Write code to serialize and deserialize java collection objects

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heartin
Write code to serialize and deserialize java collection objects

Create a class that has a HashMap as a member object. Write code to serialize and deserialize that class. Also, write utility methods to print the HashMap and use it to print data before and after serialization.

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sneha
Program

package com.javajee.forums;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map.Entry;

public class SerializableExample implements Serializable {

  private static final long serialVersionUID = 1L;
  HashMap<Integer, String> map=new HashMap<Integer, String>();
 
// METHOD FOR SERIALIZATION

public void serializeMapClass(){
    try{
    FileOutputStream fs = new FileOutputStream("testSer.ser");
    ObjectOutputStream os = new ObjectOutputStream(fs);
    os.writeObject(this);
    os.close();
    }
    catch(Exception e){
      e.printStackTrace();
    }
  }
 
//METHOD FOR DESERIALIZATION

public void deserializeAndPrint(){
    try{
      SerializableExample obj1;
      FileInputStream fis = new FileInputStream("testSer.ser");
      ObjectInputStream ois = new ObjectInputStream(fis);
      obj1 = (SerializableExample) ois.readObject();
      ois.close();
      obj1.mapValues();
      }
      catch(Exception e){
        e.printStackTrace();
      }
  }

// TESTER METHODS
   public static void main(String[] args) {
    SerializableExample obj=new SerializableExample();    
    obj.createMap();
    System.out.println("value before serialization");
    obj.mapValues();
    obj.serializeMapClass();
    System.out.println("value after serialization");
    obj.deserializeAndPrint();
  }
 
  public  createMap(){
    map.put(1,"tree");
    map.put(2, "plant");    
  }
 
  public void mapValues(){    
    for(Entry<Integer, String> s : map.entrySet()){
      System.out.println(s.getValue());
    }
  }  

}
 

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sharmarohan
HoW TO WRITE CODE TO SERIALIZE AND DESERIALIZE JAVA COLLECTION

EXLTechTo make a Java object serializable we implement the java.io.Serializable interface.
The ObjectOutputStream class contains writeObject() method for serializing an Object.

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surbhinahta
Hi,

Hi,

// Java code for serialization and deserialization 

// of a Java object

import java.io.*;

  

class Demo implements java.io.Serializable

{

    public int a;

    public String b;

  

    // Default constructor

    public Demo(int a, String b)

    {

        this.a = a;

        this.b = b;

    }

  

}

  

class Test

{

    public static void main(String[] args)

    {   

        Demo object = new Demo(1, "geeksforgeeks");

        String filename = "file.ser";

          

        // Serialization 

        try

        {   

            //Saving of object in a file

            FileOutputStream file = new FileOutputStream(filename);

            ObjectOutputStream out = new ObjectOutputStream(file);

              

            // Method for serialization of object

            out.writeObject(object);

              

            out.close();

            file.close();

              

            System.out.println("Object has been serialized");

  

        }

          

        catch(IOException ex)

        {

            System.out.println("IOException is caught");

        }

  

  

        Demo object1 = null;

  

        // Deserialization

        try

        {   

            // Reading the object from a file

            FileInputStream file = new FileInputStream(filename);

            ObjectInputStream in = new ObjectInputStream(file);

              

            // Method for deserialization of object

            object1 = (Demo)in.readObject();

              

            in.close();

            file.close();

              

            System.out.println("Object has been deserialized ");

            System.out.println("a = " + object1.a);

            System.out.println("b = " + object1.b);

        }

          

        catch(IOException ex)

        {

            System.out.println("IOException is caught");

        }

          

        catch(ClassNotFoundException ex)

        {

            System.out.println("ClassNotFoundException is caught");

        }

  

    }

}

 

Hope this will help you solve your java coding issue and if you like to know more then visit the best Java Classes in Pune.

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divyashettyy
Java code for serialization and deserialization of a Java

//Java Training

import java.io.*;  

class Demo implements java.io.Serializable

{

    public int a;

    public String b;

    // Default constructor

    public Demo(int a, String b)

    {

        this.a = a;

        this.b = b;

    }

  

}

  

class Test

{

    public static void main(String[] args)

    {   

        Demo object = new Demo(1, "geeksforgeeks");

        String filename = "file.ser";

          

        // Serialization 

        try

        {   

            //Saving of object in a file

            FileOutputStream file = new FileOutputStream(filename);

            ObjectOutputStream out = new ObjectOutputStream(file);

              

            // Method for serialization of object

            out.writeObject(object);

              

            out.close();

            file.close();

              

            System.out.println("Object has been serialized");

  

        }

          

        catch(IOException ex)

        {

            System.out.println("IOException is caught");

        }

  

  

        Demo object1 = null;

  

        // Deserialization

        try

        {   

            // Reading the object from a file

            FileInputStream file = new FileInputStream(filename);

            ObjectInputStream in = new ObjectInputStream(file);

              

            // Method for deserialization of object

            object1 = (Demo)in.readObject();

              

            in.close();

            file.close();

              

            System.out.println("Object has been deserialized ");

            System.out.println("a = " + object1.a);

            System.out.println("b = " + object1.b);

        }

          

        catch(IOException ex)

        {

            System.out.println("IOException is caught");

        }

        catch(ClassNotFoundException ex)

        {

            System.out.println("ClassNotFoundException is caught");

        }

  

    }

}

O/P:

Object has been serialized
Object has been deserialized
a = 1
b = geeksforgeeks

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