File Expression In Java Programming

Program:

import java.io.File;

import java.io.*;

import java.io.FileWriter;

import java.io.FileReader;

import java.io.BufferedReader;

import java.io.IOException;

class FS

{    

public static void main(String[] args) 

{

     String fileName = "msc1.txt";        

     readFromFile("msc.txt");

     createFile(fileName);

      writeToFile(fileName, "Hello!");

      readFromFile(fileName);

      updateFile(fileName, "\nThis is an appended line.");

      readFromFile(fileName);

      deleteFile(fileName);

}

public static void createFile(String fileName) 

{

 File file = new File(fileName);

try

{       

 if (file.createNewFile()) 

{

                System.out.println("File created: " + file.getName());

           

 } 

else {

              

  System.out.println("File already exists.");

          

  }

}catch(Exception ex){}     

 

 }

 

   

public static void writeToFile(String fileName, String content)

 {

        

try

{

 FileWriter writer = new FileWriter(fileName); 

           writer.write(content);

         

 System.out.println("Successfully wrote to the file.");

writer.flush();

writer.close();

        } 

catch (IOException e) {

            

System.out.println("An error occurred while writing to the file.");

           

 

 

       }

  

  } 

 public static void updateFile(String fileName, String content) 

{      

 try {

FileWriter writer = new FileWriter(fileName, true);

            writer.write(content);            

System.out.println("Successfully updated the file.");

writer.flush();

writer.close();      

} 

catch (IOException e) {         

 System.out.println("An error occurred while updating the file.");    

 }

    }   

 public static void readFromFile(String fileName) 

{

        try {

BufferedReader reader = new BufferedReader(new FileReader(fileName)); 

            String line;

            System.out.println("Reading from file:");

while ((line = reader.readLine()) != null)

 {

                System.out.println(line);

            }

reader.close();

        } 

catch (IOException e) {

            System.out.println("An error occurred while reading from the file.");

        }

    }

 public static void deleteFile(String fileName)

 {

        File file = new File(fileName);

       

 if (file.delete()) 

{

            System.out.println("Deleted the file: " + file.getName());

        } 

else {

            System.out.println("Failed to delete the file.");

        }

    }

}

Output: