Object Oriented? Or Not?

Perhaps the way I raised this question would be peculiar for you as I'm a newbie!
I'm willing to use oracle object oriented programing for my applications, and some senior people(work in my organization) told me that Object oriented database concept is failed in the industry. As a reason they say that; even if Object oriented databases solved some problems people had with relational databases, still Object oriented databases are failed to facilitate most of the advantages of relational databases. It's somewhat chaotic for me, as I'm new to PL developments.
They didn't mention any specific reason; but just told me that relational databases perform well and faster than object oriented databases, and for business logic, object oriented databases has some accuracy issues.
But I'm not ready to accept that it will be useless to learn 'Oracle Object Oriented Programing' or 'Object Oriented Database Concept' would be failed.
So I need to know,
1. Will it be useless to learn & use 'OOP' techniques when learning PL/SQL programing?
2. Is there any disadvantage of using 'OOP' with oracle? (If there is any, please let me know if you have time for that).
Especially, (The most pleasing answer I would like to hear from you ;-) )
3. If Object Oriented Databases concept is better and something that a "PL/SQL" developer must learn; please let me know that.
Please provide me a link if you can, which would help me to learn why should we use 'OOP' with oracle (if Object oriented database is better than Relational database)

Intruder wrote:
So I need to know,
1. Will it be useless to learn & use 'OOP' techniques when learning PL/SQL programing?No. OOP has very little do with relational database design. The two is not mutually exclusive and can co-exist easily.
2. Is there any disadvantage of using 'OOP' with oracle? (If there is any, please let me know if you have time for that).That depends on how+ you use it. If OOP was truly horrible and bad, then why does Oracle spend money on the research and development on it for their RDBMS product?
Especially, (The most pleasing answer I would like to hear from you ;-) )
3. If Object Oriented Databases concept is better and something that a "PL/SQL" developer must learn; please let me know that.OOP is not Object Orientated Database. These are two very different concepts. OOP competes with procedural programming. Object Orientated Database design competes with Relational Database Design (and others of course).
There are two primary issues with an Object Orientated Database design. Complexity. Performance.
Do you for example store the subclasses of the same abstract class in the same physical object table? You can do that in Oracle.. but then the database need to resolve the class type at run-time.. every single time.. for every single object accessed... At what cost ito performance?
How do you treat collection classes? A collection can be stored as a physical table. It can also be stored as an attribute (column) of an object (table) - in which case the physical implementation for that is a nested table. There are dire performance issues with nested tables when these are used and applied incorrectly.
There are numerous such issues.
Compare this with something as mature and robust as Relational Database Design. Easy to understand. Easy to use. And what the Oracle RDBMS product was specifically designed to support.
Which one is "+better+" (especially in the Oracle RDBMS environment)? It should be obvious.
I suggest that you read Codd's original paper on "+A Relation Model of Data for Large Shared Data Banks+", read "+The Third Manifesto+" from Chris Date, and papers from various other authors for insight.

Similar Messages

Java is 100% pure object oriented language or not?

PLS help me...?
I am get confussed.
Java is 100% pure object oriented language or not?

the only full OO programming language on thisplanet
is SmallTalk.On your planet maybe. On mine, at least Eiffel
also exists, probably more unknown others too. Some
count Ruby, but I never looked at it.Ruby is pure OO too, FYI.
the only full OO programming language on thisplanet
is SmallTalk.Care to explain it in some more detail? What
exactly is 100% OO, b.t.w.?No, I don't careWow, what an incredibly unhelpful response.
In essence, 100% OO implies that every type within the language is an object. Since Java has primitive types like int, boolean, float etc, it cannot count as 100% OO.

Java is pure object oriented programing language or not why?

please clear
java is pure object oriented programing language or not why?

And there is some concepts of object orientation that
Java not implements like: Operator
Overloading and Multiple Heritage. But, i think
that we can live without those features.
And the sucess of Java is a proof of this.I don't believe that operator overloading and multiple inheritance are required aspects of object programming.

Notes on using Object oriented concept in ABAP

Hi ,
I want somes notes on how to use Object oriented concept in ABAP.
Thanks in advance.
Chetan

