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  • Shuffling words in a sentence in javascript (coding horror - How to improve?)

    - by Bill Zimmerman
    Hi, I'm trying to do something that is fairly simple, but my code looks terrible and I am certain there is a better way to do things in javascript. I am new to javascript, and am trying to improve my coding. This just feels very messy. All I want to do is to randomly change the order some words on a web page. In python, the code would look something like this: s = 'THis is a sentence' shuffledSentence = random.shuffle(s.split(' ')).join(' ') However, this is the monstrosity I've managed to produce in javascript //need custom sorting function because javascript doesn't have shuffle? function mySort(a,b) { return a.sortValue - b.sortValue; } function scrambleWords() { var content = $.trim($(this).contents().text()); splitContent = content.split(' '); //need to create a temporary array of objects to make sorting easier var tempArray = new Array(splitContent.length); for (var i = 0; i < splitContent.length; i++) { //create an object that can be assigned a random number for sorting var tmpObj = new Object(); tmpObj.sortValue = Math.random(); tmpObj.string = splitContent[i]; tempArray[i] = tmpObj; } tempArray.sort(mySort); //copy the strings back to the original array for (i = 0; i < splitContent.length; i++) { splitContent[i] = tempArray[i].string; } content = splitContent.join(' '); //the result $(this).text(content); } Can you help me to simplify things?

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  • How does this RegEx for parsing emails work in PHP?

    - by George Edison
    Okay, I have the following PHP code to extract an email address of the following two forms: Random Stranger <[email protected]> [email protected] Here is the PHP code: // The first example $sender = "Random Stranger <[email protected]>"; $pattern = '/([\w_-]*@[\w-\.]*)|.*<([\w_-]*@[\w-\.]*)>/'; preg_match($pattern,$sender,$matches,PREG_OFFSET_CAPTURE); echo "<pre>"; print_r($matches); echo "</pre><hr>"; // The second example $sender = "[email protected]"; preg_match($pattern,$sender,$matches,PREG_OFFSET_CAPTURE); echo "<pre>"; print_r($matches); echo "</pre>"; My question is... what is in $matches? It seems to be a strange collection of arrays. Which index holds the match from the parenthesis? How can I be sure I'm getting the email address and only the email address? Update: Here is the output: Array ( [0] => Array ( [0] => Random Stranger [1] => 0 ) [1] => Array ( [0] => [1] => -1 ) [2] => Array ( [0] => [email protected] [1] => 5 ) ) Array ( [0] => Array ( [0] => [email protected] [1] => 0 ) [1] => Array ( [0] => [email protected] [1] => 0 ) )

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  • Why does jQuery fadeOut not work inside this setInterval loop?

    - by Clay McClure
    I'm trying to load random items into a div every few seconds, with a nice fadeOut/fadeIn transition between each load. Here's the code: <html> <body> <div id="item"></div> <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js"></script> <script type="text/javascript"> // Load a random item var item = $('#item'); function load_item() { item.fadeOut(5000, function() { item.load('http://dynamic.xkcd.com/comic/random/ #middleContent img', null, function() { item.fadeIn(5000); }); }); }; // Load initial featured item load_item(); // Schedule repeated loading setInterval(load_item, 15000); </script> </body> </html> This works fine the first time through, but on subsequent calls to load_item, the fadeOut() seems to stop working. It doesn't actually fade the #item div out, but jumps immediately into the callback function, ignoring the 5000 delay. What am I doing wrong?

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  • Problem painting JLabel class to another JPanel class

    - by jjpotter
    I have created a class that extends JLabel to use as my object moving around a JPanel for a game. import javax.swing.*; public class Head extends JLabel { int xpos; int ypos; int xvel; int yvel; ImageIcon chickie = new ImageIcon("C:\\Users\\jjpotter.MSDOM1\\Pictures\\clavalle.jpg"); JLabel myLabel = new JLabel(chickie); public Head(int xpos, int ypos, int xvel, int yvel){ this.xpos = xpos; this.ypos = ypos; this.xvel = xvel; this.yvel = yvel; } public void draw(){ myLabel.setLocation(xpos, ypos); } public double getXpos() { return xpos; } public double getYpos() { return ypos; } public int getXvel() { return xvel; } public int getYvel() { return yvel; } public void setPos(int x, int y){ xpos = x; ypos = y; } } I am then trying to add it onto my JPanel. From here I will randomly have it increment its x and y coordinates to float it around the screen. I can not get it to paint itself onto the JPanel. I know there is a key concept I am missing here that involves painting components on different panels. Here is what I have in my GamePanel class import java.awt.Dimension; import java.util.Random; import javax.swing.*; public class GamePanel extends JPanel { Random myRand = new Random(); Head head = new Head(20,20,0,0); public GamePanel(){ this.setSize(new Dimension(640, 480)); this.add(head); } } Any suggestions on how to get this to add to the JPanel? Also, is this a good way to go about having the picture float around the screen randomly for a game?

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  • Avoiding seasonality assumption for stl() or decompose() in R

    - by user303922
    Hello everybody, I have high frequency commodity price data that I need to analyze. My objective is to not assume any seasonal component and just identify a trend. Here is where I run into problems with R. There are two main functions that I know of to analyze this time series: decompose() and stl(). The problem is that they both take a ts object type with a frequency parameter greater than or equal to 2. Is there some way I can assume a frequency of 1 per unit time and still analyze this time series using R? I'm afraid that if I assume frequency greater than 1 per unit time, and seasonality is calculated using the frequency parameter, then my forecasts are going to depend on that assumption. names(crude.data)=c('Date','Time','Price') names(crude.data) freq = 2 win.graph() plot(crude.data$Time,crude.data$Price, type="l") crude.data$Price = ts(crude.data$Price,frequency=freq) I want frequency to be 1 per unit time but then decompose() and stl() don't work! dim(crude.data$Price) decom = decompose(crude.data$Price) win.graph() plot(decom$random[2:200],type="line") acf(decom$random[freq:length(decom$random-freq)]) Thank you.

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  • Simplifying for-if messes with better structure?

    - by HH
    # Description: you are given a bitwise pattern and a string # you need to find the number of times the pattern matches in the string # any one liner or simple pythonic solution? import random def matchIt(yourString, yourPattern): """find the number of times yourPattern occurs in yourString""" count = 0 matchTimes = 0 # How can you simplify the for-if structures? for coin in yourString: #return to base if count == len(pattern): matchTimes = matchTimes + 1 count = 0 #special case to return to 2, there could be more this type of conditions #so this type of if-conditionals are screaming for a havoc if count == 2 and pattern[count] == 1: count = count - 1 #the work horse #it could be simpler by breaking the intial string of lenght 'l' #to blocks of pattern-length, the number of them is 'l - len(pattern)-1' if coin == pattern[count]: count=count+1 average = len(yourString)/matchTimes return [average, matchTimes] # Generates the list myString =[] for x in range(10000): myString= myString + [int(random.random()*2)] pattern = [1,0,0] result = matchIt(myString, pattern) print("The sample had "+str(result[1])+" matches and its size was "+str(len(myString))+".\n" + "So it took "+str(result[0])+" steps in average.\n" + "RESULT: "+str([a for a in "FAILURE" if result[0] != 8])) # Sample Output # # The sample had 1656 matches and its size was 10000. # So it took 6 steps in average. # RESULT: ['F', 'A', 'I', 'L', 'U', 'R', 'E']

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  • grails question (sample 1 of Grails To Action book) problem with Controller and Service

    - by fegloff
    Hi, I'm doing Grails To Action sample for chapter one. Every was just fine until I started to work with Services. When I run the app I have the following error: groovy.lang.MissingPropertyException: No such property: quoteService for class: qotd.QuoteController at qotd.QuoteController$_closure3.doCall(QuoteController.groovy:14) at qotd.QuoteController$_closure3.doCall(QuoteController.groovy) at java.lang.Thread.run(Thread.java:619) Here is my groovie QuoteService class, which has an error within the definition of GetStaticQuote (ERROR: Groovy:unable to resolve class Quote) package qotd class QuoteService { boolean transactional = false def getRandomQuote() { def allQuotes = Quote.list() def randomQuote = null if (allQuotes.size() > 0) { def randomIdx = new Random().nextInt(allQuotes.size()) randomQuote = allQuotes[randomIdx] } else { randomQuote = getStaticQuote() } return randomQuote } def getStaticQuote() { return new Quote(author: "Anonymous",content: "Real Programmers Don't eat quiche") } } Controller groovie class package qotd class QuoteController { def index = { redirect(action: random) } def home = { render "<h1>Real Programmers do not each quiche!</h1>" } def random = { def randomQuote = quoteService.getRandomQuote() [ quote : randomQuote ] } def ajaxRandom = { def randomQuote = quoteService.getRandomQuote() render "<q>${randomQuote.content}</q>" + "<p>${randomQuote.author}</p>" } } Quote Class: package qotd class Quote { String content String author Date created = new Date() static constraints = { author(blank:false) content(maxSize:1000, blank:false) } } I'm doing the samples using Eclipse with grails addin. Any advice? Regards, Francisco

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  • Do I need to Salt and Hash a randomly generated token?

