Search Results

Search found 5604 results on 225 pages for 'chinese characters'.

Page 213/225 | < Previous Page | 209 210 211 212 213 214 215 216 217 218 219 220  | Next Page >

  • What am I encrypting wrong here?

    - by Katie Krueger
    So I have a wordplay project to do and I have to encrypt some characters. I am at the point where I am stuck, and when I run it and type 1 for encrypt it doesn't shift that many letters. It just prints the work over again. I am wondering what I could do to fix it where if I say "hello" it will print 1 character over and say "ifmmp" Thank you! import java.util.Scanner; public class WordPlayTester{ public static void main(String [] args){ String word, reverse=""; String original; int key= 0; String Menu= "1-Encrypt \n2-Decrypt \n3-Is Palindrome \n0-Quit \n-Select an option-"; Scanner in = new Scanner(System.in); System.out.println("-Type any word-"); word = in.nextLine(); System.out.println(Menu); int choice=in.nextInt(); if(choice==1) { System.out.println("Insert a Key number"); int select= in.nextInt(); for (int i=0; i < word.length(); i++) { char c = word.charAt(i); if (c >= 'A' && c <= 'Z') { c = (char)(c - 64); int n = c+1; n = n % 26; if (n < 0) { n = n + 26; } c = (char)(n + 65); } System.out.println(c); } } else if(choice==3) { int length = word.length(); for ( int i = length - 1 ; i >= 0 ; i-- ) reverse = reverse + word.charAt(i); if (word.equals(reverse)) System.out.println("Your word is a palindrome."); else System.out.println("Your word is not a palindrome."); } else if(choice==0) { System.exit(0); } else { System.out.println(Menu); } } }

    Read the article

  • Best approach for using Scanner Objects in Java?

    - by devjeetroy
    Although I'm more of a C++/ASM guy, I have to work with java as a part of my undergrad course at college. Our teacher taught us input using Scanner(System.in), and told us that if multiple functions are were taking user input, it would be advisable that a single Scanner object is passed around so as to reduce chances of the input stream getting screwed up. Now using this approach has gotten me into a situation where I'm trying to use a Scanner.nextLine(), and this statement does not wait for user input. It just moves on to the following statement. I figured there may be some residual cr/lf or other characters in the Scanner that might not have been retrieved are causing the problem. Here is the code. while(lineScanner.hasNext()) { if(isPlaceHolder(temp = lineScanner.next())) { temp = temp.replace("<",""); temp = temp.replace(">", ""); System.out.print("Enter "+aOrA(temp.charAt(0)) +" " +temp + " : "); temp = consoleInput.nextLine(); } outputFileStream.print(temp + " "); } All of the code is inside a function which receives a Scanner object consoleInput. Ok, so what happens when i run it is that when the program enters the if() the first time, It carries out theSystem.out.print, does not wait for user input, and moves on to the second time that it enters the 'if' block. This time, it takes the input and the rest of the program operates normally. What is even more surprising is that when i check the output file created by the program, it is perfect, just as i want to be. Almost as if the first time input using the scanner is correct. I have solved this problem by creating a new system.in Scanner in the function itself, instead of receiving the Scanner object as a parameter. But I am still very curious to know what the hell is happening and why it couldn't be solved using a simple Scanner.reset(). Would it be better to just simply create a Scanner Object for each function? Thanks, Devjeet PS. Although I know how to take input using fileinputstreams and the like, we are not supposed to use it with the homework.

    Read the article

  • How can I pipe input to a Java app with Perl?

    - by user319479
    I need to write a Perl script that pipes input into a Java program. This is related to this, but that didn't help me. My issue is that the Java app doesn't get the print statements until I close the handle. What I found online was that $| needs to be set to something greater than 0, in which case newline characters will flush the buffer. This still doesn't work. This is the script: #! /usr/bin/perl -w use strict; use File::Basename; $|=1; open(TP, "| java -jar test.jar") or die "fail"; sleep(2); print TP "this is test 1\n"; print TP "this is test 2\n"; print "tests printed, waiting 5s\n"; sleep(5); print "wait over. closing handle...\n"; close TP; print "closed.\n"; print "sleeping for 5s...\n"; sleep(5); print "script finished!\n"; exit And here is a sample Java app: import java.util.Scanner; public class test{ public static void main( String[] args ){ Scanner sc = new Scanner( System.in ); int crashcount = 0; while( true ){ try{ String input = sc.nextLine(); System.out.println( ":: INPUT: " + input ); if( "bananas".equals(input) ){ break; } } catch( Exception e ){ System.out.println( ":: EXCEPTION: " + e.toString() ); crashcount++; if( crashcount == 5 ){ System.out.println( ":: Looks like stdin is broke" ); break; } } } System.out.println( ":: IT'S OVER!" ); return; } } The Java app should respond to receiving the test prints immediately, but it doesn't until the close statement in the Perl script. What am I doing wrong? Note: the fix can only be in the Perl script. The Java app can't be changed. Also, File::Basename is there because I'm using it in the real script.

    Read the article

  • Searching for duplicate records within a text file where the duplicate is determined by only two fie

    - by plg
    First, Python Newbie; be patient/kind. Next, once a month I receive a large text file (think 7 Million records) to test for duplicate values. This is catalog information. I get 7 fields, but the two I'm interested in are a supplier code and a full orderable part number. To determine if the record is dupliacted, I compress all special characters from the part number (except . and #) and create a compressed part number. The test for duplicates becomes the supplier code and compressed part number combination. This part is fairly straight forward. Currently, I am just copying the original file with 2 new columns (compressed part and duplicate indicator). If the part is a duplicate, I put a "YES" in the last field. Now that this is done, I want to be able to go back (or better yet, at the same time) to get the previous record where there was a supplier code/compressed part number match. So far, my code looks like this: Compress Full Part to a Compressed Part and Check for Duplicates on Supplier Code and Compressed Part combination import sys import re import time ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ start=time.time() try: file1 = open("C:\Accounting\May Accounting\May.txt", "r") except IOError: print sys.stderr, "Cannot Open Read File" sys.exit(1) try: file2 = open(file1.name[0:len(file1.name)-4] + "_" + "COMPRESSPN.txt", "a") except IOError: print sys.stderr, "Cannot Open Write File" sys.exit(1) hdrList="CIGSUPPLIER|FULL_PART|PART_STATUS|ALIAS_FLAG|ACQUISITION_FLAG|COMPRESSED_PART|DUPLICATE_INDICATOR" file2.write(hdrList+chr(10)) lines_seen=set() affirm="YES" records = file1.readlines() for record in records: fields = record.split(chr(124)) if fields[0]=="CIGSupplier": continue #If incoming file has a header line, skip it file2.write(fields[0]+"|"), #Supplier Code file2.write(fields[1]+"|"), #Full_Part file2.write(fields[2]+"|"), #Part Status file2.write(fields[3]+"|"), #Alias Flag file2.write(re.sub("[$\r\n]", "", fields[4])+"|"), #Acquisition Flag file2.write(re.sub("[^0-9a-zA-Z.#]", "", fields[1])+"|"), #Compressed_Part dupechk=fields[0]+"|"+re.sub("[^0-9a-zA-Z.#]", "", fields[1]) if dupechk not in lines_seen: file2.write(chr(10)) lines_seen.add(dupechk) else: file2.write(affirm+chr(10)) print "it took", time.time() - start, "seconds." ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ file2.close() file1.close() It runs in less than 6 minutes, so I am happy with this part, even if it is not elegant. Right now, when I get my results, I import the results into Access and do a self join to locate the duplicates. Loading/querying/exporting results in Access a file this size takes around an hour, so I would like to be able to export the matched duplicates to another text file or an Excel file. Confusing enough? Thanks.

    Read the article

  • The 80 column limit, still useful?

