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  • My Oracle Support 6.3 - Knowledge Highlights

    - by JanSyss
    My Oracle Support 6.3 was released over the weekend (13-Oct-2012), and with that we released 30+ enhancements and 60+ bug fixes. Most important changes Search Suggestions are auto-correcting spelling errors, more suggestions for 'how to' type questions, enhanced usability to see the suggested additional terms. Improved Knowledge Base region on the My Oracle Support dashboard: recent searches from this region now retain the search attributions (e.g. pre-selected products or release). Search Tip: if the Knowledge Base region doesn't show up as the first region in the right column on the My Oracle Support dashboard, consider personalizing your dashboard to put it first, so that you right there for searching. Specifying the product you are researching an issue for, with optionally version and task as well, makes searches in the majority of the cases more precise. for more information, see my comments in my previous blog on the topic: https://blogs.oracle.com/supportportal/entry/mos_6_2_release Better support for searches on ORA-600 & ORA-700: no longer a difference in results between searching on 'ORA-600 [Arg1]' and 'Ora-00600: Internal Error Code, Arguments: [Arg1]'.

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  • Planning development when academic research is involved

    - by Another Anonymous User
    Dear fellow programmers, how do you do "software planning" when academic research is involved? And, on a side note, how do you convince your boss that writing software is not like building a house and it's more like writing a novel? The gory details are below. I am in charge of a small dev team working in a research lab. We started developing a software with the purpose of going public one day (i.e. sell and make money off that). Such software depends on, amongst other things, at least two independent research lines: that is, there are at least two Ph.D. candidates that will, hopefully, one day come out with a working implementation of what we need. The main software depends also on other, more concrete resources that we as developers can take care of: graphics rendering, soft bodies deformation, etc. My boss asked me to write the specifications, requirements AND a bloody GANTT chart of the entire project. Faced with the fact that I don't have a clue about the research part, and that such research is fundamental for the software, he said "make assumptions." For the clarity of the argument, he is a professor whose Ph.D. students should come up with the research we need. And he comes from a strictly engineering background: plan everything first, write down specifications and only then write down code that "it's the last part". What I am doing now: I broke down the product in features; each 'feature' is, de facto, a separate product; Each feature is built on top of the previous one; Once a feature (A) has a working prototype the team can start working on the next feature (B), while QA for is being done for A (if money allows, more people can be brought in, etc.); Features that depend on research will come last: by then, hopefully, the research part will be completed (when is still a big question) ; Also, I set the team to use SCRUM for the development of 'version 1.0', due in a few months. This deadline could be set based on reasonable assumptions: we listed all required features, we counted our availability, and we gave a reasonable estimate. So my questions, again, are: How do I make my boss happy while at the same time get something out the door? How do I write specifications for something we -the developers- have no clue whether it's possible to do or not? (We still haven't decided which libraries to use for some tasks; we'll do so when we'll need to) How do I get the requirements for that, given that there are yet no clients nor investors, just lots of interests and promises? How do I get peace in the world? I am sure at least one of my questions will be answered :) ps: I am writing this anonymously since a potential investor might backfire if this is discovered. Hope you'll understand. However I must say I do not like this mentality of 'hiding the truth': this program will likely benefit many, and not being able to talk openly about this (with my name and my reputation attached) feels like censorship. But alas, I care more about your suggestions now.

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  • My local ubuntu server is not updated

    - by Rakesh Manandhar
    I am from Nepal and it's faster to download apps from server for nepal using through ubuntu software center. But when i use np.archive.ubuntu.com server. There is no updated softwares and few softwares and nvidia driver are outdated. for e.g. i cannot even install openshot when i user server for nepal. It provides error which cannot be solved. I want to know how can the server for nepal be updated frequently with us.archive.ubuntu.com. i use ubuntu 12.10. and i want to use server for nepal since the download speed faster than 2x than from us server.