    - by wag2639
    I'm using Adam Griffiths's Authentication Library for CodeIgniter and I'm tweaking the usermodel. I came across a generate function that he uses to generate tokens. His preferred approach is to reference a value from random.org but I considered that superfluous. I'm using his fall back approach of randomly generating a 20 character long string: $length = 20; $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'; $token = ''; for ($i = 0; $i < $length; $i++) { $token .= $characters[mt_rand(0, strlen($characters)-1)]; } He then hashes this token using a salt (I'm combing code from different functions) sha1($this->CI->config->item('encryption_key').$str); I was wondering if theres any reason to to run the token through the salted hash? I've read that simply randomly generating strings was a naive way of making random passwords but is the sh1 hash and salt necessary? Note: I got my encryption_key from https://www.grc.com/passwords.htm (63 random alpha-numeric)

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  • If attacker has original data, and encrypted data, can they determine the passphrase?

    - by Brad Cupit
    If an attacker has several distinct items (for example: e-mail addresses) and knows the encrypted value of each item, can the attacker more easily determine the secret passphrase used to encrypt those items? Meaning, can they determine the passphrase without resorting to brute force? This question may sound strange, so let me provide a use-case: User signs up to a site with their e-mail address Server sends that e-mail address a confirmation URL (for example: https://my.app.com/confirmEmailAddress/bill%40yahoo.com) Attacker can guess the confirmation URL and therefore can sign up with someone else's e-mail address, and 'confirm' it without ever having to sign in to that person's e-mail account and see the confirmation URL. This is a problem. Instead of sending the e-mail address plain text in the URL, we'll send it encrypted by a secret passphrase. (I know the attacker could still intercept the e-mail sent by the server, since e-mail are plain text, but bear with me here.) If an attacker then signs up with multiple free e-mail accounts and sees multiple URLs, each with the corresponding encrypted e-mail address, could the attacker more easily determine the passphrase used for encryption? Alternative Solution I could instead send a random number or one-way hash of their e-mail address (plus random salt). This eliminates storing the secret passphrase, but it means I need to store that random number/hash in the database. The original approach above does not require this extra table. I'm leaning towards the the one-way hash + extra table solution, but I still would like to know the answer: does having multiple unencrypted e-mail addresses and their encrypted counterparts make it easier to determine the passphrase used?

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  • How to Refresh / Reload a KML layer in OpenLayers. Dynamic KML Layer.

    - by Ozaki
    TLDR See my answer below on how to refresh the layer. So far I have tried action function as follows: function RefreshKMLData(layer) { layer.loaded = false; layer.setVisibility(true); layer.redraw({ force: true }); } set interval of the function: window.setInterval(RefreshKMLData, 5000, KMLLAYER); the layer itself: var KMLLAYER = new OpenLayers.Layer.Vector("MYKMLLAYER", { projection: new OpenLayers.Projection("EPSG:4326"), strategies: [new OpenLayers.Strategy.Fixed()], protocol: new OpenLayers.Protocol.HTTP({ url: MYKMLURL, format: new OpenLayers.Format.KML({ extractStyles: true, extractAttributes: true }) }) }); the url for KMLLAYER with Math random so it doesnt cache: var MYKMLURL = var currentanchorpositionurl = 'http://' + host + '/data?_salt=' + Math.random(); I would have thought that this would Refresh the layer. As by setting its loaded to false unloads it. Visibility to true reloads it and with the Math random shouldn't allow it to cache? So has anyone done this before or know how I can get this to work? TLDR See my answer below on how to refresh the layer.

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  • Cannot Find Symbol Method?

    - by Aaron
    In my driver program, This line gives me cannot find symbol error and I don't know why, the method is clearly defined in the SavingsAccount class, and I can refer to all other methods in my driver program but just not that one, I tried changing the type to double, and etc but still not working. Refer to ** Account acct2 = new SavingsAccount (name); acct2.calculateBalance(); SavingsAccount Class Inherited from Account Class: public class SavingsAccount extends Account { private final short minBalance = 0; private double overdraftFee; private double yearlyInterestRate = 0.02; private double interestAmount; public SavingsAccount (String name) { super(name); } public double withdraw (double amount) { if (accountBalance - amount >= minBalance) { accountBalance -= amount; System.out.print ("Withdraw Successful"); } else { accountBalance -= amount; overdraftFee = accountBalance * (0.10); accountBalance += overdraftFee; System.out.print ("Withdraw Succesful, however overdraft fee of 10% has been applied to your account"); } return accountBalance; } **public void calculateBalance () { interestAmount = (accountBalance * yearlyInterestRate); accountBalance += interestAmount; }** public String toString() { return super.toString() + " Interest Received: " + interestAmount; } } Account class, if needed import java.util.Random; import java.text.NumberFormat; public abstract class Account { protected double accountBalance; protected long accountNumber; protected String accountHolder; public Account (String name) { accountHolder = name; accountBalance = 0; Random accountNo = new Random(); accountNumber = accountNo.nextInt(100000); } public double deposit (double amount) { accountBalance += amount; return accountBalance; } public String toString() { NumberFormat accountBal = NumberFormat.getCurrencyInstance(); return "Account Balance: " + accountBal.format(accountBalance) + "\nAccount Number: " + accountNumber; } public String getAccountHolder() { return accountHolder; } public double getAccountBalance() { return accountBalance; } public abstract double withdraw (double amount); }

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  • html in do_GET() method of a simple Python webserver

    - by Meeri_Peeri
    I am relatively new to Python but have been doing a lot of different things with it recently and I am liking it a lot. However, I ran into trouble/block with the following code. import http.server import socketserver import glob import random class Server(http.server.SimpleHTTPRequestHandler): def do_GET(self): self.send_response(200, 'OK') self.send_header('Content-type', 'html') self.end_headers() self.wfile.write(bytes("<html> <head><title> Hello World </title> </head> <body>", 'UTF-8')) images = glob.glob('*.jpg') rand = random.randint(0,len(images)-1) imagestring = "<img src = \"" + images[rand] + "\" height = 1028 width = 786 align = \"right\"/> </body> </html>" self.wfile.write(bytes(imagestring, 'UTF-8')) def serve_forever(port): socketserver.TCPServer(('', port), Server).serve_forever() if __name__ == "__main__": Server.serve_forever(8000) What I am trying to do here is grab a random image from multiple images in the directory and add it into the response to a web request. The code works fine but when I access the server via browser, the image is not displayed. The html of the page is as intended though. The permissions on the files are 755. Also I tried to create an index.html file in the do_GET method. That didn't work either. I mean the index.html was generated fine, but the response in the browser this time did not show anything (not even the hello world in the title). Am I missing anything very simple here? I was thinking should I overload the handle_request of the underlying SocketServer.BaseServer as the documentation says you should never override BaseHTTPServer's handle() method and should rather override the corresponding do_* method?

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  • Beginnerquestion: How to count amount of each number drawn in a Lottery and output it in a list?

    - by elementz
    I am writing this little Lottery application. Now the plan is, to count how often each number has been drawn during each iteration of the Lottery, and store this somewhere. My guess is that I would need to use a HashMap, that has 6 keys and increments the value by one everytime the respective keys number is drawn. But how would I accomplish this? My code so far: public void numberCreator() { // creating and initializing a Random generator Random rand = new Random(); // A HashMap to store the numbers picked. HashMap hashMap = new HashMap(); // A TreeMap to sort the numbers picked. TreeMap treeMap = new TreeMap(); // creating an ArrayList which will store the pool of availbale Numbers List<Integer>numPool = new ArrayList<Integer>(); for (int i=1; i<50; i++){ // add the available Numbers to the pool numPool.add(i); hashMap.put(nums[i], 0); } // array to store the lotto numbers int [] nums = new int [6]; for (int i =0; i < nums.length; i++){ int numPoolIndex = rand.nextInt(numPool.size()); nums[i] = numPool.get(numPoolIndex); // check how often a number has been called and store the new amount in the Map int counter = hashMap.get numPool.remove(numPoolIndex); } System.out.println(Arrays.toString(nums)); } Maybe someone can tell me if I have the right idea, or even how I would implement the map properly?

