Aborting new object creation

I want to test the input parameters to a constructor and determine if an invalid parameter has been supplied.
If I use:
Thingy myThingy = new Thingy("invalid value");
is it up to the programmer of the above to catch the error, either through exception handling or some other form of error checking, and perform
myThingy = null;
to render the partially initialized object ready for garbage collection?
Is there a way in the constructor itself to indicate that the object shouldn't be created and null should be returned as the result of the "new" operation?
Thanks,
John

But I'd say Clem1986 still has a point. Even in the constructor
Foo() throws Exception {
throw new Exception("Bollocks");
}there's the implicit call to super() and instance initializers before you arrive at throw. From JVM spec: The new instruction does not completely create a new instance; instance creation is not completed until an instance initialization method has been invoked on the uninitialized instance. Which is done above. Whether this qualifies in OP's context as completing instance creation or instantiating an object I don't know. But you could work with it in the constructor, and once you get to throw, memory has been allocated, all superclasses have been initialized (which might involve heavy allocation/computation), default values were assigned to fields and instance initializers have executed. Only now can you decide to "abort new object creation" by completing abruptly and not "returning" the reference to the newly-(partially-)created object to the caller.

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Use String Variable in New Object Creation

Thanks to those who review and respond. I am new to Java, so please be patient with my terminoloy mistakes and fumblings. I am reading in a file and I want to create a new object based on specific field (car for example). As you will notice I grab field 8 here label sIID.
String sIID = dts.group(8);
BTW this regex grouping works fine. The problem is seen when I try to use the sIID variable in my new object creation process.
DateParse sIID = new DateParse();
My IDE is reporting "Variable sIID is already defined in the scope"
Is this possible? The assumption is that the sIID will have different value during the processing of the file. For example, car could mean truck, sedan, etc with operators like color, number of doors, mileage, top speed, etc.

Thanks for the reply. I have include similar and much shorter code for the sake of brevity.
My problems are centered around the x variable/object below. Ideally this would translate to three objects PersonA, PersonB, etc that I could reference later in the code as PersonA.newname if I wanted to. Hopefully this makes sense.
public class TestingObjects {
public static void main(String[] argv) {
       String [] names;
       names = new String[3];
       names[0] = "PersonA";
       names[1] = "PersonB";
       names[2] = "PersonC";
       for (String x:names) {
         PN x = new PN(); // <- Problem
         x.name = x;
         x.SayName();
        System.out.println(x.newname);
public class PN {
       String name;
       String newname;
public String SayName() {
       newname = "Name = " + name;
       System.out.println(name);
      return newname;
}

New Object Creation vs. Field Setters

I know this is massively context dependent, but is there some rule of thumb to follow when it comes to deciding between
i) Making an class's fields final and creating a new object with new field values when needed, and
ii) Leaving a class's fields mutable and using setter methods to alter the field.
I tend toward option one, because not only do I tend to shy away from setters, but also because it helps prevent me from accidentally maintaining an old reference. However, purely from a performance standpoint, which option should you assume is better? How many object's of X size do I have to be making per unit of time before the performance benefits of "final" are lost?
Thanks!

I've been wishing for a while that Java would add a language level concept of immutability. Either an immutable keyword or an annotation. The compiler would bitch if you declared a class immutable and each of its fields was not final and either a primitive or a reference to an immutable class. Or perhaps it could simply check that there was no assignment to any field.
It would be handy for me as a user of a class to know that it's immutable, for things like copying and thread-safety. It might or might not allow for runtime optimizations too.
As for whether to make a given class immutable, like others say--it depends on the semantics of the class. If it's intended to represent something dynamic--e.g. a clock, or a piece on a board whose position changes with time, or the state of a network interface including packet sent and received--then it will make your code clunky and nonintuitive if you have to create a new object everytime the state of the thing you're modeling changes. But if it's something that changes less frequently, or that represents a fairly static entity or "value", then make it immutable.
I do agree with duffymo: Better that an object comes out of construction in a valid and useful state. So even if the object is mutable, pass field values to the c'tor or set them to reasonable defaults inside the c'tor (e.g., "now", etc.)

