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  • Using EclipseLink

    - by Ross Peoples
    I am still new to Java and Eclipse and I'm trying to get my application to connect to a database. I think I want to use EclipseLink, but all of the documentation on the matter assumes you already know everything there is to know about everything. I keep getting linked back to this tutorial: http://www.vogella.de/articles/JavaPersistenceAPI/article.html But it's basically useless because it doesn't tell you HOW to do anything. For the Installation section, it tells you to download EclipseLink and gives you a link to the download page, but doesn't tell you what to do with it after you download. The download page doesn't either. I used the "Install new software" option in Eclipse to install EclipseLink into Eclipse, but it gave me like 4 different options, none of which are explained anywhere. It gave me options JPA, MOXy, SDO, etc, but I don't know which one I need. I just installed them all. Everything on the web assumes you are already a Java guru and things that are second nature to Java devs are never explained, so it's very frustrating for someone trying to learn. So how do I install and USE EclipseLink in my project and what do I need to do to connect it to a Microsoft SQL server? Again, I am new to all of this so I have no clue what to do. Thanks for the help.

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  • Java: initialization problem with private-final-int-value and empty constructor

    - by HH
    $ javac InitInt.java InitInt.java:7: variable right might not have been initialized InitInt(){} ^ 1 error $ cat InitInt.java import java.util.*; import java.io.*; public class InitInt { private final int right; InitInt(){} public static void main(String[] args) { // I don't want to assign any value. // just initialize it, how? InitInt test = new InitInt(); System.out.println(test.getRight()); // later assiging a value } public int getRight(){return right;} } Initialization problem with Constructor InitInt{ // Still the error, "may not be initialized" // How to initialise it? if(snippetBuilder.length()>(charwisePos+25)){ right=charwisePos+25; }else{ right=snippetBuilder.length()-1; } }

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  • Python unit-testing with nose: Making sequential tests

    - by cool-RR
    I am just learning how to do unit-testing. I'm on Python / nose / Wing IDE. (The project that I'm writing tests for is a simulations framework, and among other things it lets you run simulations both synchronously and asynchronously, and the results of the simulation should be the same in both.) The thing is, I want some of my tests to use simulation results that were created in other tests. For example, synchronous_test calculates a certain simulation in synchronous mode, but then I want to calculate it in asynchronous mode, and check that the results came out the same. How do I structure this? Do I put them all in one test function, or make a separate asynchronous_test? Do I pass these objects from one test function to another? Also, keep in mind that all these tests will run through a test generator, so I can do the tests for each of the simulation packages included with my program.

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  • Convert string to decimal retaining the exact input format

    - by Brett
    Hi All, I'm sure this is a piece of cake but I'm really struggling with something that seems trivial. I need to check the inputted text of a textbox on the form submit and check to see if it's within a desired range (I've tried a Range Validator but it doesn't work for some reason so I'm trying to do this server-side). What I want to do is: Get the value inputted (eg. 0.02), replace the commas and periods, convert that to a decimal (or double or equivalent) and check to see if it's between 0.10 and 35000.00. Here's what I have so far: string s = txtTransactionValue.Text.Replace(",", string.Empty).Replace(".", string.Empty); decimal transactionValue = Decimal.Parse(s); if (transactionValue >= 0.10M && transactionValue <= 35000.00M) // do something If I pass 0.02 into the above, transactionValue is 2. I want to retain the value as 0.02 (ie. do no format changes to it - 100.00 is 100.00, 999.99 is 999.99) Any ideas? Thanks in advance, Brett

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  • Place the business logic in Java Beans?

    - by Lirik
    I was reading this page and I found the following statement: MVC in Java Server Pages Now that we have a convenient architucture to separate the view, how can we leverage that? Java Server Pages (JSP) becomes more interesting because the HTML content can be separated from the Java business objects. JSP can also make use of Java Beans. The business logic could be placed inside Java Beans. If the design is architected correctly, a Web Designer could work with HTML on the JSP site without interfering with the Java developer. Interestingly in my textbook I pulled the following quote: In the MVC architecture... the original request is always handled by a servlet. The servlet invokes the business logic and data access code and creates beans to represent the results (that’s the model). Then, the servlet decides which Java Server Page is appropriate to present those particular results and forwards the request there (the JSP is the view). The servlet decides what business logic code applies and which JSP should present the results (the servlet is the controller). The two statements seem slightly contradicting. What is the best way to use beans: should we place business logic in them or should we only place results in them? Are there ways in which beans are inadequate for representing a model?