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  • generate k distinct number less then n

    - by davit-datuashvili
    hi i have following question task is this generate k distinct positive numbers less then n without duplication my method is following first create array size of k where we should write these numbers int a[]=new int[k]; //now i am going to cretae another array where i check if (at given number position is 1 then generate number again else put this number in a array and continue cycle i put here a piece of code and explanations int a[]=new int[k]; int t[]=new int[n+1]; Random r=new Random(); for (int i==0;i<t.length;i++){ t[i]=0;//initialize it to zero } int m=0;//initialize it also for (int i=0;i<a.length;i++){ m=r.nextInt(n);//random element between 0 and n if (t[m]==1){ //i have problem with this i want in case of duplication element occurs repeats this steps afain until there will be different number else{ t[m]=1; x[i]=m; } } so i fill concret my problem if t[m]==1 it means that this element occurs already so i want to generate new number but problem is that number of generated numbers will not be k beacuse if i==0 and occurs duplicate element and we write continue then it will switch at i==1 i need like goto for repeat step or for (int i=0;i<x.length;i++){ loop: m=r.nextInt(n); if ( x[m]==1){ continue loop; } else{ x[m]=1; a[i]=m; continue;//continue next step at i=1 and so on } } i need this code in java please help

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  • question about permut-by-sorting

    - by davit-datuashvili
    hi i have following question from book introduction in algorithms second edition there is such problem suppose we have some array A int a[]={1,2,3,4} and we have some random priorities array P={36,3,97,19} we shoud permut array a randomly using this priorities array here is pseudo code P ERMUTE -B Y-S ORTING ( A) 1 n ? length[A] 2 for i ? 1 to n do P[i] = R ANDOM(1, n 3 ) 3 4 sort A, using P as sort keys 5 return A and result will be permuted array B={2, 4, 1, 3}; please help any ideas i have done this code and need aideas how continue import java.util.*; public class Permut { public static void main(String[]args){ Random r=new Random(); int a[]=new int[]{1,2,3,4}; int n=a.length; int b[]=new int[a.length]; int p[]=new int[a.length]; for (int i=0;i<p.length;i++){ p[i]=r.nextInt(n*n*n)+1; } // for (int i=0;i<p.length;i++){ // System.out.println(p[i]); //} } } please help

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  • Python - creating a list with 2 characteristics bug

    - by user2733911
    The goal is to create a list of 99 elements. All elements must be 1s or 0s. The first element must be a 1. There must be 7 1s in total. import random import math import time # constants determined through testing generation_constant = 0.96 def generate_candidate(): coin_vector = [] coin_vector.append(1) for i in range(0, 99): random_value = random.random() if (random_value > generation_constant): coin_vector.append(1) else: coin_vector.append(0) return coin_vector def validate_candidate(vector): vector_sum = sum(vector) sum_test = False if (vector_sum == 7): sum_test = True first_slot = vector[0] first_test = False if (first_slot == 1): first_test = True return (sum_test and first_test) vector1 = generate_candidate() while (validate_candidate(vector1) == False): vector1 = generate_candidate() print vector1, sum(vector1), validate_candidate(vector1) Most of the time, the output is correct, saying something like [1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0] 7 True but sometimes, the output is: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0] 2 False What exactly am I doing wrong?

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  • Calculating percent "x/y * 100" always results in 0?

    - by Patrick Beninga
    In my assignment i have to make a simple version of Craps, for some reason the percentage assignments always produce 0 even when both variables are non 0, here is the code. import java.util.Random; Header, note the variables public class Craps { private int die1, die2,myRoll ,myBet,point,myWins,myLosses; private double winPercent,lossPercent; private Random r = new Random(); Just rolls two dies and produces their some. public int roll(){ die1 = r.nextInt(6)+1; die2 = r.nextInt(6)+1; return(die1 + die2); } The Play method, this just loops through the game. public void play(){ myRoll = roll(); point = 0; if(myRoll == 2 ||myRoll == 3 || myRoll == 12){ System.out.println("You lose!"); myLosses++; }else if(myRoll == 7 || myRoll == 11){ System.out.println("You win!"); myWins++; }else{ point = myRoll; do { myRoll = roll(); }while(myRoll != 7 && myRoll != point); if(myRoll == point){ System.out.println("You win!"); myWins++; }else{ System.out.println("You lose!"); myLosses++; } } } This is where the bug is, this is the tester method. public void tester(int howMany){ int i = 0; while(i < howMany){ play(); i++; } bug is right here in these assignments statements winPercent = myWins/i * 100; lossPercent = myLosses/i* 100; System.out.println("program ran "+i+" times "+winPercent+"% wins "+ lossPercent+"% losses with "+myWins+" wins and "+myLosses+" losses"); } }

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  • getting duplicate array output - java

    - by dowln
    Hello, Can someone could be kind and help me out here. Thanks in advance... My code below outputs the string as duplicates. I don't want to use Sets or ArrayList. I am using java.util.Random. I am trying to write a code that checks if string has already been randomly outputted and if it does, then it won't display. Where I am going wrong and how do I fix this. public class Worldcountries { private static Random nums = new Random(); private static String[] countries = { "America", "Candada", "Chile", "Argentina" }; public static int Dice() { return (generator.nums.nextInt(6) + 1); } public String randomCounties() { String aTemp = " "; int numOfTimes = Dice(); int dup = 0; for(int i=0 ; i<numOfTimes; i++) { // I think it's in the if statement where I am going wrong. if (!countries[i].equals(countries[i])) { i = i + 1; } else { dup--; } // and maybe here aTemp = aTemp + countries[nums.nextInt(countries.length)]; aTemp = aTemp + ","; } return aTemp; } } So the output I am getting (randomly) is, "America, America, Chile" when it should be "America, Chile".

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  • Security Issues with Single Page Apps

