Java Beans are reusable software components according to the specification. A Java Bean can encapsulate many objects into a single object, and we can use them through “get” and “set” methods in various places in our application. Besides providing easy maintenance, it also allows our objects to be eligible for other tools, such as persistence tools.
To be defined as Java Beans, the class must follow some conventions, such as:
- Implement the java.io.Serializable interface (to allow the object’s state to be persisted and retrieved).
- Have a no-argument constructor (no-arg constructor).
- Have private properties accessible by “get” and “set” methods.
Example of a bean:
// Implements Serializable
public class Pessoa implements java.io.Serializable { // Has private properties private String nome; // Get methods public String getNome() { return nome; } // Set methods public void setNome(String nome) { this.nome = nome; } /* No-argument constructor */ public Pessoa() { this.nome=""; }
}