Signal and slot for java

Hi all,
I have implemented Qt's signal and slot here: http://sourceforge.net/projects/javasignalslot/
In case you are wondering what's "Qt's signal and slot", please read http://doc.trolltech.com/3.1/signalsandslots.html
My version uses String as signal, and the slot can be any public method. Currently ArrayList is used to setup the connection, for simplicity reason. In next release I will try to use HashTable and hopefully this can increase the signal propagation speed.
Please take a look and please give feedback to me. Thanks.

Thank you.
ActionListener is an interface, but the slot only needs to be a public method of a class, therefore the only "contract" is the set of parameters for that method. The "observer" needs not implement an interface like ActionListener, but only prepares a public method and uses it as its "slot", so that the �event notifier� can just call this method and pass the parameters it want.
At the time for setting up a "connection" (so that, in Swing sense, the "observer" will be able to get the notification), the only agreement between the signal and the slot is that set of parameters only; while for an object implementing ActionListener, the agreement is the entire ActionListener interface.
It wouldn't be useful to say "a set of method parameters" is better than "implementing an interface"; it is just that, "a set of method parameters" has lower requirement on the "contract", hence it will be more flexible.
No doubt in strict OO sense, any object, if it has certain kind of features, it should model that features into an interface, and implements it. However, interface would be a stronger "contract", which is more "heavy load" than just merely "a set of method parameters".
You might say that an interface will be sufficient, why I still want to make a method (which is more specific) independent of any interface (that it might/should have belonged to)? It is just another �observer� mechanism, and probably just a dare try.
This idea, as you can see from the references, is the basic message passing mechanism among different modules. If my code, in your opinion, is worthy of trying, please give it a try. I will be glad to know if you like the idea.

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Hi Pradeep:
Well that purely depends on the business application (project) your client is proposing. Following are very few factors which will drive for creating web-based applications:
VC: it's a UI modeling tool (non-programming) for creating rapid creation of web-based applications.
WD: its a powered by Java and ABAP with which you can create robust business applications.
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Opengl and directx for java or c++ or Java3D

I am new to the 3D programming and I have many queries and I hope those expect can answer me. Thank you very much.
I have some experience in writing directx 7.0 in C++. I find that the IDirect3DDevice7 in directx7.0 does not support 256 colors but direct3ddevice in directx5.0 does.
However, the direct3ddevice in directx5.0 in 16 or 32 bit color performs very strange. Distortion is found in displaying a 3D image.
1.     Do you have this experience? Does direct3ddevice in directx5.0 not work in 16 or 32 bit colors?
2.     If I want to write a 3D directx program in C++ that can be work in every resolution, what can I do?
3.     Can opengl work in every resolution 256 colors, 16, 32 bits?
4.     Does opengl work in every platform?
5.     Can I write an opengl program in window platform and run it in Linux without any modification or compilation ?
6.     Does the opengl runtime different from platform to platform ?
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8.     Opengl is claimed to be open source. What does it mean ? Can I modify the code of the opengl sdk or runtime and re-complie it and make it my own version of opengl ?
9.     I find many version of opengl sdk in the web. Some is special to a particular hardware eg. NVIDIA. Some is not bounded to any hardware. What is the different between them ? How can I choose from them ?
10.     I know that there is directx for java and opengl for java. Is it the so called java 3D ?
11.     Does opengl or directx together with Java2 become Java 3D ?
12.     However I cannot find any directx code or directive for importing the directx package in the Java 3D sample code.
13.     Does the Javax provide the utility for 3D programming by hiding the 3D device or texture surface creation ?
14.     I find some code segment from MSDN which shows the way to create a directdraw object in an applet. I wonder what is the proper way to use directx or opengl in java since my main goal is to create a directx application that can be worked in the web.
15.     Lastly, from my understanding, directx is a com api which can be used in every programming languages. Does it imply that with a directx sdk, I can write a directx application in C++, java, or vb ?
16.     But, I find that the code to do the same task in the three programming languages is very different. The object creation methods, the data structure for directx in the three programming languages is different. Is the same sdk realy used in different programming languages ? The object name for e.g. direct3ddevice is different from vb (Direct3DDevice7) and c++ (IDirect3DDevice7).

