Write a program in java that reads line of text from keyboard and write to file. Also read the content of the same file and display on monitor.

 Here's an example Java program that reads a line of text from the keyboard and writes it to a file. It then reads the contents of the file and displays it on the monitor:

import java.io.*;
public class FileReadWrite {
    public static void main(String[] args) {
        try {
            // create a BufferedReader to read from the keyboard
            BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
            
            // get a filename from the user
            System.out.print("Enter filename: ");
            String filename = br.readLine();
            
            // create a PrintWriter to write to the file
            PrintWriter pw = new PrintWriter(new FileWriter(filename));
            
            // read a line of text from the keyboard and write it to the file
            System.out.print("Enter text: ");
            String text = br.readLine();
            pw.println(text);
            
            // close the PrintWriter and BufferedReader
            pw.close();
            br.close();
            
            // create a BufferedReader to read from the file
            BufferedReader fr = new BufferedReader(new FileReader(filename));
            
            // read the contents of the file and display it on the monitor
            System.out.println("Contents of " + filename + ":");
            String line;
            while ((line = fr.readLine()) != null) {
                System.out.println(line);
            }
            
            // close the BufferedReader
            fr.close();
        } catch (IOException e) {
            System.out.println("Exception: " + e.getMessage());
        }
    }
}

This program first creates a BufferedReader to read from the keyboard and prompts the user to enter a filename. It then creates a PrintWriter to write to the specified file, prompts the user to enter a line of text, and writes that text to the file.

Next, the program creates a BufferedReader to read from the file and reads its contents line by line using a while loop. Finally, the program closes the input and output streams.

Note that this program assumes that the file is located in the same directory as the program. If the file is located in a different directory, you must specify the full path to the file.