Hi, this may help you
OOPs ABAP uses Classes and Interfaces which uses Methods and events.
If you have Java skills it is advantage for you.
There are Local classes as well as Global Classes.
Local classes we can work in SE38 straight away.
But mostly it is better to use the Global classes.
Global Classes or Interfaces are to be created in SE24.
SAP already given some predefined classes and Interfaces.
This OOPS concepts very useful for writing BADI's also.
So first create a class in SE 24.
Define attributes, Methods for that class.
Define parameters for that Method.
You can define event handlers also to handle the messages.
After creation in each method write the code.
Methods are similar to ABAP PERFORM -FORM statements.
After the creation of CLass and methods come to SE38 and create the program.
In the program create a object type ref to that class and with the help of that Object call the methods of that Class and display the data.
Example:
REPORT sapmz_hf_alv_grid .
Type pool for icons - used in the toolbar
TYPE-POOLS: icon.
TABLES: zsflight.
To allow the declaration of o_event_receiver before the
lcl_event_receiver class is defined, decale it as deferred in the
start of the program
CLASS lcl_event_receiver DEFINITION DEFERRED.
G L O B A L I N T E R N A L T A B L E S
*DATA: gi_sflight TYPE STANDARD TABLE OF sflight.
To include a traffic light and/or color a line the structure of the
table must include fields for the traffic light and/or the color
TYPES: BEGIN OF st_sflight.
INCLUDE STRUCTURE zsflight.
Field for traffic light
TYPES: traffic_light TYPE c.
Field for line color
types: line_color(4) type c.
TYPES: END OF st_sflight.
TYPES: tt_sflight TYPE STANDARD TABLE OF st_sflight.
DATA: gi_sflight TYPE tt_sflight.
G L O B A L D A T A
DATA: ok_code LIKE sy-ucomm,
Work area for internal table
g_wa_sflight TYPE st_sflight,
ALV control: Layout structure
gs_layout TYPE lvc_s_layo.
Declare reference variables to the ALV grid and the container
DATA:
go_grid TYPE REF TO cl_gui_alv_grid,
go_custom_container TYPE REF TO cl_gui_custom_container,
o_event_receiver TYPE REF TO lcl_event_receiver.
DATA:
Work area for screen 200
g_screen200 LIKE zsflight.
Data for storing information about selected rows in the grid
DATA:
Internal table
gi_index_rows TYPE lvc_t_row,
Information about 1 row
g_selected_row LIKE lvc_s_row.
C L A S S E S
CLASS lcl_event_receiver DEFINITION.
PUBLIC SECTION.
METHODS:
handle_toolbar FOR EVENT toolbar OF cl_gui_alv_grid
IMPORTING
e_object e_interactive,
handle_user_command FOR EVENT user_command OF cl_gui_alv_grid
IMPORTING e_ucomm.
ENDCLASS.
CLASS lcl_event_receiver IMPLEMENTATION
CLASS lcl_event_receiver IMPLEMENTATION.
METHOD handle_toolbar.
Event handler method for event toolbar.
CONSTANTS:
Constants for button type
c_button_normal TYPE i VALUE 0,
c_menu_and_default_button TYPE i VALUE 1,
c_menu TYPE i VALUE 2,
c_separator TYPE i VALUE 3,
c_radio_button TYPE i VALUE 4,
c_checkbox TYPE i VALUE 5,
c_menu_entry TYPE i VALUE 6.
DATA:
ls_toolbar TYPE stb_button.
Append seperator to the normal toolbar
CLEAR ls_toolbar.
MOVE c_separator TO ls_toolbar-butn_type..
APPEND ls_toolbar TO e_object->mt_toolbar.
Append a new button that to the toolbar. Use E_OBJECT of
event toolbar. E_OBJECT is of type CL_ALV_EVENT_TOOLBAR_SET.
This class has one attribute MT_TOOLBAR which is of table type
TTB_BUTTON. The structure is STB_BUTTON
CLEAR ls_toolbar.
MOVE 'CHANGE' TO ls_toolbar-function.
MOVE icon_change TO ls_toolbar-icon.
MOVE 'Change flight' TO ls_toolbar-quickinfo.
MOVE 'Change' TO ls_toolbar-text.
MOVE ' ' TO ls_toolbar-disabled.
APPEND ls_toolbar TO e_object->mt_toolbar.
ENDMETHOD.
METHOD handle_user_command.
Handle own functions defined in the toolbar
CASE e_ucomm.
WHEN 'CHANGE'.
PERFORM change_flight.
LEAVE TO SCREEN 0.
ENDCASE.
ENDMETHOD.
ENDCLASS.
S T A R T - O F - S E L E C T I O N.
START-OF-SELECTION.
SET SCREEN '100'.
*& Module USER_COMMAND_0100 INPUT
MODULE user_command_0100 INPUT.
CASE ok_code.
WHEN 'EXIT'.
LEAVE TO SCREEN 0.
ENDCASE.
ENDMODULE. " USER_COMMAND_0100 INPUT
*& Module STATUS_0100 OUTPUT
MODULE status_0100 OUTPUT.
DATA:
For parameter IS_VARIANT that is sued to set up options for storing
the grid layout as a variant in method set_table_for_first_display
l_layout TYPE disvariant,
Utillity field
l_lines TYPE i.
After returning from screen 200 the line that was selected before
going to screen 200, should be selected again. The table gi_index_rows
was the output table from the GET_SELECTED_ROWS method in form
CHANGE_FLIGHT
DESCRIBE TABLE gi_index_rows LINES l_lines.
IF l_lines > 0.
CALL METHOD go_grid->set_selected_rows
EXPORTING
it_index_rows = gi_index_rows.
CALL METHOD cl_gui_cfw=>flush.
REFRESH gi_index_rows.