Doubt in creation of a new object

Hi All,
I have one doubt in creation of a new object.If a new object is to be created and it is not a subtype
of any existing object, then what should we enter in the Program field for creating the object?
I hope I am clear with my question.
Thanks in Advance,
Saket.

Hi Saket,
Following will be required for created a custom business object.
1. Object Type - ZTEST (Internal Techincal Key)
2. Object Name - ZTESTNAME (Technical Key Name)
3. Name - TEST (Name of BO, it is used while selecting the object type)
4. Description - (Short Description of BO)
5. Program - ZTESTPROGRAM (ABAP program in which the methods of the object type are implemented)
6. Application - A or B.. etc (Area to which your BO is related)
Please remember that you can learn these basic things by giving F1 help on those fields and in HELP.SAP.COM.
Regards,
Gautham Paspala

Getting ORA-20001: Creation of new object is not allowed: !!

Hi Am getting ORA-20001: Creation of new object is not allowed while enabling constraints after importing the dumps from source to target datbase,can anyone assist me to fix this issue.

Hi Osama/Mustafa,Thanks for your quick response,can you please explain me the following things-
1)As i don't have privilege to run the DBA_XX views,am not able to run those queries-
SELECT OWNER, TRIGGER_NAME, TRIGGER_BODY FROM DBA_TRIGGERS WHERE TRIGGER_TYPE IN ('AFTER EVENT', 'BEFORE EVETN') AND TRIGGERING_EVENT LIKE '%CREATE%';
can you tell me what output it'll throw,based on this output how will we fix the issue.
2)SELECT * FROM dba_sys_privs WHERE privilege = 'UNLIMITED TABLESPACE';
why we need to check this privilege?as i don't have privilege to run this one in my db.
3)select * from dba_source where upper(text) like upper('%Creation of new object is not allowed%');
as i don't have privilege to run this one in my db,already i got the object name from my logfile
and more you have quoted"This is an error of someone that coded purposely on your database, probably dba or a developer who has privilege and again it is in a database event trigger"
4)can you explain me much more deeper about the root cause and as already sent note to my DBA,can you explain me the solution to fix this issue ?

Creation of new object link for DMS

i have searched a lot about Creation of new object link for DMS on internet .
and all replies focus on that documentation :
1. Program two screens for the following module pools for the SAP object that is to be linked additionally:
u2013 SAPLCV00
u2013 SAPLCVIN
The process logic must be according to that of screen 0204 in program SAPLCV00 and must not be changed.
2. Create the function module OBJECT_CHECK_XXXX (XXXX = name of the SAP object).
i need to know how to implement that in more detailed step by step
as i know DMS and abap also.

Hi Reda,
Hope the below URL will help to understand how the Process of adding a object link works.
Enhancement Without Modification of the Object Links - Engineering Change Management (LO-ECH) - SAP Library
Thanks & Regards,
Seshadri.

New object type creation...in MASS transaction..

Hi,
I want to create new object type for Maintainace plan mass mainainace how to do it....can anybody tell me..??
In standard MASS transaction i am not getting object type for Maintainace plan
Regards,
San Rao..

hi
O1CL-->select Table you asscosiate with class type( If it it not exists the click on New Item)
->Lets consider that it is MARA>double click on Plant->click on object types>click on New Item--->click on Object
Similerly maintain class status,Org Area etc
You can also check the existing class for Example...this will help you.
Regards
Sujit

How to show object creation in UML

How to show object creation in UML

In a sequence diagram, it's a line (with arrow) pointing to the new object and the <creates> or <new> tag as mentioned above.
| obj 1 |
     |
     |    <creates>     ----------
     | --------------> | obj 2 |
     |                  ----------or----------
| obj 1 |
     |
     |      <new>       ----------
     | --------------> | obj 2 |
     |                  ----------

Object creation of string

Hello
Please tell me what is the difference between these two object creation of string.
String str = new String("Hello");.
String str="Hello";
Thanks.

