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How do you manage all the request from your servlet? How it will be thread safe?
pradeepkmr18
- Jun 11th, 2008
By implementing single thread model we can make thread safe .Due to this it will create one instance per thread or request
bharaniprasanth
- Mar 11th, 2008
Servlets by default are not thread safe...But we need to take many steps to make them thread safe...like using synchronized blocks,varaibles...etc...
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How do you write custom tags like tag library
pradeepkmr18
- Jun 11th, 2008
To develop acustom tag1)we need to write our own .tld2)for every tag in the tld we have to write tag handler classes (Generally .jar files contains the taghandler classes)using doStartTag(),doAfterBod...
bharaniprasanth
- Mar 11th, 2008
Four elements are needed1. Tag class.2. TLD descriptor3. Inclusion of the prefix elements line in Beginning of JSP4. Using the tags with a start and end tag elements...Not to forget mention the tag library in the web.xml
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Where do you use exception implicit object in JSP?
pradeepkmr18
- Jun 11th, 2008
To display the type of exceptionone.jsp<%@ page errorPage="errorpage.jsp" %><% ----- %>errorpage.jsp<%@ page isErrorPage="true" %><% out.println(exception.getMessage()); %>
vishnu.baji
- Feb 28th, 2008
We use it in error pages. We will have details of exception thrown from the previous page and we can handle actions based on the type of exception...
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When jasper exceptions will occurs and why?
pradeepkmr18
- Jun 12th, 2008
If there is any problem during compilation servlet(converted jsp to servlet) Generally this jasper exception will comejava.lang.Object | +--java.lang.Throwable | +--java.lang.Excep...
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If we declare a page isThreadSafe="false" then how the page will act?
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satish_bakde- Member Since Dec-2007 | Dec 7th, 2007
A JSP page is by default thread unsafe. That means when server finds a request to JSP, an instance is created and the request is processed. The code inside service method is processed. While in this process, if another request arrives, Server again starts executing the code inside service method for 2nd one. Multitasking is invoked to switch CPU between execution of these 2 threads created. Both are executing same code so, so if any thread changes a variable value and then second reads it, it will get changed one.
Though this is bad programming practise to have code like this, in case becomes unavoidable. At this time make page threadSafe="true". This will make service method synchronized and at a time only one thread will execute the code. other thread have to wait till that time. Assume how bad will be the response time of server when 100s of requests arrives at a time!bharaniprasanth
- Mar 10th, 2008
Yes which is why we use servlets instead of Jsp's for handling the web requests...
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If the cookies on the client side is disable ie., no cookies to track session. Then how one will be able to track session.thanks
mytramesh
- Oct 13th, 2006
using of the UrlRewriting we con achive this.response.encodeUrl(url);response.encodeRedirectUrl(url);First check for whether the cookies are supported by browser or not. if browser supports it return ...
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Restrict JSP page errors
How do you restrict page errors display in the JSP page.
praveen439
- Jul 9th, 2008
You first set "Errorpage" attribute of PAGE directory to the name of the error page (ie Errorpage="error.jsp")in your jsp page .Then in the error jsp page set "isErrorpage=TRUE". When an error occur in your jsp page it will automatically call the error page
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How does a servlet communicate with a JSP page?
The following code snippet shows how a servlet instantiates a bean and initializes it with FORM data posted by a browser. The bean is then placed into the request, and the call is then forwarded to the JSP page, Bean1.jsp, by means of a request dispatcher for downstream processing.public void doPost (HttpServletRequest request, HttpServletResponse response){try {govi.FormBean f = new govi.FormBean();String...
mullangi13
- Jul 23rd, 2008
Hi Jose Kutty,Mr. Nanda is wrong. We can create RequestDespatcher object by two ways, either by ServletRequest object request.getRequestDispatcher("/abc....
Rajkumar
- Aug 24th, 2007
A Servlet can communicate with JSP by using the RequestDispatcher mechanism.RequestDispatching is the process hand overing the request to another web component,and this component takes the response of...
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What is the difference between http session and application session?
bh2008
- Aug 7th, 2008
HttpSession is logged is user specific. You can't access across the users.But application session (static) variables can be accessed across the users in the application.HttpSession variable life t...
vinayroz
- Aug 6th, 2008
There is nothing like application session. In simple words we can take it as how we manage session in our application, so that is by HttpSession interface or by Url rewriting, hidden fields and cookies.
