Questions in: JAVA

write ur question clearly

I think you r talking about Javascript fuction??

->assertions are using for debugging/ testing the flow of
program at the time of development and testing phases not
yet deployment phase.
we can use the assertions any where in java program is
valid but we have to use it in appropriate way.
->the syntax of Assertion is:
assertion(boolean): value;
*we can take any value after colon(:) that may be int,
char,string and method call
when ever assertion parameter is "true" then it will
proceed the remaining execution of program otherwise it
throw an exception saying"java.lang.AssertionError:xxxx"
assertion for testing purpose if assumption value is
false then it raises an exception but to handling this
exception by using "try-catch-finally" is not recommended.

Only we used in try block

what our target is get the server side information into
clientside .
put a jsp file into server and get the information from
that jsp and show to client.
pls check in google with ajax.

This is Static include.
<%@ include file="header.jsp" %>
1.the file includes static text. i.e if we use the static
include, it will merge the contents of included jsp
(header.jsp) with main jsp at compile time. and the size of
the main jsp will increase. some times it may have problem,
because the maximum size of the jsp is 64kb.
2.if the file is changed,the JSP engine may not recompile
the JSP
This is Dynamic include.
<jsp:include page="header.jsp">
1.The file includes Dynamically. i.e at run time.
2.If the included file (header.jsp) is changed,the JSP
engine recompile the included JSP, because it will include
at run time.By using this the jsp size also not increased.
For Example
Static include (<%@ include file="header.jsp" %>) like our
#include (C++)
Dynamic include (<jsp:include page="header.jsp"> ) like our
import (JAVA)

when same request and response objects are shared by
multiple JSP's in dynamic include
In static include internally,it will merge the contents(eg:
one.jsp and two.jsp) and creates a jsp as(one_two.jsp)then
generates the output of both the jsp's

Action Tags, jstl and custom tags

Serialization is a process of writing the state of the
object in a stream. The state of the object (information
available in the object)will be held in the instance
variable (not in the static variables)
There are various streams like
ByteArrayOutputStream, FileOutputStream,SocketOutputStream
all these streams can be used to store data to various
destinations like memory,file and someother program.
writeObject() method is for carryout the operation of
serialization.

Object Serialization extends the core Java Input/Output
classes with support for objects. Object Serialization
supports the encoding of objects, and the objects reachable
from them, into a stream of bytes; and it supports the
complementary reconstruction of the object graph from the
stream. Serialization is used for lightweight persistence
and for communication via sockets or Remote Method
Invocation (RMI). The default encoding of objects protects
private and transient data, and supports the evolution of
the classes. A class may implement its own external encoding
and is then solely responsible for the external format.
Serialization now includes an API that allows the serialized
data of an object to be specified independently of the
fields of the class and allows those serialized data fields
to be written to and read from the stream using the existing
protocol to ensure compatiblity with the default writing and
reading mechanisms.

application and object of ServletContext are same. In jsp
page application implicit variable represents object of
ServletContext but pageContext represent object whose super
class is SerlvetContext. the class of PageContext has some
conviniant methods for manipulation of attributes of
different scopes. These methods are findAttribute, get/set/
removeAttribute that accept last parameter as a int value
representing scope to which attribute pass to methods
belongs.
The PageContext has integral contant value for showing
scopes which are PAGE_SCOPE, REQUEST_SCOPE, SESSION_SCOPE
and APPLICATION_SCOPE. These constant values are used as a
last arguement to set/get/removeAttribute methods to
indicate to which scope the attribute belong. such a methods
and consant values are not present in its super class
ServletContext.

application and object of servlet context is same
remaining not same.

First we need to register on scjp authorized organization,
they give particular date to write online exam on the date
you need to go and write the online exam

You can approach any prometric center(for eg NIIT), pay the
amount and get the voucher. The voucher is valid till 1
year. If you are paying the amount from your pocket, wait
for SUNs offer period

<%@page import="java.sql.*,java.io.*"%>

<% @ page import = 'org.com.className' %>

Application object is used to maintain the information
related to the current webapplication which is running in
the webcontainer.
Session object is used to maintain the information related
to the browser from which the user gets the request.

A small correction at **
using session oject in jsp.
first u set using following methods
String name="ravi";
session.setAttribute("user",name);
using retrive method
String sessionuser=session.getAttribute("user");**
out.println("welcome"+sessionuser);
u give this last 2 stmts in all jsp pages. it will
display as "Welcome ravi".

using session oject in jsp.
first u set using following methods
String name="ravi";
session.setAttribute("user",name);
using retrive method
String sessionuser=session.getAttribute(name);
out.println("welcome"+sessionuser);
u give this last 2 stmts in all jsp pages. it will
display as "Welcome ravi".

jsp expressions are evaluated at the run time,
jsp compiler evaluates the expressions at the run time.

jsp expressions is a normal java expression , when we write
the jsp expression in our jsp page like
<%=some expression%> then in the servlet ie generated by
jsp compiler the jsp expression will be placed without" "
in out.printmethod.
for example :
<%
int i=10,j=20,k=30;%>
k----> <%=k%>
in the servlet equivalent to above jsp page
out.print("k---->");
out.print(k);
like that at the back the jsp expression will be placed in
the out.print()without " " so that the value of the
expresssion will be evaluated and printed.