When to use flush() in java?

Question

import java.io. * ;
public class Ser {

    public static void main(String args[]) {

        try {
            John myObj = new John(\"Sachin\", \"Cricket\");
              


        

Answer 1

1. When to use flush method and why do we use it?

This is used when there needs to be synchronous sending

For example you have a duplex (2-way) connection and you just sent a message and now need to wait for the reply on it, without flush a buffered outputstream might hold it until the buffer fills up (deadlock)

2. myObj2 = (John) ois.readObject(); Please correct me if I am wrong, I am reading the file object and storing into another object and typecasting the file object.

WRONG! You read some data from the stream typecast it into a John (which will throw if the object read wasn't a John)

3. What are the alternatives of Serialization or persisting the data in Java. I don't want the data to get into file as byte stream.

You can write it as text (write out the fields as text on a line) and provide a method to parse it into an object