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Which tag in the jsp is used to define the error page. (Multiple choice)
Skill/Topic: Programming ConstructsA) None of the above B) C)
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The tag %@include file=”.........” % > helps in including the ______ file in the JSP page (Multiple choice)
Skill/Topic: Programming ConstructsA) readOnlyB) dynamicC) staticD) None of the above
Ashique
- Aug 13th, 2008
The answer should be C) Static.Because this include directive happens at TRANSLATION TIME (i.e. The very first time your jsp page is called the code gets written to a servlet). So later on when we mak...
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Which of the following statement is true for the include directive (Multiple choice)
Skill/Topic: Programming ConstructsA) Can be used to incorporate contents from static documents B) It offers option of sharing local variables and better run time efficiencyC) Provides benefit of automatic recompilation. D) It is processed during translation and compilation and does not impose any restrictions on output buffering
Ashique
- Aug 13th, 2008
A, B and D are seems to be correct.Because A) the include directive allows you to bring in code from another file without re-writing the code.B) As this inclusion of file is done during compilation ti...
snavanethakrshnan
- Aug 12th, 2008
It is processed during translation and compilation and does not impose any restrictions on output buffering
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The jsp:useBean attribute is used to indicate the Serialized bean
Skill/Topic: Programming ConstructsA) TrueB) False
raghuprasad
- Aug 25th, 2008
The Bean class?which we write has to?extend Serializable Interface to make that bean Serialized.?The bean itself won't become Serialized automatically.Raghu.?
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What are the implicit objects in JSP & differences between them
Santhosh
- May 31st, 2005
There are nine implicit objects in JSP. 1. pageContext 2. session 3. request 4. response 5. exception 6. out 7. application 8. config 9. page ...
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Find the number of Visitors
How we can find the number of visitors in a given site?How to find the count of number of hits to a particular page irrespective of user?
maneesh.ce.2007
- Dec 10th, 2008
On load of that page...Call a function that has a static variable say count=0;now return from that method count++;so now when everytime ur method gets called this function will get load and increment the value of count....which u can get using <%=> 'Expresion'...
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The session tracking in the JSP can be done by :- 1. URL rewriting 2. Cookies 3. User-Authorization 4. Hidden Files
Skill/Topic: Session HandlingA) 1,3,4 only B) 2,3,4 only C) 1,2,4 only D) 1,2,3,4
aquakolkata
- Jan 6th, 2009
1)URL Rewriting2)Cookies3)Hidden form field4)Setting session id using response.encodeURL()...etc...
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State true or false -- ServletContext class gives information about the Request?
Skill/Topic: Programming ConstructsA) TrueB) FalseExplanation: ServletContext: Gives the information about the container. PageContext: Gives the information about the Request
nainaaltaf
- Jan 28th, 2009
False. ServletContext give info abt container while pageContext give info abt request
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How we will provide security in jsp's & servlets ?
talktoudaykumar
- Mar 2nd, 2009
One of the reasons people will use servlets is security.We can provide security in servlets in two ways1.Declaratively2.ProgramaticallyUsing this security features we can guarantee these security it...
kiran.kandem
- Nov 16th, 2008
We can provide security in JSP's and Servlets keeping the source files in WEB-INF folder.
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The ________ listeners are notified when session objects are created, invalidated, or timed out.
Skill/Topic: JSP Thread ModelA) Session AttributeB) Servlet context attributeC) Session ListenersD) Servlet context listeners
Nag
- Dec 22nd, 2006
Session Listeners
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<%
PrintWriter print = request.getWriter();
print.println("Welcome");
>%
Suppose you access this JSP file, Find out your answer.
a) A blank page will be displayed.
b) A page with the text Welcome is displayed
c) An exception will be thrown because the implicit out object is not used
d) An exception will be thrown because PrintWriter can be used in servlets only
">Write the following code for a JSP page:<%@ page language = "java" %> <%PrintWriter print = request.getWriter();print.println("Welcome");>%Suppose you access this JSP file, Find out your answer.a) A blank page will be displayed.b) A page with the text Welcome is displayedc) An exception will be thrown because the implicit out object is not usedd) An exception will be thrown because PrintWriter can be used in servlets only
A page with the text Welcome is displayed
spring
- Apr 6th, 2009
This code will print "Welcome"request does't have any getWriter() defined, only response has.<%@ page language = "java" %><%java.io.PrintWriter print = response.getWriter();print.println("Welcome");%>
bharaniprasanth
- Mar 11th, 2008
I think we have to use Jsp Writer as a part of specification ...PrintWriter is for servlets exclusively..
JSP Interview Questions
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