Interesting naming question-Keyword: Factory, Instance

Although I have written Java for a year, I still can't find this answer. What exactly means Factory, Instance in Java?
Why use these two words in some classes, say SAX, JCE KeyGeneratorFactory, KeyGenerator? What implies relation between two class from naming?

Factory relates to the Factory design pattern as described by the Gang of Four (GOF). Check out any design patterns resource for this pattern to get a more complete answer.
Essentially, though, a Factory constructs an instance of a class for you. The exact class returned is determined by the factory (for example, DocumentBuilderFactory uses a system property to get the name of the class to instantiate).
Another example is javax.swing.BorderFactory which simply instantiates TitledBorder, EmptyBorder etc instances based on the method you called.
Hope this helps.

Similar Messages

SAP Service named SAP SID _ Instance Number is missing in services.msc

Hi,
SAP Service named SAP<SID>_<Instance Number> is missing in services.msc
Example :
SID = DM0
Instance Number = 01
SAP Service Name = SAPDM0_01
Please help me to resolve the issue.
Thanks in Advance.
Warm Regards,
Sathya

SAPSTARTSRV.EXE
Values :
Operation Selected is "Install Service + Register COM Interface + Start Service"
SID = DM0
NR = 00 or 01
Startprofile = D:\usr\sap\DM0\SYS\profile\START_DVEBMGS01_sapserver
User = DOMAIN\SAPService<SID>
Password = ....
Now the SAP Service, SAP<SID>_<Instance Number> is created in services.msc.
Thanks www.sdn.sap.com
Edited by: Sathya Kala Veeraraj on May 6, 2010 12:12 AM

An interesting synchronization question

hey all, I have an interesting synchronization question to ask you.
Suppose that I have 20 tasks and 8 worker threads, each worker is assigned a task by the main thread, and then main thread suspends until one worker has finished its task. Then main thread create another task and handles to a new worker thread until all tasks are finished.
so code in main thread is something like this.
boolean has_more_task, has_more_worker;
do {
              if (has_more_task && has_more_worker)
                           * create new thread and assign it a new task
              else if ( has_more_task && !has_more_worker)
                        wait();
               else if ( !has_more_task && has_more_worker)
                          wait();
} while (has_more_task || has_more_worker)the problem is that I don't quite familiar with synchronized key word. so I don't know how to share a synchronized vaiable between main thread and worker thread. can anybody do me a help?
Remember that main thread should be waken up by either of the 8 worker threads !!

you can follow producer consumer conept
create a queue. main thread will push task in queue.
and worker threads will consumer task from queue.
you just need to synchronize operation on queue.
when there is no task in queue then worker thread will notify to main thread and
will call wait().
then main thread again put the more task in queue and send notification signal to worker thread and then call wait().
Class JobQueue
//should be called by worker thread
public synchronized getNextTask()
//shoule be invoked by main thread
public synchronized addMoreTask()
}

LVOOP design question on factory style

Hi,
I'm not sure how to do what I want to do, but essentially I'm trying to support a (slowly) evolving custom TDMS data structure. I was thinking that surely classes and inhertiance (overrides) would be perfect for this. For example, I have a data visualization tool that I've developed. Every so often, (3 times in 4 years) the internal structure of the TDMS data files have been modified (added new stuff, changed some formatting etc.) and I'm trying to make such changes be less of a PITA when maintaining my visualization code, which would need to be able to load/read files from any 'author generation'. If my base parent class has all the methods my visulaizer currently needs, I was picturing coding the tdms reads as methods using the parent class made for dynamic overrides, then if/when things change, create a child of the parent who extends and overrides the base methods as required?
I picture having a 'launcher' helper.vi (see screen below) that takes a (TDMS) file path as the input, then starting with the parent class (basic and generic tdms operations as methods in the class, tdms reference as class data) gets the 'author' version from the TDMS file, passes that to a case structure (factory-style) which then spawns the correct child. Now, because I feel I shouldn't have to close the tdms reference in the parent class and create a brand new child class, I attempt to cast 'To more Specific Class' to case/cast the already started parent class object to become the appropriate 'child', but I get an error 1448 and the description is sadly not meaningful to me.
Now, what I want to acheive may best be done in a different way and/or the way I tried to acheive it may not make sense in LVOOP, this is my FIRST attempt at leveraging inhertiance, so feel free to propose alternate ways to go about this..
Below is a screenshot showing a mock-up gist of what I intended, and a (bastardized) attempt at UML'ey describing the above ramble as a class dependency figure (created with www.draw.io, attached both as xml and picture).
QFang
CLD LabVIEW 7.1 to 2013
Attachments:
class inheritance and factory.png ‏53 KB
tdms class diagram.png ‏49 KB
TDMS Class Diagram (3).zip ‏3 KB

