Following are the JSP Lifecycle steps:
- Translation of JSP to Servlet code.
- Compilation of Servlet to bytecode.
- Loading Servlet class.
- Creating servlet instance.
- Initialization by calling jspInit () method
- Request Processing by calling _jspService () method
- Destroying by calling jspDestroy () method
- 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)
What is JSP lifecycle?
What is JSP LifeCycle? JSP Life Cycle is defined as translation of JSP Page into servlet as a JSP Page needs to be converted into servlet first in order to process the service requests. The Life Cycle starts with the creation of JSP and ends with the disintegration of that.
What are the phases of the JSP cycle?
There are certain phases in which this cycle is divided, defined as follows: Translation phase: where the JSP file gets converted into the servlet file. Compilation phase: where servlet file gets converted to servlet class. Clean up of the JSP, here servlet container will call jspDestroy () method.
What is the JSP destruction phase?
The destruction phase of the JSP life cycle represents when a JSP is being removed from use by a container. The jspDestroy() method is the JSP equivalent of the destroy method for servlets. Override jspDestroy when you need to perform any cleanup, such as releasing database connections or closing open files.
How many times do you initialize JSP?
Typically, initialization is performed only once and as with the servlet init method, you generally initialize database connections, open files, and create lookup tables in the jspInit method. This phase of the JSP life cycle represents all interactions with requests until the JSP is destroyed.
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What is the 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 many phases are there in a JSP life cycle?
The four major phases of a JSP life cycle are very similar to the Servlet Life Cycle. The four phases have been described below −
What is the destruction phase of a JSP?
The destruction phase of the JSP life cycle represents when a JSP is being removed from use by a container.
What is _jspservice in JSP?
The _jspService () method of a JSP is invoked on request basis. This is responsible for generating the response for that request and this method is also responsible for generating responses to all seven of the HTTP methods, i.e, GET, POST, DELETE, etc.
How often is initialization performed?
Typically, initialization is performed only once and as with the servlet init method, you generally initialize database connections, open files, and create lookup tables in the jspInit method.
What are the three methods that control the lifecycle of a JSP?
These are: jspInit (), _jspService () and jspDestroy ()
What is JSP life cycle?
JSP Life Cycle is defined as the translation of the JSP Page into the servlet. Because JSP Page always needs to be converted into servlet page first in to process the service requests. Every JSP page ends with .jsp extension. Whenever we were given a request to the server for a .jsp file then first .jsp will be converted into a .java file. Second, .java file is converted into .class file. Third, .class is loaded by container and managed by the container. Basically .jsp to .java and .java to .class conversion is performed by JSP engine. All .class file loading and execution is performed by the container (servlet container). The JSP Life Cycle always starts with the creation of the JSP page and ends with the disintegration of that.
What happens after a servlet is initialized?
After the servlet is initialized successfully, the container will create a thread to access the _JspService (_,_) method, for this container has to create HttpServletRequest and HttpServletResponse.
What does container check in JSP?
In this phase, the container will check whether all the tags available on the JSP page are in well-formed format or not.
When we send a request from the client to the server for a specific JSP page, what happens?
When we send a request from the client to the server for a specific JSP page then the container will devour the request, identify the requested JSP pages, and perform the subsequent life cycle actions:
What is jspdestroy in Servlet?
jspDestroy () Method: jspDestroy () method is similar to the destroy () method in Servlet. The destroy () method is automatically called when the JSP terminates normally. It isn’t called by JSP when it terminates. It is used for cleanup where resources used during the execution of the JSP are released.
When container generated thread reached the ending point of the _JSPService (_,_) method, what happens?
When container generated thread reached the ending point of the _JspService (_,_) method then that thread is going to be in a Dead state, with this container will dispatch dynamic response to the client through the Response Format.
What is the last step in JSP cleanup?
The last step is called JSP clean up; JSP has to be removed from use by the container, and the jspDestroy () method is used for the same ; this method shall be invoked once only. There is a provision to override this method, and that can be done for instances where we want to perform our custom action like connection release for database etc.
Where do we need JSP?
Well, if you are into web-based development and what we see is building dynamic websites , then JSPs play a vital role as rendering is done dynamically.
What is translation phase?
Translation phase: where the JSP file gets converted into the servlet file.
What is a no argument constructor in JSP?
After loading a class file by the web container, the JSP container now uses a no-argument constructor for creating an instance of the servlet class now; once the container initializes the objects by an invocation of the jsplnit () method.
What are modern technologies compatible with?
