Sometimes developers need to store their Java class object in database. This tip demonstrate how we can store object into database and again access the stored Java object.

//Creating a simple class.
public class SimpleExample implements Serializable{
 //Member variable.
 private int intValue;
 private String string;
 
 public void setIntValue(int intValue){
  this.intValue = intValue;
 }
 
 public void setString(String string){
  this.string = string;
 }
 
 public int getIntValue(){
  return this.intValue;
 }
 
 public String getString(){
  return this.string;
 }
 
}

/*
* creating a class which have two function getByteArrayObject and getJavaObject.
*
* getByteArrayObject convert java object into byte[] and return the byte[].
*
* getJavaObject convert byte[] to java object. and return SimpleExample object.
*
*/
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
public class ConvertObject {
  //converting SimpleExample object to byte[].
    public byte[] getByteArrayObject(SimpleExample simpleExample){
    
        byte[] byteArrayObject = null;
        try {
            
            ByteArrayOutputStream bos = new ByteArrayOutputStream();
            ObjectOutputStream oos = new ObjectOutputStream(bos);
            oos.writeObject(simpleExample);
            
            oos.close();
            bos.close();
            byteArrayObject = bos.toByteArray();
        } catch (Exception e) {
            e.printStackTrace();
            return byteArrayObject;
        }
        return byteArrayObject;
    }
    //converting byte[] to SimpleExample  
    public SimpleExample getJavaObject(byte[] convertObject){
            SimpleExample objSimpleExample = null;
            
            ByteArrayInputStream bais;
            ObjectInputStream ins;
            try {
            
            bais = new ByteArrayInputStream(convertObject);
            
            ins = new ObjectInputStream(bais);
             objSimpleExample =(SimpleExample)ins.readObject();
            
            ins.close();

            }
            catch (Exception e) {
            e.printStackTrace();
            }
            return objSimpleExample;
    }
 
}
/**
*
* Writing a main class to converting the objects.
*
**/
public class MainClass {

  public static void main(String[] a) {
    
   SimpleExample simpleExample = new SimpleExample();
   simpleExample.setIntValue(11);
   simpleExample.setString("This is intance of SimpleExample");
    
   ConvertObject convertObject = new ConvertObject();
   byte[] byteArrayObject = convertObject.getByteArrayObject(simpleExample);
   // Now we have byte[] to store in database. byte[] easly can stored into blob or Longblog field of database.
    
  // Retive byte[] from the database.
   //Now agian change the byte[] into SimpleExample class object.

   SimpleExample convertedSimpleExample = convertObject.getJavaObject(byteArrayObject);
    
   System.out.println("<------------------------------------------------------------->");
   System.out.println(convertedSimpleExample.getIntValue() + " :: " + convertedSimpleExample.getString());
   System.out.println("<------------------------------------------------------------>");
 
  }
}