Java Beans

It is a Java class, It follows conventions they are:

• It must have a no-arg constructor
• It must be serializable.
• It must provide the methods to get and set the properties

Uses Of Java Bean:

Java bean class follows the encapsulation phenomena of object-oriented programming. Java Bean is also known as a Reusable Software component.

It encapsulates many objects into one object. So that, we can access this one object in multiple ways.

Encapsulation:

It is defined as the binding of data into a single unit known as Encapsulation.

It can also hide irrelevant data, using the concept of abstraction and Data hiding.

Uses Of Encapsulation:

• Flexibility increases
• Reusability of code
• Hiding the data
• Testing the code in an easy way

BeanExample.java

      class Area {
 
  int len;
  int bre;
  Area (int len, int bre) {
    this.len = len;
    this.bre = bre;
  }
  public void getArea () {
    int area = len * bre;
    System.out.println ("Area: " + area);
  }
}
class BeanExample
{
  public static void main (String[] args) {
    Area rec = new Area (2, 16);
    rec.getArea ();
  }
}

Output:

Structure Of Java Bean Class

  public class JavaBean
  {
     private String student;
     public void setName (String student)
{
   this. student = student;
}
public void getName ()
{
   return student;
}
}

Example of Java Bean Program:

MyGoal.java

         package MyGoal
         public class Student implements java.io.Serializable{  
         private int id;  
        private String name;  
        public Student (){}  
        public void setId (int id)
        {
         this. id = id;
         }  
           public int getId ()
          { 
            return id;
           }  
          public void setName (String name)
       {
       this. name = name;}  
public String getName () {
return name;
}  
}  

Student1.java

package MyGoal;  
public class Student1
 {  
public static void main (String args[])
{  
Student s1=new Student(); // Object Creation 
s1. setName ("Abhinav"); // setting value of the object  
System.out.println (s1. getName ());  
}
}  

Output:

Accessing the Java Bean Class

• We must use getter and setter methods, to access the Java Bean class.

The syntax for setter methods:

• The nature of the method must be in public.
• The return type of method must be void.
• The method name must start with set.
• It should consider some arguments which are passing through the method.

Syntax:

public  void setMethod_Name(datatype1 var1, datatype2 var2, datatype3 var3, ….., datatypen varn)
{
body
}

Program for Setting Methods:

// Creating Department Package

Department.java

package Department;
public class Course implements java.io.Serializable
{
private int id;
private String name;
public Course ()
    {
    }
public void setId (int id)
    {
        this.id = id;
    }
public int getId ()
    {
        return id;
    }
public void setName (String name)
    {
        this.name = name;
    }
public String getName ()
    {
        return name;
    }
}

// Accessing Department package

Course1.java

package Department;
public class Course1
 {
public static void main (String args[])
    {
        Course c1 = new Course (); // object creation of class
        s.setName ("Artificial Intelligence"); // Setting names to object
        System.out.println (s.getName ());
    }
}

Output:

The Syntax for Getter methods:

• The nature of the method must be in public.
• The return type of method must not be void.
• The method name must start with get.
• It should not consider some arguments which are passing through the method.

Syntax:

public return_datatype getMethodname ()
{
Body
return variable;
}

// Example of Getter methods Boolean type of data

public class JavaTpoint
 {
private boolean emp;
public boolean getName ()
    {
        return emp;
    }
public boolean isempty ()
    {
        return emp;
    }
}

Program for Setting Methods:

Department.java

package Department;
public class Course implements java.io.Serializable
{
private int id;
private String name;
public Course ()
    {
    }
public void setId (int id)
    {
        this.id = id;
    }
public int getId ()
    {
        return id;
    }
public void setName (String name)
    {
        this.name = name;
    }
public String getName ()
    {
        return name;
    }
}

// Accessing Department package

Course2.java

package Department;
public class Course2
 {
public static void main (String args[])
    {
        Course c1 = new Course (); // object creation of class
        s.setName ("Data Science"); // Setting names to object
        System.out.println (s.getName ());
    }
}

Output:

Serialization:

It converts the state of an object into a byte stream, Deserialization is the reverse process of Serialization.

We should import java.io.Serializable to make the object serializable