ENDIF.
Read data and create objects
IF go_custom_container IS INITIAL.
Read data from datbase table
PERFORM get_data.
Create objects for container and ALV grid
CREATE OBJECT go_custom_container
EXPORTING container_name = 'ALV_CONTAINER'.
CREATE OBJECT go_grid
EXPORTING
i_parent = go_custom_container.
Create object for event_receiver class
and set handlers
CREATE OBJECT o_event_receiver.
SET HANDLER o_event_receiver->handle_user_command FOR go_grid.
SET HANDLER o_event_receiver->handle_toolbar FOR go_grid.
Layout (Variant) for ALV grid
l_layout-report = sy-repid. "Layout fo report
Setup the grid layout using a variable of structure lvc_s_layo
Set grid title
gs_layout-grid_title = 'Flights'.
Selection mode - Single row without buttons
(This is the default mode
gs_layout-sel_mode = 'B'.
Name of the exception field (Traffic light field) and the color
field + set the exception and color field of the table
gs_layout-excp_fname = 'TRAFFIC_LIGHT'.
gs_layout-info_fname = 'LINE_COLOR'.
LOOP AT gi_sflight INTO g_wa_sflight.
IF g_wa_sflight-paymentsum < 100000.
Value of traffic light field
g_wa_sflight-traffic_light = '1'.
Value of color field:
C = Color, 6=Color 1=Intesified on, 0: Inverse display off
g_wa_sflight-line_color = 'C610'.
ELSEIF g_wa_sflight-paymentsum => 100000 AND
g_wa_sflight-paymentsum < 1000000.
g_wa_sflight-traffic_light = '2'.
ELSE.
g_wa_sflight-traffic_light = '3'.
ENDIF.
MODIFY gi_sflight FROM g_wa_sflight.
ENDLOOP.
Grid setup for first display
CALL METHOD go_grid->set_table_for_first_display
EXPORTING i_structure_name = 'SFLIGHT'
is_variant = l_layout
i_save = 'A'
is_layout = gs_layout
CHANGING it_outtab = gi_sflight.
*-- End of grid setup -
Raise event toolbar to show the modified toolbar
CALL METHOD go_grid->set_toolbar_interactive.
Set focus to the grid. This is not necessary in this
example as there is only one control on the screen
CALL METHOD cl_gui_control=>set_focus EXPORTING control = go_grid.
ENDIF.
ENDMODULE. " STATUS_0100 OUTPUT
*& Module USER_COMMAND_0200 INPUT
MODULE user_command_0200 INPUT.
CASE ok_code.
WHEN 'EXIT200'.
LEAVE TO SCREEN 100.
WHEN'SAVE'.
PERFORM save_changes.
ENDCASE.
ENDMODULE. " USER_COMMAND_0200 INPUT
*& Form get_data
FORM get_data.
Read data from table SFLIGHT
SELECT *
FROM zsflight
INTO TABLE gi_sflight.
ENDFORM. " load_data_into_grid
*& Form change_flight
Reads the contents of the selected row in the grid, ans transfers
the data to screen 200, where it can be changed and saved.
FORM change_flight.
DATA:l_lines TYPE i.
REFRESH gi_index_rows.
CLEAR g_selected_row.
Read index of selected rows
CALL METHOD go_grid->get_selected_rows
IMPORTING
et_index_rows = gi_index_rows.
Check if any row are selected at all. If not
table gi_index_rows will be empty
DESCRIBE TABLE gi_index_rows LINES l_lines.
IF l_lines = 0.
CALL FUNCTION 'POPUP_TO_DISPLAY_TEXT'
EXPORTING
textline1 = 'You must choose a line'.
EXIT.
ENDIF.
Read indexes of selected rows. In this example only one
row can be selected as we are using gs_layout-sel_mode = 'B',
so it is only ncessary to read the first entry in
table gi_index_rows
LOOP AT gi_index_rows INTO g_selected_row.
IF sy-tabix = 1.
READ TABLE gi_sflight INDEX g_selected_row-index INTO g_wa_sflight.
ENDIF.
ENDLOOP.
Transfer data from the selected row to screenm 200 and show
screen 200
CLEAR g_screen200.
MOVE-CORRESPONDING g_wa_sflight TO g_screen200.
LEAVE TO SCREEN '200'.
ENDFORM. " change_flight
*& Form save_changes
Changes made in screen 200 are written to the datbase table
zsflight, and to the grid table gi_sflight, and the grid is
updated with method refresh_table_display to display the changes
FORM save_changes.
DATA: l_traffic_light TYPE c.
Update traffic light field
Update database table
MODIFY zsflight FROM g_screen200.
Update grid table , traffic light field and color field.
Note that it is necessary to use structure g_wa_sflight
for the update, as the screen structure does not have a
traffic light field
MOVE-CORRESPONDING g_screen200 TO g_wa_sflight.
IF g_wa_sflight-paymentsum < 100000.
g_wa_sflight-traffic_light = '1'.
C = Color, 6=Color 1=Intesified on, 0: Inverse display off
g_wa_sflight-line_color = 'C610'.
ELSEIF g_wa_sflight-paymentsum => 100000 AND
g_wa_sflight-paymentsum < 1000000.
g_wa_sflight-traffic_light = '2'.
clear g_wa_sflight-line_color.
ELSE.
g_wa_sflight-traffic_light = '3'.
clear g_wa_sflight-line_color.
ENDIF.
MODIFY gi_sflight INDEX g_selected_row-index FROM g_wa_sflight.
Refresh grid
CALL METHOD go_grid->refresh_table_display.
CALL METHOD cl_gui_cfw=>flush.
LEAVE TO SCREEN '100'.
ENDFORM. " save_changes
chk this blog
/people/vijaybabu.dudla/blog/2006/07/21/topofpage-in-alv-using-clguialvgrid
Reward if helpfull.
Regards Madhu.

