Java Program to Create a File and Write into the File

In this article we are going to see how we can create and write into a file by using Java programming language.

Java Program to Create a File and Write into the File

As per problem statement first we have to create a file in a specified path then we have to write into the created file.

Let’s see program to understand it clearly.

• Java Program to Create a File and Write into the File by Using Java IO Library
• Java Program to Create a File and Write into the File by Using FileOutputStream
• Java Program to Create a File and Write into the File by Using NIO

Method-1: Java Program to Create a File and Write into the File by Using Java IO Library

In this method we will be using the IO library. We will be creating two objects, one File object to create a new file and another FileWriter object to write into the file.

Approach

• Create a File object with the file name as parameter.
• Use the method createNewFile( ) of the File class to create a new file inside an If block which will print upon successful creation of the file.
• Now create a FileWriter object with the same filename as parameter.
• Write into the file using write( ) method of the FileWriter class.
• Now close the file.
• Use a catch block to catch any IO exceptions and print it.

Program:

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;

public class Main
{
    public static void main(String[] args)
    {
    	//try blockcreateNewFile()
        try
        {
            //Create object of File class and pass file name as parameter
            File fileObj = new File("BtechGeeks.txt");
            //create the file by using inbuilt createNewFile() of File class
            if(fileObj.createNewFile())
            {
                System.out.println("File "+fileObj.getName() +" has been created");
            }

            //Create a writer object to write to the file & pass file name as parameter
            FileWriter writerObj = new FileWriter("BtechGeeks.txt");
            //Writing to the file
            writerObj.write("BtechGeeks is one of the best platform to learn Java");
            writerObj.close();
        }
        //Catch block
        catch(IOException e)
        {
            System.out.println("Unable to complete the task");
            // Print the exception occurred
            e.printStackTrace();
        }
        //Prints on successful creation and writing in the file
        System.out.println("Successfully File Created and Written into File");
    }
}

Output:

Console Output:

File BtechGeeks.txt has been created
Successfully File Created and Written into File

In File Explorer the file has been created:

Written text/content inside file:

Method-2: Java Program to Create a File and Write into the File by Using FileOutputStream

In this method we will be again using the IO library.

Method Used:

• getBytes( ): Convert the string characters into a byte array.
• write( ): Takes byte array as parameter and writes it into the file.

Approach:

• Create a FileOutputStream object with the file name.
• Store the content to write in a string variable
• Convert the string into a byte array using getBytes( ) method.
• Now use the write( ) method of the file class with the byte array as parameter to write into the file.
• Now close the file.

Program:

import java.io.*;

public class Main
{
    public static void main(String[] args)
    {
        //try block
        try
        {
            // Created a FileOutputStream object with the file name as parameter
            FileOutputStream file = new FileOutputStream("file.txt", true);
            // The text to write into the file
            String text = "Hello World";
            // Convert the string into bytes
            byte[] textByte  = text.getBytes();
            // Writing into the file
            file.write(textByte);
            file.close();
            System.out.println("File written successfully");
        }
        //Catch and print any IOException caused
        catch(IOException e)
        {
            System.out.println("Unable to create file. Exception - "+e);
        }
    }
}

Output:

In Console:

File written successfully

In File Explorer:

Method-3: Java Program to Create a File and Write into the File by Using NIO

Java NIO package is also another package that handle IO operations and it  might seem a replacement to JavaIO but it is not. Both IO and NIO packages are used here together.

Approach:

• Store the file path in a string variable
• Now create a Path object to store the path
• Create the file using Files.createFile() method using the path and store its path in another path object
• Print the path of the object to the console
• Now use a FileWriter object with the same path to create an object and write into the file
• Close the file
• Catch any exceptions if caused and print the error

Program:

import java.io.*;
import java.io.*;
import java.nio.file.*;

public class Main{
    public static void main(String[] args)
    {
        //Declare a string variable as assign the file path as value
        String filePath = "C:\\Users\\DELL\\eclipse-workspace\\BtechGeeks_File.txt";
        // Creating a Path object from the file path
        Path path = Paths.get(filePath);
        //try block
        try
        {
            //Creating a file by using createFile() method 
            //and storing its path in a path object p
            Path p = Files.createFile(path);
            // Printing the file path to console
            System.out.println("File created at "+p);

            //Creating a FileWriter object and writing to the file
            FileWriter file = new FileWriter(filePath,true);
            file.write("Hello World");
            file.close();

            System.out.println("Successfully wrote to the file");
        }
        //Catch and print any IOException caused
        catch(IOException e)
        {
            System.out.println("Unable to create file. Exception - "+e);
        }
    }
}

Output:

In Console:

File created at C:\Users\DELL\eclipse-workspace\BtechGeeks_File.txt
Successfully wrote to the file

In File Explorer:

Written text/content in file:

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