When a request is made for a JSP page, the event JSP page loads. In the event JSP, the UI modules, the data providers, and the controller are declared. The modules are registered to the controller.
- JSP page translation (validation, translation, compilation phases)
- Load Class.
- Instantiate.
- jspInit method is called.
- _jspService method is called.
- jspDestroy method is called.
What is a JSP ACTION tag?
The jsp action tags allow the perform actions on the jsp pages and it forwards the http requests into the jsp or servlet page. It also includes the data contents of another jsp,html web pages within the jsp web page.
How does JSP forward tag work?
How Does JSP Forward? The jsp forward tag will use mainly in the action event in the web page that is used for forwarding the request from one-page resources it will be either the html,jsp or any java servlet files it has to be loaded after the user clicks the events or functions of the web page.
What is a JSP page?
The JSP page is called via a JSP page, HTML page, or JAVA servlet. Once it is called then the cycle mentioned below is triggered to generate dynamic content. This dynamic content is then fed on the web page. Any server can be used in the back end like wildfly, tomcat, or others for this technology to work.
How to call a java function from a JSP event?
The onclick event occurs when the user clicks on an element. This attribute has the ability to call JS functions (front end) In your case, you want to call a JAVA function (server side) so the best way is to move the java code to a servlet and use it. Anyway if you want to keep the JAVA function in the jsp, you can do this via ajax in this way
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What are the JSP lifecycle phases?
Following steps are involved in the JSP life cycle:Translation of JSP page to Servlet.Compilation of JSP page(Compilation of JSP into test. ... Classloading (test. ... Instantiation(Object of the generated Servlet is created)Initialization(jspInit() method is invoked by the container)More items...•
How many phases are there for JSP page?
Compilation process of JSP page involves three steps: Parsing of JSP. Turning JSP into servlet. Compiling the servlet.
What are the features of JSP pages?
Main features of JSPMake interactive websites.Easier to read data from user.Easier to display server response.Allows to add Java to your website.Easier to connect to the database.Tracking the User.Easy to code.
What is a JSP page?
It stands for Java Server Pages.It is a server side technology.It is used for creating web application.It is used to create dynamic web content.In this JSP tags are used to insert JAVA code into HTML pages.It is an advanced version of Servlet Technology.More items...•
What are the JSP tags?
JSP Action TagsJSP Action TagsDescriptionjsp:includeincludes another resource.jsp:useBeancreates or locates bean object.jsp:setPropertysets the value of property in bean object.jsp:getPropertyprints the value of property of the bean.4 more rows
How a JSP page is executed?
JSP ProcessingAs with a normal page, your browser sends an HTTP request to the web server.The web server recognizes that the HTTP request is for a JSP page and forwards it to a JSP engine. ... The JSP engine loads the JSP page from disk and converts it into a servlet content.More items...
What are the main 3 components of JSP pages?
There are three types of JSP elements you can use: directive, action, and scripting.
What is the syntax of JSP?
JSP ActionsS.No.Syntax & Purpose1jsp:include Includes a file at the time the page is requested.2jsp:useBean Finds or instantiates a JavaBean.3jsp:setProperty Sets the property of a JavaBean.4jsp:getProperty Inserts the property of a JavaBean into the output.6 more rows
What is the syntax of JSP page directive?
The Page directive defines a number of page dependent properties which communicates with the Web Container at the time of translation. Basic syntax of using the page directive is <%@ page attribute="value" %> where attributes can be one of the following : import attribute.
What is the full name of JSP?
JavaServer Pages (JSP) is a Java standard technology that enables you to write dynamic, data-driven pages for your Java web applications. JSP is built on top of the Java Servlet specification.
How does a JSP function?
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.
Why is JSP used?
JSP pages are precompiled for efficient server processing. JSP pages can be used in combination with servlets that handle the business logic, the model supported by Java servlet template engines.
What is JSP translation phase?