Adding color to a row in alv grid not using object oriented.

Hello Gurus.
I want to display a row in color in alv grid using normal alv, not by using object oriented programming.
I am having one of the field say spart ie division in internal table itab.
The spart has values like 12 , 45, 67, 68 ,88 ,99.
when ever spart is 12 i want to display that row in color format. Here this table is sorted by mblnr so if 1st record is 12 then may be 50 th record will be 12. so when where the record contains the value has 12 then that row should be displayed in color. So please tell me how to do it. Previously i posted the same question but i got is by using object oriented. so please tell me how to do it without using object oriented.
Thanks for all the replies.

Check this example code.
report zrich_0004
       no standard page heading.
type-pools slis.
data: fieldcat type slis_t_fieldcat_alv.
data: begin of imara occurs 0,
      matnr type mara-matnr,
      mtart type mara-mtart,
      maktx type makt-maktx,
      color_line(4) type c,
      tcolor type slis_t_specialcol_alv, "cell
      end of imara.
data: xcolor type slis_specialcol_alv.
start-of-selection.
perform get_data.
perform write_report.
* Get_Data
form get_data.
imara-matnr = 'ABC'.
imara-mtart = 'ZCFG'.
imara-maktx = 'This is description for ABC'.
append imara.
imara-matnr = 'DEF'.
imara-mtart = 'ZCFG'.
imara-maktx = 'This is description for DEF'.
append imara.
imara-matnr = 'GHI'.
imara-mtart = 'ZCFG'.
imara-maktx = 'This is description for GHI'.
append imara.
loop at imara.
    if sy-tabix = 1.
      imara-color_line = 'C410'.   " color line
    endif.
    if sy-tabix = 2.          "color CELL
      clear xcolor.
      xcolor-fieldname = 'MTART'.
      xcolor-color-col = '3'.
      xcolor-color-int = '1'. "Intensified on/off
      xcolor-color-inv = '0'.
      append xcolor to imara-tcolor.
    endif.
    modify imara.
endloop.
endform.
* WRITE_REPORT
form write_report.
data: layout type slis_layout_alv.
layout-coltab_fieldname = 'TCOLOR'.
layout-info_fieldname = 'COLOR_LINE'.
perform build_field_catalog.
* CALL ABAP LIST VIEWER (ALV)
call function 'REUSE_ALV_GRID_DISPLAY'
       exporting
            is_layout   = layout
            it_fieldcat = fieldcat
       tables
            t_outtab    = imara.
endform.
* BUILD_FIELD_CATALOG
form build_field_catalog.
data: fc_tmp type slis_t_fieldcat_alv with header line.
clear: fieldcat. refresh: fieldcat.
clear: fc_tmp.
fc_tmp-reptext_ddic    = 'Material Number'.
fc_tmp-fieldname = 'MATNR'.
fc_tmp-tabname   = 'IMARA'.
fc_tmp-outputlen = '18'.
append fc_tmp to fieldcat.
clear: fc_tmp.
fc_tmp-reptext_ddic    = 'Material Type'.
fc_tmp-fieldname = 'MTART'.
fc_tmp-tabname   = 'IMARA'.
fc_tmp-outputlen = '4'.
append fc_tmp to fieldcat.
clear: fc_tmp.
fc_tmp-reptext_ddic    = 'Material'.
fc_tmp-fieldname = 'MAKTX'.
fc_tmp-tabname   = 'IMARA'.
fc_tmp-outputlen = '40'.
fc_tmp-emphasize = 'C610'.   " color column
append fc_tmp to fieldcat.
endform.
Regards,
Rich Heilman

How to display horizontal line in top-of-page by using object oriented ALV?

How to display horizontal line in top-of-page by using object oriented ALV.
I am created top-of-page in object oriented alv.
But not be successes in showing horizontal line in it.
Can any one pls give solution for this..
Thanks and regards..

Hi
Try like this
data: gt_list_top_of_page type slis_t_listheader. " Top of page text.
Initialization.
perform comment_build using gt_list_top_of_page[].
form top_of_page.
* Note to self: the gif must be loaded into transaction OAOR with
* classname 'PICTURES' AND TYPE 'OT' to work with ALV GRID Functions.
* I Loaded NOVALOGO2 into system.
call function 'REUSE_ALV_COMMENTARY_WRITE'
     exporting
* I_LOGO = 'NOVALOGO2'
* i_logo = 'ENJOYSAP_LOGO'
         it_list_commentary = gt_list_top_of_page.
endform. " TOP_OF_PAGE
form comment_build using e04_lt_top_of_page type slis_t_listheader.
data: ls_line type slis_listheader.
      clear ls_line.
      ls_line-typ = 'A'.
      ls_line-info = 'Special'(001).
      fgrant = xgrant.
      concatenate ls_line-info fgrant
      'Stock Option Report to the board'(002)
             into ls_line-info separated by space.
                    condense ls_line-info.
      append ls_line to e04_lt_top_of_page.
endform. " COMMENT_BUILD
Use following syntex for footer print in alv:
* For End of Page
form END_OF_PAGE.
data: listwidth type i,
        ld_pagepos(10) type c,
        ld_page(10)    type c.
write: sy-uline(50).
skip.
write:/40 'Page:', sy-pagno .
endform.
* For End of Report
form END_OF_LIST.
data: listwidth type i,
        ld_pagepos(10) type c,
        ld_page(10)    type c.
skip.
write:/40 'Page:', sy-pagno .
endform.
check this link
http://abapprogramming.blogspot.com/
https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/library/uuid/5dc3e690-0201-0010-1ebf-b85b3bed962d
Changing width of a custom container dynamically
Display Page numbers in ALV
Insert picture in selection screen.
Logo in OO ALV Grid
Reward all helpfull answers
Regards
Pavan

