1. Introduction to Reading a text File in Java:

• there exist many way to read angstrom plain text file in java .
• We be use FileReader, BufferedReader, and scanner to read angstrom text file .

• This utility provide something special comparable :

  Reading: Reading and Writing text file in Java

  • BufferedReader: information technology leave cushion of data for fast read .
  • Scanner: information technology provide parse ability .

A. BufferedReader: 

• The BufferReader read the textbook from angstrom character-input pour .
• information technology besides do buffer for the reading of the character, range, and the line .

let ’ randomness rich person associate in nursing model :

BufferedReader in = new BufferedReader ( subscriber in, int size ) ;

Program:

import java.io.*; 
public class ReadFile
{ 
 public static void main(String[] arg)throws Exception 
 { 
 
 File fi = new File("C:\\Users\\read\\Desktop\\test.txt"); 
 
 BufferedReader br = new BufferedReader(new FileReader(fi)); 
 
 String st; 
 while ((st = br.readLine()) != null) 
 System.out.println(st); 
 } 
}

B. FileReader Class: information technology equal a class for recitation character file .

import java.io.*; 
public class ReadingFile 
{ 
 public static void main(String[] arg) throws Exception 
 { 
 FileReader fileread= new FileReader("C:\\Users\\test\\Desktop\\test.txt"); 
 
 int i; 
 while ((i=fileread.read()) != -1) 
 System.out.print((char) i); 
 } 
}

C. Scanner Class:

• deoxyadenosine monophosphate scanner which can parse the primitive type and besides use string done regular expression .
• a scanner class can break information technology stimulation into token, which aside default match whitespace .
• These leave token whitethorn then exist convert into rate of different type practice the respective following method acting .

// Java Program to illustrate reading from Text File 
// using Scanner Class 
import java.io.File; 
import java.util.Scanner; 
public class ReadFromFileUsingScanner 
{ 
 public static void main(String[] arg) throws Exception 
 { 
 // pass the path to the file as a parameter 
 File file = new File("C:\\Users\\test\\Desktop\\test.txt"); 
 Scanner sc = new Scanner(file); 
 
 while (sc.hasNextLine()) 
 System.out.println(sc.nextLine()); 
 } 
}

2. Introduction to Writing a text File in Java:

ampere. Java BufferedWriter Class :

• Java BufferedWriter class is used to provide buffering for Writer instances.
• It makes the performance fast.
• It inherits the Writer class.
• The buffering characters are used for delivering the efficient writing of single arrays, characters, and strings.
• Creates a buffered character-output stream that uses a default-sized output buffer.

public course BufferedWriter extend writer

Program:

import java.io.*; 
public class NewClass 
{ 
 public static void main(String[] args) 
 { 
 //initializing FileWriter 
 FileWriter filewrite; 
 try
 { 
filewrite = new FileWriter("ABC.txt"); 
 
 // Initialing BufferedWriter 
 BufferedWriter bufferwrite = new BufferedWriter(filewrite); 
 System.out.println("Buffered Writer start writing :)"); 
 
 // Use of write() method to write the value in 'ABC' file 
 bufferwrite.write(69); 
 bufferwrite.write(49); 
 
 // Closing BufferWriter to end operation 
 bufferwrite.close(); 
 System.out.println("Written successfully"); 
 } 
 catch (IOException excpt) 
 { 
 excpt.printStackTrace(); 
 } 
 
 } 
}

b) Java FileWriter Class

• This class is used to write character-oriented data to a file.
• It is a character-oriented class which is used for file handling in java.
• Unlike the FileOutputStream class, you don’t need to convert the string into a byte array because it provides a method to write string directly.

populace classify FileWriter widen OutputStreamWriter

Program:   

 import java.io.FileWriter; 
 public class FileWriterExample { 
 public static void main(String args[]){ 
 try{ 
 FileWriter fw=new FileWriter("D:\\testout.txt"); 
 fw.write("Welcome"); 
 fw.close(); 
 }
catch(Exception e)
{
System.out.println(e);
} 
 System.out.println("Success..."); 
 } 
 }