While writing the data by using FileWriter, program is responsible to insert line separators manually.
  • We can read the data character by character only by using FileReader. If increases the number of I/O operations and effect performance.

To overcome these problems sun people has introduced BufferedReader and BufferedWriter classes.

FileReader Class
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