file operation

 

  File Operation:

                            In Java, a File is an abstract data type. A named location used to store related information is known as a File. There are several File Operations like ,

• creating a new File

• getting information about File

• writing into a File

• reading from a File 

• deleting a File.

 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 FSC{

    

public static void main(String args[])throws IOException

{

int i;

DataInputStream d = new DataInputStream(System.in);

String fileName = "msc1.txt";

do

{

System.out.println("\nwhich type of file operation you want to perform?");

System.out.println("\n1.file creation\n2.read\n3.write\n4.update\n5.delete");

System.out.println("Enter your choice:");

i= Integer.parseInt(d.readLine());

switch(i)

{

  case 1:

       createFile(fileName);

       break;

  case 2:

       readFromFile(fileName);

       break;

  case 3:

       writeToFile(fileName, "Hello!");

       break;

  case 4:

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

       break;

 case 5:

       deleteFile(fileName);

       break;

 default:

      System.out.println("enter choice 1-4");

    

}

}while(i<=5);

}

    

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:

which type of file operation you want to perform?

1.file creation

2.read

3.write

4.update

5.delete

Enter your choice:

1

File created: msc1.txt

which type of file operation you want to perform?

1.file creation

2.read

3.write

4.update

5.delete

Enter your choice:

5

Deleted the file: msc1.txt

which type of file operation you want to perform?

1.file creation

2.read

3.write

4.update

5.delete

Enter your choice:

3

Successfully wrote to the file.

which type of file operation you want to perform?

1.file creation

2.read

3.write

4.update

5.delete

Enter your choice:

6

enter choice 1-4