RGEO wrote:
hello,
Is the string pool is part of a heap? Huh? I suppose yes, you could regard the String pool as part of the heap... but (I guess) that interned String objects would be placed directly into the permanent generation, which is not garbage collected... and therefore I don't really think of the permanent generation as part of the heap (except when tuning heap allocations)... but I think I'm talking over your noob head here, yes... and so to the noob-stuff.
If you get bored you might like to scan (for now) http://java.sun.com/javase/technologies/hotspot/gc/gc_tuning_6.html#generations ... and come back to it in a couple of years time (when every second word isn't new and baffling to you;-)
jvm what will do when he encounter the following code,
String s1 = new String ("hello");The VM will:
1. Create a new String object, and then
2. copy the characters 'h','e','l','l','o' from the interned String "hello" to the new String,
3. and then assign a reference to the new String to variable s1.
Note that the result is subtley different from String s1 = "hello", which just does step 3... it assigns a reference to the existing interned String object "hello" to the variable s1... it does not create and "populate" a new String object.
Try this just for fun... what is the output of the following program? Why?
package forums;
public class StringEquals
public static void main(String[] args) {
    try {
      String a = "Hello";
      String b = "Hello";
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      String c = new String("Hello");
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    } catch (Exception e) {
      e.printStackTrace();
}Now, what's the correct way to evaluate equality of String objects in Java?
HTH. Cheers. Keith.

Design and registration of new objects

We have the following three objects:
- Order, which contains:
-- OrderStatus
-- Vector: OrderStatusHistoryItem
Whenever order.setStatus(newStatus) is called we would like to create a new OrderStatusHistoryItem and add that to the vector of history inside the Order.
Our first guess was to put this in the setStatus method of the Order object, so that noone would bypass the adding to history. But... When creating the OrderStatusHistoryItem inside the Order we of course get an error from TopLink, saying that the object was not registered in the UOW.
Is there some way that we can tell TopLink that this relationship should be registered automatically on commit? If not, what would be the best way to design this? Of course we do not want to expose our domain layer to the internals of TopLink. Would a factory be the best way to handle registration upon creation?
Thanks,
Anders,

Anders,
New objects created and attached to working copies will be discovered during commit cycle and added to the persistent model including the appropriate INSERT. The only issue you will have is that you must make sure that setStatus(newStatus) is ONLY called on working copies read from or registered with a UnitOfWork. If this is true you should be able to create the new OrderStatusHistoryItem within the setStatus method and add it to the collection without registering it in the UnitOfWork.
Doug

While Loop - Object Creation

Hello,
I have a question on object creation and while loops. Have a look at the following code snippet:
while(true)
       Object obj = new Object();
       // Pass off obj to a new thread
       Thread job = new Thread(new ObjectHandler(obj));
       job.start();
}My question is, do I have to wait until the newly created Thread is finished with the Object obj before I can create a new Object called obj in the while loop?
Also does anyone have any documentation on this sort of thing?
Thanks,
Tony.

Jaxie wrote:
I'm still not sure you get what I'm on about, you might want to read up on java methods and pass by value.I think we know how it works. Most of us have been programming in Java for serveral years.
>
When you pass an object to a method in java you pass it a copy of a reference to that object. Leading on from that, before an object is eligible for garbage collection in java, all references to that object must be dropped.
So with all that in place, my question was, is the creation of an object in a while loop dependent on previous objects of the same name? Objects don't have names. Have we mentioned that before?
You have a reference, larry that is referencing an unnamed object. You can also create other references that reference the same object. The thread will have one reference. You can then make larry reference another object. That will not change anything in the thread. It will still reference the old object, and that object will not be claimed by the gc until that thread stops referencing it.
So the second time we go through the loop below, do we have to wait until larry has been garbage collected, before a new larry can be created?Read the articles/tutorials and what I have written above. What do you think?
Do also note that the GC isn't executed synchronously.