The only question in this reply/post is: where should the factory helper.vi 'live'? (scope?) -It can't be 'inside' the parent class since it uses children, and it shouldn't be in a child either, since then it would need to move with every new child? Thinking re-use library / VIPM module, should I put my classes and this helper VI in a LabVIEW library??
The rest of the post is a 'journal of discovery' since the process of writing this reply/post helped me realize several basic (and in hindsight obvious) things. I'm posting the 'journey' in case someone else finds it helpful! The below text is 'chronological' as I evolved and experimented, except *bold comments* that I went back and entered my take on the issue/question/problem after (hopefully) figuring things out! (Thanks drjdpowell for providing the answer to something I didn't know was my question in your first reply!)
Journal of self-discovery of LVOOP basics:
Forgive me for I must surely be missing something that is likely in numerous documents and posts elsewhere, but shouldn't a child object wire be able to use a parent method (didn't need to over-ride) and go on from that parent method to a child method (now I need to do something child specific)? *-Yes, but only if the class is guaranteed at compile time to be of type 'child' or inherited from 'child'!*
In the simple setup below, I have a factory helper.vi that opens a tdms, reads the author property then creates an object of the appropriate type/generation in a case structure. This all worked well until I tried adding a child method inbetween two parent methods.
Writing this post, it occurs to me that this (above) can't work, because the case structure class output could be either a parent or a child (dynamic) and this is indeterminate at compile time! As such, half (in my simple example facotry of two classes) of the factory cases would not be able to 'do some child stuff'. If 'some child stuff' was an over-ride of a parent method, I would still be fine, since the code could run 'that' method on any generation, so now my question becomes:
How do I case/add child specific code 'in-line' with generic code? -> enter lesson learned from what I was incorrectly trying to do in my opening post: use a 'to more specific class' to test the object wire!
Obviously in a real-world use-case, you probably wouldn't do 'child stuff' (or parent 'close' for that matter) inside the factory. Since the factory helper is part of the parent class library, we can add future children and update this helper/factory without breaking code that depends on the 'parent out' object from the factory because those 'legacy' users will only use parent methods and children methods that it needed when it was first created.
Now I'm a giant step closer to something I could use in my data visualization program, albeit it's a bit different than what I had envisioned/hoped for. Basically if a new child generation requires brand new methods as opposed to overriding existing (parent) methods, I would need to test the object wire and add those new method's similar to how I did 'some child stuff' in image above, but if the only thing that changes is behind the scenes stuff and the methods from past generations are still 'logical'. For example, a 'return processed data' method may know that in version 1.0 of tdms, processed data was always in a group called 'A', but for some reason, later on it is in a tdms group 'B', I can override that method for that generation, and my visualization code would only need to be recompiled with the new class libraries, no block diagram changes requried as the original 'return processed data' method would be dynamically overriden!
I feel just a bit smarter now! -I hope my 'journal' might help others down the path of (obvious?) discoveries! I think I will keep coming back to this thread as I try to further architect and develop this class hiearchy and share thoughts and progress and obstacles along the way. Kudo's if you read and are interested in more like this!
QFang
CLD LabVIEW 7.1 to 2013

Access cell factory instance

I have a tableview with a single column. I associated a cellfactory to it as given in the below code. I am trying to loop through all the cells values of a table column on click of a button. I am not sure how to get hold of cell's inner class instance i.e.EditingCell class as said in the given example. Please help me with the same code for this.
2. Also, I have a requiremet where in I want to change the alignment or for example change the value of that cell on click of a button, by looping through all the rows of a single column. I know how to change in the underlying datastructure, but this is not what I want. I want to loop thru by getting value using cellfactory or cell value factory. any help will be of great use.
Callback<TableColumn<Person,String>, TableCell<Person,String>> cellFactory =
    new Callback<TableColumn<Person,String>, TableCell<Person,String>>() {
        public TableCell<Person,String> call(TableColumn<Person,String> p) {
            return new EditingCell();
firstNameCol.setCellFactory(cellFactory);Thanks.

