Click here to watch in Youtube :
https://www.youtube.com/watch?v=vKsDURKBnck&list=UUhwKlOVR041tngjerWxVccw

FileOutputStreamDemo.java

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

/*
 * public FileOutputStream(File file)
 *              throws FileNotFoundException
 *
 * Parameters:
 * ----------
 * file - the file to be opened for writing.
 *
 */
public class FileOutputStreamDemo
{

    public static void main(String[] args) throws IOException
    {
        FileOutputStreamDemo fileOutputStreamDemo = new FileOutputStreamDemo();
        fileOutputStreamDemo.writeFile();
    }

    private void writeFile() throws IOException
    {
        FileOutputStream fileOutputStream = null;

        try
        {
            File file = new File("myfile.txt");

            /*
             * Creates a file output stream to write to the
             * file represented by the specified File
             * object.
             */

            fileOutputStream = new FileOutputStream(file);
            String str = "Peter is coming to India. ";

            /*
             * Converting string into byte array
             */
            byte[] byteArray = str.getBytes();

            /*
             * Writes b.length bytes from the specified byte
             * array to this file output stream.
             */
            fileOutputStream.write(byteArray);
            System.out.println("Successfully written to the file.");
        }
        finally
        {
            if (fileOutputStream != null)
            {
                /*
                 * Closes this file output stream and
                 * releases any system resources associated
                 * with this stream.
                 */
                fileOutputStream.close();
            }
        }
    }

}

Successfully written to the file.