    - by Tim Post
    Related: While coding, how many columns do you format for? Is there a valid reason for enforcing a maximum width of 80 characters in a code file, this day and age? I mostly use C, however this question is language agnostic. Its also subjective, so I'll tag it as such. Many individual projects set their own various coding standards, a guide to adjust your coding style. Many enforce an 80 column limit on code, i.e. don't force a dumb 80 x 25 terminal to wrap your lines in someone else's editor of choice if they are stuck with such a display, don't force them to turn off wrapping. Both private and open source projects usually have some style guidelines. My question is, in this day and age, is that requirement more of a pest than a helper? Does anyone still login via the local console with no framebuffer and actually edit code? If so, how often and why cant you use SSH? I help to manage a few open source projects, I was considering extending this limit to 110 columns, but I wanted to get feedback first. So, any feedback is appreciated. I can see the need to make certain OUTPUT of programs (i.e. a --help /h display) 80 columns or less, but I really don't see the need to force people to break up code under 110 columns long into 2 lines, when its easier to read on one line. I can also see the case for adhering to an 80 column limit if you're writing code that will be used on micro controllers that have to be serviced in the field with a god-knows-what terminal emulator. Beyond that, what are your thoughts? Edit: This is not an exact duplicate. I am asking very specific questions, such as how many people are actually still using such a display. I am also not asking "what is a good column limit", I'm proposing one and hoping to gather feedback. Beyond that, I'm also citing cases where the 80 column limit is still a good idea. I don't want a guide to my own "c-style", I'm hoping to adjust standards for several projects. If the duplicate in question had answered all of my questions, I would not have posted this one :) That will teach me to mention it next time. Edit 2 question |= COMMUNITY_WIKI

    Read the article

  • Can't insert a number into a C++ custom streambuf/ostream

    - by 0xbe5077ed
    I have written a custom std::basic_streambuf and std::basic_ostream because I want an output stream that I can get a JNI string from in a manner similar to how you can call std::ostringstream::str(). These classes are quite simple. namespace myns { class jni_utf16_streambuf : public std::basic_streambuf<char16_t> { JNIEnv * d_env; std::vector<char16_t> d_buf; virtual int_type overflow(int_type); public: jni_utf16_streambuf(JNIEnv *); jstring jstr() const; }; typedef std::basic_ostream<char16_t, std::char_traits<char16_t>> utf16_ostream; class jni_utf16_ostream : public utf16_ostream { jni_utf16_streambuf d_buf; public: jni_utf16_ostream(JNIEnv *); jstring jstr() const; }; // ... } // namespace myns In addition, I have made four overloads of operator<<, all in the same namespace: namespace myns { // ... utf16_ostream& operator<<(utf16_ostream&, jstring) throw(std::bad_cast); utf16_ostream& operator<<(utf16_ostream&, const char *); utf16_ostream& operator<<(utf16_ostream&, const jni_utf16_string_region&); jni_utf16_ostream& operator<<(jni_utf16_ostream&, jstring); // ... } // namespace myns The implementation of jni_utf16_streambuf::overflow(int_type) is trivial. It just doubles the buffer width, puts the requested character, and sets the base, put, and end pointers correctly. It is tested and I am quite sure it works. The jni_utf16_ostream works fine inserting unicode characters. For example, this works fine and results in the stream containing "hello, world": myns::jni_utf16_ostream o(env); o << u"hello, wor" << u'l' << u'd'; My problem is as soon as I try to insert an integer value, the stream's bad bit gets set, for example: myns::jni_utf16_ostream o(env); if (o.badbit()) throw "bad bit before"; // does not throw int32_t x(5); o << x; if (o.badbit()) throw "bad bit after"; // throws :( I don't understand why this is happening! Is there some other method on std::basic_streambuf I need to be implementing????

    Read the article

  • Is it possible to use .data() as a search criteria?

    - by Andrew
    I have a pretty complex chat application going on, and there are multiple chat panes, chat entries, chat submits, etc. going on in the same window. At first I was going to do something like.... <input type="text" class="chattext" id="chattext-42"> <input type="text" class="chattext" id="chattext-93"> <input type="button" class="chatsubmit" id="chatsubmit-42"> <input type="button" class="chatsubmit" id="chatsubmit-93"> ... etc. (of course this is vastly simplified, they'd be in separate divs, separate visibilities, etc) So, when they clicked on a .chatsubmit, it would then get the id of that and find the last two characters for the chat ID. This presents some problems, as it would require rewrites if IDs changed lengths, and seems just plain inelegant to me. I then remembered the .data() facility in jQuery... I thought, maybe I could do it more like this: <input type="text" class="chattext"> ... and add a .data("id", 42) to this one <input type="button" class="chatsubmit"> ... and add a .data("id", 42) So that when they click chatsubmit, it gets the ID, and then finds the chattext with that ID and processes it. But looking at the documentation, I don't see an easy way to search by this. For example, let's say the event target in this case is the chatsubmit with the data('id') of 42... var ID = $(event.target).data('id'); // Sets it to 42 var chattext = ... And here I run into the trouble. How do I find which DOM element matches a class of chattext and a data('id') of 42? Is there any easy method, or do I have to search every .chattext for the one with an id of 42? Or is there another easy way of doing this? I did consider the possibility of the container div having the ID, which would make it, I think,? slightly easier to get. But if this works, it could be dealing with things in other container divs as well, making that not a long-term solution. Edit: Literally seconds after posting this, I found this: http://james.padolsey.com/javascript/extending-jquerys-selector-capabilities/ which includes information on extending the selector to data. So I'll try that out, and in the meantime, is this a completely foolhardy way of handling this?

    Read the article

  • How can I store large amount of data from a database to XML (speed problem, part three)?

    - by Andrija
    After getting some responses, the current situation is that I'm using this tip: http://www.ibm.com/developerworks/xml/library/x-tipbigdoc5.html (Listing 1. Turning ResultSets into XML), and XMLWriter for Java from http://www.megginson.com/downloads/ . Basically, it reads date from the database and writes them to a file as characters, using column names to create opening and closing tags. While doing so, I need to make two changes to the input stream, namely to the dates and numbers. // Iterate over the set while (rs.next()) { w.startElement("row"); for (int i = 0; i < count; i++) { Object ob = rs.getObject(i + 1); if (rs.wasNull()) { ob = null; } String colName = meta.getColumnLabel(i + 1); if (ob != null ) { if (ob instanceof Timestamp) { w.dataElement(colName, Util.formatDate((Timestamp)ob, dateFormat)); } else if (ob instanceof BigDecimal){ w.dataElement(colName, Util.transformToHTML(new Integer(((BigDecimal)ob).intValue()))); } else { w.dataElement(colName, ob.toString()); } } else { w.emptyElement(colName); } } w.endElement("row"); } The SQL that gets the results has the to_number command (e.g. to_number(sif.ID) ID ) and the to_date command (e.g. TO_DATE (sif.datum_do, 'DD.MM.RRRR') datum_do). The problems are that the returning date is a timestamp, meaning I don't get 14.02.2010 but rather 14.02.2010 00:00:000 so I have to format it to the dd.mm.yyyy format. The second problem are the numbers; for some reason, they are in database as varchar2 and can have leading zeroes that need to be stripped; I'm guessing I could do that in my SQL with the trim function so the Util.transformToHTML is unnecessary (for clarification, here's the method): public static String transformToHTML(Integer number) { String result = ""; try { result = number.toString(); } catch (Exception e) {} return result; } What I'd like to know is a) Can I get the date in the format I want and skip additional processing thus shortening the processing time? b) Is there a better way to do this? We're talking about XML files that are in the 50 MB - 250 MB filesize category.

    Read the article

  • How SQLite on Android handles long stings?

    - by Levara
    Hi! I'm wondering how Android's implementation of SQLite handles long Strings. Reading from online documentation on sqlite, it said that strings in sqlite are limited to 1 million characters. My strings are definitely smaller. I'm creating a simple RSS application, and after parsing a html document, and extracting text, I'm having problem saving it to a database. I have 2 tables in database, feeds and articles. RSS feeds are correctly saved and retrieved from feeds table, but when saving to the articles table, logcat is saying that it cannot save extracted text to it's column. I don't know if other columns are making problems too, no mention of them in logcat. I'm wondering, since text is from an article on web, are signs like (",',;) creating problems? Is Android automaticaly escaping them, or I have to do that. I'm using a technique for inserting similar to one in notepad tutorial: public long insertArticle(long feedid, String title, String link, String description, String h1, String h2, String h3, String p, String image, long date) { ContentValues initialValues = new ContentValues(); initialValues.put(KEY_FEEDID, feedid); initialValues.put(KEY_TITLE, title); initialValues.put(KEY_LINK, link); initialValues.put(KEY_DESCRIPTION, description ); initialValues.put(KEY_H1, h1 ); initialValues.put(KEY_H2, h2); initialValues.put(KEY_H3, h3); initialValues.put(KEY_P, p); initialValues.put(KEY_IMAGE, image); initialValues.put(KEY_DATE, date); return mDb.insert(DATABASE_TABLE_ARTICLES,null, initialValues); } Column P is for extracted text, h1, h2 and h3 are for headers from a page. Logcat reports only column p to be the problem. The table is created with following statement: private static final String DATABASE_CREATE_ARTICLES = "create table articles( _id integer primary key autoincrement, feedid integer, title text, link text not null, description text," + "h1 text, h2 text, h3 text, p text, image text, date integer);"; Thanks!

