What is jsp?

JavaServer Pages (JSP) is a technology used for creating dynamic, platform-independent web-based applications. It is an extension of Java Servlet technology and is maintained by Oracle Corporation. JSP allows developers to embed Java code in HTML pages using special JSP tags, making it easier to build web applications combining static templates and dynamic content.

Here are some key points about JSP:

1. Syntax and Structure: JSP pages are basically HTML files with embedded Java code, enclosed within special tags like <%= %> for expressions and <% %> for scriptlets. Developers can also use directives like <%@ ... %> to specify page settings and include files.

2. Lifecycle: The JSP lifecycle includes several phases: translation, compilation, initialization, execution, and cleanup. When a client requests a JSP page, it is first translated into a Java servlet if it is not already translated, then compiled into executable code.

3. Separation of Concerns: JSP facilitates a clear separation between the presentation layer and the business logic layer, allowing designers and developers to work independently on the HTML layout and Java code, respectively.

4. Custom Tags and Tag Libraries: JSP supports the use of custom tags and tag libraries (or JSP tag libraries), which help reduce the amount of Java code in JSP files by abstracting complex Java operations into simple XML-like tags.

5. Expression Language (EL): JSP's Expression Language is a powerful feature that provides a simplified syntax to access and manipulate application data, without having to write Java code directly.

6. Integration: JSP can be seamlessly integrated with JavaBeans and Enterprise JavaBeans (EJBs) to access server-side components, making it a suitable choice for building large-scale enterprise applications.

7. Frameworks: While JSP can be used standalone, it is often used in conjunction with frameworks like JavaServer Faces (JSF) or Apache Struts, which provide additional structure and functionality for web application development.

8. Deployment: JSP pages are typically deployed on a servlet container, like Apache Tomcat or Jetty, which handles the conversion of the JSP into servlets and processes HTTP requests and responses.

Overall, JSP is a robust and mature technology for developing web applications. However, it is often used in combination with modern frameworks that offer more advanced features and better ease of use for developers.