I'm no expert in 3D graphics programming, but I have some experience. I'll try to answer some of your questions.
2.     If I want to write a 3D directx program in C++ that
can be work in every resolution, what can I do?I think both DirectX and OpenGL supports any resolution and color depth. It's more a matter of which resolutions your graphics driver supports.
3.     Can opengl work in every resolution 256 colors, 16,
32 bits?Yes.
4.     Does opengl work in every platform?OpenGL is available on many platforms. Look at GL4Java if you want to use OpenGL in Java, it's available on many platforms. Look at: http://www.jausoft.com/gl4java.html
5.     Can I write an opengl program in window platform
and run it in Linux without any modification or
compilation ?Yes, if you write it in Java. In C++ you will need to recompile the app.
6.     Does the opengl runtime different from platform to
platform ?No, it's a standard. There are some extensions that are driver dependant, but if you stick to the standard it will run unmodified on all platforms.
7.     If I deploy an opengl progam, do I need to deploy
the runtime for a particular platform with it.I don't think OpenGL is available by default on all platforms.
8.     Opengl is claimed to be open source. What does it
mean ? Can I modify the code of the opengl sdk or
runtime and re-complie it and make it my own version
of opengl ?OpenGL is not open source. OpenGL is a standard, it can't be open source since there is no source code.
9.     I find many version of opengl sdk in the web. Some
is special to a particular hardware eg. NVIDIA. Some
is not bounded to any hardware. What is the different
between them ? How can I choose from them ?If you have modern graphics card the driver includes support for OpenGL on MS Windows. For Linux you use Mesa I think. See GL4Java homepage for more info.
10.     I know that there is directx for java and opengl
for java. Is it the so called java 3D ?GL4Java implements the OpenGL functions in Java. Java3D is a high level API that runs on either OpenGL or DirectX.
11.     Does opengl or directx together with Java2 become
Java 3D ?No. The Java3D package is available for download at java.sun.com.
12.     However I cannot find any directx code or
directive for importing the directx package in the
Java 3D sample code.You can't call DirectX directly in Java3D. It hides the underlying layers.
13.     Does the Javax provide the utility for 3D
programming by hiding the 3D device or texture surface
creation ?Java3D is platform independent and hides things like the hardware, drivers etc.
14.     I find some code segment from MSDN which shows the
way to create a directdraw object in an applet. I
wonder what is the proper way to use directx or opengl
in java since my main goal is to create a directx
application that can be worked in the web.I dont know if DirectX is available for Java. I recommend that you use OpenGL instead, or Java3D if you want an easy, high level API.
15.     Lastly, from my understanding, directx is a com
api which can be used in every programming languages.
Does it imply that with a directx sdk, I can write a
directx application in C++, java, or vb ?In C++ and VB, yes. Dont know if there are any Java DirectX bindings available.
16.     But, I find that the code to do the same task in
the three programming languages is very different. The
object creation methods, the data structure for
directx in the three programming languages is
different. Is the same sdk realy used in different
programming languages ? The object name for e.g.
direct3ddevice is different from vb (Direct3DDevice7)
and c++ (IDirect3DDevice7).Don't mix programming languages in the same app. Decide if Java or C++ is the right language for you, then use the tools available for the language you choose.
My recommendation is to go for Java and Java3D if you are inexperienced with 3D graphics programming. Use Java + OpenGL if you know about vertices, textures, transforms etc.

UWL and webDynpro For Java

Hi
Experts
I am making webDynpro application in which I have to give a form with in UWL of Portal.In that one form will be appear in user 's UWL and if it clicks on <b>ok</b> then all data will be get saved and this form will be go to another user 's UWL for cross checking the input and go on.. till HOD.
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I have only knowledge of webdynpro for java.
(Don't know anything of ABAP)
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Regards
Sunny.

Hi
Some useful links are
<a href="https://www.sdn.sap.comhttp://www.sdn.sap.comhttp://www.sdn.sap.com/irj/sdn/go/portal/prtroot/docs/library/uuid/e3f07a7a-0601-0010-ebbd-b9cfb445b814">https://www.sdn.sap.comhttp://www.sdn.sap.comhttp://www.sdn.sap.com/irj/sdn/go/portal/prtroot/docs/library/uuid/e3f07a7a-0601-0010-ebbd-b9cfb445b814</a>
<a href="https://www.sdn.sap.comhttp://www.sdn.sap.comhttp://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/library/uuid/50d74ada-0c01-0010-07a8-8c118d408e59">https://www.sdn.sap.comhttp://www.sdn.sap.comhttp://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/library/uuid/50d74ada-0c01-0010-07a8-8c118d408e59</a>
<a href="http://help.sap.com/saphelp_nw04s/helpdata/en/43/e085d6421a4d9de10000000a155369/content.htm">help.sap.com/saphelp_nw04s/helpdata/en/43/e085d6421a4d9de10000000a155369/content.htm</a>
<a href="https://www.sdn.sap.comhttp://www.sdn.sap.comhttp://www.sdn.sap.com/irj/sdn/go/portal/prtroot/docs/library/uuid/259865cb-0701-0010-9a9e-d156765ec089">https://www.sdn.sap.comhttp://www.sdn.sap.comhttp://www.sdn.sap.com/irj/sdn/go/portal/prtroot/docs/library/uuid/259865cb-0701-0010-9a9e-d156765ec089</a>
<a href="http://help.sap.com/saphelp_nw04s/helpdata/en/da/a680415dc6050de10000000a1550b0/content.htm">help.sap.com/saphelp_nw04s/helpdata/en/da/a680415dc6050de10000000a1550b0/content.htm</a>
Thanks
SMitha