I think that's much too mighty for a general development user ;)But it'll teach 'them general development users' on how things work, while they're developing, using a representative dataset(!).
I would let them select anything they're interested in regarding resources, stats, execution plans etc, on the appropriate environment. To learn and understand. It's only a SELECT.
It's only giving answers on how CBO will behave or, in other words, how CBO will respond to a solution to a requirement.
Developers who want to avoid trouble after developing should be aware of this, be able to understand it and use it.
On a development environment a developer needs to be able to check how his/her queries/program works out like predicted/modeled. Access to V$ views is will help.
If he/she doesn't do anything with it/insn't allowed to use it...OK, that's fine, we'll re-evaluate when we're in production...when all goes wrong...then the developer is the fan that has spread some s**t...and we'll have to pump in another bunch of $.
I think that the fact the majority of developers who aren't allowed (by grants or privileges) to measure and test their solutions, is the same majority looking for/in search of/believing in/been told of *'Silver Bullets'*, which don't exist.
Through time a lot of people have come to the conclusion: it depends.
You need to test and measure, on your development schema.
But anyway:
v$instance is a bit of 'a strange duck in the pond' in that context ;)

Organizational Question: Keyword vs. Description

I am planning to embark on (finally) labeling all my pictures (many thousands) so that I can easily find groupings and specific picutres. I am interested in any advice as to the best method to do this - it looks like the keyword feature may be the best way with keys assigned to both my kids, wife, dog - whoever might be in the picture; but this would not allow specific things like "Kate on bicycle" that descriptions would allow. Sorry if this is a very basic question but any advice would be appreciated!
-Bob

Bob:
Keywords are the easiest and most widely used field for categorizing photos. You can use albums to group by event, birthdays, anniversaries, Thanksgiving 07, etc. The keywords can identify individuals within photos and then Comments for more detailed descriptions. When these files are exported out of iPhoto for use by other apps you can have the keywords and comments embedded in the file. Also you can use the title for describing the photos as it doesn't change the file name. The title will also be embedded when the file is exported.
I use the events as containers for an individual shoot. I have the Events folder set to import from the finder in one batch per folder. That way I can upload to a folder, give the folder a title and date and then import it into iPhoto which gives me an Event whose title is the same as the folder.
Just figure out how you would organize photos if they were hard copy and translate that into iPhoto.
Do you Twango?
TIP: For insurance against the iPhoto database corruption that many users have experienced I recommend making a backup copy of the Library6.iPhoto database file and keep it current. If problems crop up where iPhoto suddenly can't see any photos or thinks there are no photos in the library, replacing the working Library6.iPhoto file with the backup will often get the library back. By keeping it current I mean backup after each import and/or any serious editing or work on books, slideshows, calendars, cards, etc. That insures that if a problem pops up and you do need to replace the database file, you'll retain all those efforts. It doesn't take long to make the backup and it's good insurance.
I've written an Automator workflow application (requires Tiger), iPhoto dB File Backup, that will copy the selected Library6.iPhoto file from your iPhoto Library folder to the Pictures folder, replacing any previous version of it. It's compatible with iPhoto 08 libraries. You can download it at Toad's Cellar. Be sure to read the Read Me pdf file.