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  • Throw of a die in Java

    - by Arkapravo
    The throw of a die is a popular program in Java, public class Die { /* This program simulates rolling a die */ public static void main(String[] args) { int die; // The number on the die. die = (int)(Math.random()*6 + 1); System.out.println (die); } // end main() } // end class What I wish to do is make it repeat, 500 times. I have not been able to put this program into a loop of 500. I usually program in Python, thus I guess my Java has rusted ! Any help is most welcome !

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  • Python: how to enclose strings in a list with < and >

    - by Michael Konietzny
    Hello, i would like to enclose strings inside of list into < (formatted like <%s). The current code does the following: def create_worker (general_logger, general_config): arguments = ["worker_name", "worker_module", "worker_class"] __check_arguments(arguments) def __check_arguments(arguments): if len(sys.argv) < 2 + len(arguments): print "Usage: %s delete-project %s" % (__file__," ".join(arguments)) sys.exit(10) The current output looks like this: Usage: ...\handler_scripts.py delete-project worker_name worker_module worker_class and should look like this: Usage: ...\handler_scripts.py delete-project <worker_name> <worker_module> <worker_class> Is there any short way to do this ? Greetings, Michael

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  • convert bitset to string ??

    - by mr.bio
    Hi .. What is wrong with this code ? set<string> nk ; bitset<3> bs1(string("100")); nk.insert(bs1.to_string()); error: no matching function for call to `std::bitset<3u::to_string()' why?!

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  • Python learner needs help spotting an error

    - by Protean
    This piece of code gives a syntax error at the colon of "elif process.loop(i, len(list_i) != 'repeat':" and I can't seem to figure out why. class process: def loop(v1, v2): if v1 < v2 - 1: return 'repeat' def isel(chr_i, list_i): for i in range(len(list_i)): if chr_i == list_i[i]: return list_i[i] elif process.loop(i, len(list_i) != 'repeat': return 'error'()

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  • Clear all class variables between instances

    - by ensnare
    This is probably a stupid question, but what's the best way to clear class variables between instances? I know I could reset each variable individually in the constructor; but is there a way to do this in bulk? Or am I doing something totally wrong that requires a different approach? Thanks for helping ... class User(): def __init__(self): #RESET ALL CLASS VARIABLES def commit(self): #Commit variables to database >>u = User() >>u.name = 'Jason' >>u.email = '[email protected]' >>u.commit() So that each time User is called the variables are fresh. Thanks.

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  • Replace letters in a secret text

    - by kame
    Hello! I want to change every letter in a text to after next following letter. But this program doesnt work. Does anyone know why. Thanks in advance. There is also a minor problem with y and z. import string letters = string.ascii_lowercase text=("g fmnc wms bgblr rpylqjyrc gr zw fylb. rfyrq ufyr amknsrcpq ypc dmp. bmgle gr gl zw fylb gq glcddgagclr ylb rfyr'q ufw rfgq rcvr gq qm jmle. sqgle qrpgle.kyicrpylq() gq pcamkkclbcb. lmu ynnjw ml rfc spj. ") for x in range(1,24): text.replace(letters[x],letters[x+2]) print(text)

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  • What is Adobe Flex? Is it just Flash II?

    - by Adam Davis
    Question Alright, I'm confused by all the buzzwords and press release bingo going on. What is the relationship between flash and flex: Replace flash (not really compatible) Enhance flash The next version of flash but still basically compatible Separate technology altogether ??? If I'm starting out in Flash now, should I just skip to Flex? Follow up Ok, so what I'm hearing is that there's three different parts to the puzzle: Flash The graphical editor used to make "Flash Movies", ie it's an IDE that focuses on the visual aspect of "Flash" (Officially Flash CS3?) The official name for the display plugins (ie, "Download Flash Now!") A general reference to the entire technology stack In terms of the editor, it's a linear timeline based editor, best used for animations with complex interactivity. Actionscript The "Flash" programming language Flex An Adobe Flash IDE that focuses on the coding/programming aspect of "Flash" (Flex Builder?) A Flash library that enhances Flash and makes it easier to program for (Flex SDK?) Is not bound to a timeline (as the Flash IDE is) and so "standard" applications are more easily accomplished. Is this correct?

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  • very quickly getting total size of folder

    - by freakazo
    I want to quickly find the total size of any folder using python. def GetFolderSize(path): TotalSize = 0 for item in os.walk(path): for file in item[2]: try: TotalSize = TotalSize + getsize(join(item[0], file)) except: print("error with file: " + join(item[0], file)) return TotalSize That's the simple script I wrote to get the total size of the folder, it took around 60 seconds (+-5 seconds). By using multiprocessing I got it down to 23 seconds on a quad core machine. Using the Windows file explorer it takes only ~3 seconds (Right click- properties to see for yourself). So is there a faster way of finding the total size of a folder close to the speed that windows can do it? Windows 7, python 2.6 (Did searches but most of the time people used a very similar method to my own) Thanks in advance.