Trying to understand object oriented programming

Hi all,
I'm new to programming and I'm trying to learn C and Objective-C to eventually write an iPhone/iPad app.
I want to make sure I'm understanding some fundamental Object Oriented principles and so I'm starting with a very basic program.
I've produced a class called CartesianPoint which has an x and y variable plus methods to set and return these variables and also a method to calculate the magnitude from the origin.
What I would like to do now is to extend the program to have a CartesianVector class.
I'm a little unsure as to whether a Vector is a subclass of a Point or whether a Point is a subclass of a Vector... or neither?
Secondly, I'm a little unsure of how to implement the vector class to use two point objects. How should the header and implementation files be set up to receive point objects from the main.m program?
I'd like to also try and extend the program to include other ways of defining a vector (i.e. origin, unity vector and magnitude).... and then use the vectors to build 2D shapes.
Many thanks,
Glyn
Message was edited by: GlynC
Message was edited by: GlynC

Hi Glyn -
I agree with William and would vote for "neither". I see a subclass as a specialization of its superclass, not, for example, something contained by its superclass. A container relationship might apply to a subview and its superview, yet the class of the superview could be a specialization of the subview's class so the subview's class might be the parent of the superview's class. The classic example of cat as a subclass of animal (cat:animal) can be misleading if we see the relationship as member:group. Cat is a subclass of animal because it's a specialization.
Also ask, "What's accomplished by making a subclass"? Does the subclass want to use all or most of the parent's instance variables and methods? Could the job be done any other way? Are any of those ways simpler or do they lead to more reusable code?
One of the best examples (from the Cocoa docs?) is about a programmer who needs a specialized array. A newbie might immediately attempt a subclass of NSArray (a rather tricky subclassing job as it happens). In most cases however, the correct solution would be a class which includes an NSArray* type instance variable.
Hope some of the above is helpful!
\- Ray

Expose Object Oriented Service code as Web Services?

Hello All,
I would appreciate for your insight on this matter!
Web Services are basically RPC (Procedure Oriented) over Soap. Each service invocation by a client results a procedure execution on the server side (In many case, a service class may need to be instantiated before the procedure can be called).
Suppose I have developed server-side logics in Object Oriented manners. How can I expose the OO server logics as Web Services? Does JDeveloper handle OO services any different from PO (procedure-oriented) services as far as the generated wrapper code/interface and WSDL?
Specifically, I have the following example in mind. Assume we are able to successfully expose an OO services. A client calls one of the OO service (let's say service1 in portType1) the 1st time, and establish some transit state (not committing into DB), the same client subsequently calls another service (service2) of the same server portType1. How would the server retrieve the transit state established earlier by service1 while executing service2? (note, this situation would not be resulted in a procedure-oriented case. since each RPC call is independent from the others)
I realize that "stateful" deployment may be of an option. However, stateful seems relying on client cooperation (e.g., via cookies) to establish context across multiple invocations. This may or may not be possible given an arbitrary client parties write its client code based on a WSDL.
Another option I can think about is for Jdeveloper to generated different code for PO services vs. OO services. However, it seems not the case in current Jdeveloper.
Thank you so much!
jason

Web services in general have two styles of invocation: RPC style and Doc style. RPC maps as you say directly to methods on Java class (or if a DB PL/SQL package to procedures and functions).
The alternative, DOC, generally (though not all the time) maps to a message oriented interface. Often DOC style Web services map to messaging infrastructure such as Java Message Service Queues and Topics.
That said RPC works well with EJB's, the component model for J2EE.
Often what folks will do is build a service layer that is very coarse grained when exposing backend infrastructure as Web services. This abstraction typically hides a more OO underpinning (or quite often hides a very procedural backend too).
The bottom line is the Web services do not force an OO paradigm but nor do they hinder you in any way from adopting an OO paradigm.
In terms of JDeveloper currently it supports RPC and supports DOC only with some tweaking. On the server side, the Oracle9iAS infrastructure supports both DOC and RPC.
Hope this is a start to answering what I think is a hard question to answer!
Mike.

Object oriented Concept

Hi all, I feel confuse on object oriented.
Basic, I get change to developer some online form. I use java bean , Servlet, JSTL and Mysql. In my java bean I only have the attribute set and get pattern. I just wonder I put my delete , search and update action on Servlet , not in the java bean , is that means that Is not object oriented enough? How to improve it ?
thank you!