    - by Stephen.Walther
    Last week, I was asked to do a code review of a Single Page App built using the ASP.NET Web API, Durandal, and Knockout (good stuff!). In particular, I was asked to investigate whether there any special security issues associated with building a Single Page App which are not present in the case of a traditional server-side ASP.NET application. In this blog entry, I discuss two areas in which you need to exercise extra caution when building a Single Page App. I discuss how Single Page Apps are extra vulnerable to both Cross-Site Scripting (XSS) attacks and Cross-Site Request Forgery (CSRF) attacks. This goal of this blog post is NOT to persuade you to avoid writing Single Page Apps. I’m a big fan of Single Page Apps. Instead, the goal is to ensure that you are fully aware of some of the security issues related to Single Page Apps and ensure that you know how to guard against them. Cross-Site Scripting (XSS) Attacks According to WhiteHat Security, over 65% of public websites are open to XSS attacks. That’s bad. By taking advantage of XSS holes in a website, a hacker can steal your credit cards, passwords, or bank account information. Any website that redisplays untrusted information is open to XSS attacks. Let me give you a simple example. Imagine that you want to display the name of the current user on a page. To do this, you create the following server-side ASP.NET page located at http://MajorBank.com/SomePage.aspx: <%@Page Language="C#" %> <html> <head> <title>Some Page</title> </head> <body> Welcome <%= Request["username"] %> </body> </html> Nothing fancy here. Notice that the page displays the current username by using Request[“username”]. Using Request[“username”] displays the username regardless of whether the username is present in a cookie, a form field, or a query string variable. Unfortunately, by using Request[“username”] to redisplay untrusted information, you have now opened your website to XSS attacks. Here’s how. Imagine that an evil hacker creates the following link on another website (hackers.com): <a href="/SomePage.aspx?username=<script src=Evil.js></script>">Visit MajorBank</a> Notice that the link includes a query string variable named username and the value of the username variable is an HTML <SCRIPT> tag which points to a JavaScript file named Evil.js. When anyone clicks on the link, the <SCRIPT> tag will be injected into SomePage.aspx and the Evil.js script will be loaded and executed. What can a hacker do in the Evil.js script? Anything the hacker wants. For example, the hacker could display a popup dialog on the MajorBank.com site which asks the user to enter their password. The script could then post the password back to hackers.com and now the evil hacker has your secret password. ASP.NET Web Forms and ASP.NET MVC have two automatic safeguards against this type of attack: Request Validation and Automatic HTML Encoding. Protecting Coming In (Request Validation) In a server-side ASP.NET app, you are protected against the XSS attack described above by a feature named Request Validation. If you attempt to submit “potentially dangerous” content — such as a JavaScript <SCRIPT> tag — in a form field or query string variable then you get an exception. Unfortunately, Request Validation only applies to server-side apps. Request Validation does not help in the case of a Single Page App. In particular, the ASP.NET Web API does not pay attention to Request Validation. You can post any content you want – including <SCRIPT> tags – to an ASP.NET Web API action. For example, the following HTML page contains a form. When you submit the form, the form data is submitted to an ASP.NET Web API controller on the server using an Ajax request: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title></title> </head> <body> <form data-bind="submit:submit"> <div> <label> User Name: <input data-bind="value:user.userName" /> </label> </div> <div> <label> Email: <input data-bind="value:user.email" /> </label> </div> <div> <input type="submit" value="Submit" /> </div> </form> <script src="Scripts/jquery-1.7.1.js"></script> <script src="Scripts/knockout-2.1.0.js"></script> <script> var viewModel = { user: { userName: ko.observable(), email: ko.observable() }, submit: function () { $.post("/api/users", ko.toJS(this.user)); } }; ko.applyBindings(viewModel); </script> </body> </html> The form above is using Knockout to bind the form fields to a view model. When you submit the form, the view model is submitted to an ASP.NET Web API action on the server. Here’s the server-side ASP.NET Web API controller and model class: public class UsersController : ApiController { public HttpResponseMessage Post(UserViewModel user) { var userName = user.UserName; return Request.CreateResponse(HttpStatusCode.OK); } } public class UserViewModel { public string UserName { get; set; } public string Email { get; set; } } If you submit the HTML form, you don’t get an error. The “potentially dangerous” content is passed to the server without any exception being thrown. In the screenshot below, you can see that I was able to post a username form field with the value “<script>alert(‘boo’)</script”. So what this means is that you do not get automatic Request Validation in the case of a Single Page App. You need to be extra careful in a Single Page App about ensuring that you do not display untrusted content because you don’t have the Request Validation safety net which you have in a traditional server-side ASP.NET app. Protecting Going Out (Automatic HTML Encoding) Server-side ASP.NET also protects you from XSS attacks when you render content. By default, all content rendered by the razor view engine is HTML encoded. For example, the following razor view displays the text “<b>Hello!</b>” instead of the text “Hello!” in bold: @{ var message = "<b>Hello!</b>"; } @message   If you don’t want to render content as HTML encoded in razor then you need to take the extra step of using the @Html.Raw() helper. In a Web Form page, if you use <%: %> instead of <%= %> then you get automatic HTML Encoding: <%@ Page Language="C#" %> <% var message = "<b>Hello!</b>"; %> <%: message %> This automatic HTML Encoding will prevent many types of XSS attacks. It prevents <script> tags from being rendered and only allows &lt;script&gt; tags to be rendered which are useless for executing JavaScript. (This automatic HTML encoding does not protect you from all forms of XSS attacks. For example, you can assign the value “javascript:alert(‘evil’)” to the Hyperlink control’s NavigateUrl property and execute the JavaScript). The situation with Knockout is more complicated. If you use the Knockout TEXT binding then you get HTML encoded content. On the other hand, if you use the HTML binding then you do not: <!-- This JavaScript DOES NOT execute --> <div data-bind="text:someProp"></div> <!-- This Javacript DOES execute --> <div data-bind="html:someProp"></div> <script src="Scripts/jquery-1.7.1.js"></script> <script src="Scripts/knockout-2.1.0.js"></script> <script> var viewModel = { someProp : "<script>alert('Evil!')<" + "/script>" }; ko.applyBindings(viewModel); </script>   So, in the page above, the DIV element which uses the TEXT binding is safe from XSS attacks. According to the Knockout documentation: “Since this binding sets your text value using a text node, it’s safe to set any string value without risking HTML or script injection.” Just like server-side HTML encoding, Knockout does not protect you from all types of XSS attacks. For example, there is nothing in Knockout which prevents you from binding JavaScript to a hyperlink like this: <a data-bind="attr:{href:homePageUrl}">Go</a> <script src="Scripts/jquery-1.7.1.min.js"></script> <script src="Scripts/knockout-2.1.0.js"></script> <script> var viewModel = { homePageUrl: "javascript:alert('evil!')" }; ko.applyBindings(viewModel); </script> In the page above, the value “javascript:alert(‘evil’)” is bound to the HREF attribute using Knockout. When you click the link, the JavaScript executes. Cross-Site Request Forgery (CSRF) Attacks Cross-Site Request Forgery (CSRF) attacks rely on the fact that a session cookie does not expire until you close your browser. In particular, if you visit and login to MajorBank.com and then you navigate to Hackers.com then you will still be authenticated against MajorBank.com even after you navigate to Hackers.com. Because MajorBank.com cannot tell whether a request is coming from MajorBank.com or Hackers.com, Hackers.com can submit requests to MajorBank.com pretending to be you. For example, Hackers.com can post an HTML form from Hackers.com to MajorBank.com and change your email address at MajorBank.com. Hackers.com can post a form to MajorBank.com using your authentication cookie. After your email address has been changed, by using a password reset page at MajorBank.com, a hacker can access your bank account. To prevent CSRF attacks, you need some mechanism for detecting whether a request is coming from a page loaded from your website or whether the request is coming from some other website. The recommended way of preventing Cross-Site Request Forgery attacks is to use the “Synchronizer Token Pattern” as described here: https://www.owasp.org/index.php/Cross-Site_Request_Forgery_%28CSRF%29_Prevention_Cheat_Sheet When using the Synchronizer Token Pattern, you include a hidden input field which contains a random token whenever you display an HTML form. When the user opens the form, you add a cookie to the user’s browser with the same random token. When the user posts the form, you verify that the hidden form token and the cookie token match. Preventing Cross-Site Request Forgery Attacks with ASP.NET MVC ASP.NET gives you a helper and an action filter which you can use to thwart Cross-Site Request Forgery attacks. For example, the following razor form for creating a product shows how you use the @Html.AntiForgeryToken() helper: @model MvcApplication2.Models.Product <h2>Create Product</h2> @using (Html.BeginForm()) { @Html.AntiForgeryToken(); <div> @Html.LabelFor( p => p.Name, "Product Name:") @Html.TextBoxFor( p => p.Name) </div> <div> @Html.LabelFor( p => p.Price, "Product Price:") @Html.TextBoxFor( p => p.Price) </div> <input type="submit" /> } The @Html.AntiForgeryToken() helper generates a random token and assigns a serialized version of the same random token to both a cookie and a hidden form field. (Actually, if you dive into the source code, the AntiForgeryToken() does something a little more complex because it takes advantage of a user’s identity when generating the token). Here’s what the hidden form field looks like: <input name=”__RequestVerificationToken” type=”hidden” value=”NqqZGAmlDHh6fPTNR_mti3nYGUDgpIkCiJHnEEL59S7FNToyyeSo7v4AfzF2i67Cv0qTB1TgmZcqiVtgdkW2NnXgEcBc-iBts0x6WAIShtM1″ /> And here’s what the cookie looks like using the Google Chrome developer toolbar: You use the [ValidateAntiForgeryToken] action filter on the controller action which is the recipient of the form post to validate that the token in the hidden form field matches the token in the cookie. If the tokens don’t match then validation fails and you can’t post the form: public ActionResult Create() { return View(); } [ValidateAntiForgeryToken] [HttpPost] public ActionResult Create(Product productToCreate) { if (ModelState.IsValid) { // save product to db return RedirectToAction("Index"); } return View(); } How does this all work? Let’s imagine that a hacker has copied the Create Product page from MajorBank.com to Hackers.com – the hacker grabs the HTML source and places it at Hackers.com. Now, imagine that the hacker trick you into submitting the Create Product form from Hackers.com to MajorBank.com. You’ll get the following exception: The Cross-Site Request Forgery attack is blocked because the anti-forgery token included in the Create Product form at Hackers.com won’t match the anti-forgery token stored in the cookie in your browser. The tokens were generated at different times for different users so the attack fails. Preventing Cross-Site Request Forgery Attacks with a Single Page App In a Single Page App, you can’t prevent Cross-Site Request Forgery attacks using the same method as a server-side ASP.NET MVC app. In a Single Page App, HTML forms are not generated on the server. Instead, in a Single Page App, forms are loaded dynamically in the browser. Phil Haack has a blog post on this topic where he discusses passing the anti-forgery token in an Ajax header instead of a hidden form field. He also describes how you can create a custom anti-forgery token attribute to compare the token in the Ajax header and the token in the cookie. See: http://haacked.com/archive/2011/10/10/preventing-csrf-with-ajax.aspx Also, take a look at Johan’s update to Phil Haack’s original post: http://johan.driessen.se/posts/Updated-Anti-XSRF-Validation-for-ASP.NET-MVC-4-RC (Other server frameworks such as Rails and Django do something similar. For example, Rails uses an X-CSRF-Token to prevent CSRF attacks which you generate on the server – see http://excid3.com/blog/rails-tip-2-include-csrf-token-with-every-ajax-request/#.UTFtgDDkvL8 ). For example, if you are creating a Durandal app, then you can use the following razor view for your one and only server-side page: @{ Layout = null; } <!DOCTYPE html> <html> <head> <title>Index</title> </head> <body> @Html.AntiForgeryToken() <div id="applicationHost"> Loading app.... </div> @Scripts.Render("~/scripts/vendor") <script type="text/javascript" src="~/App/durandal/amd/require.js" data-main="/App/main"></script> </body> </html> Notice that this page includes a call to @Html.AntiForgeryToken() to generate the anti-forgery token. Then, whenever you make an Ajax request in the Durandal app, you can retrieve the anti-forgery token from the razor view and pass the token as a header: var csrfToken = $("input[name='__RequestVerificationToken']").val(); $.ajax({ headers: { __RequestVerificationToken: csrfToken }, type: "POST", dataType: "json", contentType: 'application/json; charset=utf-8', url: "/api/products", data: JSON.stringify({ name: "Milk", price: 2.33 }), statusCode: { 200: function () { alert("Success!"); } } }); Use the following code to create an action filter which you can use to match the header and cookie tokens: using System.Linq; using System.Net.Http; using System.Web.Helpers; using System.Web.Http.Controllers; namespace MvcApplication2.Infrastructure { public class ValidateAjaxAntiForgeryToken : System.Web.Http.AuthorizeAttribute { protected override bool IsAuthorized(HttpActionContext actionContext) { var headerToken = actionContext .Request .Headers .GetValues("__RequestVerificationToken") .FirstOrDefault(); ; var cookieToken = actionContext .Request .Headers .GetCookies() .Select(c => c[AntiForgeryConfig.CookieName]) .FirstOrDefault(); // check for missing cookie or header if (cookieToken == null || headerToken == null) { return false; } // ensure that the cookie matches the header try { AntiForgery.Validate(cookieToken.Value, headerToken); } catch { return false; } return base.IsAuthorized(actionContext); } } } Notice that the action filter derives from the base AuthorizeAttribute. The ValidateAjaxAntiForgeryToken only works when the user is authenticated and it will not work for anonymous requests. Add the action filter to your ASP.NET Web API controller actions like this: [ValidateAjaxAntiForgeryToken] public HttpResponseMessage PostProduct(Product productToCreate) { // add product to db return Request.CreateResponse(HttpStatusCode.OK); } After you complete these steps, it won’t be possible for a hacker to pretend to be you at Hackers.com and submit a form to MajorBank.com. The header token used in the Ajax request won’t travel to Hackers.com. This approach works, but I am not entirely happy with it. The one thing that I don’t like about this approach is that it creates a hard dependency on using razor. Your single page in your Single Page App must be generated from a server-side razor view. A better solution would be to generate the anti-forgery token in JavaScript. Unfortunately, until all browsers support a way to generate cryptographically strong random numbers – for example, by supporting the window.crypto.getRandomValues() method — there is no good way to generate anti-forgery tokens in JavaScript. So, at least right now, the best solution for generating the tokens is the server-side solution with the (regrettable) dependency on razor. Conclusion The goal of this blog entry was to explore some ways in which you need to handle security differently in the case of a Single Page App than in the case of a traditional server app. In particular, I focused on how to prevent Cross-Site Scripting and Cross-Site Request Forgery attacks in the case of a Single Page App. I want to emphasize that I am not suggesting that Single Page Apps are inherently less secure than server-side apps. Whatever type of web application you build – regardless of whether it is a Single Page App, an ASP.NET MVC app, an ASP.NET Web Forms app, or a Rails app – you must constantly guard against security vulnerabilities.