WRT 1900AC and Windows 7 network naming question(s)

Background: I had a Linksys E3000 up and running for about 5 years in a stable network environment. The E3000 died, and I put in a new WRT 1900AC to replace it. In the process of getting things set up correctly the main "network name" in my network displays shows up as a name assigned to a Wireless portion of my network. The "Wired" portion shows up in diagrams, and to windows, as well as both of the main wirless bands but not as the central node between either of the wired Win7 computers and the internet I would like to get the Windows 7 machines on my network to display the wired network name in Windows 7 as the primary network, and NOT one of the wireless ones. Almost everything I want to be able to do is working just fine except for the network map display in Windows 7 where I have been trying to configure a "home group" that will not yield to my efforts.,
I use "suffix" notation in the naming, so my router on ethernet is .<ame>..NET, the wireless lower band is <name>...W24 upper band is <name>...W5. I have not figured out how to get the artifacts of the "setup sequence of events" out of the Windows 7 displays in "network neighborhood" so I have a more rational picture that has Ethernet at the core and the wireless bands as additional subsidiary networks not necessarily associated with all my devices. I know this is not technicallly a Linksys issue, but... Can I simply delete alll the neworking information in Windows 7, and reboot, and then force the computer to set up a network based on the correct network node labels. provided by the router? I'm a bit worried that I might have to "reset" everything which would be a huge **bleep** since almost all of what I want to do is working just fine, I'm just not quite clear some times whether the process of connecting from one computer to another, or to a NAS attached to the router is going through the wired network or the wireless one where performance can be a big issue. My Ethernet is "certified" at 1gbps which is a lot faster than the wireless networking. Sometimes it seems that accessing the NAS attached to the router is being done "through a tiny straw, not the fast pipe in the wiered world. I used to do a lot of NETBIOS networking in Windows "back in the day" and my network naming conventions have probably not kept up with the times, but I still have two Windows XP computers wired into my household network, and when "debugging" things I think of the Ethernet as central and the wirless portions as additional networks, not the other way around. Unfortunately Windows 7 seemed to grab the wireless names first, probably because the machines in question both have wireless and wired connectivity built in and available in their hardware and the one that was set up and working with the old router when the new one got plugged in was used to do the initialization initially using the default sequence built into the router software. I was able to go back and rename everything to get rid of the default names, but my Android based network monitor only works within range of the router and not when the phone is connected to the internet outside of the house. I've never been able to get the phone support folks to help me clear that issue up either. .. When I added the second computer, the same thing happened out of the box, Windows took the name of the first wireless network it found and put it into the network neighborhood as the device in the path between the new computer and the internet, I can "see" the host name of the router correctly from everywhere, and map to the 1TB disk I have hung on it from all of my computers, but the Internet connection is actually an ethernet drop from a cable modem to an ethernet port on the router, not to either of the wireless bands that show up.

@zundapman Hi! What's the current firmware of your router? Make sure that your firmware is up to date with the latest version. Also, are you referring to the Windows explorer's map or the User Interface map of the router or the Network and sharing map of your computer?

Robohelp 8 HTML - VERY basic layout and naming question.

OK, I'm sure this must be obvious to everyone else because I can't seem to find it in the places I've searched. My personal experience with Help files isn't helping (yeah, I know, bad pun).
I'm creating a RoboHelp HTML file from a PDF file.
While importing the file I'm given the option to create a new topic based on a style. Great so far. Having done so as an experiment and looked at the output I'm of the feeling that a 'topic' is "an HTML document that would, in theory, cover an area of interest, hence the term topic".
Then I open IE's help file I see the contents like "Finding the Web Pages You Want" and "Browsing the Web Offline". Neither of them can be selected to show information in the right pane, but both open to show what I'll call 'sub-topics', each of which DOES open what appears to be an html document in the right pane.
Adobe's help files are a bit easier to deal with, I just navigate to the Help folder and there are all the HTML files.
So I'm confused and I've got a major mental block that's making it difficult to proceed without getting a layout/hierarchy. And if this information is in Robohelp's help or available someplace online, just smack me in the back of the head and point me in the right direction because I'm not seeing it.
In the Internet Explorer help, what do I call the links in the left pane on which I can click to bring up a page in the right pane? What do I call the items I can highlight that, when clicked, show a list of the clickable links? And is it accurate that if I ask RoboHelp to create a topic out of each of a given style, then I'll have a separate HTML document for each instance of that style?
Thanks,
Solon

