Program: How to store and read objects from a file?

Sometimes we need to store the objects to the file system, and need to read them whenever required. Below example shows how to store the objects to the file, and how to retrieve them from the file. ObjectInputStream and ObjectOutputStream classes can help us to store and read objects from a file.

package com.java2novice.files;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.Serializable;

public class MyObjectFileStore {

	public void storeObject(Employee emp){
		
		OutputStream ops = null;
		ObjectOutputStream objOps = null;
		try {
			ops = new FileOutputStream("MyEmpFile.txt");
			objOps = new ObjectOutputStream(ops);
			objOps.writeObject(emp);
			objOps.flush();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} finally{
			try{
				if(objOps != null) objOps.close();
			} catch (Exception ex){
				
			}
		}
		
	}
	
	public void displayObjects(){
		
		InputStream fileIs = null;
		ObjectInputStream objIs = null;
		try {
			fileIs = new FileInputStream("MyEmpFile.txt");
			objIs = new ObjectInputStream(fileIs);
			Employee emp = (Employee) objIs.readObject();
			System.out.println(emp);
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		} finally {
			try {
				if(objIs != null) objIs.close();
			} catch (Exception ex){
				
			}
		}
		
	}
	
	public static void main(String a[]){
		MyObjectFileStore mof = new MyObjectFileStore();
		Employee e1 = new Employee("Tony",1,"1000");
		mof.storeObject(e1);
		mof.displayObjects();
	}
}

class Employee implements Serializable{
	
	private String name;
	private int id;
	private String salary;
	
	public Employee(String name, int id, String salary){
		this.name = name;
		this.id = id;
		this.salary = salary;
	}
	
	public String toString(){
		return name +"=="+id+"=="+salary;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}

	public String getSalary() {
		return salary;
	}

	public void setSalary(String salary) {
		this.salary = salary;
	}
}