Java Object Creation

A general question about how can Java object creation with an average amount of data retrieval is considered as a reasonable.
For example if I am clicking on a link in a web application...to paint that page, I think, about 4-5 java object with an average data retrieval of 20 rows wud be considered as appropriate. Any other thoghts or any other parameters to take into consideration?

If you are concerned about object creation speed, you probably shouldn't. Even my laptop PC can create and garbage collect some 12 million objects per second (10,000,000 objects takes about 800 milliseconds). Test program below; remember to run with "java -server" to get the faster optimizing compiler. For laughs, write an equivalent C++ program that does new&delete in a similar loop.
public class CreateObject
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     throws Exception
     for (int m = 0; m < 5; m++)
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     long start = System.currentTimeMillis();
     for (int n = 0; n < 10 * 1000 * 1000; n++) {
         new CreateObject();
         new CreateObject();
         new CreateObject();
         new CreateObject();
         new CreateObject();
         new CreateObject();
         new CreateObject();
         new CreateObject();
         new CreateObject();
         new CreateObject();
     long end = System.currentTimeMillis();
     System.out.println((end - start) + " ms");
}

PDR Steps to create new object types

We set a demo instance of the PDR tool here and it all works well.. I would now like to add purchase info records as an object that can be sequenced with all other master data like materials, material boms, variant class and ecms in a config folder. I know that new function modules would need be created but was wondering there was a document with steps expaining the entire procedure for doing this or if any other company has yet tried this with the tool.. It allows for the creation of new objects for the packet but would like to have some sort of guideline to follow if possible.

Hello Mr Thorne,
I knew there are some SAP Consultants that know how to implement a new object type. And there is a project together with the german army that expands the PDR with several object types.
But you have to pay attention. The PDR consists of two main parts . The FOX - Frame work of Explosion and the UPS - Uniform Packaging Service.
Creating a new Object type that can be "shipped" has to be in the UPS - BUT - if you are using the transaction CRWBD that new object type will not be found if you are exploding a baseline. That is the task of the FOX.
And to add a new Object type into the FOX would be harder than add it into the UPS.
I think the Consulting solution, uses a FOX exit to add that object into the UPS after the FOX-Run.
I you need further information please contact SAP consulting (PLM).

Get error when add new object in crystal report

hi
i have this error "You are attempting to use functionality that falls under the Crystal Decisions Report Creation API license. This system does not have a valid license, or the evaluation copy of the license has expired. Please contact Crystal Decisions to obtain a Report Creation API license."
when i add new object in crystal report with vb.net
""CRReport.Sections.Item(ii).AddTextObject("new text", 1000, 0)
i do same program for 3 months ago but i lost it work without error
ihave a license key for crystal report
use cr10 with vb.net 2005
can help me
thanks

Also, check out the blog [Use of the Report Designer Component (RDC) in VS .NET|http://www.sdn.sap.com/irj/scn/weblogs;jsessionid=(J2EE3414700)ID0468837450DB00359707053703393347End?blog=/pub/wlg/15939].
Ludek
Follow us on Twitter http://twitter.com/SAPCRNetSup

Requirements to go for new TableSpace Creation ?

Hi All,
It is a more databse question than SAP,
What are requirements to go for new Tablespace creation ?
OR
Why do we need to create new Tablespace evethough, we have around 7 default tspaces there.
Eg : In my case TSpace PSAPVERTEX created; vertex is US tax tool.
I dont think database stores the application specific data in particular TSpace like vertex application -
PSAPVETEX
Please reply to me soon
RK

Hello Ramakrishna,
>> Why do we need to create new Tablespace evethough, we have around 7 default tspaces there.
That is not correct. You have one default tablespace on database level or one default tablespace for different users (user settings)... but you can never have more than one default tablespace.
SAP creates more tablespaces to seperate the data and to structure it... but the definition, which object is stored in which tablespace is specified in the create statement of the object.
So if objects are for the vertex application.. the create statement includes the vertex tablespace PSAPVERTEX.. if not the objects are created in the default tablespace for the user.
Regards
Stefan

Aborting new object creation

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