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  • Installing 12.10 messed up Xorg

    - by Ghost
    So I finally decided to upgrade from 12.04 and now my ubuntu install has been rendered unusable. I'm getting the "no screens detected" error from xorg in the console, and no mattr how many times I reinstall it xorg keeps throwing the same errors. I already had to do a bunch of hacks like nomodeset just to get to the console, else I would get an infinite tabulator after the purple boot screen. The machine has a 4200HD IGP, I even tried installing fglrx legacy (4xxx series and below are not supported in regular fglrx anymore) which was a subpar driver in 12.04 but in hopes that the machine would at least work, but nope, nothing at all. Anyone had the same problem? how do I fix it? EDIT: just wanted to add that I upgraded to 13.04 and it didn't solve anything, in fact it might have broken things even further.

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  • Fonts totally unreadable

    - by user11181
    I've just upgraded from 10.04 to 10.10 and my fonts are all just small rectangles with nothing in them. They are completely unreadable. EVEN THE FONTS IN THE TERMINAL. Thank god the fonts in my Chromium were ok, because I wouldn't be able to find this site or write this message. So far I've tried to use the Appearance - Font thing and it doesn't work. For some reason there was an error with the fonts during the installation. Please help, this is an utter nightmare...

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  • If all variables are a subset of the superkey, is the database design 5NF? [migrated]

    - by Lukazoid
    I have a table called LogMessages, which has the following columns: Level A numeric value which represents Trace, Debug, Info, Warning, Error or Fatal Time A UTC time Message Foreign key to a Messages table Source Foreign key to a Sources table User Foreign key to a Users table From what I can see, all of these columns are a part of the super key; if any single value differs to an existing row, a new row can be created. My question is, does this design comply to fifth normal form? I am unsure as some groups of data will be repeating, however I don't believe this violates 5NF? (correct me if I'm wrong)

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  • Ubuntu multiple issues (blank screen)

    - by Donavon
    Computer Specs I am having difficulties, to get Ubuntu 11.10 to work. For the 11.10 version, if I click install, or if I click try Ubuntu, I only get a blank screen, that just stays there. If I use "nomodeset", it changes to a loading screen and after about 2 minutes it goes back to black screen - however, before it goes black, i get a few errors, like: bad target number, or passwd error mode (something like that). I've also tried (xforcevesa, i915.modeset=0, nomodeset, radeon.modeset=0, i915.modeset=1) I have also tried the alternate installation, which installed fine, however when I boot up, select it from "grub", it goes black. I did manage to install 10.04, however the screen resolution was 800x600 and I couldn't fix it to 16:9 (my resolution). I don't wanna use 10.04, because I would like the new one 11.10, and would like to use it. Any help would be GREATLY appreciated. Thank you

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  • Problems instaling Wine on Ubuntu 11.10

    - by FLopes-Portugal
    I'm new on linux, and I'm trying install wine 1.3 on ubuntu 11.10, with a fresh new full install. I've got the 64bit version. The error, when i try to install via ubunto software packages is: "The package dependences could not be resolved" sorry by the english I tryed free translate from protuguese. wine1.3: PreDepends: dpkg (= 1.14.12ubuntu3) mas 1.16.1.1ubuntu3 vai ser instalado Depends: ia32-libs (= 1.6) mas 20090808ubuntu31 vai ser instalado Depends: libc6-i386 (= 2.6-1) mas 2.13-20ubuntu5 vai ser instalado I try via terminal, withe some help i saw here, but nothing results.. How can i resolve this problem. I want install some applications and some games form windows...

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  • Instructions on Installing the FreeNX server on Ubuntu Karmic (9.10) are incorrect

    - by Bob Free
    How does one fix (or report an error) on an 'immutable' help.ubuntu.community wiki page? I am a registered member of the wiki. On http://help.ubuntu.com/community/FreeNX under the section: Installing the FreeNX server on Ubuntu Karmic (9.10) and higher, step #2, bjorn-nostvold erroneously changed on 2013-01-24 "add-apt-repository" to "apt-add-repository". The original "add-apt-repository" is correct - at least on my Karmic (9.10) version of Ubuntu. By the number of confused people I've found via google search, this seems to be throwing off a lot of people, myself included.