Problem in setting path and classpath for java in RedHat linux 9

Hi ,
i am not able to set the PATH and CLASSPATH for j2sdk1.4.2_06
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in terminal
but i want to configure it as permenant way for the jre and jdk
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regards mihir...

type those in .bashrc ... save and exit
then at prompt, type 'source .bashrc'
this is the permanent solution ...
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Documentum Foundation Service (DFS) and webdynpro for java

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Raktim
Edited by: Raktim Banerjee on Jan 21, 2010 2:40 PM

We used Axis2 for proxy.

EP,ESS/MSS and webdynpro for java interview questions.

I am an ep and ESS?MSS consultant and work on webdynpro for java.I have also worked on PDK like customization of masthead and logon page.I would like to know how to prepare for an interview? I mean what should I read ? and what topics should I cover?

HI Anzar
Instead of posting this here, you could have googled it. There are no. of sites for the same thing.
Since you wrote, so just curious... EP & ESS/MSS Consultant... what does that mean?
If I am not taking it wrong, by that sentence you are trying to tell that you have worked on ESS / MSS modeule. Right?
See, if you are an EP Consultant, you must know all the below atleast -
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b. User Management
c. Internal / External Portal Configuration
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a. Calling iviews from wd applications
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c. JCO Connections
d. SC/DC Concept
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g. Singleton/Non-Singleton nodes
h. Controllers
i. Interfaces
j. Multi-lingual Applications
k. EJBs
l. PDK applications
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if question solved, close the thread after marking it answered.
Best Regards
Chander Kararia

No signal and searching for signal on iPhone 4

My son has a iPhone 4 32g with IOS5. I have a iPhone 4 16g with IOS5. My phone is working great no problems at all but my son's phone 2 days after downloading the new software started searching for signal and no signal, We have done a hard reset and a system restore told us the phone could not be restored.........

I went into the apple shop today and described the same issue. The first question the guy asked was: are you on orange? To which I replied yes! I am apparently the 8th person he has seen this weekend.
I described how it seemed to have happened straight after I downloaded IOS 5 however he said he thought this was just a coincidence. I also told him how I had restored as a new phone several times but it had made no difference.
My phone has a stuck homepage button and he said he could replace my phone based on this as I still had warranty. The new version would have the latest IOS 4 on it and not 5.
Lo and behold a brand new phone WITHOUT IOS 5 still has exactly the same problems. So it must be orange! I'm just lucky I was able to get to the bottom of it.
Next stop - the orange shop.
Good luck everyone
Why does my iPhone 4 have no signal/searching after iOS5 update?

Doom and Gloom for Java

Following seems like an interesting read.
http://www.guardian.co.uk/technology/blog/2010/nov/16/java-oracle-google-ibm-harmony-apache-crisis

abillconsl wrote:
jschell wrote:
YoungWinston wrote:
jschell wrote:
Following seems like an interesting read.
http://www.guardian.co.uk/technology/blog/2010/nov/16/java-oracle-google-ibm-harmony-apache-crisis
The saddest thing about it to me is that it all just seems to be a playground squabble.
Although I am pretty sure that Oracle plays with knives, so not a normal "playground squabble".I'd expect these kinds of teething pains after a major acquisition. I think some relevant questions to ask are:
1. How much is at stake for Oracle? Would it be trivial if Java fell off the developer's table?I think one can manage to use Oracle in C#. Pretty sure it isn't as easy. Also pretty sure the newest cool toy (linq) won't work for Oracle.
>
2. Is Apache, IBM, others nearing the "throw in the towel" phase?
Apache is open source so that part doesn't mean much. Per the article IBM is supporting the open source version of java.
3. Is C# really considered better now by a large percentage of the developer community?
I doubt it. I suppose that depends on what "large percentage" is supposed to mean.
4. Now that Apple has apparently been convinced to play nice with Oracle, and since it seems that more and more Java developers are using Apple products, will Apple stay the course?
Meaning? Apple has deprecated Java and articles I have read suggest a market driven approach to supporting languages which means only the ones Apple feels they have enough control over.

ActiveX and COM for Java

Are there any good tutorials that can explain how to wrap an existing ActiveX or COM component around Java code? At this point I am only researching possibilities as the requirements from the customer have yet to be recieved.
Would this be a JNI situation? or something else that I am unaware of. I am fairly new to Java and have not done this type of thing yet.
Thanks

I found that. I was hoping for something more detailed. Example source code would be great. The link you gave provides example apps but not the source that I can use to better understand how it works.