Thank you for the reply, I did use some of the Spring in my Project, but only limit in flower control , such as simple spring + acegi , a lot of control still in servlet. I also try some other new stuff like display tag , but that only work on if your jsp page is out of the WEB-INF. I also go through some tutorials on JSF , but not time to figure out how JSF work with acegi yet.
1 mention the display tag and JSF just try to explain, I looking for a new framework. But don?t want the whole framework to tire me up. For example in simple servlet I can use ? /WEB-INF/ + target to send my flower to any JSP page depend on the link that I click , but I don?t how to handle it spring. May be I did not get the real concept of spring yet. I looking for some framework that allow me to use new technology , but still allow me to use some old technology , like servlet then I can finish my project on time.
But what is the relation between web framework and object oriented concept??

Object-oriented programming: state and behaivor

First of all, sorry for my level english.
In Object-Oriented programming, should an object save always some state?
What about session stateless bean service? What is the sense?
These objects have only behaivour and not state.
Perhaps, the sense is that you can send a message to this object, in oposite of a static methods in utility class?
Thanks and regards.

I suppose you could argue that if it doesn't have any state, then it's not really an "object" in the OOP sense, but who cares, really.
Personally, I use state and behavior as a way to help clarify the responsibilities of various classes in the system, and if I see a codebase with a lot of objects with state but no behavior or behavior but no state, then it's a a red flag that it's a messy, poorly-thought-out design (and it usually turns out to be exactly that). The whole point of OOP (IMHO) is encapsulation, and bundling state and behavior together makes things encapsulated (you can prove that state changes only in certain areas in certain circumstances). Encapsulation makes for more easily maintainable code.
It's easy to spot the blue squares in a Mondrian. It's difficult to spot the blue bits in a Pollock. The former is well-encapsulated OOP and the latter is poorly-encapsulated spaghetti code.
That said, it's not the end of the world if you have a static utility class here and there.

Object Oriented Patterns and Visio

Visio question:
Does anyone know if there are established shapes for each (or any) of the object oriented patterns? If not, is anyone working on that or interested in that?
Since they all have names (Momento, Proxy, Iterator, Mediator, Observer, etc.) it seems like they ought to each have their own shape. Since Object Oriented is all about communication of intent, each pattern having its own recognizable shape would go a long way toward a more meaningful communication through diagram. Also, if they each had their own shape, then the super-patterns (based on commonly grouped patterns and interactions) could also be easily represented.
Blaine

I'm kind of making an assumption here and if it's in error then feel free to disregard the rest of this post.
Assumption that you're thinking terms of shapes for representing in UML the various patterns. Everything you need is right there in front of you already regardless of whether you use Visio, Rational, Poseidon or some other UML tool.
Patterns are not individual constructs. One does not make a Mediator class. One makes a Java class that is an implementation of the Mediator pattern. As such you would see in the static class diagram the same grouping of classes for an X Mediator as you would for Y Mediator. That is the image you're looking for. It's not a single widget that you drag onto the screen, it's in the pattern itself.
If, however, you're talking about something like a graphical representation to give to managers that says "Here be Momento patterns", then I would postulate that you're trying to communicate information that they don't need nor should they concern themselves with. Patterns are an implementation issue. They deal with, "How" we will solve a problem, not what problem will we solve. Mangaers, IMNSHO, need only concern themselves with what problems we will solve, not how they will be solved.
Just my 2 krupplenicks on the subject, your milage may of course vary.
PS.

Issue with internal table in object oriented ABAP.

Hello Gurus,
I am having trouble defining internal table in Object oriented ABAP. for following:
DATA: BEGIN OF IT_TAB OCCURS 0.
        INCLUDE STRUCTURE ZCUSTOM.
DATA    tot_sum   TYPE char40.
DATA END OF IT_TAB.
Can someone help ?
Regards,
Jainam.
Edited by: Jainam Shah on Feb 5, 2010 8:33 PM
Edited by: Jainam Shah on Feb 5, 2010 8:33 PM
Moderator message - Please post in the correct forum. You can easily find out for yourself by looking at SAP help for internal tables using OOP - thread locked
Edited by: Rob Burbank on Feb 5, 2010 2:49 PM

No, you can not declare internal table with header line in OO context. You have to declare the work are/header line separately
Example:
TYPES: BEGIN OF ty_it_tab.
        INCLUDE STRUCTURE mara.
TYPES: tot_sum TYPE char40.
TYPES: END OF ty_it_tab.
DATA: it_tab TYPE STANDARD TABLE OF ty_it_tab.
DATA: wk_tab TYPE ty_it_tab.
LOOP AT it_tab INTO wk_tab.
ENDLOOP.
Edited by: Dean Q on Feb 5, 2010 8:50 PM

Trying to understand the basic concept of object oriented programming.

