ObjectIOStream in Java Example

Java also supports writing and reading objects to stream (such as a file). The process of reading and writing objects in a file is called object serialization. Writing an object to a file is called serializing the object and reading the object back from a file is called deserializing an object. In Java, serialization occurs automatically. Objects can be converted into a sequence of bytes, or serialized, by using the java.io.ObjectOutputStream class and they can be deserialized or converted from bytes into a structured object, by using java.io.ObjectlnputStream class.

import java.io.*; 
 class Employee implements Serializable 
 {       
      int empid; 
      String ename; 
      double salary;   
      Employee(int id,String name,double sal) 
      {       
        empid = id; 
        ename = name; 
        salary = sal; 
      } 
      void showInformation() 
      { 
        System.out.println("Empid : " + empid); 
        System.out.println("Empid : " + ename); 
        System.out.println("Salary : " + salary); 
        System.out.println(); 
      } 
 } 
       
 class ObjectIOStreamExample 
 { 
        public static void main(String[] args) 
        {           
            Employee empData[] = {new Employee(1,"Dinesh",50000), 
                              new Employee(2,"Shubhra",15000), 
                              new Employee(3,"Punar",26000) }; 
            try 
            {    
                 FileOutputStream fout = new FileOutputStream("std.dat"); 
                 ObjectOutputStream objOut = new ObjectOutputStream(fout); 
                 for(int i=0; i<empData.length;i++) 
                       objOut.writeObject(empData[i]); 
                       objOut.close(); 
            } 
            catch(Exception e){e.printStackTrace();} 
            try 
            {            
               FileInputStream fin = new FileInputStream("std.dat"); 
               ObjectInputStream objIn = new ObjectInputStream(fin);           
               Employee emp = (Employee) objIn.readObject(); 
               emp.showInformation(); 
               emp = (Employee) objIn.readObject(); 
               emp.showInformation(); 
               emp = (Employee) objIn.readObject(); 
               emp.showInformation();             
               objIn.close(); 
            } 
            catch(Exception e){e.printStackTrace();} 
         } 
 }