Difference between PageContext and HttpServletRequest

folks i was reading that when JSP Expression language searches in this order
PageContext, then HttpServletRequest, then HttpSession, and then ServletContext
what is the difference between PageContext and HttpServletRequest because i think both are same???

PersianKamran wrote:
what is the difference between PageContext and HttpServletRequest because i think both are same???Please read the API javadocs:
[javax.servlet.jsp.PageContext|http://java.sun.com/javaee/5/docs/api/javax/servlet/jsp/PageContext.html]
[javax.servlet.http.HttpServletRequest|http://java.sun.com/javaee/5/docs/api/javax/servlet/http/HttpServletRequest.html]
If, after studying the documentation, you still think these represent the same class of object, please explain why and we can help clear up any remaining confusion.
Thanks!
~

Similar Messages

What is the difference between ServletContext and PageContext?

What is the difference between ServletContext and PageContext?

Well, the most glaring difference would be, there is one ServletContext per web application, whereas there is one PageContext per page.
ServletContext acts as the broadest of scopes, all JSPs, and Servlets in a given web application, called by every client will share the same ServletContext.
PageContext acts las the smallest scope. Each JSP in a given web application gains its own PageContext, each time the page is called, with different ones for different users, or when the same user calls the same page multiple times.

Performance difference between page and scroll

Hi experts:
What is the technical difference between paging and scrolling, especially as pertains to database access and performance? The scenario would be a table result in a view where 200 results exist for a query. A scrollable table would show all results, while the paging table would show 10/20 per page. Is the database selection the same for both approaches? Or is the paging approach going to make more trips? If there are trips - how does the UI know how many pages should be presented? Is one or the other a better approach for data which is not existing in CRM system?
regards,
bill.

If you look at the servlet translated from a JSP, you'll see these lines:
Object page = this;
pageContext = _jspxFactory.getPageContext(this, request, response,
null, true, 8192, true);
_jspx_page_context = pageContext;
application = pageContext.getServletContext();So page is simply an alias for this.
And PageContext is analogous to ServletContext but please notice, it's not the same or a replacement; application is the implicit reference to ServletContext and not pageContext. There is no equivalent of pageContext in servlets.
Please note that the page scope doesn't refer to the page object but to the pageContext. Therefore, what Manivel said above
page is used as a scope with in one jspisn't correct.
Edited by: nogoodatcoding on Sep 24, 2007 1:30 PM

What is the difference between IPortalComponentContext and ServletContext ?

1) What is the difference between IPortalComponentContext and ServletContext or PageContext?
2) Both IPortalComponentContext and ServletContext are Same . If Both are Same Both Can be interchangeably Used?
3) If Both IPortalComponentContext and ServletContext are not same ,what is the specific functionality of each. I mean when is the IPortalComponentContext used and when is ServletContext is used?
4) can any please explain the difference and functionlity of each code snippet?
Thanks and Regards
Prasad.Y

Hi Prasad,
what both contexts have in common is, that the context gives access to some resources the container provides.
Nothing else.
The servlet context is rather an application context of any java webapp and exists once per vm, a PortalComponentContext exists for every component and represents a view of the context in which the runtime runs the component.
To answer your questions shortly:
1) http://java.sun.com/j2ee/1.4/docs/api/javax/servlet/ServletContext.html
https://media.sdn.sap.com/javadocs/preNW04/SP2/60_sp2_javadocs/runtime/com/sapportals/portal/prt/component/IPortalComponentContext.html
2) NO!
3) see 1)
4) ?
Regards, Karsten

Difference between Null and null?

What is the difference between null and NULL?
When is each used?
Thanks,

veryConfused wrote:
There is a null in java, but no NULL. null means no value. However, when assigning value, the following is different:Although the empty String has no special role. Null means, the referential type is not assigned (doesn't refer) to a specific object. The empty String is just another object though, so seeing it or pointing it out as something special when it actually isn't at all (no more special than new Integer(0) or new Object[0]) just adds to the confusion.