    Read the article

  • Using a large list of terms, search through page text and replace words with links

    - by dunc
    A while ago I posted this question asking if it's possible to convert text to HTML links if they match a list of terms from my database. I have a fairly huge list of terms - around 6000. The accepted answer on that question was superb, but having never used XPath, I was at a loss when problems started occurring. At one point, after fiddling with code, I somehow managed to add over 40,000 random characters to our database - the majority of which required manual removal. Since then I've lost faith in that idea and the more simple PHP solutions simply weren't efficient enough to deal with the amount of data and the quantity of terms. My next attempt at a solution is to write a JS script which, once the page has loaded, retrieves the terms and matches them against the text on a page. This answer has an idea which I'd like to attempt. I would use AJAX to retrieve the terms from the database, to build an object such as this: var words = [ { word: 'Something', link: 'http://www.something.com' }, { word: 'Something Else', link: 'http://www.something.com/else' } ]; When the object has been built, I'd use this kind of code: //for each array element $.each(words, function() { //store it ("this" is gonna become the dom element in the next function) var search = this; $('.message').each( function() { //if it's exactly the same if ($(this).text() === search.word) { //do your magic tricks $(this).html('<a href="' + search.link + '">' + search.link + '</a>'); } } ); } ); Now, at first sight, there is a major issue here: with 6,000 terms, will this code be in any way efficient enough to do what I'm trying to do?. One option would possibly be to perform some of the overhead within the PHP script that the AJAX communicates with. For instance, I could send the ID of the post and then the PHP script could use SQL statements to retrieve all of the information from the post and match it against all 6,000 terms.. then the return call to the JavaScript could simply be the matching terms, which would significantly reduce the number of matches the above jQuery would make (around 50 at most). I have no problem with the script taking a few seconds to "load" on the user's browser, as long as it isn't impacting their CPU usage or anything like that. So, two questions in one: Can I make this work? What steps can I take to make it as efficient as possible? Thanks in advance,

    Read the article

  • GKSession sendDataToAllPeers getting invalid parameter

    - by cb4
    This is my first post and I wanted to start it by thanking the many stackoverflow contributors who will never know how much they helped me out these past several days as I worked to complete my first iOS app. I am indebted to them and to this site for giving them a place to post. To 'pay off' some of that debt, I hope this will help others as I have been helped... So, my app uses the GKPeerPickerController to make a connection to a 2nd device. Once connected, the devices can send text messages to each other. The receiving peer has the message displayed in a UIAlertView. Everything was working fine. Then I decided to experiment with locations and added code to get the current location. I convert it into latitude & longitude in degrees, minutes, and seconds and put them into one NSString. I added a button to my storyboard called 'Send Location' which, when tapped, sends the location to the connected peer. This is where I ran into the problem. Both the send text and send location methods call the sendPacket method with a NSString. sendPacket converts the string to NSData and calls sendDataToAllPeers. When I learned how to capture the error, it was "Invalid parameter for - sendDataToAllPeers:withDataMode:error:". [.....pause.....] Well, this was going to be a question but in writing all this to explain the problem, the answer just dawned on me. Did a few tests and verified it now works. The issue was not in sendDataToAllPeers, it was in the conversion of the NSString (strToSend) to NSData: packet = [strToSend dataUsingEncoding:NSASCIIStringEncoding]; Specifically, it was the degree sign character (little circle, ASCII 176). NSASCIIStringEncoding only includes ASCII characters up to 127 so don't use any above that. I'm sure there was a quicker way to find the problem, but I don't know Objective-C or Xcode's debugging facility well enough yet. Whew! Several hours to discover that little tidbit. I did learn a lot, though, and that's always a good thing!

    Read the article

  • How to pass some data to JQuery AJAX in CAKEPHP

    - by kwokwai
    Hi all, I am learning how to use JQuery to help check data availability. To start with it, I wrote a few lines of codes using cakePHP. I have written a function in a Controller for checking data input, and the URL is like this: http://www.mywebsite.com/controllers/action/avariable I was trying to pass the value in a Input TextBox field using the JQuery Ajax to the URL above,but I don't know why it is not working in passing a variable to the Controller's action. Could you help me out please? <Script language="javascript"> //<!-- $(document).ready(function(){ $(document).change(function() { var usr = $("#data\\[User\\]\\[name\\]").val(); if(usr.length >= 3){ $("#username").append('<span><img align="absmiddle" src="loader.gif" />Checking</span>'); $.ajax({ type: "POST", url: "http://www.mywebsite.com/controllers/action/", data: usr, success: function(msg){ if(msg == 'OK') { $("#username").append('<span><img align="absmiddle" src="accepted.png"/></span>'); } else { $("#username").append('<span>'+msg+'</span>'); } } }); } else { $("#username").append('<span>The username should have at least 3 characters.</span>'); } }); }); //--> </Script> <form name="adduser" id="adduser" method="post" action="/controllers/action2"> <table border=0 width="100%"> <tr> <td>Username</td> <td> <div id="username"> <input type=text name="data[User][name]" id="data[User][name]"> </div> </td> </tr> <tr> <td> <input type="submit" value="Send"> </td> </tr> </table> </form>

    Read the article

  • Reading data file into an array C#

    - by Whitey
    I have an array like this: int[,] iMap = new int[iMapHeight, iMapWidth] { { 0, 1, 2, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, { 0, 3, 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, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, { 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, { 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, { 2, 2, 2, 2, 0, 0, 0, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2}, { 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, { 0, 0, 0, 1, 1, 1, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, { 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, { 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, { 0, 0, 0, 0, 1, 1, 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, 1, 0, 0, 0, 0, 0, 0, 0, 3, 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, 1, 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, 1, 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, 3, 0, 0, 0, 0}, { 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, }; And I want the same thing coming from a data file. The file should be structured like this preferably: 0000000000000000000000000 0000000000000000000000000 0000000000000000000000000 0000000000000000000000000 0000000000000000000000000 0000000000000000000000000 0000000000000000000000000 0000000000000000000000000 0000000000000000000000000 0000000000000000000000000 0000000000000000000000000 0000000000000000000000000 0000000000000000000000000 0000000000000000000000000 Which will ultimately make an array like above with all values set to 0. What would be the best way to do this? Would I read one line from the file and then split each characters separately and transfer it to the new array? Or perhaps read a line, and then read each character and put that in the array? Thanks for any help.

    Read the article

  • File sorting, Comparison method violates its general contract

    - by user2677383
    My file sorting comparator sometimes invoke java.lang.IllegalArgumentException in android app. I cannot figure out the reason. could you explain that? here is my code block: Comparator cc = new Comparator<File>() { @Override public int compare(File f1, File f2) { if (f1.isDirectory() && !f2.isDirectory()) { return 1; } if (f2.isDirectory() && !f1.isDirectory()) { return -1; } if ((f1.isFile() && f2.isFile()) || (f1.isDirectory() && f2.isDirectory())) { if (sort == 1) { return Util.compareFileName(f2.getName(), f1.getName()); } else if (sort == 2) { return (int) (f1.lastModified() - f2.lastModified()); } else if (sort == 3) { return (int) (f2.lastModified() - f1.lastModified()); } else if (sort == 4) { return (int) (f1.length() - f2.length()); } else if (sort == 5) { return (int) (f2.length() - f1.length()); } else return Util.compareFileName(f1.getName(), f2.getName()); } return f1.compareTo(f2); } }; Util.compareFileName is as followings: public static int compareFileName(String s1, String s2) { int thisMarker = 0; int thatMarker = 0; int s1Length = s1.length(); int s2Length = s2.length(); while (thisMarker < s1Length && thatMarker < s2Length) { String thisChunk = getChunk(s1, s1Length, thisMarker); thisMarker += thisChunk.length(); String thatChunk = getChunk(s2, s2Length, thatMarker); thatMarker += thatChunk.length(); // If both chunks contain numeric characters, sort them numerically int result = 0; if (isDigit(thisChunk.charAt(0)) && isDigit(thatChunk.charAt(0))) { // Simple chunk comparison by length. int thisChunkLength = thisChunk.length(); result = thisChunkLength - thatChunk.length(); // If equal, the first different number counts if (result == 0) { for (int i = 0; i < thisChunkLength; i++) { result = thisChunk.charAt(i) - thatChunk.charAt(i); if (result != 0) { return result; } } } } else { result = thisChunk.compareTo(thatChunk); } if (result != 0) return result; } return s1Length - s2Length; }