Lex and yacc for java?

I've found "jack" and a few other tools for this. I would prefer to use the syntax of the lex/flex and yacc/bison files (as opposed to jack's combined file).
I'm interested in folks recommendation for the best lex/yacc tools for generating .java files for a parser.
Thanks,
Tom

There is something called JavaCC. It includes a lectical analyzer, but it generates top-down parsers which you might or might not like.
http://www.experimentalstuff.com/Technologies/JavaCC/
Cyric

Devleoper Studio and Workplace for Java application development

1. Can someone please help me know what is netweaver developer studio and developer workplace ?
2. I came across EP master guide that says :
You install an AS Java centrally and the developer workplace on each developer host.
This option is recommended for large development projects with a need for local and central testing. Developers can test their developments locally using the developer workplace. For integration tests, they deploy their changes on the central AS Java.Ûê.® |
You install an AS Java centrally and Developer Studio instances on each developer host.
This option requires fewer hardware resources per developer host. In this landscape scenario you can set up an AS Java in development mode centrally and connect to it from the other hosts in the landscape using the Developer Studio.
How does Java application development take place ? Does this say that we need Developer Studio instances installed on every developer's host (suppose I have 3 developers) or do I need one server setup for Dev Studio and developers using some client program to connect to it ?
I suppose developers create programs on their local pc's, port them to Dev studio for testing and transfer them to EP Dev server ? Is that correct.. ? Thereby, we need CTS+ to promote developments to Qlty and Prod ?

Hi,
Please check-out the following links to understand NWDS, Developer studio and the installation procedure:
SAP NetWeaver Developer Studio 7.1 Overview
http://help.sap.com/saphelp_47x200/helpdata/en/cb/f4bc3d42f46c33e10000000a11405a/content.htm
/thread/705153 [original link is broken]
http://www.sapgeek.net/2010/05/how-to-install-nwds/
Hope these help.
Regards,
Varun

Question about classes15.jar vs ttjdbc5.jar and support for Java 1.6

The docs note the use of ttjdbc5.jar vs ttjdbc14.jar depending on Java version. In the tt70_32 distribution (lib dir) I also see jars named classes14.jar, classes15.jar, and classes16.jar. They look to have the same content as ttjdbc5.jar. Can someone clarify when to use these jars?
Also, are there any known issues on Java 6?
Thanks

The classes+nn+.jar files are just the old names we used to use and we still ship the files under these names for backwards compatiility. The new names are ttjdbc14.jar (JDK 1.4), ttjdbc5.jar (JDK 1.5 or Java 5) and ttjdbc6.jar (JDK 1.6 or Java 6). However, due to a packaging error in some of the earlier 7.0 release we omitted to ship ttjdbc6.jar. But you can just copy/rename classes16.jar to ttjdbc6.jar.
I'd recommend using the ttjdbc files as this is the 'new' naming convention. I am not aware of any issues with Java 6. I have used it extensivley with TimesTen and not seen any problems.. It is faster than Java 5 in many instances.
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X61s and slot for sim card slot

Good day.
Some time ago i noticed that i have sim card slot near RAM modules. Machine type: 7666-B4G.
So, i have a question: is it a WWAN modem installed in my notebook?

s0n1q wrote:
Good day.
Some time ago i noticed that i have sim card slot near RAM modules. Machine type: 7666-B4G.
So, i have a question: is it a WWAN modem installed in my notebook?
All X61 models have the moulding in the body shell for a SIM slot, but they don't all have a SIM reader or antennas installed, let alone a 3G card.
Your 7666-B4G config shows as this....
L7700(1.8GHz), 2GB RAM, 100GB 7200rpm HD, 12.1in 1024x768 LCD, Intel X3100, Intel 802.11agn wireless, Bluetooth, Modem, 1Gb Ethernet, Secure chip, Fingerprint reader, 8c Li-Ion, WinVista Business
... so, IMO, its unlikely it is WWAN-ready at any level.
My 7676-3PM came in this config:
T7100(1.8GHz), 1GB RAM, 80GB 5400rpm HD, 12.1in 1024x768 LCD, Intel X3100, Bluetooth, Modem, 1Gb Ethernet, Fingerprint reader, 8c Li-Ion, WinVista Business
... and its very definitely not WWAN ready.
Cheers,
Bill
I don't work for Lenovo

Tracking a ramping signal and checking for range thresholds

I have a signal which ramps at 0.05 volts/second. During this state, there is a possibility that the ramp rate
exceeds the 0.05 v/sec. operation (runaway condition). Does anyone have any ideas about how to track this and
respond to the runaway condition?
Solved!
Go to Solution.

How is the signal being generated? How are you sampling it?
You could just take the difference between two samples and if their rate is out of a certain range, take care of it.
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Signal and slot for java

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