Difference between GUI_UPLOAD and WS_UPLOAD

Hi,
Please make me clear about the difference between GUI_UPLOAD and WS_UPLOAD. In which cases we need to use these modules...??
Thanks,
Satish

I would suggest to always use the GUI_UPLOAD. I say this because this is the function module which is used in the GUI_UPLOAD method of the class CL_GUI_FRONTEND_SERVICES.   Really, you should probably use the class/method instead of the function module.
data: filename type string.
filename = p_file.
call method cl_gui_frontend_services=>gui_upload
         exporting
              filename                = filename
              filetype                = 'ASC'
         changing
              data_tab                = iflatf
         exceptions
              file_open_error         = 1
              file_read_error         = 2
              no_batch                = 3
              gui_refuse_filetransfer = 4
              no_authority            = 6
              unknown_error           = 7
              bad_data_format         = 8
              unknown_dp_error        = 12
              access_denied           = 13
              others                  = 17.
Regards,
Rich Heilman

Difference between char and varchar, also the difference between varchar2

Hi,
Can anyone explain me the difference between char and varchar, and also the difference between varchar and varchar2...

Varchar2 is variable width character data type, so if you define column with width 20 and insert only one character to tis column only, one character will be stored in database. Char is not variable width so when you define column with width 20 and insert one character to this column it will be right padded with 19 spaces to desired length, so you will store 20 characters in the dattabase (follow the example 1). Varchar data type from Oracle 9i is automaticlly promoted to varchar2 (follow example 2)
Example 1:
SQL> create table tchar(text1 char(10), text2 varchar2(10))
2 /
Table created.
SQL> insert into tchar values('krystian','krystian')
2 /
1 row created.
SQL> select text1, length(text1), text2, length(text2)
2 from tchar
3 /
TEXT1 LENGTH(TEXT1) TEXT2 LENGTH(TEXT2)
krystian 10 krystian 8
Example 2:
create table tvarchar(text varchar(10))
SQL> select table_name,column_name,data_type
2 from user_tab_columns
3 where table_name = 'TVARCHAR'
4 /
TABLE_NAME COLUMN_NAME DATA_TYPE
TVARCHAR TEXT VARCHAR2
Best Regards
Krystian Zieja / mob

The difference between Lion and Mountain Lion

Can some one explain to me the difference between Lion and Mtn Lion? I'm currently 10.6.8 Is it beneficiall for me to upgrade?

Mountain Lion is an enhanced version of previous OS X and so that is Mavericks.
About upgrading it all depends on what your needs are and if your hardware supports it.
System requirements for OS X Lion
System requirements for OS X Mountain Lion
OS X Mavericks: System Requirements
Please check also applications compatibility. From Lion onward, you cannot run PPC application.

The difference between N80 and N80IE ?

What is the difference between M80 and N80ie?

02-Jan-2007
07:45 PM
korngear wrote:
The Nokia N80 Internet Edition is a new version of this handset with the same hardware as the normal N80. It is due for release in Q4 of 2006 and will be available in Patina Bronze or Pearl Black, and has the following additional software included.
Yahoo Go! for Mobile
Flickr
Some Amazon Branded Software
'Download!' App management
Internet Telephone - SIP VOIP Frontend
WLAN Wizard
Gizmo VOIP - Gizmo Project VOIP Frontend.
\\en.wikipedia.org//
@Korngear
Thanks.
Could N80 be upgraded to N80IE?

The difference between SFP+ and X2

Dear Expert,
I need to know what is the difference between SFP+ and X2! and can I use SFP+ card and module instead of X2?
Thanks,
Mohammad Saeed

Hi,
They are both used for 10Gig interfaces. The difference is the connector type.
SFP+ is LC and X2 is SC.
You can not put an SFP+ into an X2 slot or X2 optic into a SFP+.
HTH