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  • Thread not behaving correctly

    - by ivor
    Hello, I wonder if anyone can help me to understand where I could be going wrong with this code; Basically I'm working on a turorial and calling the class below from another class - and it is getting the following error; Exception in thread "Thread-1" java.lang.NullPointerException at org.newdawn.spaceinvaders.TCPChat.run(TCPChat.java:322) at java.lang.Thread.run(Unknown Source) I realise the error is beibg flagged in another class- but I have tested the other class with a small class which sets up a separate thread - and it works fine, but as soon as I try and implement a new thread in this class - it causes all sorts of problems. Am I setting up the thread correctly in this class? Basically I can set up a thread in this class, with a test loop and it's fine, but when I bring in the functionality of the rest of the game it sometimes hangs, or does not display at all. Any suggestions on where I could be going wrong would be greatly appreciated. Thanks for looking. package org.newdawn.spaceinvaders; import java.awt.BorderLayout; import java.awt.Canvas; import java.awt.Color; import java.awt.Dimension; import java.awt.FlowLayout; import java.awt.Graphics2D; import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyAdapter; import java.awt.event.KeyEvent; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import java.awt.image.BufferStrategy; import java.util.ArrayList; import java.util.Scanner; import java.awt.*;//maybe not needed import javax.swing.*;//maybenot needed import java.util.Random; //import java.io.*; /** * The main hook of our game. This class with both act as a manager * for the display and central mediator for the game logic. * * Display management will consist of a loop that cycles round all * entities in the game asking them to move and then drawing them * in the appropriate place. With the help of an inner class it * will also allow the player to control the main ship. * * As a mediator it will be informed when entities within our game * detect events (e.g. alient killed, played died) and will take * appropriate game actions. * * @author Kevin Glass */ public class Game extends Canvas implements Runnable{ /** The stragey that allows us to use accelerate page flipping */ private BufferStrategy strategy; /** True if the game is currently "running", i.e. the game loop is looping */ private boolean gameRunning = true; /** The list of all the entities that exist in our game */ private ArrayList entities = new ArrayList(); /** The list of entities that need to be removed from the game this loop */ private ArrayList removeList = new ArrayList(); /** The entity representing the player */ private Entity ship; /** The speed at which the player's ship should move (pixels/sec) */ private double moveSpeed = 300; /** The time at which last fired a shot */ private long lastFire = 0; /** The interval between our players shot (ms) */ private long firingInterval = 500; /** The number of aliens left on the screen */ private int alienCount; /** The number of levels progressed */ private double levelCount; /** high score for the user */ private int highScore; /** high score for the user */ private String player = "bob"; //private GetUserInput getPlayer; /** The list of entities that need to be removed from the game this loop */ /** The message to display which waiting for a key press */ private String message = ""; /** True if we're holding up game play until a key has been pressed */ private boolean waitingForKeyPress = true; /** True if the left cursor key is currently pressed */ private boolean leftPressed = false; /** True if the right cursor key is currently pressed */ private boolean rightPressed = false; /** True if we are firing */ private boolean firePressed = false; /** True if game logic needs to be applied this loop, normally as a result of a game event */ private boolean logicRequiredThisLoop = false; //private Thread cThread = new Thread(this); //public Thread t = new Thread(this); //private Thread g = new Thread(this); void setHighscore(int setHS) { highScore = setHS; } public int getHighscore() { return highScore; } public void setPlayer(String setPlayer) { player = setPlayer; } public String getPlayer() { return player; } public void run() { //setup(); System.out.println("hello im running bob"); /*int count = 1; do { System.out.println("Count is: " + count); count++; try{Thread.sleep(1);} catch(InterruptedException e){} } while (count <= 2000000);*/ //Game g =new Game(); //Game g = this; // Start the main game loop, note: this method will not // return until the game has finished running. Hence we are // using the actual main thread to run the game. //setup(); //this.gameLoop(); //try{thread.sleep(1);} //catch{InterruptedException e} } /** * Construct our game and set it running. */ public Game () { //Thread t = new Thread(this);//set up new thread for invaders game //t.run();//run the run method of the game //Game g =new Game(); //setup(); //Thread t = new Thread(this); //thread.start(); //SwingUtilities.invokeLater(this); Thread er = new Thread(this); er.start(); } public void setup(){ //initialise highscore setHighscore(0); // create a frame to contain our game JFrame container = new JFrame("Space Invaders 101"); // get hold the content of the frame and set up the resolution of the game JPanel panel = (JPanel) container.getContentPane(); panel.setPreferredSize(new Dimension(800,600)); //panel.setLayout(null); // setup our canvas size and put it into the content of the frame setBounds(0,0,800,600); panel.add(this); // Tell AWT not to bother repainting our canvas since we're // going to do that our self in accelerated mode setIgnoreRepaint(true); // finally make the window visible container.pack(); container.setResizable(false); container.setVisible(true); // add a listener to respond to the user closing the window. If they // do we'd like to exit the game container.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { //cThread.interrupt(); System.exit(0); } }); // add a key input system (defined below) to our canvas // so we can respond to key pressed addKeyListener(new KeyInputHandler()); // request the focus so key events come to us requestFocus(); // create the buffering strategy which will allow AWT // to manage our accelerated graphics createBufferStrategy(2); strategy = getBufferStrategy(); // initialise the entities in our game so there's something // to see at startup initEntities(); } /** * Start a fresh game, this should clear out any old data and * create a new set. */ private void startGame() { // clear out any existing entities and intialise a new set entities.clear(); initEntities(); //initialise highscore setHighscore(0); // blank out any keyboard settings we might currently have leftPressed = false; rightPressed = false; firePressed = false; } /** * Initialise the starting state of the entities (ship and aliens). Each * entitiy will be added to the overall list of entities in the game. */ //private void initEntities() { public void initEntities() { Random randomAlien = new Random(); // create the player ship and place it roughly in the center of the screen //ship = new ShipEntity(this,"sprites/ship.gif",370,550);//orignal ship = new ShipEntity(this,"sprites/ship.gif",700,300);//changed postioning to right hand side entities.add(ship); // create a block of aliens (5 rows, by 12 aliens, spaced evenly) alienCount = 0; levelCount = 1.02; for (int row=0;row<7;row++) {//altered number of rows for (int x=0;x<5;x++) { int r = randomAlien.nextInt(100);//loop added to produce random aliens if (r < 50){ //Entity alien = new AlienEntity(this,"sprites/alien.gif",/*100+*/(x*50),(50)+row*30); Entity alien = new AlienEntity(this,"sprites/alien.gif",100+(x*90),(12)+row*85); entities.add(alien); alienCount++; } } } } //private void initEntities() { public void initAlienEntities() { Random randomAlien = new Random(); // create the player ship and place it roughly in the center of the screen //ship = new ShipEntity(this,"sprites/ship.gif",370,550);//orignal //ship = new ShipEntity(this,"sprites/ship.gif",700,300);//changed postioning to right hand side //entities.add(ship); // create a block of aliens (5 rows, by 12 aliens, spaced evenly) alienCount = 0; levelCount = levelCount + 0.10;//this increases the speed on every level for (int row=0;row<7;row++) {//altered number of rows for (int x=0;x<5;x++) { int r = randomAlien.nextInt(100);//loop added to produce random aliens if (r < 50){//randome check to show alien //Entity alien = new AlienEntity(this,"sprites/alien.gif",/*100+*/(x*50),(50)+row*30); Entity alien = new