Java Program to Read Content From One File and Write it into Another File

// Java program to read content from one file
// and write it into another file

// Custom paths for this program 
// Reading from - gfgInput.txt
// Writing to - gfgOutput.txt

// Importing input output classes
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

// Class
class GFG {

    // Main driver method
    public static void main(String[] args)
    {

        // The file reading process may sometimes give
        // IOException

        // Try block to check for exceptions
        try {

            // Creating a FileReader object and
            // file to be read is passed as in parameters
            // from the local directory of computer
            FileReader fr = new FileReader("gfgInput.txt");

            // FileReader will open that file from that
            // directory, if there is no file found it will
            // through an IOException

            // Creating a FileWriter object
            FileWriter fw = new FileWriter("gfgOutput.txt");

            // It will create a new file with name
            // "gfgOutput.text", if it is already available,
            // then it will open that instead

            // Declaring a blank string in which
            // whole content of file is to be stored
            String str = "";

            int i;

            // read() method will read the file character by
            // character and print it until it end the end
            // of the file

            // Condition check
            // Reading the file using read() method which
            // returns -1 at EOF while reading
            while ((i = fr.read()) != -1) {

                // Storing every character in the string
                str += (char)i;
            }

            // Print and display the string that
            // contains file data
            System.out.println(str);

            // Writing above string data to
            // FileWriter object
            fw.write(str);

            // Closing the file using close() method
            // of Reader class which closes the stream &
            // release resources that were busy in stream
            fr.close();
            fw.close();

            // Display message
            System.out.println(
                "File reading and writing both done");
        }

        // Catch block to handle the exception
        catch (IOException e) {

            // If there is no file in specified path or
            // any other error occurred during runtime
            // then it will print IOException

            // Display message
            System.out.println(
                "There are some IOException");
        }
    }
}

// Java program to read content from one file
// and write it into another file

// Custom paths for this program
// Reading from - gfgInput.txt
// Writing to - gfgOutput.txt

// Importing FileWriter class
// to write into a file
import java.io.FileWriter;
// Also importing IOException class to
// throw exception if occurs
import java.io.IOException;

// Class
class GFG {

    // Main driver method
    public static void main(String[] args)
    {
        // The file writing and creating process may give
        // some IOException, that's why it is mandatory to
        // use try block

        // Try block to check for exception/s
        try {

            // Creating a FileWriter object which will
            // create a new file and if already available
            // it will open it
            FileWriter fw = new FileWriter("gfg.txt");

            // Content to be written on file
            // Custom input string

            // write() method will write the string
            // in the file
            fw.write("We love GeeksForGeeks");

            // Closing the file freeing up resources
            // in the memory
            fw.close();

            // Print and display message
            System.out.println("\nFile write done");
        }

        // Catch block to catch if exception/s occurs
        catch (IOException e) {

            // Print and display message
            System.out.println(
                "There are some IOException");
        }
    }
}