How Does A JSP Page Work?

Which is mandatory in tag?

Mandatory Tags allow implementers to specify ContentTags and ObjectTags that must have their Tag Parts filled with their correct required values before the page can be published..

How are JSP pages handled?

Exception Handling is the process to handle the runtime errors. … In JSP, there are two ways to perform exception handling: By errorPage and isErrorPage attributes of page directive. By element in web.

How can a servlet call an error JSP page?

If any type of exception occurs while executing an action, the servlet catches it, sets the javax. servlet. jsp. jspException request attribute to the exception object, and forwards the request to the error JSP page.

How do I debug a JSP file?

ProcedureIn the Project Explorer view, open your JSP file. … Verify that you are using the Source page of the editor. … From the JSP file’s context menu in the Project Explorer view, click Debug As> Debug on Server. … In the Debug view, step through the code and make the necessary changes to the JSP file. … Save the JSP file.More items…

Which tag in JSP is used to define a page as an error page?

isErrorPageIn order to make any JSP page as an error page, you need to use “isErrorPage” attribute of page directive and mark it true. This is a preferred way of showing error messages in Java web application if you have custom error messages based on JSP and it also supersedes any application-wide error page defined in web.

Should I learn JSP and servlets?

Short answer: no, you don’t need to learn Servlets and JSPs as a pre-requisite for Spring MVC and many other Java web frameworks. … It’s a persistence layer framework and it doesn’t have anything to do with Servlets and JSPs. Servlet API is the lowest level for almost all Java web frameworks.

What has replaced JSP?

JSP Is Legacy Technology JSP is Java EE’s legacy web programming technology, which was released in the first version of J2EE back in 1999. Later it was replaced in 2003 by JSF, but its development continued with the latest version 2.3, released in Java EE 7.

Are JSPs dead?

Servlets and JSPs are considered outdated technologies and no longer chosen for the new projects. These were found in use significantly for legacy projects. Servlet JSPs were used enormously in around 2000. With the popularity of emerging MVC frameworks like Struts, Webwork, Spring etc.

Does JSP need to be compiled?

As long as it is JSP, you dont need to compile/convert. The application server automatically translates your JSP into corresponding servlet, a Java file (on the first hit to the JSP), and then compiles it to class file. … JSPs and will compile them to Servlet classes and reload if needed.

What is error page in JSP?

JSPJava 8Object Oriented ProgrammingProgramming. JSP gives you an option to specify Error Page for each JSP using page attribute. Whenever the page throws an exception, the JSP container automatically invokes the error page. Following is an example to specifiy an error page for a main.

Is JSP interpreted or compiled?

At run time, the JSP code is interpreted by the JSP compiler, which parses out all the special features in the JSP code and translates them to Java code. The Java class created from each JSP implements Servlet . … Still at run time, it is compiled into bytecode and then into machine code.

Can we override JSP service method?

You cannot override the _jspService() method within a JSP page. You can however, override the jspInit() and jspDestroy() methods within a JSP page. jspInit() can be useful for allocating resources like database connections, network connections, and so forth for the JSP page.

Is JSP still used 2020?

Why is the technology that has been defined as “old” a few years ago is still hot in 2020, and every year someone still asks: “Do you still need to learn JSP?” I think the reason is also very simple:JSP used a lot before! When I was learning Java, I often heard: JSP and PHP can writedynamic webpages”My Teacher”.

Which JSP life cycle is in the correct order?

Which one is the correct order of phases in JSP life cycle? Explanation: The correct order is Compilation, Initialization, Execution, Cleanup.

What is JSP life cycle?

A JSP life cycle is defined as the process from its creation till the destruction. This is similar to a servlet life cycle with an additional step which is required to compile a JSP into servlet.

How JSP is compiled?

The JSP engine compiles the servlet into an executable class and forwards the original request to a servlet engine. A part of the web server called the servlet engine loads the Servlet class and executes it. During execution, the servlet produces an output in HTML format.

What is the first stage in the JSP life cycle?

A Java servlet file is generated from a JSP source file. This is the first step of JSP life cycle. In translation phase, container validates the syntactic correctness of JSP page and tag files.