AlienEntity(this,"sprites/alien.gif",-250+(x*90),(12)+row*85); entities.add(alien); alienCount++; } } } advanceAlienSpeed(levelCount); } /** * Notification from a game entity that the logic of the game * should be run at the next opportunity (normally as a result of some * game event) */ public void updateLogic() { logicRequiredThisLoop = true; } /** * Remove an entity from the game. The entity removed will * no longer move or be drawn. * * @param entity The entity that should be removed */ public void removeEntity(Entity entity) { removeList.add(entity); } /** * Notification that the player has died. */ public void notifyDeath() { message = "Oh no! They got you, try again?"; waitingForKeyPress = true; } /** * Notification that the player has won since all the aliens * are dead. */ public void notifyWin() { message = "Well done! You Win!"; waitingForKeyPress = true; } /** * Notification that an alien has been killed */ public void notifyAlienKilled() { // reduce the alient count, if there are none left, the player has won! alienCount--; if (alienCount == 0) { //notifyWin();win not relevant here... this.initAlienEntities();//call fresh batch of aliens } // if there are still some aliens left then they all need to get faster, so // speed up all the existing aliens advanceAlienSpeed(1.30); } public void advanceAlienSpeed(double speed) { // if there are still some aliens left then they all need to get faster, so // speed up all the existing aliens for (int i=0;i<entities.size();i++) { Entity entity = (Entity) entities.get(i); if (entity instanceof AlienEntity) { // speed up by 2% entity.setHorizontalMovement(entity.getHorizontalMovement() * speed); //entity.setVerticalMovement(entity.getVerticalMovement() * 1.02); } } } /** * Attempt to fire a shot from the player. Its called "try" * since we must first check that the player can fire at this * point, i.e. has he/she waited long enough between shots */ public void tryToFire() { // check that we have waiting long enough to fire if (System.currentTimeMillis() - lastFire < firingInterval) { return; } // if we waited long enough, create the shot entity, and record the time. lastFire = System.currentTimeMillis(); ShotEntity shot = new ShotEntity(this,"sprites/shot.gif",ship.getX()+10,ship.getY()-30); entities.add(shot); } /** * The main game loop. This loop is running during all game * play as is responsible for the following activities: * <p> * - Working out the speed of the game loop to update moves * - Moving the game entities * - Drawing the screen contents (entities, text) * - Updating game events * - Checking Input * <p> */ public void gameLoop() { long lastLoopTime = System.currentTimeMillis(); // keep looping round til the game ends while (gameRunning) { // work out how long its been since the last update, this // will be used to calculate how far the entities should // move this loop long delta = System.currentTimeMillis() - lastLoopTime; lastLoopTime = System.currentTimeMillis(); // Get hold of a graphics context for the accelerated // surface and blank it out Graphics2D g = (Graphics2D) strategy.getDrawGraphics(); g.setColor(Color.black); g.fillRect(0,0,800,600); // cycle round asking each entity to move itself if (!waitingForKeyPress) { for (int i=0;i<entities.size();i++) { Entity entity = (Entity) entities.get(i); entity.move(delta); } } // cycle round drawing all the entities we have in the game for (int i=0;i<entities.size();i++) { Entity entity = (Entity) entities.get(i); entity.draw(g); } // brute force collisions, compare every entity against // every other entity. If any of them collide notify // both entities that the collision has occured for (int p=0;p<entities.size();p++) { for (int s=p+1;s<entities.size();s++) { Entity me = (Entity) entities.get(p); Entity him = (Entity) entities.get(s); if (me.collidesWith(him)) { me.collidedWith(him); him.collidedWith(me); } } } // remove any entity that has been marked for clear up entities.removeAll(removeList); removeList.clear(); // if a game event has indicated that game logic should // be resolved, cycle round every entity requesting that // their personal logic should be considered. if (logicRequiredThisLoop) { //g.drawString("Press any key",(800-g.getFontMetrics().stringWidth("Press any key"))/2,300); for (int i=0;i<entities.size();i++) { Entity entity = (Entity) entities.get(i); entity.doLogic(); } logicRequiredThisLoop = false; } // if we're waiting for an "any key" press then draw the // current message //show highscore at top of screen //show name at top of screen g.setColor(Color.white); g.drawString("Player : "+getPlayer()+" : Score : "+getHighscore(),20,20); if (waitingForKeyPress) { g.setColor(Color.white); g.drawString(message,(800-g.getFontMetrics().stringWidth(message))/2,250); g.drawString("Press any key",(800-g.getFontMetrics().stringWidth("Press any key"))/2,300); } // finally, we've completed drawing so clear up the graphics // and flip the buffer over g.dispose(); strategy.show(); // resolve the movement of the ship. First assume the ship // isn't moving. If either cursor key is pressed then // update the movement appropraitely ship.setVerticalMovement(0);//set to vertical movement if ((leftPressed) && (!rightPressed)) { ship.setVerticalMovement(-moveSpeed);//**took out setHorizaontalMOvement } else if ((rightPressed) && (!leftPressed)) { ship.setVerticalMovement(moveSpeed);//**took out setHorizaontalMOvement } // if we're pressing fire, attempt to fire if (firePressed) { tryToFire(); } // finally pause for a bit. Note: this should run us at about // 100 fps but on windows this might vary each loop due to // a bad implementation of timer try { Thread.sleep(10); } catch (Exception e) {} } } /** * A class to handle keyboard input from the user. The class * handles both dynamic input during game play, i.e. left/right * and shoot, and more static type input (i.e. press any key to * continue) * * This has been implemented as an inner class more through * habbit then anything else. Its perfectly normal to implement * this as seperate class if slight less convienient. * * @author Kevin Glass */ private class KeyInputHandler extends KeyAdapter { /** The number of key presses we've had while waiting for an "any key" press */ private int pressCount = 1; /** * Notification from AWT that a key has been pressed. Note that * a key being pressed is equal to being pushed down but *NOT* * released. Thats where keyTyped() comes in. * * @param e The details of the key that was pressed */ public void keyPressed(KeyEvent e) { // if we're waiting for an "any key" typed then we don't // want to do anything with just a "press" if (waitingForKeyPress) { return; } // if (e.getKeyCode() == KeyEvent.VK_LEFT) { ////leftPressed = true; ///} //// if (e.getKeyCode() == KeyEvent.VK_RIGHT) { //rightPressed = true; if (e.getKeyCode() == KeyEvent.VK_UP) { leftPressed = true; } if (e.getKeyCode() == KeyEvent.VK_DOWN) { rightPressed = true; } if (e.getKeyCode() == KeyEvent.VK_SPACE) { firePressed = true; } } /** * Notification from AWT that a key has been released. * * @param e The details of the key that was released */ public void keyReleased(KeyEvent e) { // if we're waiting for an "any key" typed then we don't // want to do anything with just a "released" if (waitingForKeyPress) { return; } if (e.getKeyCode() == KeyEvent.VK_UP) {//changed from VK_LEFT leftPressed = false; } if (e.getKeyCode() == KeyEvent.VK_DOWN) {//changed from VK_RIGHT rightPressed = false; } if (e.getKeyCode() == KeyEvent.VK_SPACE) { firePressed = false; } } /** * Notification from AWT that a key has been typed. Note that * typing a key means to both press and then release it. * * @param e The details of the key that was typed. */ public void keyTyped(KeyEvent e) { // if we're waiting for a "any key" type then // check if we've recieved any recently. We may // have had a keyType() event from the user releasing // the shoot or move keys, hence the use of the "pressCount" // counter. if (waitingForKeyPress) { if (pressCount == 1) { // since we've now recieved our key typed // event we can mark it as such and start // our new game waitingForKeyPress = false; startGame(); pressCount = 0; } else { pressCount++; } } // if we hit escape, then quit the game if (e.getKeyChar() == 27) { //cThread.interrupt(); System.exit(0); } } } /** * The entry point into the game. We'll simply create an * instance of class which will start the display and game * loop. * * @param argv The arguments that are passed into our game */ //public static void main(String argv[]) { //Game g =new Game(); // Start the main game loop, note: this method will not // return until the game has finished running. Hence we are // using the actual main thread to run the game. //g.gameLoop(); //} }

