A JavaBean is just a regular Java class that:
- Has a public no-argument constructor (so the server can create it easily).
- Has private fields (data) with public getter and setter methods.
- Implements Serializable interface (optional, but often recommended for distributed apps).
✅ It’s like a data holder: it stores information and allows you to get/set it cleanly.
🎯 Example of a JavaBean
package com.example;
public class User {
private String name;
private int age;
// Public no-argument constructor
public User() {}
// Getter and Setter for name
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
// Getter and Setter for age
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
name and age are private fields.
getName(), setName(), getAge(), setAge() are public access methods.
📜 How JavaBeans are used in JSP?
Using action tags, you can create a bean, set properties, and get properties without writing Java code manually.
Example JSP:
<jsp:useBean id="user" class="com.example.User" scope="session" />
<jsp:setProperty name="user" property="name" value="Stanley" />
<jsp:setProperty name="user" property="age" value="30" />
<p>Hello, <jsp:getProperty name="user" property="name" />!</p>
<p>You are <jsp:getProperty name="user" property="age" /> years old.</p>
What happens here:
useBeancreates a newUserobject and stores it in thesession.setPropertysets thenameandage.getPropertyreads them and outputs into the page.
Result:
Hello, Stanley!
You are 30 years old.
📢 Important points about JavaBeans:
- They are not enterprise-level EJBs (Enterprise JavaBeans).
➔ JavaBeans are simple, lightweight classes for holding data. - JSPs use JavaBeans to bind form fields to backend objects easily.
- JavaBeans help separate business logic (Java code) from presentation (JSP HTML).
🎯 In short:
When I said “beans” earlier, I meant simple Java objects (JavaBeans) that are easy to create, set, and read inside JSP using special action tags.