Difference between ok_code and sy-ucomm

Hi,
Can any one tell me the difference between ok_code and sy-ucomm

Hi,
Actually OK_CODE and SY-Ucomm are the same. But experts suggest use of OK code for following reason:
In each PAI event that a user triggers by choosing either a pushbutton on the screen or an element in a GUI status, the corresponding function code is placed into the system field SYST-UCOMM or SY-UCOMM and placed in the OK_CODE field (as long as the function code is not empty). Empty function codes are placed in neither the SY-UCOMM field nor the OK_CODE field.
In your ABAP programs, you should work with the OK_CODE field instead of SY-UCOMM. There are two reasons for this: Firstly, the ABAP program has full control over fields declared within it, and secondly, you should never change the value of an ABAP system field. However, you should also always initialize the OK_CODE field in an ABAP program for the following reason:
In the same way that the OK_CODE field in the ABAP program and the system field SY-UCOMM receive the contents of the corresponding screen fields in the PAI event, their contents are also assigned to the OK_CODE screen field and system field SYST-UCOMM in the PBO event. Therefore, you must clear the OK_CODE field in the ABAP program to ensure that the function code of a screen is not already filled in the PBO event with an unwanted value. This is particularly important when the next PAI event can be triggered with an empty function code (for example, using ENTER). Empty function codes do not affect SY-UCOMM or the OK_CODE field, and consequently, the old field contents are transported.

What is difference between abstraction and encapsulation ?

Hi,
I am trying to figure out the difference between abstraction and encapsulation but confused.
Both are used for data hiding then what is the exact difference ?
Thanks.

Tushar-Patel wrote:
I am trying to figure out the difference between abstraction and encapsulation but confused.
Both are used for data hiding then what is the exact difference ?This is the picture I have:
When you encapsulate something you get an inside and an outside. The outside is the abstraction. It describes how the encapsulated entity behaves viewed from the outside. This is also called the type. Hidden inside is the implementation. It holds detail information about how the type's behaviour is accomplished.
It's a very simplified picture but I think it's quite accurate and it works for me.

What is difference between Iterator and Collection Wrapper?

Hi all,
I dont understand the actual difference between Iterator and Collection Wrapper. I observed both are used for the same purpose. Could any one please let me know when to use Collection Wrapper and when to use Iterator??
Thanks,
Chinnu.

L_Kiryl is right.
Collections support global iteration (through collection->get_next( )) and local iteration (through iterator->get_next( )).
Each collection has a focus object. Initially, the first object has the focus.
Any global iteration moves the focus, which is published by the event FOCUS_CHANGED of the collection.
If you want to iterate on the collection without moving the focus (and without triggering timeconsuming follow-up processes) you can use local iteration. To do so, request an iterator object from the collection and use this to iterate.
And one more advantage of using iterator: it takes care of deleted entities. If you use global iteration then when you reach deleted entity it will be an exception. But there is no exception with iterator in the same situation.

What is difference between modify and update i am using

hi
what is difference between mofify and update
my requiremen is to have three condition checkec while mofifying or updating from a internal table
the three fields are
cus no
status
date these all are primary key in the database table
so which sould i use modify or update
there might be entry already existing in database table or new entry to be created if already existin it should check on the primary keys and updatat if not it should add a record
pls suggest whihc to use and how to implement the check on teh threee primary key
like if modify ztable from table it_test
now where condition ? can be used or not with modify? and if yes how
if not should i use update will update create a new entry if no entry is there and please give syntex
regards
Arora

Hi Nishant Arora,
Modify: It works in performing two actions.
They are: Insert + Update.
For Example If a record that is exited in database, so you are modifying that record, it updates that particular record.
Similarly, If the is not existed in the database, you are modifying it, it inserts a new record.
Update: Update means just it updates the status, I mean it only updates the record. It doesn't inserts any new record if that particular record is not present in the database.
These are the cases you need to write these statements.
Syntaxes: :
Go through this links please.,
http://help.sap.com/saphelp_nw04/helpdata/en/e7/968aa8b2384dd9835f91e7f8470064/content.htm
http://help.sap.com/saphelp_nw70/helpdata/en/fc/eb35eb358411d1829f0000e829fbfe/content.htm
Reward points if useful
Cheers,
Swamy Kunche
Edited by: Swamy Kunche on Jun 11, 2008 2:41 PM

What is Difference between SXMB_MONI and SXMB_MONITOR?

what is Difference between SXMB_MONI and SXMB_MONITOR?
Can any explain to this question.please?

Hello,
Both are same.
SXMB_MONI is area menu which will contain all multiple transactions pertaining to monitoring.
SXMB_MONI contains some functions viz monitoring for Bridging, Archived Msgs, Job overview, persistence layer analysis.
SXI_monitor directly leads to the message monitoring for the IS, which is part of the SXMB_MONI.
SXI_MONITOR directly executes the monitoring report.
Thanks,
Satya

Difference between PageContext and HttpServletRequest

Similar Messages

Maybe you are looking for