Hi there and welcome to the wonderful wild and wacky world of Help Authoring!
The area on the left side is typically called a "Navigation Pane". The Navigation Pane usually has different views. Table of Contents (TOC), Index, Glossary and of course, Search.
The Table of Contents view has a Books and Pages metaphor. Each Book contains Pages inside. Each Page links directly to an individual HTML file (Topic).
Indeed if you are sucking content in from PDF, RoboHelp has to be told what the criteria is to break the long PDF document into individual HTML topic pages.
Hopefully this helps a smidge... Rick
Helpful and Handy Links
RoboHelp Wish Form/Bug Reporting Form
Begin learning RoboHelp HTML 7 or 8 within the day - $24.95!
Adobe Certified RoboHelp HTML Training
SorcerStone Blog
RoboHelp eBooks

Scale out question: how does instance name affect primary/secondary node

Hi:
OBIEE 11.1.1.6.4, Windows 2008
On a test instance the following happened:
1. Enterprise install of OBIEE 11g had problems
2. Reinstalled OBIEE 11g, but the installer created an instance2
3. All was well with this install
4. Performed all necessary shared catalog and RPD steps
5. On a second server, installed OBIEE 11g using the scale-out option
6. On second server, this created an instance1 directory
7. All components start up and we can log into OBIEE using either server1 or server2
Question:
Does OBIEE use the instance names in a scale-out? Our primary node is instance2 and the secondary node is instance1, though on a separate server. Will this cause a problem?
Thanks for any help.

Hello,
This can be run on any of the replicas that the availability group participates in to return the primary instance:
select primary_replica FROM sys.dm_hadr_name_id_map nim
inner join sys.dm_hadr_availability_group_states ags
on nim.ag_id = ags.group_id
WHERE nim.ag_name = 'MyAvailabilityGroupNameHere'
Sean Gallardy | Blog | Microsoft Certified Master

Question about final instance variables

Hi, I recently have come across a situation that I realized I did not understand and I could not find the answer after a bit of googling and searching the forum so I thought I would quickly pose the question to the crowd. Basically I want to know if declaring a final instance variable and assigning it to an existing Object will make an immutable copy of that Object. For example:
Dimension myDims;
public void someMethod()
myDims = new Dimension(320, 240);
doSomething();
public void doSomething()
final myFinalDims = myDims;
This is not real code (obviously) and I made it quickly just to get my point across. Basically my question is if I create an Anonymous Inner class within the doSomething() method that accesses the myFinalDims variable, will the inner class actually access the myDims variable (which could have its value changed before the inner class accesses the variable) or will it be accessing a copy of the myDims Object that will have the same value as when the final variable was declared and instantiated?

Basically I want to know if declaring
a final instance variable and assigning it to an
existing Object will make an immutable copy of that
Object. Big no. It will neither make a copy, nor will anything be immutable. Final just means that once the value or reference of the attribute or variable is set, it can't be altered.
final StringBuffer sb = new StringBuffer();
sb.append("!");still works.
Your inner class will access the instance of Dimensions stored in myDims. There won't be any other instance.

General Question About common Instance Names in Flash CS4 (AS3)

I tried something interesting recently. I had code effecting an object with the instance name : object_mc.
Now I added another object and gave it the same instance name.
The result was, that the code only effected the most recent added object (no error).
Is there a way in flash to have multiple objects with the same instance name all being affected by one piece of code?
~ Thanks for any thoughts, advice or facts. ~

Advice: avoid it... if you want to control different instances, give them different instance names.
It depends on what you mean by "one piece of code". Directly using the instance name to target the movieclips will work as you have seen already... Last one added gets the attention.
To use the instance name to take action is doable more along the lines of testing each movie to see if it has the name, but still, you would have to target each using a different means.
For the piece of code below I have some number of objects on the stage and I test to see if they have an instance name assigned (object_mc) that is shared by some of them, and I am able to move them if they do, but I cannot use the instance name to target each of them for action... in this case I use the getChildAt method.
for(var i=0; i<this.numChildren; i++){
if(this.getChildAt(i).name == "object_mc"){
this.getChildAt(i).x += 200;
object_mc.x += 25; // only moves the last object added

CS6 File Naming Question

Since using CS6, there is something that has changed and has me confused:
I used to be able to save a document with a different name, and the original name would not change.
For instance, if I were working on a file named: 'Nature 1', and wanted to save a version of it with another name: 'Nature 2', I would be able to do so and 'Nature 1' would not change.
Now, it seems, when I do this, 'Nature 1' is renamed 'Nature 2' - it's title overwritten.
This has caused me to overwrite files when saving because the original name is changed.
Is there a simple workaround for this?

