Java Beans

Java Bean

A Java Bean is a java class that should follow following conventions:

• It should have a no-arg constructor.
• It should be Serializable.
• It should provide methods to set and get the values of the properties, known as getter and setter methods.

Why use Java Bean?

According to Java white paper, it is a reusable software component. A bean encapsulates many objects into one object, so we can access this object from multiple places. Moreover, it provides the easy maintenance.

Simple example of java bean class

1. //Employee.java  
2.   
3. package mypack;  
4. public class Employee implements java.io.Serializable{  
5. private int id;  
6. private String name;  
7.   
8. public Employee(){}  
9.   
10. public void setId(int id){this.id=id;}  
11.   
12. public int getId(){return id;}  
13.   
14. public void setName(String name){this.name=name;}  
15.   
16. public String getName(){return name;}  
17.   
18. }  

How to access the java bean class?

To access the java bean class, we should use getter and setter methods.

1. package mypack;  
2. public class Test{  
3. public static void main(String args[]){  
4.   
5. Employee e=new Employee();//object is created  
6.   
7. e.setName("Arjun");//setting value to the object  
8.   
9. System.out.println(e.getName());  
10.   
11. }}  

Note: There are two ways to provide values to the object, one way is by constructor and second is by setter method.