    Read the article

  • Socket connection to a telnet-based server hangs on read

    - by mixwhit
    I'm trying to write a simple socket-based client in Python that will connect to a telnet server. I can test the server by telnetting to its port (5007), and entering text. It responds with a NAK (error) or an AK (success), sometimes accompanied by other text. Seems very simple. I wrote a client to connect and communicate with the server, but it hangs on the first attempt to read the response. The connection is successful. Queries like getsockname and getpeername are successful. The send command returns a value that equals the number of characters I'm sending, so it seems to be sending correctly. But in the end, it always hangs when I try to read the response. I've tried using both file-based objects like readline and write (via socket.makefile), as well as using send and recv. With the file object I tried making it with "rw" and reading and writing via that object, and later tried one object for "r" and another for "w" to separate them. None of these worked. I used a packet sniffer to watch what's going on. I'm not versed in all that I'm seeing, but during a telnet session I can see my typed text and the server's text coming back. During my Python socket connection, I can see my text going to the server, but packets back don't seem to have any text in them. Any ideas on what I'm doing wrong, or any strategies to try? Here's the code I'm using (in this case, it's with send and recv): #!/usr/bin/python host = "localhost" port = 5007 msg = "HELLO EMC 1 1" msg2 = "HELLO" import socket import sys try: skt = socket.socket(socket.AF_INET, socket.SOCK_STREAM) except socket.error, e: print("Error creating socket: %s" % e) sys.exit(1) try: skt.connect((host,port)) except socket.gaierror, e: print("Address-related error connecting to server: %s" % e) sys.exit(1) except socket.error, e: print("Error connecting to socket: %s" % e) sys.exit(1) try: print(skt.send(msg)) print("SEND: %s" % msg) except socket.error, e: print("Error sending data: %s" % e) sys.exit(1) while 1: try: buf = skt.recv(1024) print("RECV: %s" % buf) except socket.error, e: print("Error receiving data: %s" % e) sys.exit(1) if not len(buf): break sys.stdout.write(buf)

    Read the article

  • Do While loop breaks after incorrect input?

    - by Daminkz
    I am trying to have a loop continue to prompt the user for an option. When I get a string of characters instead of an int, the program loops indefinitely. I have tried setting the variable result to NULL, clearing the input stream, and have enclosed in try{}catch blocks (not in this example). Can anyone explain to me why this is? #include <iostream> #include <vector> #include <string> using namespace std; int menu(string question, vector<string> options) { int result; cout << question << endl; for(int i = 0; i < options.size(); i++) { cout << '[' << i << ']' << options[i] << endl; } bool ans = false; do { cin >> result; cin.ignore(1000, 10); if (result < options.size() ) { ans = true; } else { cout << "You must enter a valid option." << endl; result = NULL; ans = false; } } while(!ans); return result; } int main() { string menuQuestion = "Welcome to my game. What would you like to do?"; vector<string> mainMenu; mainMenu.push_back("Play Game"); mainMenu.push_back("Load Game"); mainMenu.push_back("About"); mainMenu.push_back("Exit"); int result = menu(menuQuestion, mainMenu); cout << "You entered: " << result << endl; return 0; }

    Read the article

  • Problems Embedding Video using FCK Editor

    - by Exline
    Hello, I am using FCK Editor 2.6.4 and having problems trying to embed a (non-YouTube) video into a content area. I found this previous question / post: [EDIT -- as a new user, I am only able to post one link in this post. The post in question is titled, "Can I embed video using FCK Editor?") and have investigated all of the proposed solutions, but none of them work properly: 1 -- Using the "Embed Flash" button in the control panel almost works. However, the video I am attempting to add contains a querystring with parameters, like this: http://static.animoto.com/swf/w.swf?w=swf/vp1&e=1275795594&f=mGQklEgxXKs9vfEIdGnWsA&d=132&m=p&r=w&i=m&ct=Homes%20in%20Eagle%20Creek&cu=http://hometoindy.com/eagle-creek-real-estate.php&options= and in using the Flash embed tool, it encodes all of the "&" characters to "&", thus breaking them. If it were just for me, I could manually change them back, but clients who use this will not know how to do that. 2 -- I have installed the YouTube video plugin, and it works great... for YouTube. But it cannot be used to embed non-YouTube videos (it automatically changes the URL to YouTube, no matter what). 3 -- I have installed the EmbedMovies plugin, but it throws a javascript error when attempting to add a video file (such as the above) to a page. (The EmbedMovies plugin page on SourceForge says it has been updated for FCK Editor 2.6, but it does not work.) 4 -- Pasting directly into the editor window (of course) does not work. The only way I've been able to make this work is by pasting into the Source panel, and this is not a good option for clients who are not familiar with HTML. So, is there a good, working plugin for FCK editor that will allow me to quickly and easily embed a video such as the one above into a content area? I don't need to be able to see or preview it in the editor window; I just need it to work when the page is loaded on the front end. Thanks!

    Read the article

  • Disable Dojo validation on certain fields

    - by Eric LaForce
    I would like to disable client side validation on certain fields in my user form. Currently I have two sets of fields that are displayed depending on the value of a previous drop down list. i.e. if the drop down list is set to value "A" 1 new field appears in the form. If the drop down list is set to value "B" 3 new fields appear in the form (mutually exclusive from the new form field when "A" is selected). Currently my Dojo client side validation fails because the fields that are not shown to the user (and thus no data can be inserted into those fields) fails to validate. Currently I determined that I can set the "validate" attribute to return true like so: <input type="text" id="companycity" name="companycity" class="textinput" value="<?php echo set_value('companycity'); ?>" style="<?php if(isset($errorData['companycity'])){echo $errorData['companycity'];} ?>" dojotype="dijit.form.ValidationTextBox" required="true" trim="true" validate='return true'" regexp="([a-zA-Z]{1,25})" invalidMessage="Invalid value. Must be between 1 and 25 alphabetic characters long."> This fixes my issue for hidden fields. However this now means that no validation is performed when this field becomes visible to the user (i.e. the validate attribute is still set to return true). I have tried removing the validate property when a field is displayed to the user like so: dijit.byId('companycode').attr('validate',''); This just set the attribute to nothing. This however gives errors in firebug saying validate method not found, so I take that to mean I did not remove this attribute correctly or removing this attribute is not the appropriate way to do this. I have also looked at overriding the validator method here but this doesnt seem like what I want either. I do not want to have to rewrite all the validation methods in place of dojo's. I just want dojo not to validate if the field is not visible to the user. Thanks for any advice or help.

    Read the article

  • 1) PasswordResets emails user when requesting password reset

    - by Surge Pedroza
    I've been trying to add a password reset for users that forget their password. The users clicks on forgot password? on sign up page. Then the user types their email and clicks reset password, which creates a token and sends an email with a link to reset their password. For the most part, it was working well, and then it suddenly stopped working. When a user clicks password reset, it brings up the error message: Password cant be blank, password is too short(6 min) Ran into this error in video 275 How I Test. on 11:20 Failure/Error: click_button "Reset Password" ActiveRecord::RecordInvalid: Validation failed: Password can't be blank, Password is too short (minimum is 6 characters), Password confirmation can't be blank # ./app/models/user.rb:30:in send_password_reset' # ./app/controllers/password_resets_controller.rb:7:increate' # (eval):2:in click_button' # ./spec/requests/password_resets_spec.rb:9:inblock (2 levels) in ' Finished in 13.66 seconds 95 examples, 1 failure This is some of the code being used. user.rb # == Schema Information # # Table name: users # # id :integer not null, primary key # name :string(255) # email :string(255) # created_at :datetime not null # updated_at :datetime not null # class User < ActiveRecord::Base attr_accessible :name, :email, :password, :password_confirmation has_secure_password before_save { |user| user.email = email.downcase } before_save :create_remember_token validates :name, presence: true, length: { maximum: 50 } VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-.]+\.[a-z]+\z/i validates :email, presence: true, format: { with: VALID_EMAIL_REGEX }, uniqueness: { case_sensitive: false } validates :password, presence: true, length: { minimum: 6 } validates :password_confirmation, presence: true def send_password_reset generate_token(:password_reset_token) self.password_reset_sent_at = Time.zone.now save! UserMailer.password_reset(self).deliver end def generate_token(column) begin self[column] = SecureRandom.urlsafe_base64 end while User.exists?(column => self[column]) end def self.search(search) if search find(:all, :conditions => ['name LIKE ?', "%#{search}%"]) else find(:all) end end private def create_remember_token self.remember_token = SecureRandom.urlsafe_base64 end end password_resets_controller.rb class PasswordResetsController < ApplicationController def new end def create user = User.find_by_email(params[:email]) user.send_password_reset redirect_to root_url, :notice => "Email sent with password reset instructions." end def edit @user = User.find_by_password_reset_token!(params[:id]) end end new.html.erb <h1>Reset Password</h1> <%= form_tag password_resets_path, :method => :post do %> <div class="field"> <%= label_tag :email %> <%= text_field_tag :email, params[:email] %> </div> <div class="actions"><%= submit_tag "Reset Password" %></div> <% end %>