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  • Help file formats - MSHA files v CHM files

    - by TATWORTH
    Recently I was tasked with producing a help file from a C#/WPF/Crystal Reports application using Sandcastle. I have previously blogged about the problems in doing that and the change that is going into the next version of Sandcastle that allows the vagaries of Crystal (this missing BusinessObjects.Licensing.KeycodeDecoder) to be handled. At http://social.msdn.microsoft.com/Forums/en-US/devdocs/thread/0b110502-f5bb-4c56-96a5-4347a2a7a68a/, I describe how I tried each of the formats. Two of the formats could not be built and the error messages were not exactly helpful as to the cause. These two formats turned out to be obsolete. The MSHA format worked but was not suitable for a standalone application, so that left me with the older CHM format. I therefore asked on that thread "will the HTML Help 1 (CHM) format continue to be supported for the foreseeable future?".Rob Chandler, MVP in help systems, gave a very helpful answer, to the effect that there is not yet a replacement for the CHM format.

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  • Macbook Pro late 2011 screen brightness issue

    - by buchzumlesen
    The keys to set the screen brightness work properly but everytime I reboot, the screen brightness is reverted to 100%, which is very annoying. I've already tried to add the following lines to /etc/rc.local but with no success (only the keyboard backlight stays off): #!/bin/sh -e # # rc.local # # This script is executed at the end of each multiuser runlevel. # Make sure that the script will "exit 0" on success or any other # value on error. # # In order to enable or disable this script just change the execution # bits. # # By default this script does nothing. echo '1' > /sys/devices/platform/applesmc.768/leds/smc::kbd_backlight/brightness echo '6' > /sys/class/backlight/acpi_video0/brightness rfkill block bluetooth exit 0` This worked for me when I was using Ubuntu 12.04 and also did after the upgrade to 12.10 but then after rebooting the screen brightness always reverted to 100%. Would be nice if anyone knows how to fix this. My device: Macbook Pro 13" Late 2011 Thanks in advance!

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  • how do i stop root from running a program

    - by joe Lovick
    I would like to prevent my root user from running certain applications that can change the permissions of files which in turn prevents normal users from running those applications again. for example, if i sudo to root, and then run thunderbird from the command prompt, it changes the permissions of files within my home dir / profile so i can no longer run it as a normal user; what i would like to do is prevent root from running thunderbird and hence stop this user error from repeating itself. any suggestions? to clarify, if i have a lot of administration to do i use "sudo -s" which gives me a root shell, its just once a year or so, i shoot myself in the foot.

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  • How can I get a 1920x1080 resolution?

    - by Sam T.
    I a newbie Linux and have just installed Ubuntu in a dual boot with Windows 7. I love the interface of Ubuntu but unfortunately I can only get a 800x600 or 1024x728 resolution with black bars all around the screen. I have an nVidia GTX 570 graphics card and an Asus 1080p 23" monitor. What may be of note is that I had to use the nomodeset command on installation of the boot would get stuck at a line with "nouveau", which I understand is to do with the drivers. Additionally, when I type in xrandr to the terminal, it comes up with the error message "failed to get size of gamma for output default". I guess what I am looking for here is someone who could explain to me really simply the steps I have to take to get a full 1080p resolution, at which point I am sure i will become a great fan of the OS! Thanks in advance, Sam T.