Modern technologies are compatible with JSPs and are used by struts and spring -like frameworks that find a place in big applications related to banking, SCM, retail stores, etc. Compatible with AJAX calls for dynamic rendering.
What is JSP in content?
JSP enables separation of content generation and content presentation
Why is JSP an ideal place in many frameworks?
So JSP finds an ideal place in many frameworks due to their flexibility.
What is the JSP life cycle?
JSP Life Cycle is defined as translation of JSP Page into servlet as a JSP Page needs to be converted into servlet first in order to process the service requests. The Life Cycle starts with the creation of JSP and ends with the disintegration of that.
How often is initialization called in JSP?
It is only called once during a JSP life cycle, the method for initialization is declared as shown above
What is a JSP container?
A JSP container is an extension of servlet container as both the container support JSP and servlet. A JSPPage interface which is provided by container provides init () and destroy () methods. There is an interface HttpJSPPage which serves HTTP requests, and it also contains the service method. Initialization.
What is demo.jsp?
demo.jsp, is a JSP where one variable is initialized and incremented. This JSP is converted to the servlet (demo_jsp.class ) wherein the JSP engine loads the JSP Page and converts to servlet content.
Which code line is overriding the service method of jsp?
Code Line 2,3: Overriding the service method of jsp i.e. _jspservice which has HttpServletRequest and HttpServletResponse objects as its parameters
When the browser asks for a JSP, what engine first checks whether it needs to compile the page?
When the browser asks for a JSP, JSP engine first checks whether it needs to compile the page. If the JSP is last compiled or the recent modification is done in JSP , then the JSP engine compiles the page.
When does Java source page translation happen?
The translation of java source page to its implementation class can happen at any time between the deployment of JSP page into the container and processing of the JSP page.
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 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.
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.
What is the JSP execution phase?
In the execution phase of JSP page, first JSP page is translated into an equivalent Servlet, then the source file of the Servlet is compiled into a .class file. Every time a JSP page is requested, its corresponding Servlet will be executed. So life cycle of JSP is similar to Servlet life cycle.
What is the life cycle of a program?
Life cycle of a program includes the phases starting from creating objects for the class, execution, and at last destruction of objects. For this life cycle, JSP needs some life cycle methods.
What is JSP container?
In this stage, JSP container compiles the Java source code i.e. the equivalent servlet code and converts into Java byte (.class) code. Generally, most servers like web logic, discard the generated source code after compilation phase.
What is the process of converting JSP code into an equivalent Servlet program code called?
Page compilation: The process of converting JSP code into an equivalent Servlet program code is called JSP page compilation.
What is a request processing web container?
Request processing: In this stage, web container uses the successfully initialized ISP equivalent Servlet objects to process client request. As per Servlet life cycle web container invokes service (-,-) method on the Servlet object by passing the request object of HttpServletRequest and response object of HttpServletResponse. In case of JSP equivalent Servlet. the container invokes the _jspService () method.
How to initialize a servlet class?
After that the container initializes the objects by invoking the init (ServletConfig) method. This method is called jsplnit () method.
How to destroy a servlet instance?
After the current threads complete their operations on service ( -,-) method , then the container calls the destroy () method on a Servlet instance, which invokes the jspDestroy () method.
Where Do We Need Jsp?
Life Cycle of Jsp
- There are certain phases in which this cycle is divided, defined as follows: 1. Translation phase:where the JSP file gets converted into the servlet file. 2. Compilation phase:where servlet file gets converted to servlet class. 3. Class loading 4. Instantiation of the servlet object 5. Servlet container calls jspInit() method for initialization 6. ...
Conclusion
- Hence we learned that dynamic websites have their frontend rendered via JSPs, while static pages can be directly put to HTML purely as they do not need any data/content manipulations thenceforth.
- Modern technologies are compatible with JSPs and are used by struts and spring-like frameworks that find a place in big applications related to banking, SCM, retail stores, etc.
- Hence we learned that dynamic websites have their frontend rendered via JSPs, while static pages can be directly put to HTML purely as they do not need any data/content manipulations thenceforth.
- Modern technologies are compatible with JSPs and are used by struts and spring-like frameworks that find a place in big applications related to banking, SCM, retail stores, etc.
- Compatible with AJAX calls for dynamic rendering.
- An application cannot be of type single page as every time page is required to be loaded from the backend.
Recommended Articles
- This has been a guide to JSP Life Cycle. Here we discussed the basic concept, steps, and example of the JSP Life Cycle, respectively. You can also go through our other suggested articles to learn more – 1. JSP vs ASP 2. JSP vs Servlet 3. JSP in Java 4. JSP Redirect