I am trying to understand the basic concept of object oriented programming.
Object - a region of storage that define is defined by both state/behavior.
( An object is the actual thing that behavior affects.)
State - Represented by a set of variables and the values they contain.
(Is the location or movement or action that is the goal that the behavior is trying to accomplish.)
Variables- (What does this mean?)
Value - (What does this mean?)
Behavior - Represented by a set of methods and the logic they implement.
( A set of methods that is built up to tell's the how object to change it's state. )
Methods - A procedure that is executed when an object receives a message.
( A very basic comand.For example the method tells the object to move up, another method tells the method to go left. Thus making the object move up/left that combination is the behavior.)
Class - A template from which the objects are created.
( I am very confused on what classes are.)
- The definitions of the words I obtained from the "Osborne Teach Yourself Java". The () statements are how I interperate the Mechanisms (I do not know if Thats what you call them.) interact with each other. I understand my interpretation may be horribly wrong. I will incredibly appreciate all the support I may get from you.
Thank you

Object oriented programming is a replacement for the older idea of procedural programming (you can research procedural programming in google). As I understand it, in procedural programming, you have a step by step set of function calls to accomplish some task. Each function receives a data structure, manipulates it, and passes it to the next function. The problem with this is that each function preforms some action for the overall task and can't easily be reused by some other task. Its also harder to read the flow of what is happening with raw data structures flying all over the place.
In object oriented programming, an object calls a function of another object and receives back, not a data structure, but another object. Objects contain a data structure that can only be accessed by its functions. An object is not so much a sub component of a bigger task, as it is a service that any other task can use for any purpose. Also, when you pass an object to the caller, the caller can ask questions about the data structure via its functions. The developer doesnt have to know what the previous function did to the data by reading up on any documentation, or having to reverse engineer the code.
I suggest the best way of learning this is to code something like a library object.
A library object contains a collection of book objects
A book object contains a collection of chapter objects
A chapter object contains a collection of paragraph objects
A paragraph object contains a collection of sentence objects
A sentence object contains a collection of word objects.
Add functions to each object to provide a service
Example: A library object should have a:
public void addBook(Book book)
public Book getBook(String title)
public boolean isBookInLibrary(String title)
The key is to add functions to provide a service to anyone who uses your object(s)
For example, what functions (service) should a paragraph object provide?
It shouldn't provide a function that tells how many words there are in a sentence. That function belongs to a sentence object.
Lets say you want to add a new chapter to a book. The task is easy to read
if you write your objects well:
Sentence sentence1=new Sentence("It was a dark and stormy night");
Sentence sentence2=new Sentence("Suddenly, a shot ran out");
Paragraph paragraph=new Paragraph();
paragraph.addSentence(sentence1);
paragraph.addSentence(sentence2);
Paragraphs paragraphs=new Paragraphs();
paragraphs.addParagraph(paragraph);
Library library= new Library();
library.getBook("My Novel").addChapter("Chapter 1",paragraphs).
Now, lets say you want to have a word count for the entire book.
The book should ask each chapter how many words it contains.
Each chapter should ask its paragraphs, each paragraph should ask
its sentences. The total of words should ripple up and be tallied at each
stage until it reaches the book. The book can then report the total.
Only the sentence object actually counts words. The other objects just tallies the counts.
Now, where would you assign a librarian? What object(s) and functions would you provide?
If written well, the project is easily extensible.

Object-Oriented Programming

I'm working on a code associated with object-oriented programming:
The StreetAddress class has this constructor:
StreetAddress( String street, String city,
               String state, String zip );
and the following methods:
void SetStreet( String street ); and String GetStreet();
void SetCity( String city); and String GetCity();
void SetState( String state ); and String GetState();
void SetZIP( String zip ); and String GetZIP();
String MailingLabel();.
The last of these returns the mailing address in the following form:
street
city, state zipand this is what i have so far:
public class StretAddress
private String myStreet;
private String myCity;
private String myState;
private String myZip;
public StreetAddress( String street, String city, String state, String zip)
    myStreet = street;
    myCity = city;
    myState = state;
    myZip = zip;
public String getStreet()
      return myStreet;
public void SetStreet( String street )
    myStreet = street;
public String getCity()
      return myCity;
public void SetCity( String city )
    myCiy = city;
public String getState()
     return myState;
public void SetState( String state )
    myState = state;
public String getZip()
    return myZip;
public void SetZip( String zip )
    myZip = zip;
public String MailingLabel()
System.out.println(street \n city, state + " " + zip);
}I have no idea what to do now, can someone please help me with this?

ejp wrote:
personally, i don't think you need all four in order to be object-oriented.Without all four it might be class-based, or object-based, but not object-oriented. See Peter Wegner's paper which defined all this in 1987:
http://www.cse.msu.edu/~stire/cse891f04/wegner.pdf
With all due respect, I find this "definition" more meaningful:
http://www.youtube.com/watch?v=bfx7tvGisbA

Object oriented programming in LabVIEW

Please send this message to everybody who has an opinion about this.
Please try to keep it short, but if you can't control yourselves, let
it all out!
I would like to have your opinions about the nature of Labview and it's
ability to support object oriented programming.
I have a couple of questions to fire the discussion.
1- Do you think that LV was built to support OO Programming?
2- Is OO the only way we have to support large applications, or is it
feasible to support it with a good dataflow architecture including all
the flowcharts and all the data definitions?
3- Is LV going to stay "dataflow" or is it going to become OO?
4- What would be the great benefits of turning LV to OO that we don't
already have w
ith the dataflow approach?
5- My opinion is that trying to implement OO in LabVIEW, is like trying
to
Thank you all for your time.
Sent via Deja.com
http://www.deja.com/