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  • How to fix Ubuntu 12.04.3 boot to black screen full of errors in white text, after upgrading on dell inspiron 1501

    - by Ibuntu
    I am running a Dell Inspiron 1501 I use Linux only. No Microsoft or Apple operating systems (or really anything closed-source). I've only been using Linux for a little over a year but I'm starting to gain a comfortable level of familiarity with the system and terminology. I've been having some issues with Quantel Quetzal and Raring Ringtail, especially with older hardware, so I opted to install Ubuntu 12.04.3 Precise Pangolin on the Inspiron 1501. I checked my MD5 sum after downloading my ISO and all was good. I have in fact used this iso/dvd to install Precise Pangolin successfully on a few other systems (some of which are even older than this laptop). Install goes fine. The wireless card doesn't work out of the box but this is a known issue which is fairly easy to fix. So, first thing I did was open up a terminal and run sudo apt-get update && sudo apt-get upgrade which, part way through, crashed (I assume lightdm and possibly X) and took me to a black screen filled with white lines of text that were either errors or just the ouputs of commands. The reason I say that is because I was unable to gleam any useful information from the output on the screen. I did take a picture however and will post a link. After that, every time I boot the system it goes right to that black screen posting all the error messages or output in white text. I never get a purple Ubuntu splash, so from what I can tell after reading this wiki article: https://wiki.ubuntu.com/X/Troubleshooting/BlankScreen That means that after the kernel is selected, it is unable to correctly implement the settings it needs. If the purple splash never shows, the frame buffer was never set correctly right? This leads me to believe that it could be a kernel issue? The wiki suggested to try and pinpoint the issue by rolling back kernels until I find one that works. Is this my best option? I think I'm going to give it a try anyways and will let everyone know if I am able to solve the issue this way. I have since done a few reinstalls and some trouble-shooting including a couple hours scouring the net for anyone with any kind of similar issue. Most of the issues I could find involved getting a black screen after login and none of them said anything about any information output on this black screen. My reinstalls have taught me that there is no issue updating, but as soon as I run sudo apt-get upgrade my system goes to the black screen and every time I boot it up it does the same thing. The only way to fix is by reinstall. I never get any ability to log in. After a hard power off to the laptop (because I cannot use ctrl+alt+del to reboot) when it boots again it goes to the grub boot menu and I can select between regular boot, recovery mode and the two memtest options. I never tried the memtest options but the other two both lead to the same black screen. Some people having a black/blank screen issue claim to have fixed it by using 12.10 or 13.04 but I believe they were having a different issue where they got a black/blank screen after logging in. I think I will still give these images a try, but mostly figured I would just wait another day or two for 13.10. Other things I figured I would try from the following three articles: After logging in, there's a black screen and my cursor, nothing else! in Ubuntu 12.10 Black Screen on Login After Upgrading to 12.04 I can't get to the login screen include opening a terminal using ctrl+alt+f1 and trying a variety of reseting unity, x settings, lightdm (or switching to gdm); but I doubt this will work or that I will even be able to access a terminal. I'm pretty sure the whole system is stuck after it loads the last line on the black screen. I will try these things and post more information when I have. Hopefully someone has an idea in the meantime and I will keep checking back trying to find a solution. Thank you. Here are 3 different pictures of the error message. I had to take with my phone: http://ubuntuone.com/album/0TBBkxmVajJIQQtoN9mVdN

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  • Do I need to notify a user if I am using statistics software in an iPhone app?

    - by Chris
    Hello, I am currently creating a (very simple) Objective-C client to send basic statistical data to my server for an iPhone app - just things like the state of the app (first-launch or launch, error, etc), along with the make/model/version (i.e.: "iPod touch 4.2"). No personally identifiable information or location data is sent. Is there anything, in the Apple Developer agreement or otherwise, that states that I must notify the user if I am doing this? I'm not interested in selling the data or anything, I just want to use the data to make my apps better. I am not adverse to telling the user I am doing this if it is required, I just don't want to scare the users (the paranoid "oooh, they're tracking me, they know exactly where I am" crowd) if I don't have to. Thanks for any advice.

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  • Is it relevant to warn about truncating real constants to 32 bits?

