Satyen Singh

Hello Friends,

I have a question:

What is the name of the jar files in which java.lang package is present? and in which folder is that jar file?

Thanks in advance

Hi Friends,

My question is,

can we have 2 objects of same hashcode in java?

if yes, how?

thanks in advance dear friends.

Thanks Bear,

Also I will take your advice of Interrogative Sentences Seriously.

Thanks once again.

Hey Tim,

What is the name of those Classes???
Does Container creates its own class???
when does those classes get loaded to execute the function definition ???

please reply,
Thanks Tim.

Hello freinds,

I am little confused about the various methods implementations.
Actually, I was Learning Servlet and JSP and I found many methods like

request.getSession();
response.getWriter();

and many more............

so please, can any one tell me where(In which class) the implementation of methods(getSession(), getWriter(), etc) are present ?

Thanks in advance, freinds.

even i use Notepad++.
It is good. you should use it

Hey Karl,

Don't think that Scanner is confusing or hard understand.
Remember Java's 1st Feature is that Java is "Simple" so, nothing is hard in java.
Scanner is very easy.
I will explain you how to use it and why .......

Now, If you want to read user input age from the console.
following is the code snippet in java using scanner.

class Myclass { public static void main(String args[]) { Scanner sc=new Scanner(System.in); //this line will create an object of Scanner class and it is going to read input from "System.in" means, from the console int age=sc.nextInt(); System.out.println(age); //if suppose you want to read String value like name then, use the below commented code. //String name=sc.next(); <-------- This line read the next token(word) from the console. or you can use the following. //String fullname=sc.nextLine() <----------- This line reads the whole line with spaces and words entered by the user on the console. } }

Thanks Rob,
It is working.......

Following is my code which throws "Null Pointer Exception" can anyone please tell me where exactly I am wrong

import javax.servlet.*; import javax.servlet.http.*; import java.io.*; public class ServletChain extends HttpServlet { public void doGet(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException { int number=0; try { number=Integer.parseInt(request.getParameter("txtNumber")); System.out.println("Servlet 1 :- You have Entered a Valid Number. Good!!!"); request.setAttribute("number",""+number); RequestDispatcher requestDispatcher=getServletContext().getRequestDispatcher("/chain2"); requestDispatcher.forward(request,response); } catch(NumberFormatException numberException) { System.out.println("Servlet 1 :- Sorry! You have Entered an Invalid Number"); } catch(Exception exception) { exception.printStackTrace(); } } }

And Following is the Error

java.lang.NullPointerException at ServletChain.doGet(ServletChain.java:16) at javax.servlet.http.HttpServlet.service(HttpServlet.java:627) at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appl icationFilterChain.java:269) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationF ilterChain.java:188) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperV alve.java:213) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextV alve.java:172) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.j ava:127) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.j ava:117) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineVal ve.java:108) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.jav a:174) at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcesso r.java:843) at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.pr ocess(Http11AprProtocol.java:679) at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:13 03) at java.lang.Thread.run(Thread.java:595)

Thanks in Advance.........

Guys, I got the Solution for this question

Actually we have a class in servlet known as InvokerServlet
you can open your web.xml file which resides in your JBoss Directory Structure and the code
with servlet and servlet-mapping tags for a InvokerServlet will there just Uncomment the code
and then DONE

You can execute your servlet/jsp application without editing your local web.xml



If I am wrong
OR
If someone has anything related to InvokerServlet, please post it. It will be appreciated.

thanks

hi Dustin,

please, specify the exact line on which you are getting error.

warm Welcome!!! diego franco.

check out these link I hope you may get Java SE 7u1 in one of these.


[url]
http://www.oracle.com/technetwork/java/javase/downloads/jdk-7u1-download-513651.html

http://www.softpedia.com/progDownload/Sun-Java-JDK-Download-82226.html

http://www.filecluster.com/downloads/Java-SE-Development-Kit-JDK-.html
[/url]

I had given an interview in indiagames for the post of game developer
they grilled me on java's threading concept

so i would recommend you go for both C++ as well as Java(Threading with detail knowledge)

The following code in your programme

System.out.println(b1);
System.out.println(tree);

internally it means:

System.out.println(b1.toString());
System.out.println(tree.toString());

the method toString() in the above code returns String Representation of your object's hashcode which is a unique code for each object in java.
if you want to get the String value specified by you in the Constructor as title property of your book class you must override toString() method
from the Object's Class and write your code to print the title of your book like i mentioned below.

@Override public String toString() { return title; }

now the code

System.out.println(b1);

will print it's title("How cats work") on your console.

Hii guys,

I have seen one JSP/Servlet based application whose Deployment Descriptor wasn't has anything like mapping and all but then also that application was working fine.

what I think is that it might be a feature of JBoss Application Server ....

Can any one please explain me about this ???


Thanks in advance