JSPs and Servlets Tutorial 14 - Using jspInit and InitParams

Here we'll see how our understanding of the init concepts of servlets translates to JSPs.

[@Ruzveld83]

For those who also got confused with jspInit() and _jspInit() methods. A JSP-servlet extends abstract class HttpJspBase which is an HttpServlet. In HttpJspBase: public final void init(ServletConfig config) throws ServletException { super.init(config); jspInit(); _jspInit(); } the underscored method is redefined by Tomcat while creating a servlet and the other method stays empty in order to let the user redefine it.

[@זוהרנייגו]

Hello Koushik , just wanted to brace you for this wonderful tutorial , you great lecture and it was not just increase my knowledge it also very fun engaged to watch all of your other tutorial ... well done I wish you will deliver more great tutorials in future . Thank and great regards , Zohar N

[@sparkman786]

Dude these videos are awesome! Thank you so much for doing this. I have learned more from these videos than anything else.

[@ankitjain8849]

Thanks for the sharing the tutorial they are helping in knowing the starting blocks for JSP!!

[@suri4uonutube]

Thanks for the tutorial, I have one question. You are overriding the init() method in JSP file(generated code). But i noticed in Parent class method signatures, its name starts with _(underscore), but in your overridden method , underscore is not there. Did you miss that or it is the way it should be, then in that case, it cannot be overriding. Please correct me if i am wrong

[@LiveLoveLaughEveryday]

You made my Thanksgiving long weekend :-)

[@EurekaYoga]

At your command line prompt try: find -mtime 0 | fgrep _jsp.java > /home/dir.txt That should create a text file with the path to *_jsp.java. Mine was deep inside the hidden folder .metadata.

[@neerajmahajan1305]

Good Video and explanation.

[@thevagabond85yt]

Java Brains earlier when we used servlets you showed us how we can use init params using both ( in web.xml and @WebInitParam annotations in servlet itself) but in JSP there's no alternative to use the Annotation method(right?). So the conclusion : while using JSP and desiring for init params you are forced to use web.xml

[@bruno199131]

thanks for this explanation, but i have a question, when i do "super." to see the method that i m overriding this method don't appear in the eclipse list. I think that this happens because ecplise don't recognize this jsp like a HttpJspPage but like a Servlet. M.i wrong?

[@tejaaravind5271]

You are using ServletContext in JspInit method.... can we use application object to set the value...when i check in my own editor by giving application .setAttribute in place odf servletContext it is showing error. i dont know why.... i am having doubt with implicit objects...can we use implicit objects in the Jspinit method or any in anyother method. plz help me

[@sparkman786]

does your jsp-file tag match the spelling and case of your filename?

[@sonnix31]

Thanks alot!

[@kaushiksinha786]

init /init.jsp test me init /init.jsp Then in my init.jsp I can get the init params using getServletContext.getInitParameter.. However, I am using WebSevlet 3.0 annotations and I can't see equivalent jsp-file annotation. I am looking for something along these lines @WebServlet(initParams=@WebInitParam(name="hello", value = "hello"),description = "A Simple Servlet", urlPatterns = { "/init.jsp" }) where I can use jsp-file annotation. So I need to set the jsp init params without using web.xml.

[@hussainv1]

The default user from the servlet config is: getServletConfig().getInitParameter("defaultUser") defined in initpage.jsp is returning null for me. Any idea why wat might have went wrong in my code as i have configured exactly as the one done in tutorial?

[@MrIcecreamAttack]

I have the same problem. :/ Did you find any solution?

[@denisrodriguez2054]

verify that the init method is correctly written public void jspInit(){....}

[@AkashSingh-el1ew]

In place of TOMCAT, I am using Glassfish, I found the java file for the init JSP file, but didn't find the jspInit() and destroy method in there, not sure why...anyone has any clue?

[@SoeaOu]

yes, thats more intuitive

[@rashikashreshtha118]

sir i am getting null value, i dont understand how to rectify the same.. Please help me

[@nehasinha4736]

Reload the Tomcat server and run the initpage.jsp file, I also got the same issue :-)

[@ManpreetSingh-qe8wn]

Why does the default username show up even if I give the username in the URL.... strange

[@devanggaur2511]

Manpreet Singh the username you gave in the URL was an attribute of the request object . It doesn't belong to servlet config or context.

[@EurekaYoga]

I couldn't find it either.

[@echelecopao]

If you can't find the generated servlet files, go to stackoverflow (.) com and search for question: 4543868

[@agastyapatashala9and10]

voice is not so clear....please record the voice clearly

[@AnirbanGorai]

It is clear enough.

[@dazelmann6589]

yes its crisp and clear.