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  • Dynamic type for List<T>?

    - by Brett
    Hi All, I've got a method that returns a List for a DataSet table public static List<string> GetListFromDataTable(DataSet dataSet, string tableName, string rowName) { int count = dataSet.Tables[tableName].Rows.Count; List<string> values = new List<string>(); // Loop through the table and row and add them into the array for (int i = 0; i < count; i++) { values.Add(dataSet.Tables[tableName].Rows[i][rowName].ToString()); } return values; } Is there a way I can dynamically set the datatype for the list and have this one method cater for all datatypes so I can specify upon calling this method that it should be a List<int or List<string> or List<AnythingILike>? Also, what would the return type be when declaring the method? Thanks in advance, Brett

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  • How to 'assign' a value to an output reg in Verilog?

    - by Rafael Almeida
    ( insert really basic question disclaimer here ) More specifically, I have the following declaration: output reg icache_ram_rw And in some point of the code I need to put the zero value in this reg. Here's what I've tried and the outcomes: assign icache_ram_rw = 1'b0; ( declarative lvalue or port sink reg icache_ram_rw must be a wire ) icache_ram_rw <= 1'b0; ( instance gate/name for type "icache_ram_rw" expected - <= read ) How do I do it after all?!

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  • Using singleton instead of a global static instance

    - by Farstucker
    I ran into a problem today and a friend recommended I use a global static instance or more elegantly a singleton pattern. I spent a few hours reading about singletons but a few things still escape me. Background: What Im trying to accomplish is creating an instance of an API and use this one instance in all my classes (as opposed to making a new connection, etc). There seems to be about 100 ways of creating a singleton but with some help from yoda I found some thread safe examples. ..so given the following code: public sealed class Singleton { public static Singleton Instance { get; private set; } private Singleton() { APIClass api = new APIClass(); //Can this be done? } static Singleton() { Instance = new Singleton(); } } How/Where would you instantiate the this new class and how should it be called from a separate class? EDIT: I realize the Singleton class can be called with something like Singleton obj1 = Singleton.Instance(); but would I be able to access the methods within the APIs Class (ie. obj1.Start)? (not that I need to, just asking) EDIT #2: I might have been a bit premature in checking the answer but I do have one small thing that is still causing me problems. The API is launching just fine, unfortunately Im able to launch two instances? New Code public sealed class SingletonAPI { public static SingletonAPI Instance { get; private set; } private SingletonAPI() {} static SingletonAPI() { Instance = new SingletonAPI(); } // API method: public void Start() { API myAPI = new API();} } but if I try to do something like this... SingletonAPI api = SingletonAPI.Instance; api.Start(); SingletonAPI api2 = SingletonAPI.Instance; // This was just for testing. api2.Start(); I get an error saying that I cannot start more than one instance.

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  • exceptions with python unicode encode/decode functions (why doesn't errors=ignore actually ignore th

    - by gatoatigrado
    Does anyone know why the string conversion functions throw exceptions when errors="ignore" is passed? How can I convert from regular Python string objects to unicode without errors being thrown? Thanks very much! python -c "import codecs; codecs.open('tmp', 'wb', encoding='utf8', errors='ignore').write('?????')" returns Traceback (most recent call last): File "", line 1, in File "/usr/lib/python2.6/codecs.py", line 686, in write return self.writer.write(data) File "/usr/lib/python2.6/codecs.py", line 351, in write data, consumed = self.encode(object, self.errors) UnicodeDecodeError: 'ascii' codec can't decode byte 0xd0 in position 0: ordinal not in range(128)

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  • Good beginners' level book about mobile telecommunication

    - by vito
    I've recently joined a company who specialize in the mobile telecommunication domain. I'm encountering a lot of jargons, and I'm feeling a bit lost in most of the conversations. Although I'm quickly searching for the new terms on the web and learning stuff on the job, I would like to read an introductory book that will take me through the basics of the mobile world. Thanks for your recommendations!

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  • Implementing a linear, binary SVM (support vector machine)

    - by static_rtti
    I want to implement a simple SVM classifier, in the case of high-dimensional binary data (text), for which I think a simple linear SVM is best. The reason for implementing it myself is basically that I want to learn how it works, so using a library is not what I want. The problem is that most tutorials go up to an equation that can be solved as a "quadratic problem", but they never show an actual algorithm! So could you point me either to a very simple implementation I could study, or (better) to a tutorial that goes all the way to the implementation details? Thanks a lot!

