JSP Actions (also called JSP Action Tags or JSP Action Elements) are special XML-like tags that perform predefined tasks when a JSP page is processed.

They are part of the JSP specification itself (not user-defined or third-party) and are executed on the server-side during page request handling.

🎯 Purpose of JSP Actions:

• Encapsulate functionality (like including other resources, forwarding requests, working with JavaBeans) without writing Java code manually.
• Simplify interaction with backend logic.
• Promote reuse and cleaner JSP code.
• Help JSP remain more declarative (tag-based) rather than imperative (Java code blocks).

🔥 Syntax of Action Tags

<jsp:actionName attribute="value" />

They look like XML elements: start with <jsp:, followed by the action name.

They must be properly closed (either self-closing or with explicit end tag).

🔵 Common JSP Action Elements

Action Tag	Purpose
<jsp:useBean>	Locate or instantiate a JavaBean
<jsp:setProperty>	Set a property value on a bean
<jsp:getProperty>	Get a property value from a bean
<jsp:include>	Dynamically include another resource
<jsp:forward>	Forward request to another resource
<jsp:param>	Add parameters to include or forward
<jsp:plugin>	Download and run a Java plugin (like Applet)

🔥 Short Examples for Each:

1. <jsp:useBean>

Create or find a JavaBean instance.

<jsp:useBean id="user" class="com.example.User" scope="session" />

• If no user exists in session, create it.

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2. <jsp:setProperty>

Set property values inside a JavaBean.

<jsp:setProperty name="user" property="name" value="Stanley" />

Sets user.setName("Stanley");

You can also populate properties automatically from request parameters:

<jsp:setProperty name="user" property="*" />

➔ Sets all matching properties.

3. <jsp:getProperty>

Retrieve property values from a bean.

<p>Welcome, <jsp:getProperty name="user" property="name" />!</p>

Output: Welcome, Stanley!

4. <jsp:include>

Include another file at request time (dynamic inclusion).

<jsp:include page="footer.jsp" />

• Runs footer.jsp and inserts its output here.

You can also pass parameters:

<jsp:include page="header.jsp">
    <jsp:param name="title" value="Home Page" />
</jsp:include>

5. <jsp:forward>

Forward request internally to another resource.

<jsp:forward page="login.jsp" />

• Stops further processing and sends request to login.jsp.

You can also pass parameters similarly with <jsp:param>.

6. <jsp:plugin>

Embed Java applets or JavaBeans dynamically.

<jsp:plugin type="applet" code="MyApplet.class" width="300" height="300">
    <jsp:params>
        <jsp:param name="color" value="blue" />
    </jsp:params>
</jsp:plugin>

(Not very common anymore — applets are obsolete today.)

📌 Important points about Action Tags:

• They are server-side only: the browser never sees them.
• They provide a declarative, tag-based alternative to embedding Java code (<% %>).
• Some actions, like <jsp:include>, happen at runtime (not at translation time).

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🛠️ Why are Action Tags Important?

• Cleaner and more readable JSPs (instead of mixing lots of Java code).
• Help integrate JavaBeans with the UI layer easily.
• Make JSPs easier to maintain and extend.
• Support separation of concerns: JSPs handle presentation; JavaBeans handle business data.

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🎯 Final Recap:

Aspect	Description
What are they?	Built-in JSP tags for predefined tasks
Look like?	XML-style, <jsp:actionName>
Why use them?	Cleaner, more modular, server-side dynamic behavior