    Read the article

  • Delete duplicate rows, do not preserve one row

    - by Radley
    I need a query that goes through each entry in a database, checks if a single value is duplicated elsewhere in the database, and if it is - deletes both entries (or all, if more than two). Problem is the entries are URLs, up to 255 characters, with no way of identifying the row. Some existing answers on Stackoverflow do not work for me due to performance limitations, or they use uniqueid which obviously won't work when dealing with a string. Long Version: I have two databases containing URLs (and only URLs). One database has around 3,000 urls and the other around 1,000. However, a large majority of the 1,000 urls were taken from the 3,000 url database. I need to merge the 1,000 into the 3,000 as new entries only. For this, I made a third database with combined URLs from both tables, about 4,000 entries. I need to find all duplicate entries in this database and delete them (Both of them, without leaving either). I have followed the query of a few examples on this site, but whenever I try to delete both entries it ends up deleting all the entries, or giving sql errors. Alternatively: I have two databases, each containing the separate database. I need to check each row from one database against the other to find any that aren't duplicates, and then add those to a third database. Edit: I've got my own PHP solution which is pretty hacky, but works. I cannot answer my own question for 8 hours because I'm new, so here it is for now: I went with a PHP script to accomplish this, as I'm more familiar with PHP than MySQL. This generates a simple list of urls that only exist in the target database, but not both. If you have more than 7,000 entries to parse this may take awhile, and you will need to copy/paste the results into a text file or expand the script to store them back into a database. I'm just doing it manually to save time. Note: Uses MeekroDB <pre> <?php require('meekrodb.2.1.class.php'); DB::$user = 'root'; DB::$password = ''; DB::$dbName = 'testdb'; $all = DB::query('SELECT * FROM old_urls LIMIT 7000'); foreach($all as $row) { $test = DB::query('SELECT url FROM new_urls WHERE url=%s', $row['url']); if (!is_array($test)) { echo $row['url'] . "\n"; }else{ if (count($test) == 0) { echo $row['url'] . "\n"; } } } ?> </pre>

    Read the article

  • Cannot get document.getElementById() to find my textarea

    - by Slruh
    Maybe I've been working on my site for to long, but I can't get the following to work. I am having my textarea fire an onkeyup() event called limiter which is supposed to check the textarea and limit the text in the box, while updated another readonly input field that shows the amount of characters left. This is the javascript code: <script type="text/javascript"> var count = "500"; function limiter(){ var comment = document.getElementById("comment"); var form = this.parent; var tex = comment.value; var len = tex.length; if(len > count){ tex = tex.substring(0,count); comment.value =tex; return false; } form.limit.value = count-len; } </script> The form looks like this: <form id="add-course-rating" method="post" action="/course_ratings/add/8/3/5/3" accept- charset="utf-8"><div style="display:none;"><input type="hidden" name="_method" value="POST" /> //Other inputs here <div id="comment-name" style="margin-top:10px"> <div id="comment-name-text"> <b>Comments</b><br /> Please leave any comments that you think will help anyone else. </div> <style type="text/css"> .rating-form-box textarea { -moz-border-radius:5px 5px 5px 5px; } </style> <div class="rating-form-box"> <textarea name="data[CourseRatings][comment]" id="comment" onkeyup="limiter()" cols="115" rows="5" ></textarea> <script type="text/javascript"> document.write("<input type=text name=limit size=4 readonly value="+count+">"); </script> </div> <input type="submit" value="Add Rating" style="float: right;"> </form> If anyone can help that would be great.

    Read the article

  • jQuery validation plugin addMethod firing incorrectly

    - by LoganEtherton
    I must be missing something obvious, but everything that I've tried for this is leaving me empty handed, so I'm a bit puzzled. I'm attempting to use the jQuery validation plugin with custom validation methods, but it seems to be hit or miss. It seems that I am able to successfully add rules to a certain extent, but some of the methods are not applied. Or the specified method is not applied, and the incorrect method is instead applied. So, for example, this works without a hitch: $.validator.addMethod("emailValidation", function(value, element) { return /^((([a-z]|\d|[!#\$%&'\*\+\-\/=\?\^_`{\|}~]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])+(\.([a-z]|\d|[!#\$%&'\*\+\-\/=\?\^_`{\|}~]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])+)*)|((\x22)((((\x20|\x09)*(\x0d\x0a))?(\x20|\x09)+)?(([\x01-\x08\x0b\x0c\x0e-\x1f\x7f]|\x21|[\x23-\x5b]|[\x5d-\x7e]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(\\([\x01-\x09\x0b\x0c\x0d-\x7f]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]))))*(((\x20|\x09)*(\x0d\x0a))?(\x20|\x09)+)?(\x22)))@((([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])*([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])))\.)+(([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])*([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])))\.?$/.test(value); }, "Please enter a valid email address." ); $.validator.addMethod("password", function(value, element) { return /[^\s]{6,25}/.test(value); }, "Please enter a password between 6 and 25 characters long." ); ... $(function(){ $("#registrationForm").validate({ rules: { email: { required: true, emailValidation: true }, password: { required: true, password: true }, } }); }); Both the password validation and email validation work. But then I add, in the same exact manner, a validation test for names. So, right below where the password method ends, I add: $.validator.addMethod("name", function(value, element) { return /[^\s]{6,25}/.test(value); }, "Please enter a valid name." ); Which turns the validate call into: $(function(){ $("#registrationForm").validate({ rules: { email: { required: true, emailValidation: true }, password: { required: true, password: true }, studentFirstName: { name: true } } }); }); And suddenly, everything is only validating for names. Both the email and password fields now validate using the name method, as does the name field. This is confusing! I've added console.log calls to all methods, and indeed, it's not that one is being called after the other - the only one being called is name. I've checked and double checked that the element selection is good. I've checked that everything is groovy with the methods themselves. Any ideas?

    Read the article

  • c# .net MVC4 Model to represent table or form

    - by Matthew Chambers
    Hello I am a little confused with regards to models in mvc 4 and thought someone may be able to point me in the right direction. This would be most appreciated. For example if i have a table that has the following fields [StringLength(100, ErrorMessage = "The {0} must be at least {2} characters long.", MinimumLength = 5)] public string UserName { get; set; } [Required(ErrorMessage="Email Address is Required")] [StringLength(15, ErrorMessage = "Email Address must be between {0} and {1} in size",MinimumLength = 5 )] [DataType(DataType.EmailAddress)] [Display(Name="Email")] public string Email { get; set; } [MaxLength(25)] [Display(Name="Mobile Telephone Number")] public string Mobile {get;set;} [MaxLength(500)] [Display(Name="Headline")] public string Headline {get;set;} [Required] [StringLength(200)] [Display(Name = "First Name")] public string FirstName {get;set;} [Required] [StringLength(200)] [Display(Name="Surname")] public string Surname { get; set;} public virtual int? DayOfBirthId { get; set; } public virtual DayOfBirth DayOfBirth { get; set; } public virtual int? MonthOfBirthId { get; set; } public virtual MonthOfBirth MonthOfBirth { get; set; } public virtual int? YearOfBirthId { get; set; } public virtual YearOfBirth YearOfBirth{get;set;} This is my user profile table in the database. However I would like a form that the user registers to the site with. When they first register i do not need all the details such as telephone all i really need is there username, email address and password. Do i create another model for this. Or do i have one model and on the controller set the fields to null or empty string that are not required on registration. I have validation also so would this be set for data that has not been entered on the form. My question is ultimately should all forms represent models- should the database be redesigned to meet this required. Or should the controller set the values that are not required. Or should there be another model that represents the form be created which maps to this table. I am a little confused on this and clarification of anyone would be most appreciated.