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  • Blackjack game reshuffling problem

    - by Jam
    I am trying to make a blackjack game where before each new round, the program checks to make sure that the deck has 7 cards per player. And if it doesn't, the deck clears, repopulates, and reshuffles. I have most of the problem down, but for some reason at the start of every deal it reshuffles the deck more than once, and I can't figure out why. Help, please. Here's what I have so far: (P.S. the imported cards and games modules aren't part of the problem, I'm fairly sure my problem lies in the deal() function of my BJ_Deck class.) import cards, games class BJ_Card(cards.Card): """ A Blackjack Card. """ ACE_VALUE = 1 def get_value(self): if self.is_face_up: value = BJ_Card.RANKS.index(self.rank) + 1 if value > 10: value = 10 else: value = None return value value = property(get_value) class BJ_Deck(cards.Deck): """ A Blackjack Deck. """ def populate(self): for suit in BJ_Card.SUITS: for rank in BJ_Card.RANKS: self.cards.append(BJ_Card(rank, suit)) def deal(self, hands, per_hand=1): for rounds in range(per_hand): for hand in hands: if len(self.cards)>=7*(len(hands)): top_card=self.cards[0] self.give(top_card, hand) else: print "Reshuffling the deck." self.cards=[] self.populate() self.shuffle() top_card=self.cards[0] self.give(top_card, hand) class BJ_Hand(cards.Hand): """ A Blackjack Hand. """ def init(self, name): super(BJ_Hand, self).init() self.name = name def __str__(self): rep = self.name + ":\t" + super(BJ_Hand, self).__str__() if self.total: rep += "(" + str(self.total) + ")" return rep def get_total(self): # if a card in the hand has value of None, then total is None for card in self.cards: if not card.value: return None # add up card values, treat each Ace as 1 total = 0 for card in self.cards: total += card.value # determine if hand contains an Ace contains_ace = False for card in self.cards: if card.value == BJ_Card.ACE_VALUE: contains_ace = True # if hand contains Ace and total is low enough, treat Ace as 11 if contains_ace and total <= 11: # add only 10 since we've already added 1 for the Ace total += 10 return total total = property(get_total) def is_busted(self): return self.total > 21 class BJ_Player(BJ_Hand): """ A Blackjack Player. """ def is_hitting(self): response = games.ask_yes_no("\n" + self.name + ", do you want a hit? (Y/N): ") return response == "y" def bust(self): print self.name, "busts." self.lose() def lose(self): print self.name, "loses." def win(self): print self.name, "wins." def push(self): print self.name, "pushes." class BJ_Dealer(BJ_Hand): """ A Blackjack Dealer. """ def is_hitting(self): return self.total < 17 def bust(self): print self.name, "busts." def flip_first_card(self): first_card = self.cards[0] first_card.flip() class BJ_Game(object): """ A Blackjack Game. """ def init(self, names): self.players = [] for name in names: player = BJ_Player(name) self.players.append(player) self.dealer = BJ_Dealer("Dealer") self.deck = BJ_Deck() self.deck.populate() self.deck.shuffle() def get_still_playing(self): remaining = [] for player in self.players: if not player.is_busted(): remaining.append(player) return remaining # list of players still playing (not busted) this round still_playing = property(get_still_playing) def __additional_cards(self, player): while not player.is_busted() and player.is_hitting(): self.deck.deal([player]) print player if player.is_busted(): player.bust() def play(self): # deal initial 2 cards to everyone self.deck.deal(self.players + [self.dealer], per_hand = 2) self.dealer.flip_first_card() # hide dealer's first card for player in self.players: print player print self.dealer # deal additional cards to players for player in self.players: self.__additional_cards(player) self.dealer.flip_first_card() # reveal dealer's first if not self.still_playing: # since all players have busted, just show the dealer's hand print self.dealer else: # deal additional cards to dealer print self.dealer self.__additional_cards(self.dealer) if self.dealer.is_busted(): # everyone still playing wins for player in self.still_playing: player.win() else: # compare each player still playing to dealer for player in self.still_playing: if player.total > self.dealer.total: player.win() elif player.total < self.dealer.total: player.lose() else: player.push() # remove everyone's cards for player in self.players: player.clear() self.dealer.clear() def main(): print "\t\tWelcome to Blackjack!\n" names = [] number = games.ask_number("How many players? (1 - 7): ", low = 1, high = 8) for i in range(number): name = raw_input("Enter player name: ") names.append(name) print game = BJ_Game(names) again = None while again != "n": game.play() again = games.ask_yes_no("\nDo you want to play again?: ") main() raw_input("\n\nPress the enter key to exit.")

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