    - by zneak
    I'm toying around with LLVM and looking at what it would take to make yet another strongly-typed language, and now that I'm around the syntax, I've noticed that it seems to be a pet peeve of strongly typed language to warn people that their constants won't fit inside a float: // both in Java and C# float foo = 3.2; // error: implicitly truncating a double into a float // or something along these lines Why doesn't this work in Java and C#? I know it's easy to add the f after the 3.2, but is it really doing anything useful? Must I really be that aware that I'm using single-precision reals instead of double-precision reals? Maybe I'm just missing something (which, basically, is why I'm asking). Note that float foo = [const] is not the same thing as float foo = [double variable], where requiring the cast seems normal to me.

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  • Laptop won't get to grub after meddling with kernels

    - by Joren
    I recently found out I had different kernel versions installed, so I removed the 3.9 kernel as proposed in this answer on my earlier question. After that, I updated my grub, but My laptop won't seem to reach it. Output of aptitude search linux | grep ^i: i libselinux1 - SELinux runtime shared libraries i libselinux1:i386 - SELinux runtime shared libraries i linux-firmware - Firmware for Linux kernel drivers i A linux-headers-3.11.0-12 - Header files related to Linux kernel versi i A linux-headers-3.11.0-12-generic - Linux kernel headers for version 3.11.0 on i linux-headers-3.11.4-031104 - Header files related to Linux kernel versi i linux-headers-3.11.4-031104-gen - Linux kernel headers for version 3.11.4 on i linux-headers-generic - Generic Linux kernel headers i linux-libc-dev - Linux Kernel Headers for development i linux-sound-base - base package for ALSA and OSS sound system i pptp-linux - Point-to-Point Tunneling Protocol (PPTP) C i syslinux - collection of boot loaders i syslinux-common - collection of boot loaders (common files) i syslinux-legacy - Bootloader for Linux/i386 using MS-DOS flo i util-linux - Miscellaneous system utilities How do I proceed to fix this error from my live cd?

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  • Need some help on tomcat URL mod_rewrite or mod_jk

    - by Redbull Fan
    I am trying to remove the context name from the url of my server. Current URL - http://www.domainname.com/MyApp/ What I need to make is to make it avaialble at - www.domainname.com/ So it is only going to host one main app and that needs to be displayed when we open www.domainname.com/ on browser. I have already tried couple of things like below - RewriteEngine On RewriteCond %{REQUEST_URI} !^/(Context/.*)$ RewriteRule ^/(.*)$ /Context/$1 [P,L] OR redirect permanent /MyApp/ abcd://domainname.com OR Using JKMount - JkMount /MyApp/* ajp13 JkMount /MyApp* ajp13 OR Deploy war file to ROOT of tomcat and make relevant chagnes in web and server.xml All of these aren't working and I keep getting a intenal error. I need a way to basically trim the tomcat URL to make short. Thanks, Andy

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  • dual boot, Sony Viao, all in one portable desktop, not working and crashes

    - by user287513
    I am a fan of Ubuntu but ever since I bought my new computers, both Sony Vaio, I can't get them running together with windows 8.1. When I try wubi, it doesn't show the install box, but some other information box. If I remove wubi from the iso and run it as admin on my desktop, it runs and installs but after rebooting, grub never comes up and it gives the error screen.. On my laptop, I had to make a usb install and partition everything myself and that worked for my laptop, for a little while. Windows boot loader would override and grub wouldn't come up no more, unless I try to boot from usb, with no usb in, and after it reboots because there is no usb, now grub opens, but doesn't cont. That is what happens with my Sony 2 in 1 laptop. My all in one portable just wont boot it period. Bios is the problem but I disabled everything that was necessary. Help

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  • How to install Adobe Master Collection CS6 in Ubuntu 12.10

    - by Shadow
    I have Dell Inspiron 1545 Laptop with Windows 7 installed on it.Also I have installed Ubuntu 12.10 on a separate drive.I want to install Adobe Master Collection CS6 on Ubuntu 12.10.I tried using wine but what wine does is,it just installs the software & doesn't allow me to use it.While I click on any Adobe product say Adobe Photoshop & hit enter to run it it pops out an error message. How should I tackle this?Is there any other software apart from virtual Machine Ware or Wine to install & successfully run Adobe Master Collection CS6 in Ubuntu 12.10?