    Read the article

  • Comparing char for validation in C++

    - by Corey Starbird
    /* PROGRAM: Ch6_14.cpp Written by Corey Starbird This program calculates the balance owed to a hospital for a patient. Last modified: 10/28/13 */ #include <iostream> #include <fstream> #include <iomanip> #include <string> using namespace std; // Prototypes for In-patient and Out-patient functions. double stayTotal (int, double, double, double); // For In-patients double stayTotal (double, double); // For Out-patients int main() { char patientType; // In-patient (I or i) or Out-patient (O or o) double rate, // Daily rate for the In-patient stay servCharge, // Service charge for the stay medCharge, // Medication charge for the stay inTotal, // Total for the In-patient stay outTotal; // Total for the Out-patient stay int days; // Number of days for the In-patient stay // Find out if they were an In-patient or an Out-patient cout << "Welcome, please enter (I) for an In-patient or (O) for an Out-patient:" << endl; cin >> patientType; while (patientType != 'I' || 'i' || 'O' || 'o') { cout << "Invalid entry. Please enter either (I) for an In-patient or (O) for an Out-patient:" << endl; cin >> patientType; } cout << "FIN"; return 0; } Hey, brand new to C++ here. I am working on a project and I'm having trouble figuring out why my validation for patientTypeisn't working properly. I first had double quotes, but realized that would denote strings. I changed them to single quotes, my program will compile and run now, but the while loop runs no matter what I enter, I, i, O, o, or anything else. I don't know why the while loop isn't checking the condition, seeing that I did enter one of the characters in the condition, and move on to cout. Probably a simple mistake, but I thank you in advance.

    Read the article

  • Upload File to Windows Azure Blob in Chunks through ASP.NET MVC, JavaScript and HTML5