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  • Oracle User Communities and Enterprise Manager

    - by Anand Akela
    Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Cambria","serif"; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin;} Contributed by Joe Dimmer, Senior Business Development Manager, Oracle Enterprise Manager Heightened interest and adoption of Oracle Enterprise Manager has led to keen interest in “manageability” within the user group community.  In response, user groups are equipping their membership with the right tools for implementation and use manageability through education opportunities and Special Interest Groups.  Manageability is increasingly viewed not only as a means to enable the Oracle environment to become a competitive business advantage for organizations, but also as a means to advance the individual careers of those who embrace enterprise management.  Two Oracle user groups – the Independent Oracle User Group (IOUG) and the United Kingdom Oracle User Group (UKOUG) – each have Special Interest Groups where manageability is prominently featured.  There are also efforts underway to establish similarly charted SIGs that will be reported in future blogs.  The good news is, there’s a lot of news! First off, the IOUG will be hosting a Summer Series of live webcasts:  “Configuring and Managing a Private Cloud with Enterprise Manager 12c” by Kai Yu of Dell, Inc.              Wednesday, June 20th from Noon – 1 PM CDT , Click here for details & registration “What is User Experience Monitoring and What is Not? A case study of Oracle Global IT’s implementation of Enterprise Manager 12c and RUEI” by Eric Tran Le of Oracle            Wednesday, July 18th from Noon – 1 PM CDT , Click here for details & registration “Shed some light on the ‘bumps in the night’ with Enterprise Manager 12c” by David Start of Johnson Controls            Wednesday, August 22nd from Noon – 1 PM CDT, Click here for details & registration   In addition, the UKOUG Availability and Infrastructure Management (AIM) SIG is hosting its next meeting on Tuesday, July 3rd at the Met in Leeds where EM 12c Cloud Management will be presented.  Click here for details & registration.  In future posts from Joe, look for news related to the following: ·         IOUG Community Page and Newsletter devoted to manageability ·         Full day of manageability featured during Oracle OpenWorld 2012 “SIG Sunday” ·         Happenings from other regional User Groups that feature manageability Stay Connected: Twitter |  Face book |  You Tube |  Linked in |  Newsletter

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  • Silverlight Cream for May 13, 2010 -- #861

    - by Dave Campbell
    In this Issue: Sigurd Snørteland, Jeff Prosise, DaveDev, Joe Zhou, Chris Eargle, John Papa(-2-, -3-), and David Anson(-2-). Shoutouts: In with the links I've listed below, Sigurd Snørteland also sent a link to this app he's working on which is actually pretty cool to see: ZuneLight. The code is not yet available. He also has a no-code demo of a Silverlight Media Center Pieter Voloshyn, Luiz Thadeu, and Jhun Iti have a very nice Silverlight image editor up: Thumba From SilverlightCream.com: WP7 - Silverlight on mobile Sigurd Snørteland submitted some links for me that have been translated to English from his blog. I hope the pages come out good because he's got a lot of good stuff on there. This one has a link to a presentation he did, and 4 projects you can load up in the emulator that he's converted to the phone: weather, worldclock, coverflow, and solitaire ... pretty cool... thanks for the links Sigurd! Understanding Page Orientation in Silverlight for Windows Phone Jeff Prosise has a really nice post up on page orientation in WP7 ... what it means to your app, how to detect it, and example code for what to do then... also love a quote by Jeff: "Silverlight for Windows Phone is the hottest thing since color TV" Why you should check out Expression Blend Behaviors when using Silverlight DaveDev has a post up describing Behaviors and why we should use them, plus tons of external links to resources, blogs, videos... all good stuff... Fiddler inspector for WCF Silverlight Polling Duplex and WCF RIA Joe Zhou announces and provides a link to a new Fiddler inspector that understands the framing in Polling Duplex and also raw binary xml and binary SOAP. Windows Phone Controls v0.7 Chris Eargle reports the release of Version 0.7 of the Windows Phone Controls project on CodePlex ... this includes a Pivot Control and a Panorama Control... both very nicely done. Binding to Silverlight ComboBox and Using SelectedValue, SelectedValuePath and DisplayMemberPath John Papa responds to a user question and put up a nice post about binding to a ComboBox and then go from the selected item to some other property ... code included No More Boxes! Exploring the PathListBox (Silverlight TV #25) Silverlight TV 25 went up on Tuesday ... thought it was going to be Thursday?? anyway ... John Papa and Adam Kinney are discussing the PathListBox and looking at some cool demos thereof. Exposing SOAP, OData, and JSON Endpoints for RIA Services (Silverlight TV 26) Since today IS Thursday, we have a new Silverlight TV, number 26, and John Papa is chatting with Deepesh Mohnani of the WCF RIA Services team about exposing all sorts of endpoints... should be something in there for everybody :) Workaround for a Silverlight data binding bug affecting various scenarios - including DataGrid+ContextMenu David Anson details the rabbit-trail he and others on the team followed in response to a problem reported via Twitter where the binding on a DataGrid seemed off by a row(!) ... weird but true, validated, and SL3/4 are bug-for-bug compatible with this too! ... But David wouldn't leave us there.. he also has a workaround. Sharing the code for a simple Silverlight 4 REST-based cloud-oriented file management app for Azure and S3 David Anson had an opportunity to build an app he's wanted to build for a while and shares it with us: Blobstore -- a small, lightweight Silverlight 4 application that acts as a basic front-end for the Windows Azure Simple Data Storage and the Amazon Simple Storage Service (S3) -- and remember I said he shared the source :) Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

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  • Silverlight Cream for December 13, 2010 -- #1010