> 1- Do you think that LV was built to support OO Programming?
LV was initially designed in 1983. OOP existed at that point,
but LV wasn't designed to be OO. It was designed to allow
engineers and researchers a simple language appropriate
for controlling their research labs from a computer.
> 2- Is OO the only way we have to support large applications, or is it
> feasible to support it with a good dataflow architecture including all
> the flowcharts and all the data definitions?
OO lends itself to large projects because it provides
abstraction, encapsulation, and organizes code into
modules that can more easily be implemented independent
of one another since they can be specified in finer
detail. Also, the compilers help to enforce the
specifications providing they can be encoded in the
interface between objects.
These OO principles were already a part of big projects
long before there were OO languages. It was just that
the language didn't necessarily have features which
supported it. Similarly, they can be a part of big
projects today despite the language being used.
LV 2 style globals, which as the name suggests were
in use long ago, encapsulate data with an interface.
They disallow arbitrary access to the data and can be
used to enforce correct access. With other functions
layered on top, you get a nice interface to stored data.
Functions and structs/clusters abstract away details.
Building a subVI that does an FFT means that for 99%
of the uses, you don't need any more information except
that this block performs an abstract mathematical function,
an FFT. The implementation can be completely changed
to speed it up or make it more accurate and your code
isn't affected. Its abstract definition still holds, so
your code still works.
There are other things that OO languages bring to the
table that LV, and GOOP don't yet offer. In my opinion,
a few more OO features can be added to LV to allow for
even larger projects in the future provided they are used
well.
Earlier posts pointed out that C++ doesn't guarantee that
a project will succeed. OO features are just another tool,
and the tool can be misused leading to a failed project.
This is true to LV, C, C++, and all other engineering tools.
The key is using the tools at hand to best solve the
problems we face. Not glorifying or blaming the tools for
the state of the project.
> 3- Is LV going to stay "dataflow" or is it going to become OO?
LV is dataflow to the core. The definition of what data
is flowing may be expanded, but it will still be data
flowing down wires from one node to another that accounts
for how the program executes.
One of the limitations of the current GOOP is that all
objects are dealt with by a reference. By adding
language features, objects could be made to flow down
the wire, just like strings and arrays, meaning that
branching a wire doesn't lead to side-effects,
and there is no need to dispose objects.
> 4- What would be the great benefits of turning LV to OO that we don't
> already have with the dataflow approach?
Remember when LV didn't have typedefs? It was easy for
a cluster datatype to change once a project was underway.
That usually led to lots of edits on other panels to get
them back in synch. Without the unbundle by name, you
then went through the diagrams fixing all of the bundlers
and unbundlers to have the right number of terminals.
Changing the order of the cluster was even worse since
the diagrams may not bread, they might just access the
wrong field instead.
In many respects, an object is just another step along the
same path. An object is a typedef that can have code
associated with it for access -- maybe like Array and
Cluster Tools. Some of the typedef contents might be
publicly accessable, like now, while other elements are
hidden, only available to the implementation of the
typedef. That would force the user to use your functions
to manipulate things rather than hacking away at the
typedef contents. As an example, a LV string is really
just a cluster of size and characters. Since the diagram
can only modify the string using the string functions, you
never get the size and characters out of synch. That is
until you take it into LV generated code, a DLL or CIN
where you have access to the inner fields.
A related problem is that current typedefs are transparent
to built-in LV functions. If your typedef is just some
numbers, LV will be happy to perform arithmetic on your
typedef. Maybe this is what you want, but if this doesn't
make sense on your typedef, then your left with adding a
Boolean or a string so that the arithmetic isn't allowed.
Ideally, you would be able to state that = makes sense, >
and < don't, + and - only operates on the first numeric, and
* is something that you implement yourself. There would be
some safeguards so that the user of your typedef, which
includes you, wouldn't accidentally mangle the typedef
contents.
These may not seem like much at first, but they allow for
much more abstraction and better encapsulation. Finally,
there is a technique called inheritance that allows for
similar objects to be acted on by common code in one
location, and by specific code in another location depending
on which type of object is actually there at runtime.
This of usually done today by switching out on some inner
tag and dealing with each type in its own diagram. This
works fine until projects get large and teams get large.
Inheritance is a different way of implementing the exact
same thing that usually works much better for bigger teams
and bigger projects.
> 5- My opinion is that trying to implement OO in LabVIEW, is like trying
> to
Is this a fill-in-the blank question? It is difficult today
because the LV language doesn't yet support OO very well.
Early C++ was implemented on top of C using just a bunch
of macros and the preprocessor to mangle the C++ back into
C so that it could be compiled and run. Debugging was
done on practically unreadable text that vaguely resembled
your original code. By comparison, GOOP actually looks
pretty good. It is written entirely on top of the current
LV language and makes clever use of things like datalog
refnums to make strict types.
Over time I think GOOP will mature, and like typedefs,
some users will come to rely on it in a big way.
Other users will hopefully not even notice that anything
changed. If their project grows in complexity and they
need another tool to manage things, it will be just
another feature that helps them to get useful things done.
Greg McKaskle

Object Oriented? Or Not?

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