    - by Shaun
    Originally posted on: http://geekswithblogs.net/shaunxu/archive/2013/07/01/upload-file-to-windows-azure-blob-in-chunks-through-asp.net.aspxMany people are using Windows Azure Blob Storage to store their data in the cloud. Blob storage provides 99.9% availability with easy-to-use API through .NET SDK and HTTP REST. For example, we can store JavaScript files, images, documents in blob storage when we are building an ASP.NET web application on a Web Role in Windows Azure. Or we can store our VHD files in blob and mount it as a hard drive in our cloud service. If you are familiar with Windows Azure, you should know that there are two kinds of blob: page blob and block blob. The page blob is optimized for random read and write, which is very useful when you need to store VHD files. The block blob is optimized for sequential/chunk read and write, which has more common usage. Since we can upload block blob in blocks through BlockBlob.PutBlock, and them commit them as a whole blob with invoking the BlockBlob.PutBlockList, it is very powerful to upload large files, as we can upload blocks in parallel, and provide pause-resume feature. There are many documents, articles and blog posts described on how to upload a block blob. Most of them are focus on the server side, which means when you had received a big file, stream or binaries, how to upload them into blob storage in blocks through .NET SDK.  But the problem is, how can we upload these large files from client side, for example, a browser. This questioned to me when I was working with a Chinese customer to help them build a network disk production on top of azure. The end users upload their files from the web portal, and then the files will be stored in blob storage from the Web Role. My goal is to find the best way to transform the file from client (end user’s machine) to the server (Web Role) through browser. In this post I will demonstrate and describe what I had done, to upload large file in chunks with high speed, and save them as blocks into Windows Azure Blob Storage.   Traditional Upload, Works with Limitation The simplest way to implement this requirement is to create a web page with a form that contains a file input element and a submit button. 1: @using (Html.BeginForm("About", "Index", FormMethod.Post, new { enctype = "multipart/form-data" })) 2: { 3: <input type="file" name="file" /> 4: <input type="submit" value="upload" /> 5: } And then in the backend controller, we retrieve the whole content of this file and upload it in to the blob storage through .NET SDK. We can split the file in blocks and upload them in parallel and commit. The code had been well blogged in the community. 1: [HttpPost] 2: public ActionResult About(HttpPostedFileBase file) 3: { 4: var container = _client.GetContainerReference("test"); 5: container.CreateIfNotExists(); 6: var blob = container.GetBlockBlobReference(file.FileName); 7: var blockDataList = new Dictionary<string, byte[]>(); 8: using (var stream = file.InputStream) 9: { 10: var blockSizeInKB = 1024; 11: var offset = 0; 12: var index = 0; 13: while (offset < stream.Length) 14: { 15: var readLength = Math.Min(1024 * blockSizeInKB, (int)stream.Length - offset); 16: var blockData = new byte[readLength]; 17: offset += stream.Read(blockData, 0, readLength); 18: blockDataList.Add(Convert.ToBase64String(BitConverter.GetBytes(index)), blockData); 19:  20: index++; 21: } 22: } 23:  24: Parallel.ForEach(blockDataList, (bi) => 25: { 26: blob.PutBlock(bi.Key, new MemoryStream(bi.Value), null); 27: }); 28: blob.PutBlockList(blockDataList.Select(b => b.Key).ToArray()); 29:  30: return RedirectToAction("About"); 31: } This works perfect if we selected an image, a music or a small video to upload. But if I selected a large file, let’s say a 6GB HD-movie, after upload for about few minutes the page will be shown as below and the upload will be terminated. In ASP.NET there is a limitation of request length and the maximized request length is defined in the web.config file. It’s a number which less than about 4GB. So if we want to upload a really big file, we cannot simply implement in this way. Also, in Windows Azure, a cloud service network load balancer will terminate the connection if exceed the timeout period. From my test the timeout looks like 2 - 3 minutes. Hence, when we need to upload a large file we cannot just use the basic HTML elements. Besides the limitation mentioned above, the simple HTML file upload cannot provide rich upload experience such as chunk upload, pause and pause-resume. So we need to find a better way to upload large file from the client to the server.   Upload in Chunks through HTML5 and JavaScript In order to break those limitation mentioned above we will try to upload the large file in chunks. This takes some benefit to us such as - No request size limitation: Since we upload in chunks, we can define the request size for each chunks regardless how big the entire file is. - No timeout problem: The size of chunks are controlled by us, which means we should be able to make sure request for each chunk upload will not exceed the timeout period of both ASP.NET and Windows Azure load balancer. It was a big challenge to upload big file in chunks until we have HTML5. There are some new features and improvements introduced in HTML5 and we will use them to implement our solution.   In HTML5, the File interface had been improved with a new method called “slice”. It can be used to read part of the file by specifying the start byte index and the end byte index. For example if the entire file was 1024 bytes, file.slice(512, 768) will read the part of this file from the 512nd byte to 768th byte, and return a new object of interface called "Blob”, which you can treat as an array of bytes. In fact,  a Blob object represents a file-like object of immutable, raw data. The File interface is based on Blob, inheriting blob functionality and expanding it to support files on the user's system. For more information about the Blob please refer here. File and Blob is very useful to implement the chunk upload. We will use File interface to represent the file the user selected from the browser and then use File.slice to read the file in chunks in the size we wanted. For example, if we wanted to upload a 10MB file with 512KB chunks, then we can read it in 512KB blobs by using File.slice in a loop.   Assuming we have a web page as below. User can select a file, an input box to specify the block size in KB and a button to start upload. 1: <div> 2: <input type="file" id="upload_files" name="files[]" /><br /> 3: Block Size: <input type="number" id="block_size" value="512" name="block_size" />KB<br /> 4: <input type="button" id="upload_button_blob" name="upload" value="upload (blob)" /> 5: </div> Then we can have the JavaScript function to upload the file in chunks when user clicked the button. 1: <script type="text/javascript"> 1: 2: $(function () { 3: $("#upload_button_blob").click(function () { 4: }); 5: });</script> Firstly we need to ensure the client browser supports the interfaces we are going to use. Just try to invoke the File, Blob and FormData from the “window” object. If any of them is “undefined” the condition result will be “false” which means your browser doesn’t support these premium feature and it’s time for you to get your browser updated. FormData is another new feature we are going to use in the future. It could generate a temporary form for us. We will use this interface to create a form with chunk and associated metadata when invoked the service through ajax. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: if (window.File && window.Blob && window.FormData) { 4: alert("Your brwoser is awesome, let's rock!"); 5: } 6: else { 7: alert("Oh man plz update to a modern browser before try is cool stuff out."); 8: return; 9: } 10: }); Each browser supports these interfaces by their own implementation and currently the Blob, File and File.slice are supported by Chrome 21, FireFox 13, IE 10, Opera 12 and Safari 5.1 or higher. After that we worked on the files the user selected one by one since in HTML5, user can select multiple files in one file input box. 1: var files = $("#upload_files")[0].files; 2: for (var i = 0; i < files.length; i++) { 3: var file = files[i]; 4: var fileSize = file.size; 5: var fileName = file.name; 6: } Next, we calculated the start index and end index for each chunks based on the size the user specified from the browser. We put them into an array with the file name and the index, which will be used when we upload chunks into Windows Azure Blob Storage as blocks since we need to specify the target blob name and the block index. At the same time we will store the list of all indexes into another variant which will be used to commit blocks into blob in Azure Storage once all chunks had been uploaded successfully. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10:  11: // calculate the start and end byte index for each blocks(chunks) 12: // with the index, file name and index list for future using 13: var blockSizeInKB = $("#block_size").val(); 14: var blockSize = blockSizeInKB * 1024; 15: var blocks = []; 16: var offset = 0; 17: var index = 0; 18: var list = ""; 19: while (offset < fileSize) { 20: var start = offset; 21: var end = Math.min(offset + blockSize, fileSize); 22:  23: blocks.push({ 24: name: fileName, 25: index: index, 26: start: start, 27: end: end 28: }); 29: list += index + ","; 30:  31: offset = end; 32: index++; 33: } 34: } 35: }); Now we have all chunks’ information ready. The next step should be upload them one by one to the server side, and at the server side when received a chunk it will upload as a block into Blob Storage, and finally commit them with the index list through BlockBlobClient.PutBlockList. But since all these invokes are ajax calling, which means not synchronized call. So we need to introduce a new JavaScript library to help us coordinate the asynchronize operation, which named “async.js”. You can download this JavaScript library here, and you can find the document here. I will not explain this library too much in this post. We will put all procedures we want to execute as a function array, and pass into the proper function defined in async.js to let it help us to control the execution sequence, in series or in parallel. Hence we will define an array and put the function for chunk upload into this array. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4:  5: // start to upload each files in chunks 6: var files = $("#upload_files")[0].files; 7: for (var i = 0; i < files.length; i++) { 8: var file = files[i]; 9: var fileSize = file.size; 10: var fileName = file.name; 11: // calculate the start and end byte index for each blocks(chunks) 12: // with the index, file name and index list for future using 13: ... ... 14:  15: // define the function array and push all chunk upload operation into this array 16: blocks.forEach(function (block) { 17: putBlocks.push(function (callback) { 18: }); 19: }); 20: } 21: }); 22: }); As you can see, I used File.slice method to read each chunks based on the start and end byte index we calculated previously, and constructed a temporary HTML form with the file name, chunk index and chunk data through another new feature in HTML5 named FormData. Then post this form to the backend server through jQuery.ajax. This is the key part of our solution. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: blocks.forEach(function (block) { 15: putBlocks.push(function (callback) { 16: // load blob based on the start and end index for each chunks 17: var blob = file.slice(block.start, block.end); 18: // put the file name, index and blob into a temporary from 19: var fd = new FormData(); 20: fd.append("name", block.name); 21: fd.append("index", block.index); 22: fd.append("file", blob); 23: // post the form to backend service (asp.net mvc controller action) 24: $.ajax({ 25: url: "/Home/UploadInFormData", 26: data: fd, 27: processData: false, 28: contentType: "multipart/form-data", 29: type: "POST", 30: success: function (result) { 31: if (!result.success) { 32: alert(result.error); 33: } 34: callback(null, block.index); 35: } 36: }); 37: }); 38: }); 39: } 40: }); Then we will invoke these functions one by one by using the async.js. And once all functions had been executed successfully I invoked another ajax call to the backend service to commit all these chunks (blocks) as the blob in Windows Azure Storage. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: ... ... 15: // invoke the functions one by one 16: // then invoke the commit ajax call to put blocks into blob in azure storage 17: async.series(putBlocks, function (error, result) { 18: var data = { 19: name: fileName, 20: list: list 21: }; 22: $.post("/Home/Commit", data, function (result) { 23: if (!result.success) { 24: alert(result.error); 25: } 26: else { 27: alert("done!"); 28: } 29: }); 30: }); 31: } 32: }); That’s all in the client side. The outline of our logic would be - Calculate the start and end byte index for each chunks based on the block size. - Defined the functions of reading the chunk form file and upload the content to the backend service through ajax. - Execute the functions defined in previous step with “async.js”. - Commit the chunks by invoking the backend service in Windows Azure Storage finally.   