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  • Configuring php on Ubuntu server

    - by mk_89
    I have been following this tutorial http://www.howtoforge.com/installing-apache2-with-php5-and-mysql-support-on-ubuntu-12.04-lts-lamp And I have got to the part where I am running a simple test to determine whether php has been installed properly the installation went fine, I installed php5 using the following command apt-get install php5 libapache2-mod-php5 and I then restarted the server. to see whether php5 has been installed I did the following created a file vi /var/www/info.php edited the file <?php phpinfo(); ?> after trying to run it on my server I get a 404 Not Found error. What could be the problem?

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  • function names - "standartised" prefixes

    - by dnsmkl
    Imagine you have such routines /*just do X. Fail if any precondition is not met*/ doX() /*take care of preconditions and then do X*/ takeCareOfPreconditionsCheckIfNeededAtAllAndThenDoX() A little bit more concrete example: /*create directory. Most probably fail with error if any precondition is not met (folder already exists, parent does not exists)*/ createDirectory(path_name) /*take care of preconditions (creates full path till folder if needed, checks if not exists yet) and then creates the directory*/ CheckIfNotExistsYet_CreateDirectory_andFullPathIfNeeded(path_name) How do you name such routines, so it would be clear what does what? I have come to some my own "convetion" like: naiveCreateDirectory, ForceDirectoryExists, ... But I imagine this is very standard situation. Maybe there already exists some norms/convetions for this?

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  • How to get rid of crawling errors due to the URL Encoded Slashes (%2F) problem in Apache

    - by user14198
    The Google web crawler has indexed a whole set of URLs with encoded slashes (%2F) for our site. I assume it has picked up the pages from our XML sitemap file. The problem is that the live pages will actually result in a failure because of the Url Encoded Slashes Problem in Apache. Some solutions are mentioned here We are implementing a 301 redirect scheme for all the error pages. This should make the Google bot delete the pages from the crawling errors (no more crashing pages). Does implementing the 301s require the pages to be "live"? In that case we may be forced to implement solution 1 in the article. The problem is that solution 1 will pose a security vulnerability..

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  • How to safely and painlessly switch from Kubuntu to Lubuntu?

    - by cdshines
    I've had Kubuntu installed for several years, updating from one major release to another, and now I think I'd like to try to switch to Lubuntu. But since my distribution is already tuned and shaped to satisfy my needs, I'd like not to get a fresh installation, but just purge kubuntu-desktop and install lubuntu-desktop. But when I execute sudo apt-get install lubuntu-desktop, it gives me an error of the following essence: The following packages have unmet dependencies: lubuntu-desktop : Depends: usb-modeswitch but it is not going to be installed E: Unable to correct problems, you have held broken packages. So, I investigate the modeswitch problem and get The following packages have unmet dependencies: usb-modeswitch : Depends: usb-modeswitch-data (>= 20110227-1~) but it is not going to be installed E: Unable to correct problems, you have held broken packages. But: Reading state information... Done usb-modeswitch-data is already the newest version. So, my question is: what actions should I take in order to obtain a clean and fresh installation of Lubuntu? And also, how do I safely remove all the kubuntu-desktop-related stuff?

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  • Collaborative Whiteboard using WebSocket in GlassFish 4 - Text/JSON and Binary/ArrayBuffer Data Transfer (TOTD #189)