    - by Dave Campbell
    In this Issue: Rénald Nollet, Benjamin Gavin, Dennis Doomen, Tim Greenfield, Mike Taulty, Jeff Blankenburg, Michael Crump, Laurent Duveau, Dragos Manolescu, KeyboardP, Yochay Kiriaty. Above the Fold: Silverlight: "Silverlight RIA Services and Basic, Anonymous Authentication" Benjamin Gavin WP7: "lving Circular Navigation in Windows Phone Silverlight Applications" Yochay Kiriaty SQL Azure: "SQL Azure Database Manager – Part 1 : How to connect to your SQL Azure DB" Rénald Nollet Shoutouts: Yochay Kiriaty has a post up on the Windows Phone Devloper Blog about open source (MSPL) projects helping WP7 devs: Windows Phone Recipes – Helping the Community Jesse Liberty's latest Yet Another Podcast is up and thie time it's Joe Stagner: Yet Another Podcast #18 – Joe Stagner Josh Schwartzberg sent me this link to what is apparently his yearly web-only rock Christmas album: MetalXmas... done in Silverlight and RIA Services From SilverlightCream.com: SQL Azure Database Manager – Part 1 : How to connect to your SQL Azure DB Rénald Nollet posted Part 1 of a series on a SQL Azure database manager all in Silverlight... has a live demo running, some description, and is making us wait for the next part! Silverlight RIA Services and Basic, Anonymous Authentication Benjamin Gavin has a quick post up resolving a basic RIA Services problem that I bet a lot of folks are looking for the answer on... like 500 series errors... cool little find he ferreted out... A night of Silverlight, WPF, unit testing and Caliburn Micro Dennis Doomen in concert with his employer gave a couple talks at the local DotNED user group, and covered literally a cornucopia of topics... slides, and example code for both talks... lotsa material here... Tim Greenfield on PuzzleTouch WP7 Application Tim Greenfield is the latest WP7 app developer to be interviewed by the SilverlightShow crew... lots of interesting comments and insight from Tim. Rebuilding the PDC 2010 Silverlight Application (Part 4) Mike Taulty has part 4 of his PDC 2010 Silverlight app construction project up and is taking the app into Blend, and the considerations that brought to the table. What I Learned In WP7 – Issue #2 Jeff Blankenburg continues his "What I Learned" series with this discussion about fonts, the Non-Linear Navigation service I mention below, and possible WP7 jobs. Part 3 of 4 : Tips/Tricks for Silverlight Developers Michael Crump has Part 3 of his Tips/Tricks up today. Lots of goodies this time: underlining in a TextBlock, getting browser info, startup params, VisualTreeHelper, and child windows. My Windows Phone 7 presentation in Montreal Laurent Duveau gave a WP7 presentation in Montreal as part of the Microsoft Windows Phone 7 Developer's Briefing, and has posted his materials and slide deck WP7 Code: Mocking Event Streams with IEnumerable Dragos Manolescu has a very cool post up on using IEnumerable to Mock event streams by leveraging the IObservable/IEnumerable duality, and uses the 2D bubble app that you can run and test in the emulator without needing an accelerometer Transparent Wallpapers – Video Tutorial KeyboardP has had so many queries about his Transparent wallpaper for WP7 that he produced a video tutorial for it... Solving Circular Navigation in Windows Phone Silverlight Applications Yochay Kiriaty discusses the first recipe they are releasing ... see the shoutout above, a Nonlinear Navigation Service ... to help with apps that have loops in navigation. Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

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  • Silverlight Cream for March 09, 2011 -- #1057

    - by Dave Campbell
    In this Issue: Dennis Doomen, Peter Kuhn, Michael Crump, Joe McBride, Martin Krüger, Jeremy Likness, Manas Patnaik, Jesse Liberty(-2-), WindowsPhoneGeek(-2-). Above the Fold: Silverlight: "A highlighting AutoCompleteBox in Silverlight" Peter Kuhn WP7: "WP7 WatermarkedTextBox custom control" WindowsPhoneGeek Training: "" Shoutouts: Karl Shifflett announced that he and Josh Smith have heard the developers and released a demo: Mole 2010 Demo Released This is a somewhat older post, but the material is good and I was reminded of it while talking to Josh Smith at the MVP summit last week: Advanced MVVM ... money well-spent From SilverlightCream.com: Introducing the Silverlight Cookbook Dennis Doomen unveils a Codeplex site "containing a Silverlight 4 app that includes most of the complexities you might run into" ... I'm tagging this in my WynApse outlookbar... great stuff, Dennis! A highlighting AutoCompleteBox in Silverlight Peter Kuhn took on a task in response to a forum query and created a highlighting AutoCompleteBox, and is giving it to us... this really looks cool, Peter, and great explanation. Taking a look at the Mindscape Phone Elements for WP7. Michael Crump takes a good look at the Mindscape Phone Elements for WP7... and if you read closely you might still be able to get a free license! Windows Phone – “Can’t connect to your phone. Disconnect it, Restart it, then try connecting again.” Joe McBride explains a way out of an issue that many should be seeing as we repave or replace machines... how to get our device recognized on the updated machine... without giving cryptic messages. How to: only with the full visibility of an application in the browser window start an action Martin Krüger continues his journey in starting storyboards and tackles the condition that the application is completely in the browser window prior to the storyboard starting. A Numeric Input Control for Windows Phone 7 Jeremy Likness came up with a great idea for numeric input for WP7 ... you'll smile when you see it, but what a great idea... and a NumericTextBox to go along with it. Performing CRUD on Relational Data (Multiple table) using RIA in SL4 Manas Patnaik has a post up that breaks the normal blog post or demo mold by having two tables with a relational constraint and doing CRUD operations on them. Plenty of diagrams and good information. Select Many: Reactive Extensions’ Mother Of All Operators [Chaining] Jesse Liberty has part 9 in his Rx series up, and is looking at SelectMany this time, and chaining calls. He's using WPF for the sample, but the goodness is all there for us Silverlight guys too. The Full Stack 8–Adding Search to the Phone Client Jesse Liberty and Jon Galloway have part 8 of their Full Stack series up ... this is the MVC3, ASP.NET, Silverlight, and WP7 app development series... this time out they're putting Search in the Phone client. All about ResourceDictionary in WP7 WindowsPhoneGeek is discussing ResourceDictionaries in this post... beginning with What is a ResourceDictionary and continuing out through creating and using one, plus a good comment on merging. WP7 WatermarkedTextBox custom control In his next post, WindowsPhoneGeek walks us through the creation of a WatermarkedTextBox for WP7 right from the derivation from TextBox... very nice tutorial and lots of code/examples. Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

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  • MIXing it Up a Bit

    - by andrewbrust
    Another March, another MIX.  For the fifth year running now, Microsoft has chosen to put on a conference aimed less at software development, per se, and more at the products, experiences and designs that software development can generate.  In all four prior MIX events, the focus of the show, its keynotes and breakout sessions has been on Web products.  On day 1 of MIX 2010 that focus shifted to Windows Phone 7 Series (WP7). What little we had seen of WP7 had been shown to us in a keynote presentation, given by Microsoft’s Joe Belfiore, at the Mobile World Congress in Barcelona, Spain last month.  And today, Mr. Belfiore reprised his showmanship for the MIX 2010 audience.  Joe showed us the ins and outs of WP7 and, in a breakout session, even gave us a sneak peek of Office (specifically, Excel) on WP7.  We didn’t get to see that one month ago in Barcelona, nor did get to see email messages opened for reading, which we saw today. But beyond a tour of the phone itself, impressive though that is, we got to see apps running on it.  Those apps included Associated Press news, Seesmic (a major Twitter client) and Foursquare (a social media darling).  All three ran, ran well, and looked markedly different and better from their corresponding versions on iPhone and Android.  And the games we saw looked even better. To me though, the best demos involved the creation of WP7 apps, using Silverlight in Visual Studio and Expression Blend.  These demos were so effective because they showed important apps being built in very few steps, and by Microsoft executives to boot.  Scott Guthrie showed us how to build a Twitter API app in Visual Strudio.   Jon Harris showed us how to build a photo management and viewer application in Expression Blend, using virtually no code.  Demos of apps built from scratch to F5 without the benefit of a teacher, could be challenging.  But they went off fine, without a hitch and without a ton of opaque, generated code.  Everything written, be it C# or XAML, was easily understood, and the results were impressive. That means lots of developers can do this, and I think it means a lot will.  What I’ve seen, thus far, of iPhone and Android development looks very tedious by comparison.  Development for those platforms involve a collection of tools that integrate only to a point.  Dev work for WP7 involves use of Visual Studio, Silverlight and the same debugging experience .NET developers already know.  This was very exciting for me. All the demos harkened back to days of building apps for with Visual Basic…design the front-end, put in code-behind and then hit F5.  And that makes sense, because the phone platform, and the PC of the early 90s are both, essentially, client OS machines.  The Web was minimal and the “device” was everything. Same is true of this phone.  It’s a client app contraption that fits in your pocket. And if the platforms are comparable, hopefully so too will be the draw of ease-of-development.   WP7 has the potential to make mobile developers want to switch over, and to convince enterprise developers to get into the phone scene.  Will this propel the new phone platform to new heights, and restore Microsoft’s competiveness in the mobile arena? I hope so.  I think so.  And if Microsoft uses developers to build themselves a victory, that would be beneficial and would show that Microsoft has learned from its failures, as well as its successes.  Today I saw a few beautiful apps.  Tomorrow I hope I see a slew of others; maybe not as polished, but plentiful, attractive and stable.  That would be a victory for Microsoft, and for developers.  And it would show everyone else that developers are the kingmakers.  They need cheap, efficient dev tools and lots of respect.  Microsoft has always been the company to provide that.  Hopefully, with WP7, they will return to that persona and see how very timeless it is.

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