What are the scope areas in Java Beans that you know?

In Java Beans, there are several standard scopes that define the lifetime and visibility of bean instances in web applications:

• request: One bean instance is created for each HTTP request. The bean is available during the request's lifetime, including server-side processing and sending the response to the client. Useful for data specific to a single request.

• session: One bean instance is created for each HTTP session of a user. The bean is available throughout the session’s activity. Suitable for storing data related to a specific user across multiple requests.

• application: One bean instance is created for the entire web application. The bean is available to all users and requests for the duration of the application's runtime. Used for global data or resources.

• page: (In JSP) One bean instance is created for each JSP page. The bean is only available on that specific page during its processing. Less common in modern frameworks compared to other scopes.

• none: (Sometimes used in frameworks like Spring) It is not a standard scope in the context of JSP/Servlets. It means a new bean instance is created each time it is requested or injected. Essentially, a new object is provided each time.

Example of usage in JSP with GSP tags:

<%-- bean with request scope --%>
<jsp:useBean id="myRequestBean" class="com.example.MyBean" scope="request"/>

<%-- bean with session scope --%>
<jsp:useBean id="mySessionBean" class="com.example.MyBean" scope="session"/>

<%-- bean with application scope --%>
<jsp:useBean id="myApplicationBean" class="com.example.MyBean" scope="application"/>

In modern frameworks like Spring, scopes can be extended and customized, but the main concepts of request, session, and application remain fundamental. Spring, for example, adds Singleton (similar to application) and Prototype (similar to none).