Save Chunks as Blocks into Blob Storage In above we finished the client size JavaScript code. It uploaded the file in chunks to the backend service which we are going to implement in this step. We will use ASP.NET MVC as our backend service, and it will receive the chunks, upload into Windows Azure Bob Storage in blocks, then finally commit as one blob. As in the client side we uploaded chunks by invoking the ajax call to the URL "/Home/UploadInFormData", I created a new action under the Index controller and it only accepts HTTP POST request. 1: [HttpPost] 2: public JsonResult UploadInFormData() 3: { 4: var error = string.Empty; 5: try 6: { 7: } 8: catch (Exception e) 9: { 10: error = e.ToString(); 11: } 12:  13: return new JsonResult() 14: { 15: Data = new 16: { 17: success = string.IsNullOrWhiteSpace(error), 18: error = error 19: } 20: }; 21: } Then I retrieved the file name, index and the chunk content from the Request.Form object, which was passed from our client side. And then, used the Windows Azure SDK to create a blob container (in this case we will use the container named “test”.) and create a blob reference with the blob name (same as the file name). Then uploaded the chunk as a block of this blob with the index, since in Blob Storage each block must have an index (ID) associated with so that finally we can put all blocks as one blob by specifying their block ID list. 1: [HttpPost] 2: public JsonResult UploadInFormData() 3: { 4: var error = string.Empty; 5: try 6: { 7: var name = Request.Form["name"]; 8: var index = int.Parse(Request.Form["index"]); 9: var file = Request.Files[0]; 10: var id = Convert.ToBase64String(BitConverter.GetBytes(index)); 11:  12: var container = _client.GetContainerReference("test"); 13: container.CreateIfNotExists(); 14: var blob = container.GetBlockBlobReference(name); 15: blob.PutBlock(id, file.InputStream, null); 16: } 17: catch (Exception e) 18: { 19: error = e.ToString(); 20: } 21:  22: return new JsonResult() 23: { 24: Data = new 25: { 26: success = string.IsNullOrWhiteSpace(error), 27: error = error 28: } 29: }; 30: } Next, I created another action to commit the blocks into blob once all chunks had been uploaded. Similarly, I retrieved the blob name from the Request.Form. I also retrieved the chunks ID list, which is the block ID list from the Request.Form in a string format, split them as a list, then invoked the BlockBlob.PutBlockList method. After that our blob will be shown in the container and ready to be download. 1: [HttpPost] 2: public JsonResult Commit() 3: { 4: var error = string.Empty; 5: try 6: { 7: var name = Request.Form["name"]; 8: var list = Request.Form["list"]; 9: var ids = list 10: .Split(',') 11: .Where(id => !string.IsNullOrWhiteSpace(id)) 12: .Select(id => Convert.ToBase64String(BitConverter.GetBytes(int.Parse(id)))) 13: .ToArray(); 14:  15: var container = _client.GetContainerReference("test"); 16: container.CreateIfNotExists(); 17: var blob = container.GetBlockBlobReference(name); 18: blob.PutBlockList(ids); 19: } 20: catch (Exception e) 21: { 22: error = e.ToString(); 23: } 24:  25: return new JsonResult() 26: { 27: Data = new 28: { 29: success = string.IsNullOrWhiteSpace(error), 30: error = error 31: } 32: }; 33: } Now we finished all code we need. The whole process of uploading would be like this below. Below is the full client side JavaScript code. 1: <script type="text/javascript" src="~/Scripts/async.js"></script> 2: <script type="text/javascript"> 3: $(function () { 4: $("#upload_button_blob").click(function () { 5: // assert the browser support html5 6: if (window.File && window.Blob && window.FormData) { 7: alert("Your brwoser is awesome, let's rock!"); 8: } 9: else { 10: alert("Oh man plz update to a modern browser before try is cool stuff out."); 11: return; 12: } 13:  14: // start to upload each files in chunks 15: var files = $("#upload_files")[0].files; 16: for (var i = 0; i < files.length; i++) { 17: var file = files[i]; 18: var fileSize = file.size; 19: var fileName = file.name; 20:  21: // calculate the start and end byte index for each blocks(chunks) 22: // with the index, file name and index list for future using 23: var blockSizeInKB = $("#block_size").val(); 24: var blockSize = blockSizeInKB * 1024; 25: var blocks = []; 26: var offset = 0; 27: var index = 0; 28: var list = ""; 29: while (offset < fileSize) { 30: var start = offset; 31: var end = Math.min(offset + blockSize, fileSize); 32:  33: blocks.push({ 34: name: fileName, 35: index: index, 36: start: start, 37: end: end 38: }); 39: list += index + ","; 40:  41: offset = end; 42: index++; 43: } 44:  45: // define the function array and push all chunk upload operation into this array 46: var putBlocks = []; 47: blocks.forEach(function (block) { 48: putBlocks.push(function (callback) { 49: // load blob based on the start and end index for each chunks 50: var blob = file.slice(block.start, block.end); 51: // put the file name, index and blob into a temporary from 52: var fd = new FormData(); 53: fd.append("name", block.name); 54: fd.append("index", block.index); 55: fd.append("file", blob); 56: // post the form to backend service (asp.net mvc controller action) 57: $.ajax({ 58: url: "/Home/UploadInFormData", 59: data: fd, 60: processData: false, 61: contentType: "multipart/form-data", 62: type: "POST", 63: success: function (result) { 64: if (!result.success) { 65: alert(result.error); 66: } 67: callback(null, block.index); 68: } 69: }); 70: }); 71: }); 72:  73: // invoke the functions one by one 74: // then invoke the commit ajax call to put blocks into blob in azure storage 75: async.series(putBlocks, function (error, result) { 76: var data = { 77: name: fileName, 78: list: list 79: }; 80: $.post("/Home/Commit", data, function (result) { 81: if (!result.success) { 82: alert(result.error); 83: } 84: else { 85: alert("done!"); 86: } 87: }); 88: }); 89: } 90: }); 91: }); 92: </script> And below is the full ASP.NET MVC controller code. 1: public class HomeController : Controller 2: { 3: private CloudStorageAccount _account; 4: private CloudBlobClient _client; 5:  6: public HomeController() 7: : base() 8: { 9: _account = CloudStorageAccount.Parse(CloudConfigurationManager.GetSetting("DataConnectionString")); 10: _client = _account.CreateCloudBlobClient(); 11: } 12:  13: public ActionResult Index() 14: { 15: ViewBag.Message = "Modify this template to jump-start your ASP.NET MVC application."; 16:  17: return View(); 18: } 19:  20: [HttpPost] 21: public JsonResult UploadInFormData() 22: { 23: var error = string.Empty; 24: try 25: { 26: var name = Request.Form["name"]; 27: var index = int.Parse(Request.Form["index"]); 28: var file = Request.Files[0]; 29: var id = Convert.ToBase64String(BitConverter.GetBytes(index)); 30:  31: var container = _client.GetContainerReference("test"); 32: container.CreateIfNotExists(); 33: var blob = container.GetBlockBlobReference(name); 34: blob.PutBlock(id, file.InputStream, null); 35: } 36: catch (Exception e) 37: { 38: error = e.ToString(); 39: } 40:  41: return new JsonResult() 42: { 43: Data = new 44: { 45: success = string.IsNullOrWhiteSpace(error), 46: error = error 47: } 48: }; 49: } 50:  51: [HttpPost] 52: public JsonResult Commit() 53: { 54: var error = string.Empty; 55: try 56: { 57: var name = Request.Form["name"]; 58: var list = Request.Form["list"]; 59: var ids = list 60: .Split(',') 61: .Where(id => !string.IsNullOrWhiteSpace(id)) 62: .Select(id => Convert.ToBase64String(BitConverter.GetBytes(int.Parse(id)))) 63: .ToArray(); 64:  65: var container = _client.GetContainerReference("test"); 66: container.CreateIfNotExists(); 67: var blob = container.GetBlockBlobReference(name); 68: blob.PutBlockList(ids); 69: } 70: catch (Exception e) 71: { 72: error = e.ToString(); 73: } 74:  75: return new JsonResult() 76: { 77: Data = new 78: { 79: success = string.IsNullOrWhiteSpace(error), 80: error = error 81: } 82: }; 83: } 84: } And if we selected a file from the browser we will see our application will upload chunks in the size we specified to the server through ajax call in background, and then commit all chunks in one blob. Then we can find the blob in our Windows Azure Blob Storage.   Optimized by Parallel Upload In previous example we just uploaded our file in chunks. This solved the problem that ASP.NET MVC request content size limitation as well as the Windows Azure load balancer timeout. But it might introduce the performance problem since we uploaded chunks in sequence. In order to improve the upload performance we could modify our client side code a bit to make the upload operation invoked in parallel. The good news is that, “async.js” library provides the parallel execution function. If you remembered the code we invoke the service to upload chunks, it utilized “async.series” which means all functions will be executed in sequence. Now we will change this code to “async.parallel”. This will invoke all functions in parallel. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: ... ... 15: // invoke the functions one by one 16: // then invoke the commit ajax call to put blocks into blob in azure storage 17: async.parallel(putBlocks, function (error, result) { 18: var data = { 19: name: fileName, 20: list: list 21: }; 22: $.post("/Home/Commit", data, function (result) { 23: if (!result.success) { 24: alert(result.error); 25: } 26: else { 27: alert("done!"); 28: } 29: }); 30: }); 31: } 32: }); In this way all chunks will be uploaded to the server side at the same time to maximize the bandwidth usage. This should work if the file was not very large and the chunk size was not very small. But for large file this might introduce another problem that too many ajax calls are sent to the server at the same time. So the best solution should be, upload the chunks in parallel with maximum concurrency limitation. The code below specified the concurrency limitation to 4, which means at the most only 4 ajax calls could be invoked at the same time. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: ... ... 15: // invoke the functions one by one 16: // then invoke the commit ajax call to put blocks into blob in azure storage 17: async.parallelLimit(putBlocks, 4, function (error, result) { 18: var data = { 19: name: fileName, 20: list: list 21: }; 22: $.post("/Home/Commit", data, function (result) { 23: if (!result.success) { 24: alert(result.error); 25: } 26: else { 27: alert("done!"); 28: } 29: }); 30: }); 31: } 32: });   Summary In this post we discussed how to upload files in chunks to the backend service and then upload them into Windows Azure Blob Storage in blocks. We focused on the frontend side and leverage three new feature introduced in HTML 5 which are - File.slice: Read part of the file by specifying the start and end byte index. - Blob: File-like interface which contains the part of the file content. - FormData: Temporary form element that we can pass the chunk alone with some metadata to the backend service. Then we discussed the performance consideration of chunk uploading. Sequence upload cannot provide maximized upload speed, but the unlimited parallel upload might crash the browser and server if too many chunks. So we finally came up with the solution to upload chunks in parallel with the concurrency limitation. We also demonstrated how to utilize “async.js” JavaScript library to help us control the asynchronize call and the parallel limitation.   Regarding the chunk size and the parallel limitation value there is no “best” value. You need to test vary composition and find out the best one for your particular scenario. It depends on the local bandwidth, client machine cores and the server side (Windows Azure Cloud Service Virtual Machine) cores, memory and bandwidth. Below is one of my performance test result. The client machine was Windows 8 IE 10 with 4 cores. I was using Microsoft Cooperation Network. The web site was hosted on Windows Azure China North data center (in Beijing) with one small web role (1.7GB 1 core CPU, 1.75GB memory with 100Mbps bandwidth). The test cases were - Chunk size: 512KB, 1MB, 2MB, 4MB. - Upload Mode: Sequence, parallel (unlimited), parallel with limit (4 threads, 8 threads). - Chunk Format: base64 string, binaries. - Target file: 100MB. - Each case was tested 3 times. Below is the test result chart. Some thoughts, but not guidance or best practice: - Parallel gets better performance than series. - No significant performance improvement between parallel 4 threads and 8 threads. - Transform with binaries provides better performance than base64. - In all cases, chunk size in 1MB - 2MB gets better performance.   Hope this helps, Shaun All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

    Read the article

< Previous Page | 209 210 211 212 213 214 215 216 217 218 219 220  | Next Page >