    - by arungupta
    This blog has published a few blogs on using JSR 356 Reference Implementation (Tyrus) as its integrated in GlassFish 4 promoted builds. TOTD #183: Getting Started with WebSocket in GlassFish TOTD #184: Logging WebSocket Frames using Chrome Developer Tools, Net-internals and Wireshark TOTD #185: Processing Text and Binary (Blob, ArrayBuffer, ArrayBufferView) Payload in WebSocket TOTD #186: Custom Text and Binary Payloads using WebSocket One of the typical usecase for WebSocket is online collaborative games. This Tip Of The Day (TOTD) explains a sample that can be used to build such games easily. The application is a collaborative whiteboard where different shapes can be drawn in multiple colors. The shapes drawn on one browser are automatically drawn on all other peer browsers that are connected to the same endpoint. The shape, color, and coordinates of the image are transfered using a JSON structure. A browser may opt-out of sharing the figures. Alternatively any browser can send a snapshot of their existing whiteboard to all other browsers. Take a look at this video to understand how the application work and the underlying code. The complete sample code can be downloaded here. The code behind the application is also explained below. The web page (index.jsp) has a HTML5 Canvas as shown: <canvas id="myCanvas" width="150" height="150" style="border:1px solid #000000;"></canvas> And some radio buttons to choose the color and shape. By default, the shape, color, and coordinates of any figure drawn on the canvas are put in a JSON structure and sent as a message to the WebSocket endpoint. The JSON structure looks like: { "shape": "square", "color": "#FF0000", "coords": { "x": 31.59999942779541, "y": 49.91999053955078 }} The endpoint definition looks like: @WebSocketEndpoint(value = "websocket",encoders = {FigureDecoderEncoder.class},decoders = {FigureDecoderEncoder.class})public class Whiteboard { As you can see, the endpoint has decoder and encoder registered that decodes JSON to a Figure (a POJO class) and vice versa respectively. The decode method looks like: public Figure decode(String string) throws DecodeException { try { JSONObject jsonObject = new JSONObject(string); return new Figure(jsonObject); } catch (JSONException ex) { throw new DecodeException("Error parsing JSON", ex.getMessage(), ex.fillInStackTrace()); }} And the encode method looks like: public String encode(Figure figure) throws EncodeException { return figure.getJson().toString();} FigureDecoderEncoder implements both decoder and encoder functionality but thats purely for convenience. But the recommended design pattern is to keep them in separate classes. In certain cases, you may even need only one of them. On the client-side, the Canvas is initialized as: var canvas = document.getElementById("myCanvas");var context = canvas.getContext("2d");canvas.addEventListener("click", defineImage, false); The defineImage method constructs the JSON structure as shown above and sends it to the endpoint using websocket.send(). An instant snapshot of the canvas is sent using binary transfer with WebSocket. The WebSocket is initialized as: var wsUri = "ws://localhost:8080/whiteboard/websocket";var websocket = new WebSocket(wsUri);websocket.binaryType = "arraybuffer"; The important part is to set the binaryType property of WebSocket to arraybuffer. This ensures that any binary transfers using WebSocket are done using ArrayBuffer as the default type seem to be blob. The actual binary data transfer is done using the following: var image = context.getImageData(0, 0, canvas.width, canvas.height);var buffer = new ArrayBuffer(image.data.length);var bytes = new Uint8Array(buffer);for (var i=0; i<bytes.length; i++) { bytes[i] = image.data[i];}websocket.send(bytes); This comprehensive sample shows the following features of JSR 356 API: Annotation-driven endpoints Send/receive text and binary payload in WebSocket Encoders/decoders for custom text payload In addition, it also shows how images can be captured and drawn using HTML5 Canvas in a JSP. How could this be turned in to an online game ? Imagine drawing a Tic-tac-toe board on the canvas with two players playing and others watching. Then you can build access rights and controls within the application itself. Instead of sending a snapshot of the canvas on demand, a new peer joining the game could be automatically transferred the current state as well. Do you want to build this game ? I built a similar game a few years ago. Do somebody want to rewrite the game using WebSocket APIs ? :-) Many thanks to Jitu and Akshay for helping through the WebSocket internals! Here are some references for you: JSR 356: Java API for WebSocket - Specification (Early Draft) and Implementation (already integrated in GlassFish 4 promoted builds) Subsequent blogs will discuss the following topics (not necessary in that order) ... Error handling Interface-driven WebSocket endpoint Java client API Client and Server configuration Security Subprotocols Extensions Other topics from the API

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