Well, I do have Photoshop CS4 on windows and I see no difference in file behavior, but I work differently.
I would need a step-by-step description of what you do to get this problem to see if I can duplicate it.
My files already have names when I open them, so if I make a change, File > Save respects that filename and won't change it.
Where I might get in trouble is File > New, if I type "nature1" in the title box and hit enter opening it up in Photoshop. I then make a few changes and go to File > Save. There I have a chance to name the file and even change the location. So if I type "nature2" and click Save, I just renamed the file,but I did not overwrite an earlier version.
Anyway Photoshop CS6 won't overwrite a file without warning you.
Gene

Quick naming question

Wasnt sure if its a naming issue or not but Ive never ran into the problem and Im not sure how to describe it....so here goes.
Question: Is there a way to insert a string into the name of a component name and have java see it as the actual component name. (see that question still sounds incorrect)
What I mean is......
you have 10 buttons named oneB, twoB, threeB,......tenB
I need to either change a whole lot of code and make what I want to be simple, very large and complex or, find a way to....
"one"B.setLocation(whereverNotImportant);
or
(someObject.getString( ) ) + B.setLocation(whereverNotImportant);
It looks really odd to me. If theres a way to do it, it just saved me a lot of annoyance.....if not well, Im gonna need more energy drinks.

Paul5000 wrote:
Fair enough. I kept adding features onto the code and it grew into needing something different. Was just hoping there was a quick workaround so I didnt have to go back and recode half of it.When you've got Franken-code, the answer is to recode it.

Trivial Lock Question - nested synchronized instance method call

Hi there. I have a question surrounding the following code block:
        public synchronized void bow(Friend bower)
            System.out.format("%s: %s has bowed to me!%n",
                    this.name, bower.getName());
            bower.bowBack(this);
        public synchronized void bowBack(Friend bower)
            System.out.format("%s: %s has bowed back to me!%n",
                    this.name, bower.getName());
        }If the bow method is invoked by the currently executing thread that has obtained the lock on the current instance and the
call "bower.bowBack()" is invoked, what happens? Is the lock released then obtained again by the current thread? or does it hold onto it since the method
"bowBack" is called within the method "bow"?
Thank you!
Regards

thank you as always mr. verdagen!
regards

Trying to understand threads; interesting synchronize question

Ladies and Gentlemen,
what would happen if:
class c {
public synchronized void a() {
//do some stuff
b();
public synchronized void b() {
// do some stuff
this should cause a deadlock situation, should it not? The compiler doesnt complain when I try this.
Can someone confirm if this is correct:
any class method can be synchronized; it doesnt have to be a method in a thread you ahve created. Presumable, this method and its object are being manipulated by threads, so synchronization of data is necessary. I have a program that has multiple threads. Each thread get a reference to manager object (there is one object for all the threads, not one for each). Each thread has its own instance of an analysis object. The analysis object takes teh reference to the manager object in its constructor, so the end result is mulitple threads each have their own analysis object, and all of these objects point to one manager object. I want the methods of the manager object to be synchronized to avoid read/write conflicts and inconsistencies.
Thank you in advance

You are right it is not officially deadlock. but it
is a situation that will produce an error if one is
not careful. b is called in a, and they both require
a lock, so the processing in b cant be done while a is
running. No, I'm telling you that is not the case. You can call b() from a() because if a thread is in a() it already has the lock needed to call b(). There is no possiblity of deadlock with the code you have written.
In order for a deadlock to be possible, you'd need to do something like this:
class Example
   final lockObjectA = new Object();
   final lockObjectB = new Object();
   void a()
      synchronized(lockObjectA)
          b();
   void b()
      synchronized(lockObjectB)
          a();
}

Interesting naming question-Keyword: Factory, Instance

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