During the translation phase each type of data in a JSP page is treated differently. Static data is transformed into code that will emit the data into the response stream. JSP elements are treated as follows: Directives are used to control how the web container translates and executes the JSP page.
What is the syntax of JSP page directive?
The Page directive defines a number of page dependent properties which communicates with the Web Container at the time of translation. Basic syntax of using the page directive is <%@ page attribute="value" %> where attributes can be one of the following : import attribute.
What is correct about JSP scriptlet?
In JavaServer Pages (JSP) technology, a scriptlet is a piece of Java-code embedded in the HTML-like JSP code. The scriptlet is everything inside the <% %> tags. Between these the user can add any valid Scriptlet i.e. any valid Java Code. In AppleScript, a scriptlet is a small script.
What level is event in HTML?
Events are a part of the Document Object Model (DOM) Level 3 and every HTML element contains a set of events which can trigger JavaScript Code.
What is an Event ?
JavaScript's interaction with HTML is handled through events that occur when the user or the browser manipulates a page.
What is an event when a user clicks a button?
When the user clicks a button, that click too is an event. Other examples include events like pressing any key, closing a window, resizing a window, etc.
What is onsubmit in a form?
onsubmit is an event that occurs when you try to submit a form. You can put your form validation against this event type.
When a user navigates to a page ending with a.jsp extension in their web browser?
When a user navigates to a page ending with a .jsp extension in their web browser, the web browser sends an HTTP request to the webserver.
What is the life cycle of a JSP page?
A JSP page life cycle is defined as a process from its translation phase to the destruction phase. This lesson describes the various stages of a JSP page life cycle.
What happens if a JSP page is not compiled?
If the JSP page's compiled version does not exist, the file is sent to the JSP Servlet engine, which converts it into servlet content (with .java extension ). This process is known as translation. The web container automatically translates the JSP page into a servlet. So as a developer, you don't have to worry about converting it manually.
How many times does servlet initialize?
This initialization is done only once with the servlet's init method where database connection, opening files, and creating lookup tables are done.
When is the destruction phase invoked?
This destruction phase is invoked when the JSP has to be cleaned up from use by the container. The jspDestroy () method is invoked. You can incorporate and write cleanup codes inside this method for releasing database connections or closing any file.
1. Directive Elements
Defines page-dependent attributes, such as session tracking, error page, and buffering requirements.
3. Scripting Element
Scriptlet elements must be written within the <% … %> tags.The Scriptlet tag allows writting Java code statements within the JSP page.The tag is responsible for implementing the functionality of “_jspService ()” by scripting the java code.The JSP engine will process any code written within the pair of <% and %> tags and any other code is treated as plain text while translating the JSP page.
What are actions in JSP?
In this chapter, we will discuss Actions in JSP. These actions use constructs in XML syntax to control the behavior of the servlet engine. You can dynamically insert a file, reuse JavaBeans components, forward the user to another page, or generate HTML for the Java plugin.
When is jsp:setProperty executed?
Here, the jsp:setProperty is executed only if a new object was instantiated, not if an existing one was found.
What is a forward action in Java?
The forward action terminates the action of the current page and forwards the request to another resource such as a static page, another JSP page, or a Java Servlet.
How many syntaxes are there for action elements?
There is only one syntax for the Action element, as it conforms to the XML standard −
Why is the action important in XML?
The word dynamically is important, because it means that the XML elements can be generated at request time rather than statically at compile time.
Can you use jsp:setProperty after jsp:useBean?
You can use jsp:setProperty after, but outside of a jsp:useBean element, as given below −
What is JSP used for?
It is used for creating web application. It is used to create dynamic web content. In this JSP tags are used to insert JAVA code into HTML pages. It is an advanced version of Servlet Technology. It is a Web based technology helps us to create dynamic and platform independent web pages.
Is JSP easy to code?
Coding in JSP is easy :- As it is just adding JAVA code to HTML/XML.
What is JSP in web application?
The JSP has a set of different features for creating the web pages in the application will be more sophisticated. Among this jsp have set of predefined tags for working the functions of the web applications we have used mostly navigate the web pages using include and forward tags the tag which is used for forwarding the request from one page into another page it may be any resources like jsp, servlet or html the given request be either parametrized or non-parameterized based on the user requirement but the main focus is to terminate the current web page and also binded with the forward page.
How Does JSP Forward?
The jsp forward tag will use mainly in the action event in the web page that is used for forwarding the request from one-page resources it will be either the html ,jsp or any java servlet files it has to be loaded after the user clicks the events or functions of the web page. The jsp action tags allow the perform actions on the jsp pages and it forwards the http requests into the jsp or servlet page. It also includes the data contents of another jsp,html web pages within the jsp web page. We can create the java bean used to create the instance of the html ui tag elements like getter and setter methods we can set the values of its instance variables.
What is a JSP forward directive?
The jsp forward directive and action tags are two different types for translate the jsp codes into the jsp containers we can add all other extension files in the single web page for work in the navigation for web applications. We can forward the web pages but in url, the menu does not change the page.
Syntax
How Does Jsp Page Work in Jsp?
- JSP pages use primarily three functions to initialize, process, and finally, destroy the deployed page to print the dynamic content after interacting with the server. These three functions are jspInit(), _jspService() and jspDestroy() respectively. This is performed only when the JSP file is converted into a JAVA servlet internally. This JAVA file ...
Conclusion
- JSP pages are a simplified version of JAVA servlet owing to their simplicity and easier maintenance in comparison to JAVA servlets. It comes with the added advantages of custom tags and multiple useful libraries like JSTL multiplying the number of users for JSP technology. This is extensively used and undoubtedly one of the quickest ways to develop interactive web pa…
Recommended Articles
- This is a guide to JSP Page. Here we discuss How does JSP Page work in JSP along with respective examples for better understanding. You may also have a look at the following articles to learn more – 1. JSP Login Page 2. JSP Checkbox 3. JSP Redirect 4. JSP in Java
Translation Phase
- When a user navigates to a page ending witha .jspextension in their web browser,the web browser sends an HTTP request to the webserver.
- The webserver checks if a compiled version of the JSP pagealready exists.
- If the JSP page's compiled version does not exist, the file issent to the JSP Servlet engine, whichconverts it into servlet content (with .javaextension). This process is knownas translati…
- When a user navigates to a page ending witha .jspextension in their web browser,the web browser sends an HTTP request to the webserver.
- The webserver checks if a compiled version of the JSP pagealready exists.
- If the JSP page's compiled version does not exist, the file issent to the JSP Servlet engine, whichconverts it into servlet content (with .javaextension). This process is knownas translation.
- The web container automatically translates the JSP page into aservlet. So as a developer, you don't have to worry aboutconverting it manually.
Compilation Phase
- In case the JSP page was not compiled previously or at anypoint in time, then the JSP page is compiled by the JSPengine.
- In this compilation phase, the Translated.java file of the servlet is compiled into the Javaservlet .classfile.
Initialization Phase
- In this Initialization phase: Here, the container will: 1. Load the equivalent servlet class. 2. Create instance. 3. Call the jspInit()method for initializing theservlet instance. This initialization is done only once with the servlet's initmethod where database connection, opening files, and creatinglookup tables are done.
Execution Phase
- This Execution phase is responsible for all JSP interactions andlogic executions for all requests until the JSP gets destroyed. Asthe requested JSP page is loaded and initiated, the JSP engine hasto invoke the _jspService() method. This method isinvoked as per the requests, responsible for generating responsesfor the associated requests, and responsible for all HTTPmethods.
Destruction(Cleanup) Phase
- This destruction phase is invoked when the JSP has to be cleanedup from use by the container. The jspDestroy()method is invoked. You can incorporate and write cleanup codesinside this method for releasing database connections or closingany file.